RADIATION OSTEITIS AND INSUFFICIENCY FRACTURES AFTER PELVIC IRRADIATION FOR GYNECOLOGIC MALIGNANCIES

Damage to the pelvic bones after radiotherapy for gyne logical malignancies is uncommon with megavoltage radio therapy. It can be misdiagnosed as bony metastases and is diagnosis of exclusion. We report 12 women, who were treated for endometrial or cervical carcinoma who developed osteitis, femoral head or neck necrosis, or insufficiency fractures of the acetabulum, pubic symphysis or sacroiliac bones after radiotherapy. Many had multiple areas of bone damage. The prescribed external beam dose ranged from 40.0 to 61.2 Gy. All but one patient developed bony discomfort or pain as a symptom. Bony changes of the pelvic girdle appeared between 6 months and 8 years after irradiation. Radiographic studies including plain films, CT or bone scans were performed in these patients and showed correlative changes. Bone scans showed increased radionuclide uptake in affected bones. The subsequent favorable clinical course and outcome with resolution of symptoms confirmed the diagnosis of radiation osteitis. Therapy recommendations are conservative with avoidance of weight-bearing, use of analgesics and physical therapy. Femoral head necrosis/fractures required arthroplasty. Proper shielding, use of multifield technique, treatment of all fields per day, and awareness of tolerance doses are recommended.