Early experience with intensity modulated proton therapy for lung-intact mesothelioma: A case series

Purpose: The purpose of this study was to describe our experience implementing intensity modulated proton therapy (IMPT) for lung-intact malignant pleural mesothelioma (MPM), including patient selection, treatment planning, dose verification, and process optimization. Methods and materials: Seven patientswith epithelioidMPMwere reviewed; 6 underwent pleurectomy, whereas 1 had biopsy alone. Four patients received IMPT and 3 received intensity modulated radiation therapy. Treatment plans for the other modality were created for dosimetric comparisons. Quality assurance processes included dose verification and robustness analysis. Image-guided setup was performed with the first isocenter, and couch shifts were applied to reposition to the second isocenter. Results: Treatmentwith IMPT waswell tolerated and completed without breaks. IMPT planswere designed with 2 isocenters, 4 beams, and <= 64 energy layers per beam. Dose verification processeswere completed in 3 hours. Total daily treatment time was approximately 45 minutes (20 minutes for setup and 25 minutes for delivery). IMPT produced lower mean doses to the contralateral lung, heart, esophagus, liver, and ipsilateral kidney, with increased contralateral lung sparing when mediastinal boost was required for nodal disease. Conclusions: Our initial experience showed that IMPT was feasible for routine care of patients with lung-intact MPM. (C) 2015 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.