Radiotherapy in the Management of Giant Cell Tumor of Bone

Objectives:To evaluate the long-term treatment outcomes for patients with giant cell tumor of bone (GCTB) treated with radiotherapy with or without surgical resection. Methods:This retrospective review includes 34 patients with GCTB treated with megavoltage radiotherapy between January 1973 and January 2008 at the University of Florida. Patients' ages ranged from 16 to 85 years (median, 29). Tumor sizes ranges from 2.5 to 12 cm (median, 4.8 cm) in the maximum dimension. Twenty-one patients received radiation for gross disease, either de novo (22 patients) or recurrent (12 patients). Thirteen patients were treated with postoperative radiation after gross total resection. The median dose was 45 Gy in both the definitive and adjuvant settings. Results:The median follow-up was 16.8 years. The 5- and 10-year local-control (LC) rates were 85% and 81%, respectively. Six patients developed an isolated local recurrence (2/13 treated postoperatively and 4/21 who were treated for gross disease). All 6 patients who developed a local recurrence were successfully salvaged with surgery; therefore, the ultimate LC rate was 100%. Both the 5- and 10-year freedom from distant metastasis rates were 91%. Three patients developed lung metastases, including 1 patient who experienced GCTB transformation into a high-grade sarcoma. The 5- and 10-year progression-free survival rates were both 78%. Conclusions:Moderate-dose radiotherapy for GCTB provides a long-term LC >80%, justifying its role as an alternative to morbid surgery.