Purpose: Optimal management of radiotherapy (RT) for intracranial germinoma remains controversial. This study was conducted to evaluate the long-term results of RT in patients with these tumors.
Methods and materials: The study group consisted of 126 patients with intracranial germinoma (50 patients with pathologically verified germinoma and 76 clinically diagnosed with germinoma by clinical and neuroradiologic signs) who were treated by RT alone between 1980 and 2001. The median age at diagnosis was 17 years (range, 2-47), and various radiation doses and treatment fields were used. Serum human chorionic gonadotropin (hCG) levels were elevated in 18 patients. The median follow-up of the 114 surviving patients was 122 months (range, 13-263).
Results: The 10-year actuarial overall survival and cause-specific survival rate for all patients was 90% and 95%, respectively. The 10-year actuarial cause-specific survival rate for patients with and without elevated hCG levels was 94%. Relapses were noted in 10 patients, 7 of whom died of the disease. No in-field relapses at primary sites were observed in 72 patients treated with total doses of 40-50 Gy. The incidence of spinal relapses was 4% (2 of 56) for patients treated with spinal irradiation and 3% (2 of 70) for those without spinal irradiation. After a median 10-year follow-up, 54 (92%) of 59 patients with tumors not involving the neurohypophyseal region and 42 (76%) of 55 patients with tumors involving the neurohypophyseal region had Karnofsky performance status scores of 90-100%. With regard to school education and occupation, 54 (92%) of 59 patients with tumors not involving the neurohypophyseal region and 39 (71%) of 55 patients with tumors involving the neurohypophyseal region were attending school or undertaking occupations. Hormonal replacement therapy was required in 50 (44%) of 114 surviving patients before RT; only 4 patients (4%), all with neurohypophyseal tumors, required hormonal replacement therapy after RT. Clinically evident severe neurocognitive dysfunctions were documented in 10 patients before RT, and no patients treated with total doses of <55 Gy developed apparent neurocognitive dysfunctions or other complications after RT.
Conclusion: RT was a curative treatment for intracranial germinoma, and elevated serum hCG levels did not affect the prognosis of patients treated by RT alone. A total dose of 40-50 Gy to adequate treatment fields was effective in preventing intracranial relapse, and the incidence of spinal relapses was too low to warrant routine spinal irradiation. Karnofsky performance status scores, educational achievement, and the ability to work were generally good, particularly in patients with tumors that did not involve the neurohypophyseal region. Because most complications, such as hormonal deficiency and neurocognitive dysfunction, were documented before RT and newly diagnosed complications after RT were infrequent, the treatment toxicity faced by germinoma patients appears to be less than anticipated.