Proton‐based radiotherapy for unresectable or incompletely resected osteosarcoma

Abstract

Purpose To assess clinical outcome and the role of proton-therapy (PT) for local control (LC) of osteosarcoma (OSA). Methods All patients who received PT or mixed photon-proton radiotherapy from 1983–2009 at the Massachusetts General Hospital were reviewed. Criteria for PT were the need for high dose in the context of highly conformal radiotherapy of unresected or partially resected OSA, positive postoperative margins, postoperative imaging studies with macroscopic disease, or incomplete resection as defined by the surgeon. The primary endpoint was local control (LC) of the site treated; secondary endpoints were disease-free survival (DFS), overall survival (OS), long term toxicity, and prognostic factors associated with clinical outcome. Results 55 patients with a median age of 29 (2 to 76) were offered PT. The mean dose was 68.4 Gy, (standard deviation 5.4 Gy). 58.2% (11–100%) of the total dose was delivered with protons. LC after three and five years was 82 % and 72 %, respectively. The distant failure rate was 26% after three and five years. The five-year DFS was 65%, and the five-year OS was 67%. The extent of surgical resection did not correlate with outcome. Risk factors for local failure were ≥2 grade disease (p<0.0001) and total treatment length (p=0.008). Grade 3–4 late toxicity was seen in 30.1 % of patients. One patient died from treatment-associated acute lymphocytic leukemia, and one from secondary carcinoma of the maxilla. Conclusion PT to deliver high RT doses allows organ-preserving locally curative treatment with high doses for unresectable or incompletely resected OSA.

Radiotherapy and gemcitabine–docetaxel chemotherapy in children and adolescents with unresectable recurrent or refractory osteosarcoma

“…Disease control rate was 50%, yet, did not result in improved long-term survival. Recent developments in radiotherapy allow the application of higher tumor doses in inoperable osteosarcoma without increased side effects in the palliative settings (19). In 78 patients with osteosarcoma of the trunk, carbon ion radiotherapy provided a good local control (62%), a survival advantage and good long-term functional results without unacceptable morbidity (20).…”

Common Musculoskeletal Tumors of Childhood and Adolescence

“…In a recent report of 55 patients with unresectable or subtotally resected OS treated with proton radiotherapy, local control at 3 and 5 years was 82% and 72%, respectively, with a median tumor dose of 68.4 Gy. 53 Heavier ions, such as carbon, have a radiobiologic advantage for radioresistant tumors and are being investigated in OS. 54,55 Carbon ion doses of 70.4 Gy were associated with 92% local control at 3 years in patients with unresectable head and neck OS.…”

Osteosarcoma of the spine: prognostic variables for local recurrence and overall survival, a multicenter ambispective study

“…While not traditionally considered a radiosensitive tumor, advanced radiation techniques (e.g., stereotactic radiotherapy delivery and proton beam therapy) may be able to deliver tumoricidal doses while not exceeding local neurological or adjacent organ toxicity constraints. 11,18 At present, adjuvant radiotherapy remains investigational as a primary or adjuvant local control modality for spinal osteosarcoma.…”