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WG Medical Radiation Physics Pius-Hospital and Carl von Ossietzky University Oldenburg

1

Master Thesis

The clinical performance of the DAVID-system for the

in vivo verification of VMAT irradiation

Presented by Mustafa Saibu Danpullo

1st supervisor

Prof DrBPoppe

2nd supervisor

Dr HK Looe

WG Medical Radiation Physics Pius-Hospital and Carl von Ossietzky University Oldenburg2

Layout

I Introduction

II Theory

VMAT and IMRT

MLC Design and Agility

MWPC and DAVID system

III Materials amp Methods

Equipment alignment patient data stability of DAVID chamber

Beam property Error detection

Deconvolution

DAVID QA software

IV Results Discussion

V Conclusion


I Introduction

IMRT (Intensity-modulated radiation therapy)

VMAT (Volumetric Modulated Arc Therapy)

Why In vivo verification

ICRU report 24 (1976) recommended that certain types of tumors

requires improve accuracy from 5 to 35

To detect Equipment-related errors and deviations from the initial plan

Complexity of planning and delivery techniques increases risk for

treatment-related error incidents

In 1992 to 2007 more than 4000 near misses without adverse

outcome to patientrsquos case were reported more than 50 were related

to the planning or treatment delivery stage


In vivo dosimetry methods

in vivo intracavitary dosimetry with TLD

Diodes

DAVID (Device for Advanced Verification of IMRT deliveries

In-vivo verification during treatment

Online measurement of differences in dose to reference

Error detection of the Multi Leaf Collimator (MLC)

I Introduction


5

II Theory

Mostly Siemens Elekta and Varian have introduced new LINAC

control systems that will be able to change the MLC leaf positions

IMRT uses many small fields to generated by beam-shaping

devices (MLC) to deliver a single dose of radiation

IMRT Intensity-modulated Radiation Therapie


II TheoryVMAT Volumetric Modulated Arc Therapy

VMAT is a rotational IMRT that can be delivered using

conventional LINAC with MLC

Elekta and Varian have introduced new LINAC control systems

that will be able to change the MLC leaf positions and dose rate

while the gantry is rotating

Precise Beam infinity and Rapid Arc


A schematic drawing of the Siemens type A Elekta type B and Varian type C MLC [18]

Stepped leafs for different manufacturers [34]

II Theory


II Theory Agility MLC design

bull 160 tungsten leafs

bull rounded arc edge

bull 5 mm width

bull High speed(2x normal MLC) of up to

3cmsec

bull large field MLC enable clinicians to

shape radiation

bull extremely low transmission of about

lt05

bull 45 cm isocenter clearance from

accessory holder

MLC Motor


Inventor

Prof Georges Charpak

France1968

Nobel Prize in Physics (1992)

II Theory Multi wire proportional chamber (MWPC)

The DAVID chamber is a multi-wire

ionization chamber designed by PTW

Freiburg based on Charparks multi wire

proportional chamber


Compton scattering Electric field causes electrons move to the

anode(wire) and ionizied atomsmolecules to the

cathode(plate)

Each detection wire accumulates charge which

loads a C

After the voltage at the capacitor is read out it is set

to zero and charged again

The voltage achieved is read out by the associated

amplifier at a rate of 1 Hz

Performed by multi-channel electrometer

(MULTIDOS) + additional Software

II Theory DAVID system functioning principle


11

Signal interpretation

Ri reading of a single channel (ion charge collected)

C cross section of the lengthy collection volume along the wire

Ii ionization density (x1 start of wire x2 end of wire)

li1-li2 aperture of the associated leave pair

II Theory

II Theory


12

Front Plate

Back Plate

Air Volume

II Theory DAVID system signal recording

3 groups of secondary electrons contributing to the signala)ldquoprimary signalrdquo

b)scattered signal

c)leakage radiation

(background signal)


