LearningRadiology - Radioosteonecrosis

Radiation-Induced Osteosarcoma

• 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

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