Treatment Outcomes of Radiation Therapy of Paragangliomas of the Head and Neck at a Single Institution.

BACKGROUND/OBJECTIVES: Stereotactic radiosurgery and photon therapy for the locoregional management of head and neck paragangliomas (HNPGLs) have been shown to provide long-term tumor control and symptomatic relief. We report proton therapy (PT) outcomes for HNPGLs at a single institution and describe stereotactic radiosurgery (SRS) and intensity-modulated radiation therapy (IMRT) outcomes as institutional context for modality selection. The primary goal is to report outcomes including tumor control, toxicity, and overall recovery, while evaluating differences across radiation modalities. MATERIALS/METHODS: This is a retrospective review of 52 adult patients with 54 non-metastatic HNPGLs receiving radiation therapy in a single institution. There were 9 tumors treated with IMRT, 23 with SRS, and 22 with PT. Median dose was 45 Gy (cobalt Gray equivalent [CGE]). RESULTS: Out of 52 patients (14 male, 38 female) with a current median age of 65 (range 27-93), there were 30 jugular paragangliomas (PGLs), 1 tympanic PGL, 8 jugulotympanic PGLs, 3 vagal PGLs, 11 carotid body tumors, and 1 spinal PGL. The median age at the start of treatment was 59.5 years (range 18-85). Median follow-up was 50.3 months (range 3.6-147.2 months), with 52 (100%) patients alive at last follow-up. Local control, distant control, and overall survival were 98%, 100%, and 100%, respectively. No grade 3 to 5 toxicities were reported. At the end of follow-up, 53 (98%) tumors had a partial treatment response or were stable, and 20 (37%) experienced a decrease in volume. Of the 20 tumors that had a decrease in volume, 8 were treated with PT, 8 with SRS, and 4 with IMRT. PT was used more frequently for larger or anatomically complex tumors; SRS was preferred for small, well-circumscribed lesions; and IMRT was selected for moderate-sized or irregularly shaped tumors near critical structures before PT was available. CONCLUSION: PT was particularly useful in treating large or anatomically complex tumors, while SRS and IMRT offered strong outcomes for smaller or anatomically suitable lesions. We report favorable feasibility, local tumor control, survival, and toxicity of PT for HNPGLs.