GCT-01. Pediatric intracranial germ cell tumors and primary polyuria-polydipsia syndrome: a 13-year single institutional experience

Abstract

Abstract Intracranial germ cell tumors (IGCTs) represent about 4% of all childhood brain tumors. They are common in both the pineal and pituitary regions and sometimes they can be bifocal. Suprasellar and bifocal IGCTs usually present stereotypical symptoms, including primary polyuria-polydipsia syndrome (PPS). Consolidated IGCTs’ therapy is based on the International Society of Pediatric Oncologic (SIOP) CNS GCT II protocol consisting of primary pre-radiation chemotherapy combining etoposide, carboplatin and/or cisplatin and ifosfamide. PPS management in these patients requires monitoring of electrolytes and fluids during chemotherapy, especially for cisplatin and/or ifosfamide-based cycles, for which hyperhydratation is required. We report the results of our single-center cohort of patients with IGCTs treated between 2008 and 2021, focusing on the clinical presentation, treatment and long-term follow-up. Thirty-one patients were analyzed (median age=13 years, 87% male). Twelve children (39%) presented a PPS and needed desmopressin treatment, maintained at long-term follow-up data update in all. Over these PPS patients, 6 had bifocal germinomas, 4 suprasellar germinomas, 1 metastatic germinoma and 1 non-germinomatous IGCT. Eleven PPS children (92%) received cisplatin and/or ifosfamide-based chemotherapy: all of them had optimal biochemical urine and blood investigations before, during and after chemotherapy. None of them presented serious complications during treatment. After a median follow-up of 5 years, two patients (6.5%) died (1 IGCT-related, 1 non-cancer related) and one had a second malignancy (parotid gland mucoepidermoid carcinoma, 6 years after IGCT diagnosis). Childhood IGCTs have an excellent prognosis, but present a significant risk of long-lasting severe endocrine sequelae which may be worsened by the primary oncological strategy, requiring careful management of complications related to fluid and electrolytes disturbances. In order to avoid post-treatment pituitary insufficiency, guidelines for diabetes insipidus management when cisplatin and/or ifosfamide-based protocols are used should be established and all patients should receive meticulous endocrine follow-up.