Operative approaches to midline tumors.

We have now operated and confirmed 80 tumors of the pineal region. Our experience is that 30 percent of these are benign, encapsulated and can be removed, and that only 30 percent represent germinomas. Another 30 percent are astrocytomas of varying grade. The preferred therapy in the majority of these tumors is radiotherapy and its extent depends upon the analysis of the lumbar spinal fluid. Chemotherapy has been reserved for tumors of the primitive embryonic type. The result of surgery for benign tumors has been excellent and the recurrence rate extremely low. In the germinoma series, the response to radiation therapy in our experience has been promising initially with resolution of the tumor by CT scan. However, we have noted recurrence of some of these tumors after radiotherapy approximately 6 to 8 years after the institution of therapy. The pineoblastomas are extremely difficult to treat by whatever means and the same holds true for the malignant pineocytomas. Our experience is too limited to say what the outcome will be in the chemotherapeutic management of the more primitive and embryonal tumors.