VMAT Planning

Treatment Planning System ONCENTRA Masterplan Version 43

ELEKTA Synergy accelerator with an Agility 80 leaf-pair MLC

bull Desktop Pro TM 7011 is Elektas third generation fully integrated

digital control system MOSAIQ DAVID software version 20

DAVID T34065

III Materials and Methods


Patient data configuration chart


Reference

1st session


DAVID Analysis

bull PTW DAVID 20 software


Warning level 3

Alarm level 5



bullVMAT 4 (1 HampN 3 Prostates)

bull180deg to -180deg Clockwise and anti clockwise

Stability of the DAVID system

bullIMRT 1 (Prostate)

bull0deg

bull90deg

bull270deg

(Prostate and Head and Neck) 14 days


III Materials amp MethodsThe beam property of the DAVID chamber

bullPercentage depth dose (PDD)

bullRoos chamber 34001

bullMP3 water phantom

bullTransmission factor for 6 and 15 MV

bullSemifex T31010 (Diff Field sizes)

Setup conditions

bull With and without DAVID

bull SSD 100 and 80 cm

bull Photon energy 6 and 15

MV

bull Different field sizes


1 Successive opening of 1 leaf on 1

side

III Materials amp MethodsVMAT Plan Editing for error detection

bull MATLAB script to change the MLC-positions

3 Field shift of a leaf gap (size of leave

gap remains)

2 Successive shift of a leaf gap (size of

leave gap remains)



side

VMAT Plan Editing for error detection



gap remains)


leave gap remains)



DeconvolutionIII Materials amp Methods

S(x) measured signal as convolution of

P(x) True bdquodoseldquo profile with

LRF fɛ(x)

S(x) = P(x) f(x)

bdquovan Cittertldquo iterative deconvolution

algorithm


opened MLC at every 10th interval from 1st to 80th

pairs

Nine MLC slit through the entire DAVID chamber

IV Results and Discussion Alignment


IV Results and Discussion Stability of DAVID System

bull IMRT prostate

bull Deviation of plusmn2 (+2)

bull VMAT prostate

bull Deviation of plusmn1 (-1)


IV ResultsDiscussion Stability of DAVID System

bull IMRT prostate


bull VMAT HampN

bull Deviation of lt05


IV ResultsDiscussion Transmission factor

The average KDAVID

bull 0939 plusmn0003 for 6 MV

and

bull 0953 plusmn 0004 for 15 MV

Reduction of dose at isocenter

due to 8mm of PMMA

By measuring the attenuation

factor the output value can be

corrected

Attenuation of the beam by the DAVID chamber


100 cm SSDIncreased about

032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID

IV ResultsDiscussion Changes in PDD


100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID

IV ResultsDiscussion


Surface dose

Increase with increase in field size

Increase with increase in energy

Increase with decrease in SSD



Pronounce with

decrease in SSD and

increase in photon energy and

increase in field size

Increase in surface dose is

due to scattered secondary

electrons from the DAVID

chamber reaching the

water phantom surface

(electron contamination)

6 cm

45 cm

100 cm



Deconvolution test

by iteration method

IV ResultsDiscussion Deconvolution


Deconvolution

bulldoes not depend on the length of the slit

bull40 cm slit results showed a small decrease in the tail signals

10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31


Deconvoluted slit signal at 40th and 65th wire

Deconvolution test


32

10x10cm fields before and after deconvolution

Single arc prostate plan before and after deconvolution (3 mm )

