Objectives Skull base
chordoma is a rare, locally aggressive
tumor located adjacent to critical structures. Gross total resection is difficult to achieve, and
proton therapy has the conformal advantage of delivering a high postoperative dose to the
tumor bed. We present our experience using
proton therapy to treat 33 patients with skull base
chordomas. Design Retrospective outcomes study. Setting University of Florida
Proton Therapy Institute; 2007 to 2011. Participants A total of 33 patients with skull base
chordomas received postoperative three-dimensional conformal
proton therapy. The patients were 79% male and 6% diabetic; 27% had received a gross total resection. Main Outcome Measures The gross
tumor/
tumor bed received a dose between 77.4 CGE and 79.4 CGE. Local control and overall survival were tracked, and radiation toxicity was assessed using a modified
Radiation Therapy Oncology Group/European Organization for Research and Treatment of
Cancer Late Radiation Morbidity Scoring Scheme. Results Median follow-up for all patients was 21 months. Local control and overall survival rates at 2 years were 86% and 92%, respectively. Grade 2 toxicity was observed in 18% of our cohort in the form of
unilateral hearing loss partially corrected with a
hearing aid. No grade 2 or higher optic or brainstem toxicities were observed. Conclusions Proton
therapy is an effective treatment modality for skull base
chordomas.