Acute toxicity of proton beam radiation for pediatric central nervous system malignancies.

BACKGROUND: Proton beam therapy (PBT) for pediatric CNS malignancies may reduce late toxicity, but acute toxicity is not well defined. We examined acute toxicity for children with CNS malignancies treated with PBT. PROCEDURE: We conducted a retrospective review of 48 children with malignant brain tumors treated with PBT at our facility from 2010 to 2012. For each patient, we recorded age at diagnosis, tumor location, histologic subtype, radiation dose, extent of radiation, and use of concurrent chemotherapy. Acute toxicity scores were recorded per the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0 at weekly on treatment visits. Maximum grade of fatigue, headache, insomnia, anorexia, nausea, vomiting, alopecia, and dermatitis over the radiation therapy treatment course were recorded, and rates of acute toxicity were calculated. RESULTS: The cohort consisted of 16 glial tumors, 9 medulloblastomas, 6 germinomas, 5 ependymomas, 4 craniopharyngiomas, 3 atypical teratoid rhabdoid tumors, and 5 other CNS tumors. The mean age was 10.8 years, and median dose was 5,400 cGy (RBE). Acute toxicities were generally low-grade and manageable. The most commonly observed acute toxicities were fatigue, alopecia, and dermatitis. The least common were insomnia and vomiting. Higher maximum grades for headache, nausea, and vomiting over the treatment course were associated with infratentorial location, while higher maximum grades for anorexia, nausea, and alopecia were associated with craniospinal radiation. CONCLUSIONS: PBT appears to be well tolerated in pediatric patients with CNS malignancies. Acute toxicity can be managed with supportive care.