Dipg-59. Radiation-Induced Dipg in a Child Previously Irradiated for Craniopharyngioma: Case Report and Literature Review

BACKGROUND Radiation-induced second malignancies occur in a subset of patients following cranial radiation therapy (RT). In Craniopharyngioma (CP), adjuvant RT is commonly recommended for residual tumor or recurrence, and radiation-induced malignant gliomas (RIMGs) are rarely reported. METHODS We report a case of radiation-induced diffuse intrinsic pontine glioma (DIPG) in pediatric Craniopharyngioma and conducted a review of previously reported cases. RESULTS A 14-year-old boy presented with complaints of headaches and vomiting for 1 month; difficulty in walking, and slurred speech for 1 week, with Lansky Performance Score (LPS) of 20. Eight years before this admission, he underwent surgical excision and 3D-conformal RT for Craniopharyngioma. His recent MRI brain was suggestive of DIPG and after a multidisciplinary discussion re-irradiation (30Gy in 10 fractions) was given. He has been alive for 5 months since diagnosis with improved symptoms and LPS (70). Including the index case, 19 cases of RIMGs in CP were identified. All except one were reported from high-income countries. Only 4 involved the pons/brainstem. The median age at CP diagnosis was 7.0 years (2.0-22.0 years), and with RIMG was 18 (6.8-41.0 years). Median latency period was 10.0 years (4.5-25.0 years). The female-to-male ratio was 1.8:1. The median previous RT dose was 54.8 Gy (49.3-60.1 Gy) with 37% cases treated with 3D conformal and 37% with conventional RT (not specified in 26%). Cerebral cortex (66.6%) was the most common site for the RIMG with temporal lobe predisposition. Chemotherapy was given in 56%, surgical excision in 50% and repeat RT in 31% cases with a median survival of 4 months (0-13 months). CONCLUSION We report the first case of radiation-induced DIPG in pediatric Craniopharyngioma in an LMIC. RIMG appears to be a rare occurrence in CP and doesn’t seem to be associated with the RT type. The overall prognosis is extremely poor.