A 12-year-old girl has Ewing's sarcoma of the ilium judged unresectable after neoadjuvant chemotherapy. Local control is planned with external beam radiotherapy. The standard total dose delivered for local control of Ewing's sarcoma is approximately:
- A 20 to 30 Gy
- B 35 to 40 Gy
- C 50 to 60 Gy ✓
- D 70 to 80 Gy
Correct answer: C. 50 to 60 Gy
Explanation
Ewing's sarcoma is highly radiosensitive, and definitive radiotherapy for unresectable disease or residual disease after incomplete surgery delivers approximately 50 to 60 Gy to the tumour volume, following initial chemotherapy. Doses below 45 Gy give unacceptable rates of local failure for gross disease, while doses above 65 Gy add morbidity such as secondary sarcoma and growth plate damage without improving control in this radiosensitive tumour.
Reference: Campbell's Operative Orthopaedics, 14th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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