Abstract 80: Experience of Peptide Receptor Radionuclide Therapy (PRRT) in neuroendocrine tumors in a tertiary care center

177Lu-DOTATATE-based peptide receptor radionuclide therapy (PRRT) is a promising therapy for metastatic and/or inoperable pheochromocytoma and metastatic insulinomas that can result in reduced tumor burden and improved quality of life. We present our experience with 2 cases of metastatic pheochromocytoma and metastatic insulinoma who received PRRT. Case 1: A 35 year male presented with pain in left lumbar region, palpitations, episodic sweating and headache in 2017. Metanephrines and normetanephrines in urine were 587 ng/L and 1062 ng/L respectively. On CT abdomen there was a left suprarenal mass. After adequate preparation he underwent left adrenalectomy in 2017. He was lost to follow up till 4 years after surgery. Now again he presented with episodic palpitations, anxiety, sweating and headache. Metanephrines and normetanephrines in urine were 338 ng/L (7.90-88) and 809 ng/L (20-135) respectively. On Gallium 68 DOTANOC PETCT there were multiple nodular densities in postoperative bedand metastasis to left paraaortic, peripancreatic lymph nodes and multiple vertebrae. After adequate preparation he was given 150mCi Lu DOTATATEiv. After 30 minutes into transfusion, patient had sudden onset palpitations,15 episodes of vomitings, his BP was 200/150 mm Hg and heart rate was 149bpm. He was given Metoprolol and prazosin and after 10 min his BP was 76/45mm Hg and HR was 193bpm. USG abdomen showed collapsed inferior venacava. He was stabilized with iv fluids. He was under observation for 10 days. During this period he had recurrent episodes of vomitings, nausea, palipitations and fluctuating BP. At the time of discharge his BP was stable. This case illustrates the risk of crisis episodes in metastatic pheochromocytoma and the need to monitor for crisis episodes for 10 daysafter undergoing PRRT. Case 2: A 21 year male known case of MEN 1, initially presented with pituitary microadenoma and insulinoma in 2014, underwent distal pancreatosplenectomy and in 2018 underwent parathyroid adenoma excision. After 4 years he presented with hypoglycemic episodes. Ga 68 DOTATATE PET CT showed an enhancing lesion at post operative site of 1.4 X 1 cm with multiple peripancreatic nodal and peritoneal metastasis. He was on injection octreotide 30 mg IM depot monthly. After stopping injection octreotide, he was given 150 mCi lutetiumiv. He did not develop any hypoglycemic or hypercalcemic crisis after PRRT. Now he was off injection octreotide and doing well with no further hypoglycemic episodes after PRRT. As the treatment options are limited in metastatic neuroendocrine tumors, we subjected them to PRRT which is minimally invasive, improved symptoms of both the patients and both are under followup.