1818F-FET PET Compared with F-FET PET Compared with 1818F-F-FDG PET and CT in Patients with FDG PET and CT in Patients with

Head and Neck CancerHead and Neck Cancer

Present by Intern Present by Intern 羅穎駿羅穎駿

Journal of Nuclear MedicineJournal of Nuclear MedicineVol. 47 No. 2 256-261 © 2006Vol. 47 No. 2 256-261 © 2006

INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION CONCLUSION

INTRODUCTION

Characteristics of tumor lesion:Characteristics of tumor lesion: Increased glucose metabolismIncreased glucose metabolism Increased DNA synthesisIncreased DNA synthesis Increased amino acid transportationIncreased amino acid transportation Increased presentation of some Increased presentation of some

receptors and antigensreceptors and antigens

INTRODUCTION

Discrimination between tumor and reactive Discrimination between tumor and reactive tissue changes may be difficult based tissue changes may be difficult based solely on morphologic criteria, for solely on morphologic criteria, for example, by CT and MRIexample, by CT and MRI

1818F-FDGF-FDG has a sensitivity of 80%–100% for has a sensitivity of 80%–100% for the detection of primary tumors, tumor the detection of primary tumors, tumor recurrences, and occult metastases, but is recurrences, and occult metastases, but is not specific for cancer cells and not specific for cancer cells and exhibits exhibits high uptake in macrophages, fibroblasts, high uptake in macrophages, fibroblasts, and granulation tissueand granulation tissue

INTRODUCTION

Artificial Artificial amino acidamino acid that is not that is not incorporated into proteins but incorporated into proteins but exhibits high uptake in tumor cells exhibits high uptake in tumor cells because of increased transport via because of increased transport via the the amino acid transport systemsamino acid transport systems L L and Band B0,+0,+

Animal experiments show that Animal experiments show that 1818F-F-FETFET, in contrast to , in contrast to 1818F-FDG, exhibits F-FDG, exhibits no uptake in inflammatory cells or in no uptake in inflammatory cells or in inflammatory lymph nodesinflammatory lymph nodes

INTRODUCTION

Squamous cell carcinoma (SCC) is Squamous cell carcinoma (SCC) is the major histologic type of the head the major histologic type of the head and neck neoplasmand neck neoplasm

Selective uptake of Selective uptake of O-O-(2-(2-[18F]fluoroethyl)-L-tyrosine (FET)[18F]fluoroethyl)-L-tyrosine (FET) in in cerebral gliomas and in SCCcerebral gliomas and in SCC

Good distinction between tumor and Good distinction between tumor and inflammationinflammation

INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION CONCLUSION

MATERIALS AND METHODS

Twenty-one patients (3 women and 18 Twenty-one patients (3 women and 18 men; age range, 41–80 y; mean, 61 y) men; age range, 41–80 y; mean, 61 y) with suspected head and neck tumors with suspected head and neck tumors underwent underwent 1818F-FET PET, F-FET PET, 1818F-FDG PET, and F-FDG PET, and CT within 1 wk before operationCT within 1 wk before operation

After coregistration, the images were After coregistration, the images were evaluated by 3 independent observers and evaluated by 3 independent observers and an ROC analysis was performed, with the an ROC analysis was performed, with the histopathologic result used as a referencehistopathologic result used as a reference

MATERIALS AND METHODS

The CT images, the The CT images, the 1818F-FDG PET images, F-FDG PET images, and the and the 1818F-FET PET imagesF-FET PET images

For each patient, the observers evaluated For each patient, the observers evaluated 5 anatomic regions or levels: 5 anatomic regions or levels:

level 1, nasopharynx; level 2, oropharynx; level 1, nasopharynx; level 2, oropharynx; level 3, hypopharynx/larynx; region 4, level 3, hypopharynx/larynx; region 4, right cervical lymph nodes; region 5, left right cervical lymph nodes; region 5, left cervical lymph nodescervical lymph nodes

MATERIALS AND METHODS

Each observer recorded suspected Each observer recorded suspected lesions and gave each level a lesions and gave each level a confidence rating based on a confidence rating based on a 6-point 6-point scalescale, a rating score of 4 or greater , a rating score of 4 or greater was considered positive for tumor was considered positive for tumor tissue tissue

Furthermore, the maximum Furthermore, the maximum standardized uptake values (SUVs) in standardized uptake values (SUVs) in the lesions were determined the lesions were determined

INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION CONCLUSION

RESULTS

In 18 of 21 patients, histologic In 18 of 21 patients, histologic examination revealed SCC, and in 2 examination revealed SCC, and in 2 of these patients, a second SCC of these patients, a second SCC tumor was found at a different tumor was found at a different anatomic siteanatomic site

In 3 of 21 patients, inflammatory In 3 of 21 patients, inflammatory tissue and no tumor were identifiedtissue and no tumor were identified

RESULTS

Eighteen of 20 SCC tumors were Eighteen of 20 SCC tumors were positive for both positive for both 1818F-FDG uptake and F-FDG uptake and 1818F-FET uptake, one 0.3-cm SCC F-FET uptake, one 0.3-cm SCC tumor was detected neither with tumor was detected neither with 1818F-F-FDG PET nor with FDG PET nor with 1818F-FET PET, and F-FET PET, and one 0.7-cm SCC tumor in a 4.3-cm one 0.7-cm SCC tumor in a 4.3-cm ulcer was overestimated as a 4-cm ulcer was overestimated as a 4-cm tumor on tumor on 1818F-FDG PET and missed on F-FDG PET and missed on 1818F-FET PET.F-FET PET.

