Objective : We report the initial clinical experience with scanned proton beams at the Italian National Center for Hadrontherapy (CNAO).
Methods : In September 2011, CNAO commenced patient treatment with scanned proton beams under two prospective phase II protocols approved by the Italian Health Ministry. Patients with chondrosarcoma or chordoma of the skull base or spine were eligible. By December 2011, four patients (one with skull-base chordoma, one with skull-base chondrosarcoma, two with sacral chordomas) had completed treatment. Immobilization was performed using rigid non-perforated thermoplastic-masks and customized head-rests or body-pillows as indicated. Non-contrast CT scans with immobilization devices in place and MRI scans in supine position were performed for treatmentplanning.
For chordoma, the prescribed doses were 74CGE and 54CGE to PTV1 and PTV2, respectively. For chondrosarcoma, the prescribed doses were 70CGE and 54CGE to PTV1 and PTV2, respectively. Treatment was delivered 5 days a week in 35-37 fractions. Prior to treatment, the patients’ positions were verified using an optical tracking system and orthogonal x ray images. Proton beams were delivered using fixed-horizontal portals on a robotic couch. Weekly MRI incorporating diffusion-weighted-imaging was performed during the course of proton therapy. Patients were reviewed once weekly and acute toxicities were graded with the Common Terminology Criteria for Adverse Events (CTCAE).
Results : Mean age of patients = 54.5 years. All four patients completed the proton therapy without major toxicities and without treatment interruption. Median dose delivered was 74CGE. The maximum toxicity recorded was skin desquamation (CTCAE Grade 2) in one patient.
Conclusions : Our preliminary data demonstrates the clinical feasibility of scanned proton beams in Italy. We continue patient accrual to 50 patients (30 for skull base and 20 for spine) and results will be updated.