RADT-19. CLINICAL OUTCOMES OF RADIATION THERAPY FOR BRAIN STEM GLIOMA

Abstract

Abstract PURPOSE/OBJECTIVES Brain stem gliomas are up to 20% of all brain tumor in children and unusual in adults. Radiotherapy is mainstay of treatment. Surgery for brain stem glioma is difficult because of anatomical location. This study was performed to evaluate the clinical outcomes of radiotherapy in brain stem glioma. METHODS Retrospective analysis of brain stem glioma patients treated with radiation therapy (54Gy/30 fractions of IMRT/ 3D CRT) with or without surgery or chemotherapy or other agents. RESULTS Twenty-four patients (median age 11.8 years) were treated between 2016 and 2020. Male to female ratio was 2:3. Surgical approach (biopsy and partial removal) was done in 16 patients. Histology revealed that anaplastic ependymoma in 2 patients, low grade astrocytoma in 2 patients, anaplastic astrocytoma in 8 patients, glioblastoma in 4 patients and remaining 8 patients had no histologic diagnosis. Radiotherapy (dose- 54Gy/ 30 fractions) was given with the technique of IMRT or 3D CRT. At the time of follow up, 8 patients had local recurrence, 10 patients died of due to disease and recurrence, 14 patients were alive. Among alive patients, 2 patients were treated with chemotherapy and 12 patients with temozolomide for 12 cycles. Patients who received temozolomide got improvement in performance status and reduced clinical symptoms; among them, 6 patients had more than 50% objective tumor response in radiological findings for follow-up 3-6 months after radiotherapy. The 2-years overall survival (OS) rate was 58.3% and 2-years Event-free Survival (EFS) rate was 50%. The median survival time was 14 months. There is no grade 3 or greater acute and late toxicities. CONCLUSION As the LMIC country with limited resources, our results of radiotherapy followed by temozolomide in brain stem glioma have optimal outcomes. However, prospective studies of this select group of patients with larger number and longer follow up is required.