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radiotherapy of bone metastases,Vakalis

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Text of radiotherapy of bone metastases,Vakalis

  • 1. .
  • 2. Disclosures None
  • 3. Metastatic Bone Disease Metastasis Sites Vertebra (69%) Pelvis (41%) Femur (25%) Hip (14%) Malawer, MM and Delaney, TF. Treatment of Metastatic Cancer to the Bone. In: Devita VT, Hellman S, Rosenberg SA (eds). Cancer: Principles and Practice of Oncology. 4th ed. Philadelphia: JB Lippincott; 1993:2225-2245.
  • 4. Level of Metastases Thoracic 70% Lumbar 20% Cervical 10%
  • 5. Radiology: How to Evaluate Imaging tests X-ray Bone scan Sensitive, not specific. False positives: trauma, arthritis, infection CT (CAT scan) PET scan MRI scan Bone biopsy for confirmation Blood tests Calcium, alkaline phosphatase Bone Scan
  • 6. Bone Scan A nuclear medicine bone scan would show bone mets as dark areas
  • 7. PET scans may show the mets very clearly
  • 8. PET scans can show bone mets that are in hard to see areas like the ribs or scapula
  • 9. An MRI may show a bone met better than a regular X-ray
  • 10. MRI imaging T1 T2
  • 11. Clinical features of bony metastases Bone pain Pathological fracture Nerve compression Hypercalcaemia
  • 12. APPROACH Life expectancy Biopsy Histology to predict the response to non operative management Stability Clinical presentation Pain and Neurological status
  • 13. Treatment of bone metstasis Multi-disciplinary approach Medical. Surgical. Radiotherapy. Radionuclid. Chemotherapy & Hormonal Therapy
  • 14. Radiation Therapy 1. Localized irradiation 2. Hemibody irradiation
  • 15. How does RT reduce pain ? Cell kill reduced tumor size and pressure effects Endothelial damage of micro-vasculature reduced blood flow. Reduces edema Reduces pain related neuro-transmitter concentrations Bone promotes re-mineralisation leading to structural stability.
  • 16. Indications of Radiotherapy As Primary Treatment 1. Radiosensitive tumor not previously irradiated 2. Widespread spinal metastases with multilevel neural compression 3. Total neurological deficits below the level of compression > 48 hours 4. Patients condition (or prognosis) precludes surgery: high surgical risk or short life expectancy Penas-Prado M, Loghin ME. Spinal cord compression in cancer patients: review of diagnosis and treatment. Curr Oncol Rep. 2008 Jan;10(1):78- 85.
  • 17. Radiotherapy Modalities Conventional External Beam Radiotherapy (EBRT) Intensity-modulated radiation therapy (IMRT) Stereotactic radiotherapy Stereotactic radiosurgery Radioisotopes Finn MA, Vrionis FD, Schmidt MH. Spinal radiosurgery for metastatic disease of the spine. Cancer Control. 2007 Oct;14(4):405-11.
  • 18. Radiation Results Overall 85% response rate Complete relief in 54% 50% respond by 2 weeks, 80% by 1 month Median duration of pain relief 12-15 weeks The Xrays or scans may take months to show improvement (Recalcification by 2-3 months)
  • 19. Bone met at L2 Radiation field A typical course of radiation is 10 treatments ( in some cases it is necessary to go slower, 20 to 25)
  • 20. Palliative xrt - bone metastases treatment planning M. Raphael Pfeffer,Oncology Institute, Chaim Sheba Medical Center good margins e.g. add 1-2 vertebrae on each side include nearby asymptomatic lesions avoid irradiating entire limb circumference reduce irradiated volume of bowel/bladder bone marrow toxicity
  • 21. Fractionation regimens 8 Gy in 1 fraction 20 Gy in 5 fractions 24 Gy in 6 fractions 30 Gy in 10 fractions Endpoints using pain relief, narcotic relief and quality of life measures show consistent similarity in the regimens
  • 22. Single Vs Multi-Fraction
  • 24. Single fraction v multifraction more convenient less costly shorter time with acute side effects fear of high doses per fraction higher retreatment rate( 2-2,5 times higher) concern about toxicity in long-term survivors flare of bone pain maybe be higher
  • 25. Single fraction v multifraction caution Problematic retreatment Previous treatment to the spine Femoral axial cortical involvment > 3 cm Surgical stabilization procedure Spinal cord compression or radicular nerve pain
  • 26. Re-irradiation Not covering the spinal cord 1 x 8 Gy or 5 x 4Gy(Grade C) Covering the spinal cord 8 x 2,5 Gy (Grade D)
  • 27. Adjuvant Radiotherapy Done after operative decompression Patchell et al study Wait 3 weeks for wound healing before starting radiation
  • 28. Post-operative Patient received 30Gy/10fx
  • 29. Radiopharmaceuticals Use of Radiopharmaceuticals does not obviate the need for EBRT. Ideal for osteoblastic, multi-focal and wide-spread disease.
  • 30. Hemi-body Irradiation For multiple lesions, when facilities for radionuclide therapy is un-available. More suited for lower hemibody than upper. Ideally treated using 6MV photons or higher Keep lung dose to < 6 Gy for upper HBI
  • 31. Palliative xrt -single fraction half body iradiation lower half body 8 Gy upper half body 6 Gy good short term palliation (~3 months) onset of pain relief Half Body xrt 50% @ 3 days, 100% @ 14 days Focal XRT 50% @ 7 days, 80% @ 14 days Salazar Cancer 1986 M. Raphael Pfeffer,Oncology Institute, Chaim Sheba Medical Center
  • 32. Bisphosphonates and RT Bisphosphonates and RT can be given