IV ResultsDiscussion Deconvolution with DAVID software


33

before deconvolution 61 mm

Gradients of the linear fit

before deconvolution 047 and

after deconvolution 29 mm


after deconvolution 094

IV ResultsDiscussion Enhance sensitivity after deconvolution


34

before deconvolution after deconvolution

HampN 6mm error


False alarmwarning effect before deconvolution

The effect is eliminated after deconvolution


35

Undeconvoluted

deconvoluted

Measuring the deconvolution matrix with

the DAVID software as manual LSF of single middle slit is measured and

used to generate the 80x80 LRF matrix with

MAT LAB and installed in the DAVID software

for deconvolution

IV ResultsDiscussion Limitations of DAVID-160 system


36

2mm MLC error single bank shift2mm MLC error single leaf

Analyzing both the maximum deviation

and total deviation in two different plots

at the same time



37

Max Dose 7599GyMax Dose 5727Gc

IV ResultsDiscussion Artificial MLC bang shift Error 2

cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n

Undetectable error Design of the chamber

DAVID Gap-Shift (prostate with OAR rectum back wall)



39

DAVID Quality Assurance software (DQA)

MAT LAB 2011b and 2012b

analyzes the daily session for all patients data with 2 clicks online

bull NDD- Non deconvoluted data

bull DD-Deconvoluted data

bull ED- Electrical data



40

Analysis only specific data on

specific date session and only print

out the deconvoluted data (DD)



41

Patient text file from DQA software

Sample patient 2014-01-12

Display only datas with MLC error

indicating the data type (DD)Beam

number Session segment and

particular MLC with error



42

The DQA software displays the warning and alarm errors

Warning and error dialogs at future date entry and invalid date entry respectively

year-month-day `yyyy-mm-dd



43

VMAT and IMRT plans sessions



DAVID chamber

bull Linear dependency on leaf opening

bull Sensitivity dependent on leaf gap opening

bull How much radiation pass through the opening

bull Deconvolution double the sensitivity

DAVID is design for specifics LINACS

Independent from the LINAC

In-vivo verification of MLC malfunction during VMAT

bull Undetectability field shifts due to chamber design

(Suggestion perpendicular wires or gradient)

V Conclusions


V Conclusion

Single MLC bank shift error

Maximum and total deviation to be analysed

Deconvolution matrix

To be generated for each linac

To be generated by single single slit

bull In comparison to other techniques measurement of undisturbed

signals

-gt no dependence on patient position(EPID)

-gt measurement of the complete delivered dose(TLD diode or MOSFET

detectors)

bull Suggestions for future development Standard design for software

bull Deconvolution program to be integrated

bull DQA to be integrated

bull Design two chambers perpendicular to each other

Co-operate directly with LINAC vendors for specifics designs


Sources

1 [1] Ezzel GA Galvin JM Low D Palta JR Rosen I Sharpe MB Xia P Xiao Y Xing L and Yu CX Guidance on delivery

treatment planning and clinical implementation of IMRT report of the IMRT subcommittee of the AAPM radiation

therapy committee Med Phys 2003 302089-115

2 [2] ESTRO Booklet No 9 2008 Guidelines for the verification of IMRT edited by Ben Mijnheer and Dietmar Georg

ISBN 90-804532-9

3 [3] Schneider F Polednik M Wol D Steil V Delana A Wenz F Menegotti L Optimization of the gafchromic EBT

protocol for IMRT QA Z Med Phys 2009 19(1)29-37

4 [4] Poppe B Blechschmidt A Djouguela A Kollho R Rubach A and Harder D Two-dimensional ionisation-chamber

arrays for IMRT plan verication Med Phys 2006 331005-15

5 [5] Poppe B Thieke C Beyer D Kollho R Djouguela A Ruumlhmann A Willborn KC and Harder D DAVID-a translucent

multi-wire transmission ionization chamber for in vivo verication of IMRT and conformal irradiation techniques Phys

Med Biol 2006 511237-48

6 [9] Poppe B Looe H K Chofor N Ruumlhmann A Harder D and Willborn K Clinical Performance of a Transmission

Detector Array for the Permanent Supervision of IMRT Deliveries Radiother Oncol 2010 95158-65

7 [10] Looe H K Harder D Ruumlhmann A Willborn K and Poppe B Enhanced accuracy of the permanent surveillance of

IMRT deliveries by iterative deconvolution of DAVID chamber signal proles Phys Med Biol 2010 553981-92

