Optimal treatment for intracranial germinoma: can we lower radiation dose without chemotherapy?

To review the effectiveness of reduced-dose and restricted-volume radiation-only therapy in the treatment of intracranial germinoma and to assess the feasibility of reducing or eliminating the use of chemotherapy.

Between January 1996 and March 2007, a retrospective analysis was performed that included 38 patients who received either reduced radiation alone (30 Gy for 26 patients) or reduced radiation with chemotherapy (n = 12 patients). All 38 patients received extended focal (including whole-ventricle) irradiation and were followed up until February 2008. Overall survival (OS) and relapse-free survival (RFS) rates were calculated. Variables associated with survival were evaluated by univariate Cox proportional hazards regression.

Median follow-up was 62.4 months (range, 10.1-142.5 months). The total 5-year OS rate was 93.7%. The 5-year OS and RFS rates for patients receiving radiation only were 100% and 96.2%, respectively. The rates for those receiving radiation plus chemotherapy were 83.3 % and 91.7%, respectively (not statistically significant). No predictive factor was significantly associated with the OS or RFS rate. Chemotherapy had no significant effect on survival but was associated with a higher incidence of treatment-related toxicity.

A further decrease in the radiation dose to 30 Gy with whole-ventricle irradiation is sufficient to treat selected patients with intracranial germinoma. Wide-field irradiation or chemotherapy should be avoided as these methods are unnecessary. Thus, reduction of the radiation dose to 30 Gy may be feasible, even without chemotherapy.