Radiation therapy for histologically confirmed primary central nervous system germinoma

Abstract

Purpose : To evaluate survival and patterns of recurrence in patients with primary central nervous system germinoma treated with radiation therapy. Methods and Materials : Data regarding 48 patients with histologically confirmed, primary central nervous system germinoma were reviewed. All had been operated on at the Mayo Clinic between the years 1935 and 1993. Thirty-two patients (67%) were treated since 1973. The study group included 39 males and 9 females, with a median age at diagnosis of 17 years (range, 6–42 years). Twelwe patients (25%) were treated with craniospinal axis irradiation, 11 (23%) received whole-brain irradiation without spinal axis irradiation, and 24 (50%) underwent partial-brain irradiation. Treatment volumes were unknown in one patient. The median dose to the primary tumor was 44.00 Gy (range, 7.44–59.40 Gy). The median follow-up was 5.5 years (range, 4 months to 37 years). Results : Actuarial 5-year and 10-year survival for the entire study group of patients was 80%. There was a trend toward improved survival in patients treated after 1973 (introduction of computed tomography) with 5-year and 10-year survival of 91% vs. 63% in prior years ( p = 0.07). For the group of 31 patients treated since 1973 with known treatment volumes, the spinal axis failure rate at 5 years was 49% for patients treated with partial brain fields (11 patients) vs. 0% for those having undergone whole brain (10 patients) or craniospinal axis (10 patients) irradiation ( p = 0.007). The rate of brain failure was also significantly higher in patients receiving less than whole-brain irradiation; at 5 years, 45% of the patients treated with partial-brain fields had intracranial recurrence of disease compared to 6% of patients treated with craniospinal axis or whole-brain irradiation ( p = 0.01). Among the 32 modern era patients, the rate of brain failure was higher in patients who received doses less than 40 Gy (median dose, 48.55 Gy; range, 30.60-59.40 Gy) to the primary tumor (5-year brain failure rate 52% vs. 11%, p = 0.002). Conclusion : The long-term survival of patients with histologically proven CNS germinoma treated with radiation is excellent. Whole-brain or craniospinal axis irradiation appears to result in fewer spine and brain failures than does partial-brain irradiation. Furthermore, the administration of doses greater than 40 Gy to the primary tumor is associated with better local control.