Treatment of Pineal Region Tumors and CNS Germ Cell Tumors ; Evolution of Treatment Policy and Results

ABSTRACT

A retrospective analysis has been made of 40 patients with pineal region tumors and CNS germ cell tumors who were treated at Yonsei University Hospital, Department of Radiation Oncology between 1971 and 1985. A tissue diagnosis was obtained before radiotherapy in 19 patients and 21 patients were irradiated without histological diagnosis. Among 19 biopsy-proven cases, 14 were germinomas, 2 were teratomas, and the others were two pineocytomas and one pineoblastoma. In the earlier period, every attempt was made to obtain a tissue pathology by either stereotaxic biopsy or open craniotomy before irradiation. However, in recent years, with the advent of CT scan, a trial radiotherapy with a modest dose of 20 Gy in 2 weeks was attempted in cases of highly suspected germinomas by CT scan findings. Further management after trial radiation depended on the radiation response shown on the follow-up CT scan and tumor marker study. Radiation fields varied from a small local field to whole brain or entire neuroaxis irradiation. Most patients received 40-50 Gy to the primary tumor site and 20-30 Gy to the neuroaxis. Twenty-nine of the total 40 patients are alive without of disease 22-144 months after treatment and the overall 5-year recurrence-free survival rate was 74.4%, Univariate analysis of prognostic factors at presentation showed that tumor type was highly correlated with outcome. Two of fourteen biopsy-proven germinomas and none of nine presumed germinomas by trial radiation recurred. On the other hand, five of six patients who showed poor response to trial radiation died of uncontrolled disease and only one patient with elevated AFP in serum and CSF was salvaged by chemotherapy. On the basis of the results of this study, application of trial radiation therapy without tissue biopsy is well justified as a treatment modality in a suspected germinoma by CT scan finding. Aggressive combined modality approaches with surgery, radiotherapy and chemotherapy need to be investigated to improve results in radioresistant tumors.