Proton Beam Therapy for Intracranial Germ Cell Tumors in Pediatric, Adolescent, and Young Adult Patients: A Single-Center Experience.

BACKGROUND

Radiotherapy is essential for the treatment of intracranial germ cell tumor (ICGCT), but late effects are a concern. Proton beam therapy (PBT) is a promising modality as it reduces the radiotherapy dosage needed for the normal brain. Herein, we report the long-term outcomes for one of the largest samples of pediatric/adolescent and young adult patients with ICGCT treated with PBT at our institution.

MATERIALS AND

METHODS

We retrospectively analyzed patients aged <30 years who received PBT for ICGCT at our institution. Overall survival (OS) and progression-free survival (PFS) were estimated, and adverse events (AEs) were graded.

RESULTS

Thirty-six patients were enrolled: 23 with pure germinoma (PG) and 13 with non-germinomatous germ cell tumor (NGGCT). Most patients received upfront chemotherapy. The median prescribed doses were 25.2 Gy (relative biological effectiveness [RBE]) for PG and 48.6 Gy (RBE) for NGGCT. The median follow-up duration was 58 months. The 5-year OS rates were 91% and 88% for PG and NGGCT, respectively, with corresponding 5-year PFS rates of 94% and 90%. Two patients experienced locoregional relapse. Grade ≥2 late AEs included seizure, hearing impairment, and newly diagnosed learning disability. Nearly all patients, excluding the one with learning disability, attended regular classes after PBT. All 12 high-school graduates at the time of the analysis pursued higher education or employment.

CONCLUSIONS

PBT for ICGCT yielded a survival rate comparable with that documented in previous reports, with favorable safety profiles.