Intensity-modulated radiotherapy for head-and-neck rhabdomyosarcoma.

PURPOSE: To determine the preliminary results of intensity-modulated radiotherapy (IMRT) for head-and-neck rhabdomyosarcoma.

METHODS AND MATERIALS: Twenty-eight patients underwent IMRT as a part of multimodality therapy. Twenty-one tumors were parameningeal, three were orbital, and four were in other sites. The median age was 8 years (range, 1-29 years). Most (89%) had Group III disease. Intracranial extension was present in 71% of parameningeal tumors. A 1.5-cm margin was used, and the median dose was 50.4 Gy (range, 30-55.8 Gy).

RESULTS: The actuarial 3-year survival rate for patients with parameningeal tumors was 65%. The 3-year actuarial freedom from failure rate was 95% locally, 90% in regional nodes, 88% in the central nervous system, and 80% at distant sites. No failures occurred among patients with orbit tumors; a single central nervous system failure occurred in 1 patient with a lip/cheek tumor. Disease-free survival was significantly worse for patients with alveolar histologic features (p = 0.01). Acute radiation toxicity was similar to that reported by the Intergroup Rhabdomyosarcoma Study Group. Late radiation toxicity was recorded and was mild.

CONCLUSION: IMRT with image fusion results in outstanding local control despite the use of a reduced margin. However, survival among patients with alveolar histologic findings or intracranial extension remains unacceptably low.