8 [11] Heukelom S el alWedge factor constituents of high-energy photon beams Head and phantom scatter dose

components Radiother Oncol 32 (1994) 66-3

9 12] Jursinic P A Changes in incident photon uence of 6 and 18 MV x rays caused by blocks and block trays Med

Phys 26 (1999) 2092-8

10 [13] v Klevens H Dependence of the tray transmission factor on collimator setting and sourcesurface distance Med

Phys 27 (2000) 2117-3

11 [14] Sharma SC el al Recommendations for measurement of tray and wedge factors for high energy photons Med

Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49


Description of the Elekta synergy DAVID160 system

50

David58

David160


51

bullΦ constant with depth

(small interactions)

bullSame electrons set in

motion in each square

bullie interactions per

volume constant through

target

bulldose reaches a

maximum at R (kerma

constant with depth

equals absorbed dose

beyond )

Number of electron tracks set in motion by

photon interaction


52


53


54


55


56


Layout

I Introduction

II Theory

VMAT and IMRT

MLC Design and Agility

MWPC and DAVID system


Equipment alignment patient data stability of DAVID chamber

Beam property Error detection

Deconvolution

DAVID QA software

IV Results Discussion

V Conclusion


I Introduction















Diodes





I Introduction


5

II Theory

















II Theory





bull 5 mm width


3cmsec


shape radiation


lt05


accessory holder

MLC Motor


Inventor


France1968










cathode(plate)


loads a C









11






II Theory

II Theory


12

Front Plate

Back Plate

Air Volume



b)scattered signal

c)leakage radiation

(background signal)


VMAT Planning





DAVID T34065





Reference

1st session


DAVID Analysis



Warning level 3

Alarm level 5







bull0deg

bull90deg

bull270deg









Setup conditions




MV




side




gap remains)


leave gap remains)



side




gap remains)


leave gap remains)






LRF fɛ(x)

S(x) = P(x) f(x)


algorithm



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


I Introduction















Diodes





I Introduction


5

II Theory

















II Theory





bull 5 mm width


3cmsec


shape radiation


lt05


accessory holder

MLC Motor


Inventor


France1968










cathode(plate)


loads a C









11






II Theory

II Theory


12

Front Plate

Back Plate

Air Volume



b)scattered signal

c)leakage radiation

(background signal)


VMAT Planning





DAVID T34065





Reference

1st session


DAVID Analysis



Warning level 3

Alarm level 5







bull0deg

bull90deg

bull270deg









Setup conditions




MV




side




gap remains)


leave gap remains)



side




gap remains)


leave gap remains)






LRF fɛ(x)

S(x) = P(x) f(x)


algorithm



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56




Diodes





I Introduction


5

II Theory

















II Theory





bull 5 mm width


3cmsec


shape radiation


lt05


accessory holder

MLC Motor


Inventor


France1968










cathode(plate)


loads a C









11






II Theory

II Theory


12

Front Plate

Back Plate

Air Volume



b)scattered signal

c)leakage radiation

(background signal)


VMAT Planning





DAVID T34065





Reference

1st session


DAVID Analysis



Warning level 3

Alarm level 5







bull0deg

bull90deg

bull270deg









Setup conditions




MV




side




gap remains)


leave gap remains)



side




gap remains)


leave gap remains)






LRF fɛ(x)

S(x) = P(x) f(x)


algorithm



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


5

II Theory

















II Theory





bull 5 mm width


3cmsec


shape radiation


lt05


accessory holder

MLC Motor


Inventor


France1968










cathode(plate)


loads a C









11






II Theory

II Theory


12

Front Plate

Back Plate

Air Volume



b)scattered signal

c)leakage radiation

(background signal)


VMAT Planning





DAVID T34065





Reference

1st session


DAVID Analysis



Warning level 3

Alarm level 5







bull0deg

bull90deg

bull270deg









Setup conditions




MV




side




gap remains)


leave gap remains)



side




gap remains)


leave gap remains)






