Indications for salvage surgery during treatment for intracranial germ cell tumors.

This study retrospectively reviewed our single institute experience to clarify the optimal indication and timing of salvage surgery. Retrospective analysis of 159 consecutive cases with germ cell tumors identified 20 cases with salvage surgery. These cases were classified based on the radiological response to neoadjuvant treatment before salvage surgery into increase (growing group, five cases), no change (stable group, seven cases), and decrease (shrinkage group, eight cases) in tumor size. Changes in tumor markers, histological findings, and the pattern of failure after salvage surgery were reviewed. Growing teratoma syndrome (GTS) is defined as enlargement of tumor consisting of mature teratoma after chemotherapy with normalization of tumor markers. In growing group, two cases presented GTS, whereas other three cases did not fulfill the criteria for GTS. All cases in stable and shrinkage group had elevated levels of tumor markers at presentation and decreased levels after neoadjuvant treatment. Histologically, sparse components of mature teratoma with extensive fibrosis were found in cases with GTS and seven of eight cases in shrinkage group, whereas mature teratoma without fibrosis was found in six of seven cases in stable group. Six cases recurred after salvage surgery. We identified three factors as risks for recurrence after salvage surgery, as follows: (1) growing lesion which did not fulfill the criteria for GTS, (2) non-normalized level of tumor marker before salvage surgery, and (3) residual germinoma component. In conclusion, salvage surgery is recommended for patients with GTS, or with normalized tumor markers in stable or shrinkage group.