Current treatment strategy of optic pathway/hypothalamic glioma: contribution of chemotherapy and neuroendoscopic surgery

<p>The main strategies for the treatment of optic pathway/hypothalamic glioma (OPHG) focus on chemotherapy to slow tumor growth, and on surgery to preserve function rather than achieve a high removal rate. Minimally invasive neuroendoscopy plays a significant role in this treatment strategy. We show the practical clinical course of the recent treatment of OPHG at our institution, where chemotherapy is the mainstream treatment and neuroendoscopy is intensively used in surgery. Five patients were included in this study, three of whom received endoscopic biopsy. Four patients received chemotherapy and were responsive to it, all of whom were switched from first-line carboplatin and etoposide to second-line vinblastine. In three cases, the cause of change was hypersensitivity to carboplatin. The main surgical procedures are shunt surgery for hydrocephalus and endoscopic cyst fenestration, but craniotomy for tumor volume reduction is not performed in the follow-up periods. Patients with OPHG can expect to require multiple regimens of chemotherapy and multiple surgeries in the long-term treatment period. A tailored treatment strategy should be considered to control tumor growth and to preserve the growth and neurological function. Our institution has been able to achieve the goals with the use of chemotherapy and neuroendoscopy. Neuroendoscopy is especially beneficial in the control of cyst enlargement. Hypersensitivity due to carboplatin is a problem. Another problem is the lack of evidence for other chemotherapy options. Several clinical trials for molecular targeting drugs and anticancer agents, such as Vemurafenib, Dabrafenib, Tak580, and Ulixertinib which inhibit the BRAF/MEK/ERK pathway, Selumetinib and Trametinib which are MEK inhibitors, and Binimetinib which is the MAPK inhibitor, are in progress. When the opportunity to perform surgery for tumor volume reduction come, the timing of surgery, extent of surgical removal, and objectives of surgery should be appropriately determined by a team that includes pediatrician and radiologist, oncologist as well as neurosurgeon.</p>