COSMIC: A Regimen of Intensity Modulated Radiation Therapy Plus Dose-Escalated, Raster-Scanned Carbon Ion Boost for Malignant Salivary Gland Tumors: Results of the Prospective Phase 2 Trial

Treatment was tolerated, with moderate acute and late toxicity. The LC at 3 years was promising. No significant difference could be shown regarding resection status; hence, extensive and mutilating surgical procedures should be rediscussed. Further dose escalation may be limited in view of potential vascular adverse events.