RESULTS

18F-FDG PET (A), CT (B), and 18F-FET PET (C)Images of a 52-y-old man with a 0.7-cm SCC in 4.3-cm ulcer with inflammatory tissue (arrows)

RESULTS

Inflammatory tissue was positive for Inflammatory tissue was positive for 1818F-FDG uptake (SUV, 3.7–4.7) but F-FDG uptake (SUV, 3.7–4.7) but negative for negative for 1818F-FET uptake (SUV, F-FET uptake (SUV, 1.3–1.6)1.3–1.6)

18F-FDG PET (A), CT (B), and 18F-FET PET (C)

RESULTS

The SUVs of The SUVs of 1818F-FDG in SCC were F-FDG in SCC were significantly higher (13.0 ± 9.3) than significantly higher (13.0 ± 9.3) than those of those of 1818F-FET (4.4 ± 2.2)F-FET (4.4 ± 2.2)

18F-FDG PET (A), CT (B), and 18F-FET PET (C)

RESULTS

In the In the lymph node metastaseslymph node metastases ( (nn = = 5), with an average size of 1.1 ± 0.6 5), with an average size of 1.1 ± 0.6 cm, cm, no increased no increased 1818F-FET uptakeF-FET uptake could be identified (mean SUV, 1.4 ± could be identified (mean SUV, 1.4 ± 0.3; range, 1.0–1.9)0.3; range, 1.0–1.9)

The corresponding SUV for The corresponding SUV for 1818F-FDGF-FDG uptake ranged from 1.6 to 3.3 uptake ranged from 1.6 to 3.3 (mean, 2.3 ± 0.7); (mean, 2.3 ± 0.7); 2 of 5 lymph 2 of 5 lymph node metastases had an SUV above node metastases had an SUV above 2.5 and 3 of 5 had an SUV below 2.52.5 and 3 of 5 had an SUV below 2.5

RESULTS

The sensitivity of The sensitivity of 1818F-FDG PET was F-FDG PET was 93%, specificity was 79%, and 93%, specificity was 79%, and accuracy was 83%.accuracy was 83%.

1818F-FET PET yielded a lower sensitivity F-FET PET yielded a lower sensitivity of 75% but a substantially higher of 75% but a substantially higher specificity of 95% (accuracy, 90%)specificity of 95% (accuracy, 90%)

RESULTS

The ROC analysis showed The ROC analysis showed significantly significantly superiorsuperior detection of detection of SCC with SCC with 1818F-FET PET or F-FET PET or 1818F-FDG PET F-FDG PET than with CTthan with CT

No significant difference (No significant difference (PP = 0.71) = 0.71) was found between was found between 1818F-FDG PET and F-FDG PET and 1818F-FET PETF-FET PET

INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION CONCLUSION

DISCUSSION

Detection of SCC was not better with Detection of SCC was not better with 1818F-FET PET than with F-FET PET than with 1818F-FDG PET, F-FDG PET, and and no significant differenceno significant difference in in accuracy was identified in an ROC accuracy was identified in an ROC analysisanalysis

The The specificity of specificity of 1818F-FET PETF-FET PET for the for the detection of SCC was superior to that detection of SCC was superior to that of of 1818F-FDG PET and CT F-FDG PET and CT

DISCUSSION

The differences in sensitivity and The differences in sensitivity and specificity may be attributed partly to specificity may be attributed partly to the the relatively low relatively low 1818F-FET uptake in F-FET uptake in the tumorsthe tumors

This low uptake leads to a This low uptake leads to a poorer poorer detection rate, especially in small detection rate, especially in small tumorstumors, which are missed because of , which are missed because of partial-volume effects partial-volume effects

DISCUSSION

Because uptake and sensitivity are Because uptake and sensitivity are lower for lower for 1818F-FET than for F-FET than for 1818F-FDGF-FDG, , 1818F-F-FET does not represent an ideal FET does not represent an ideal tracer for the evaluation of tracer for the evaluation of primary primary SCCSCC of the head and neck region of the head and neck region

DISCUSSION

The higher specificity makes The higher specificity makes 1818F-FETF-FET PET an interesting additional tool in PET an interesting additional tool in the the follow-upfollow-up of patients with SCC of patients with SCC

Monitoring of Monitoring of radio- or chemotherapyradio- or chemotherapy of SCC, because the reaction of the of SCC, because the reaction of the tumor tissue may be specifically tumor tissue may be specifically detected detected without the interfering without the interfering uptake by inflammatory or reactive uptake by inflammatory or reactive tissuetissue

INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION CONCLUSION

CONCLUSION

1818F-FET may not replace F-FET may not replace 1818F-FDG in the F-FDG in the PET diagnostics of head and neck PET diagnostics of head and neck cancer but may be a helpful cancer but may be a helpful additional tool in selected patients by additional tool in selected patients by allowing better differentiation of allowing better differentiation of tumor tissue from inflammatory tumor tissue from inflammatory tissuetissue

The sensitivity of The sensitivity of 1818F-FET PET in SCC, F-FET PET in SCC, however, was inferior to that of however, was inferior to that of 1818F-F-FDG PET because of lower SUVsFDG PET because of lower SUVs

Thank you forThank you foryour attention!your attention!

1818F-FET PET Compared with F-FET PET Compared with 1818F-F-FDG PET and CT in Patients with FDG PET and CT in Patients with

Head and Neck CancerHead and Neck Cancer

Presented by Intern Presented by Intern 羅穎駿羅穎駿

Journal of Nuclear MedicineJournal of Nuclear MedicineVol. 47 No. 2 256-261 © 2006Vol. 47 No. 2 256-261 © 2006