Extended focal radiotherapy of 30 Gy alone for intracranial synchronous bifocal germinoma: a single institute experience

Abstract

To evaluate the disease characteristics and treatment outcomes for patients with intracranial synchronous bifocal germinomas treated with extended focal irradiation alone. Between January 1996 and March 2007, seven patients (three males and four females) with intracranial synchronous bifocal germinomas treated at Taipei Veterans General Hospital were reviewed. The median age at diagnosis was 14 years (range, 11-28 years). Four patients had surgery before radiotherapy. All patients underwent extended focal irradiation encompassing the whole ventricle system with a total radiation dose of 30 Gy (2 Gy daily). No patient received scheduled systemic chemotherapy before or after radiotherapy. Disease characteristics, treatment outcomes, and the impact of lesion numbers (single vs. bifocal) on survivals were investigated. With a median follow-up time of 49 months (range, 20-66 months), the 2- and 5-year survival rates were both 100%. After treatment, all patients had good performance without recurrence. No severe complication was observed. In comparison, the overall survival (OS, p = 0.475) and the disease-free survival (DFS, p = 0.537) rates were not significantly different between bifocal- and single-lesion groups. Lesion numbers did not affect both OS and DFS. In addition, the incidence of neuraxial seeding was not higher in patients with bifocal germinomas as compared to those with single lesion. Intracranial germinomas are extremely radiosensitive. Young patients with synchronous bifocal germinomas could be successfully treated with extended focal 30-Gy radiotherapy alone. The therapeutic advantage using this regimen needs to be further evaluated with larger sample size and longer follow-up time.