LRF fɛ(x)

S(x) = P(x) f(x)


algorithm



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56












II Theory





bull 5 mm width


3cmsec


shape radiation


lt05


accessory holder

MLC Motor


Inventor


France1968










cathode(plate)


loads a C









11






II Theory

II Theory


12

Front Plate

Back Plate

Air Volume



b)scattered signal

c)leakage radiation

(background signal)


VMAT Planning





DAVID T34065





Reference

1st session


DAVID Analysis



Warning level 3

Alarm level 5







bull0deg

bull90deg

bull270deg









Setup conditions




MV




side




gap remains)


leave gap remains)



side




gap remains)


leave gap remains)






LRF fɛ(x)

S(x) = P(x) f(x)


algorithm



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56




II Theory





bull 5 mm width


3cmsec


shape radiation


lt05


accessory holder

MLC Motor


Inventor


France1968










cathode(plate)


loads a C









11






II Theory

II Theory


12

Front Plate

Back Plate

Air Volume



b)scattered signal

c)leakage radiation

(background signal)


VMAT Planning





DAVID T34065





Reference

1st session


DAVID Analysis



Warning level 3

Alarm level 5







bull0deg

bull90deg

bull270deg









Setup conditions




MV




side




gap remains)


leave gap remains)



side




gap remains)


leave gap remains)






LRF fɛ(x)

S(x) = P(x) f(x)


algorithm



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56





bull 5 mm width


3cmsec


shape radiation


lt05


accessory holder

MLC Motor


Inventor


France1968










cathode(plate)


loads a C









11






II Theory

II Theory


12

Front Plate

Back Plate

Air Volume



b)scattered signal

c)leakage radiation

(background signal)


VMAT Planning





DAVID T34065





Reference

1st session


DAVID Analysis



Warning level 3

Alarm level 5







bull0deg

bull90deg

bull270deg









Setup conditions




MV




side




gap remains)


leave gap remains)



side




gap remains)


leave gap remains)






LRF fɛ(x)

S(x) = P(x) f(x)


algorithm



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


Inventor


France1968










cathode(plate)


loads a C









11






II Theory

II Theory


12

Front Plate

Back Plate

Air Volume



b)scattered signal

c)leakage radiation

(background signal)


VMAT Planning





DAVID T34065





Reference

1st session


DAVID Analysis



Warning level 3

Alarm level 5







bull0deg

bull90deg

bull270deg









Setup conditions




MV




side




gap remains)


leave gap remains)



side




gap remains)


leave gap remains)






LRF fɛ(x)

S(x) = P(x) f(x)


algorithm



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56




cathode(plate)


loads a C









11






II Theory

II Theory


12

Front Plate

Back Plate

Air Volume



b)scattered signal

c)leakage radiation

(background signal)


VMAT Planning





DAVID T34065





Reference

1st session


DAVID Analysis



Warning level 3

Alarm level 5







bull0deg

bull90deg

bull270deg









Setup conditions




MV




side




gap remains)


leave gap remains)



side




gap remains)


leave gap remains)






LRF fɛ(x)

S(x) = P(x) f(x)


algorithm



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


11






II Theory

II Theory


12

Front Plate

Back Plate

Air Volume



b)scattered signal

c)leakage radiation

(background signal)


VMAT Planning





DAVID T34065





Reference

1st session


DAVID Analysis



Warning level 3

Alarm level 5







bull0deg

bull90deg

bull270deg









Setup conditions




MV




side




gap remains)


leave gap remains)



side




gap remains)


leave gap remains)






LRF fɛ(x)

S(x) = P(x) f(x)


algorithm



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


12

Front Plate

Back Plate

Air Volume



b)scattered signal

c)leakage radiation

(background signal)


