Trattamento con protonterapia dei tumori cerebrali primitivi: analisi degli outcomes

Background: Radiation therapy (RT) is an essential and effective part of the management of adult brain tumors. Proton therapy (PT) has emerged as an alternative radiation treatment modality. Although the number of patients receiving PT for a brain tumor is increasing, the potential clinical superiority of PT over photon RT in patients with brain tumors remains a matter of debate due to the lacking of comparative trials. Matherial and methods: Aim of the project was to select subgroups of patients with primary brain tumors who received PT. Data analysis focused on recurrent glioblastomas (rGBM) and patients with intracranial WHO grade II (atypical) meningiomas. Results: Concerning rGBM, 54 patients (pts) with rGBM were re-irradiated with PT. All pts received 36 GyRBE in 18 fractions. PT was delivered with or without CHT. The median OS after PT was 8.5 months. The median PFS was 4 months. There was no grade 3 or higher acute and late toxicities. Regarding AMs, 56 adults and 5 pediatric pts (total of 61) with intracranial AMs were treated with PT at our institution. All adult pts were treated with a PT total dose of 60 GyRBE (2 GyRBE/fraction, 5 fractions/week). In the pediatric population the PT dose ranged from 50.4 to 59.4 GyRBE. After a median follow-up after PT of 43 months, the estimated 3- and 5-year PFS was 77% and 67% for the entire cohort, respectively. The 3- and 5-year OS was 89% and 67% respectively for the entire population. There was no grade 3 or higher acute and late toxicities. Conclusions: Present data are among the largest series to date reporting outcomes of PT for rGBM and AMs pts. Our analysis indicates that PT is well tolerated and offers efficacy rates similar or even superior to previously reported photon and proton series.