Optimal treatment strategy for intracranial germ cell tumors: a single institution analysis

Abstract

This study retrospectively analyzed the long-term outcomes of 108 consecutive patients to establish the classification and optimal treatment strategy for each subgroup of newly diagnosed germ cell tumors (GCTs). A retrospective review of medical records from the authors' department between April 1989 and March 2007 identified 108 patients with newly diagnosed intracranial GCT. The diagnoses were germinoma in 83 patients, and nongerminomatous GCT (NGGCT) in 25 patients. In patients with germinoma, the 10-year overall and progression-free survival (PFS) rates at a median follow-up period of 99 months were 86 and 74%, respectively. Recurrences developed during a range of 6 to 153 months (median 26 months) after starting the initial therapy. Patients treated only with chemotherapy demonstrated a shorter PFS rate, and patients treated with chemotherapy followed by reduced-dose radiation therapy to the whole ventricle, whole brain, or craniospinal axis showed significantly better PFS than patients treated with only radiation or reduced-dose radiation therapy to the focal field. Nongerminomatous GCTs were divided into good, intermediate, and poor prognosis groups as proposed by the Japanese Pediatric Brain Tumor Study Group. In the good and intermediate prognosis groups, the 10-year overall and PFS rates were 100 and 93%, respectively. In the poor prognosis group, the 3-year overall and PFS rates were 56 and 29%, respectively. All patients with NGGCTs, in whom the lesions on MR imaging disappeared after combination therapies consisting of resection, radiation therapy, and chemotherapy, remained alive. Chemotherapy followed by reduced-dose radiation therapy covering the whole ventricle improves the prognosis for patients with germinoma. Combined therapy of radiation therapy, chemotherapy, and radical resection as an initial or salvage treatment achieved excellent tumor control in the intermediate prognosis NGGCT group. The outcomes were still dismal in the poor prognosis NGGCT group, so initial therapy should target complete disappearance of all lesions on MR imaging.