Proton Therapy for Skull Base Chordomas: An Outcome Study from the University of Florida Proton Therapy Institute

• Published in: Journal of neurological surgery. Part B, Skull base Skull base, 2014-02, Vol.75 (1), p.053-057
• Main Authors: Deraniyagala, Rohan L., Yeung, Daniel, Mendenhall, William M., Li, Zuofeng, Morris, Christopher G., Mendenhall, Nancy P., Okunieff, Paul, Malyapa, Robert S.
• Format: Article
• Language: English
• Subjects: Original Article
• ISSN: 2193-6331; 2193-634X
• DOI: 10.1055/s-0033-1354579

Abstract 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.