Emerging role of proton beam radiation therapy for chordoma and chondrosarcoma of the skull base.

Chordomas and chondrosarcomas of the skull base are rare, indolent tumors with a natural history of locally invading their surroundings. Safe, maximal resection is the mainstay of treatment, followed by adjuvant radiation therapy. Even with multimodality therapy, local recurrence remains the most common failure pattern, translating to an adverse overall survival. Compared with other forms of radiation therapy, proton beam therapy has been used to increase the dose delivered to the tumor while elegantly sparing dosing to adjacent critical normal structures.