Supervoltage radiotherapy in the treatment of difficult giant cell tumors of bone.

Fifteen patients with giant cell tumor were treated by supervoltage radiotherapy. Each patient had been referred for therapy because adequate surgery would have been difficult or disfiguring. No patient who received appropriate therapy experienced a recurrence, and there were no cases of malignant transformation of a giant cell tumor after a mean follow-up period of 12 years. Radiotherapy is not recommended for primary treatment of giant cell tumor but may be indicated in exceptional circumstances.