Osteonecrosis Following Radiation and Osteoporosis

Objective: This case report describes osteonecrosis of the pelvis, two and half years after receiving radiation therapy for a leiomyosarcoma of the vagina in a 40 year old female. Methods: The patient presented with a vaginal mass measuring 8 cm which on biopsy showed a leiomyosarcoma (20 mitotic figures / 10 high power fields). She had a resection of the tumor followed by radiotherapy to the pelvis and 6 months of Doxil chemotherapy finishing in March of 2013. Three years later she presented with pelvic pain and instability of walking. A combination of radiologic imaging including a CT scan of her pelvis, a bone scan and a MRI scan of her lumbosacral spine revealed necrotic lesions in the pelvic ischium and bilateral pelvic insufficiency fractures in the sacrum. Biopsy of the tissues showed necrotic tissue but no cancer. A DEXA scan was performed which showed diagnostic T scores as L spine -0.6, femoral neck -3.1, total hip -3.1, giving a WHO classification of osteoporosis. Results: Her treatment for osteonecrosis and osteoporosis includes calcium, vitamin E, oyster shell, weight bearing exercises and Fosamax 70 milligrams daily. Her pain has improved and she no longer requires utilizing a walker. Conclusions: In women who present with pelvic pain after pelvic radiotherapy, bony destruction and fractures can be indicative of a late radiation effect rather than osseous metastases. Patients with osteoporosis are at a much higher risk for developing post-radiotherapy osteonecrosis and fractures. Conservative treatment together with Fosamax have begun to show improvement in the clinical condition of the patient. Radiological imaging will be utilized as appropriate to determine improvement in the status of the pelvic bone.