VMAT Planning





DAVID T34065





Reference

1st session


DAVID Analysis



Warning level 3

Alarm level 5







bull0deg

bull90deg

bull270deg









Setup conditions




MV




side




gap remains)


leave gap remains)



side




gap remains)


leave gap remains)






LRF fɛ(x)

S(x) = P(x) f(x)


algorithm



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


VMAT Planning





DAVID T34065





Reference

1st session


DAVID Analysis



Warning level 3

Alarm level 5







bull0deg

bull90deg

bull270deg









Setup conditions




MV




side




gap remains)


leave gap remains)



side




gap remains)


leave gap remains)






LRF fɛ(x)

S(x) = P(x) f(x)


algorithm



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56




Reference

1st session


DAVID Analysis



Warning level 3

Alarm level 5







bull0deg

bull90deg

bull270deg









Setup conditions




MV




side




gap remains)


leave gap remains)



side




gap remains)


leave gap remains)






LRF fɛ(x)

S(x) = P(x) f(x)


algorithm



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


DAVID Analysis



Warning level 3

Alarm level 5







bull0deg

bull90deg

bull270deg









Setup conditions




MV




side




gap remains)


leave gap remains)



side




gap remains)


leave gap remains)






LRF fɛ(x)

S(x) = P(x) f(x)


algorithm



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56







bull0deg

bull90deg

bull270deg









Setup conditions




MV




side




gap remains)


leave gap remains)



side




gap remains)


leave gap remains)






LRF fɛ(x)

S(x) = P(x) f(x)


algorithm



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56








Setup conditions




MV




side




gap remains)


leave gap remains)



side




gap remains)


leave gap remains)






LRF fɛ(x)

S(x) = P(x) f(x)


algorithm



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56



side




gap remains)


leave gap remains)



side




gap remains)


leave gap remains)






LRF fɛ(x)

S(x) = P(x) f(x)


algorithm



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56



side




gap remains)


leave gap remains)






LRF fɛ(x)

S(x) = P(x) f(x)


algorithm



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56





LRF fɛ(x)

S(x) = P(x) f(x)


algorithm



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56



pairs





bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56



bull IMRT prostate


bull VMAT prostate




bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56



bull IMRT prostate


bull VMAT HampN




The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56



The average KDAVID


and



due to 8mm of PMMA



corrected




032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56



032 with DAVID

No change of

Dmax

14 cm with

and without DAVID

80 cm SSD

An increased about

426 with DAVID

slight change of

Dmax

13 cm with DAVID

14 cm without DAVID



100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


100 cm SSD

An increased about

067 with DAVID

Dmax

26 cm No change

80 cm SSD

An increased about

18 with DAVID

slight change of

Dmax

18 cm with DAVID

24 cm without DAVID



Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


Surface dose






Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


Pronounce with

decrease in SSD and









6 cm

45 cm

100 cm



Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


Deconvolution test

by iteration method



Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


Deconvolution



10 x 10 cm

10 cm slit

40 cm slit

20 cm slit

30 cm slit



31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


31



Deconvolution test


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


32





33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


33









34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


34


HampN 6mm error





35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


35

Undeconvoluted

deconvoluted





for deconvolution



36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


36




at the same time



37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


37



cm


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


0

1

2

3

4

5

6

7

8

0 8 10 12 14 16 18 20

shift mm

dose

in

cre

ase

G

y

ma

xim

al d

evia

tio

n





39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


39









40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


40






41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


41









42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


42






43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


43




DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


DAVID chamber










V Conclusions


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


V Conclusion







signals



detectors)







Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


Sources





ISBN 90-804532-9







Med Biol 2006 511237-48








Phys 26 (1999) 2092-8


Phys 27 (2000) 2117-3


Phys 21 (1994) 573-5


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


Thank you for your

attention


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


Additional Slides


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


49



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56



50

David58

David160


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


51







target

bulldose reaches a

maximum at R (kerma

constant with depth


beyond )


photon interaction


52


53


54


55


56


52


53


54


55


56


53


54


55


56


54


55


56


55


56


56