Role of Neuroendoscopic Procedures in “Minimally-Invasive” Preferential Management of Pineal Region Tumors

Introduction: This prospective study is based on a consecutive series of 20 patients with pineal region tumors who underwent “minimally-invasive” preferential management. Aim: The purpose of this report is to discuss the role of neuroendoscopic procedures as a future prospect in the historical trend of controversy in the management of pineal region tumors. Material and Methods: 1. Initial procedure: If the tumor markers (α fetoprotein: AFP, human chorionic gonadtropin: HCG) were negative in serum and there was significant ventricular dilatation on neuroimagings, neuroendoscopic surgery was first applied for tumor debulking with tissue diagnosis and gross morphological analysis of the tumor and the intraventricular structures, followed by third ventriculostomy. 2. Subsequent procedures in verified individual tumors: a) Germinoma (G) and Pineoblastoma (PB): If no tumor dissemination was confirmed in the pre-/ intra-/ post-operative findings, stereotactic radiotherapy or radiosurgery was performed after one course of chemotherapy with ICE regimen [Isofomid + Cisplatin + Etoposide] and followed by 2 additional courses of chemotherapy. b) Malignant germ cell tumors (MGC): After extensive surgery, adjuvant chemotherapy with ICE regimen was performed in 3 courses in all cases. Then radiation therapy was started by various methodologies depending on the evidence of tumor dissemination. c) Teratoma (TRT) and Neuroectodermal tumors (NET) other than PB: Extensive surgical removal was performed. As for adjuvant therapy, if the tumor was low-grade glioma or the patient was under 5 years of age, the postoperative course did not include radiation. If the tumor was malignant TRT or high grade glioma, conventional focal radiotherapy was performed, followed by chemotherapy with ICE for one year. Results: All treated patients except 2 had ventriculomegaly. The neuroendoscopic procedures were consequently applied to 6 of 15 treated patients. Neuroendoscopic biopsy with tumor debulking offered enough material for tissue diagnosis, including immunohistochemical analysis, and revealed evidence of radiologically-negative tumor dissemination in one case. There was no shunt required in any patient undergoing endoscopic third ventriculostomy, with one exception. Stereotactic radiotherapy was performed in the indicated cases. Favorable therapeutic outcomes were obtained in all cases with G and PB with follow-up ranging from 24 months to 6 and half years. Conclusion: Our “minimally-invasive” preferential regimen clarified the precise indication for neuroendoscopic procedures, and the majority of our patients with negative tumor markers and dilated ventricle were treated satisfactorily with effective neuroendoscopic procedures as the initial procedure, avoiding unnecessary craniotomy and radiation and promising excellent therapeutic outcomes. The treatment for malignant pineal region tumors remains a subject for further study.