Radiation therapy in bone tumors
Radiation therapy has been used in both the neoadjuvant and adjuvant setting in the treatment of Ewing’s sarcoma. Osteosarcomas do not respond well to radiation therapy and its use in this tumor (tumour) has been limited to only very select situations.
Regimes for treatment of Ewing’s sarcoma differ according to site and center. When used alone, doses up to 6600 rads may be necessary to produce local control. In contrast, 3000 to 4000 rads in divided doses are given in this condition when surgery is combined with radiation therapy. Because of their propensity to cause premature physeal closure and bone necrosis, the role of radiation therapy in local control in some institutions has been limited to the treatment of spine and pelvic lesions. In these settings the treatment may be used solely or intraoperatively in conjunction with surgery . In the treatment of extremity lesions a purely surgical approach may be desirable reserving radiation for when margins of resection are compromised. There is the additional concern of radiation sarcoma developing in these genetically altered patients in whom alkylating agents have been used. Hence in general this modality is best used judiciously.
While not studied specifically in the pediatric age group, radiation therapy has been shown to increase wound complications in the perioperative period which is another factor to consider if the patient is to have chemotherapy as this occurrence would result in the delay of resumption of chemotherapy.