NCOG-35. A SINGLE INSTITUTION SERIES ON PINEAL PARENCHYMAL TUMORS OF INTERMEDIATE DIFFERENTIATION (PPTID)

Abstract

Abstract INTRODUCTION First classified in 2000, pineal parenchymal tumor of intermediate differentiation (PPTID) is an uncommon intracranial malignancy. Given recent codification and rarity, there is no consensus on management and treatment is often provider dependent. METHODS Within an institutional database, we identified 10 patients with PPTID diagnosed between 2009 and 2022. Medical records were reviewed for demographic data, presenting symptoms, extent of disease, surgical interventions, radiation therapy, and chemotherapy. Progression free survival, overall survival, and neurocognitive outcomes were reviewed. RESULTS Median age at diagnosis was 36 (range 13-73), 40% women, 60% Caucasian. Nine patients had tumor involvement limited to the pineal region and one patient had multifocal intracranial tumor involvement with leptomeningeal disease. Two patients had gross total resection (GTR) alone, three had GTR followed by adjuvant radiation therapy (RT), two had subtotal resection (STR) followed by craniospinal irradiation (CSI), two had biopsy followed by adjuvant RT, and one had biopsy with CSI and chemotherapy. At median follow up of 31 months (range 3-88 months), only one patient, who had received biopsy, CSI, and chemotherapy, had progression of disease and no patients are deceased. Two patients treated with CSI had adverse neurocognitive outcomes, which was not observed with focal RT. CONCLUSIONS Our limited case series suggests GTR followed by surveillance, GTR followed by focal RT, and any extent resection followed by CSI may all achieve durable disease control in patients with PPTID. Treatment selection should be individualized and potential neurocognitive toxicities should be considered.