LGG-58. A Multi-Center Retrospective Case Series of Surgical Outcomes for Intraventricular Juvenile Pilocytic Astrocytoma

INTRODUCTION Juvenile pilocytic astrocytoma (JPA) is a common pediatric grade I astrocytoma. Prognosis is excellent with gross total resection (GTR) and 10-year survival rates of up to 95%. However, undesirable outcomes may occur, such as when tumors are in poorly accessible locations. Intraventricularly tumors present a unique surgical challenge due to their midline location in a fluid filled space with any intraparenchymal invasion involving critical neurologic structures. Here we retrospectively describe the clinical features of intraventricular JPA neoplasms from two centers to highlight the challenges in caring for this uncommon presentation. METHODS We retrospectively searched the electronic medical record from 2000-2023 for patients with neurosurgical treatment for intraventricular JPA at two centers. Intraventricular location was verified by a neuroradiologist. Data were collected on demographics, pathology, tumor location, extent of resection, adjuvant therapies, reoccurrence, progression, and neurological deficit. RESULTS We identified 28 surgical treated patients with intraventricular JPA. Females were 15/28 (54%) of patients with a mean age of 11.2±6.4 years. Most tumors presented in the 4th ventricle 15/28 (53.5%), followed by 9/28 (32%) in 3rd ventricle locations, and 4/28 (14%) in lateral ventricles. GTR was achieved in 12/28 patients (43%) and STR in 16/28 patients (57%). Progression/recurrence was noted in 8/28 (29%) and the 5-year PFS was 56% (10/18). Adjuvant treatment was used in 11/28 (39%) patients and repeat surgery was required in 4/28 patients (14%). Chemotherapy in 8/28 (29%) patients and radiation in 4/28 (14%) patients. A pre/post-operative neurological deficit was noted in 10/28 (36%) patients. A BRAF protein fusion was noted in 7 patients and 1 patient demonstrated a v600E mutation (some molecular data not available). Average follow up was 92 months with no deaths. CONCLUSION We observed that intraventricular JPA tumors commonly undergo subtotal resection with frequent progression/recurrence. Subsequently, recurrent surgeries and adjuvant therapies can be necessary.