Radiation Osteonecrosis

Radiation changes in bone occur above 3000 rads

     • Growth disturbances

              • Scoliosis or retarded growth of long bones

     • Radiation osteonecrosis

              • Especially mandible

     • Tumor induction

• Radiation-induced tumors

            • Benign tumors

             • Benign exostoses have been reported in the treatment field of growing bones

            • Malignant tumors

            • Osteosarcoma is most common but undifferentiated fibrosarcoma is nearly as frequent

          • Head and neck are most common sites for induced osteosarcoma

                  • Mandible in adults

                 • Orbits in children (retinoblastoma)

         • Chondrosarcoma may also occur

        • Suspect clinically when pain and swelling occur in irradiated area many years after treatment

• Stage I carcinoma of the cervix can be treated with a combination of external and intracavitary radiation

      • External dose was 4000 rads through four opposed fields

     • Intracavitary dose was 3000 to 6000 rads to cervix but bones of pelvis receive little radiation normally