Treatment outcome of radiation therapy for intracranial germinoma: adaptive radiation field in relation to response to chemotherapy.

ABSTRACT

AIM: To determine the optimal radiotherapy (RT) target volume in correlation with tumor response to chemotherapy in patients with intracranial germinoma. PATIENTS AND METHODS: Seventy-two patients received chemotherapy followed by RT. The RT field was tailored to chemotherapy response. RESULTS: Five-year recurrence-free survival (RFS) was 87% and overall survival was 97%. RT field was significantly associated with RFS, with 5-year RFS rates of 95%, 91%, and 62% in those who received craniospinal irradiation, whole-brain/whole-ventricle RT, and focal RT, respectively (p=0.01). In the complete-response group after chemotherapy, 5-year RFS rates were 100% after whole-brain RT/whole-ventricle RT and 70% after focal RT (p=0.04). In the partial-response group, 5-year RFS rates after craniospinal irradiation, whole-brain RT, and focal RT were 100%, 85%, and 33%, respectively (p<0.01). CONCLUSION: Regardless of response, those treated with focal RT had an excessively high relapse rate. Whole-brain/whole-ventricle RT could be applied to patients who show a complete response to chemotherapy, but the optimal strategy for patients with partial response needs further investigation.