Peptide Receptor Radionuclide Therapy With Lu-DOTATATE for Symptomatic Control of Refractory Carcinoid Syndrome

Context: Peptide receptor radionuclide therapy (PRRT) with [Lutetium-177-DOT[A.sup.0]-Ty[r.sup.3]] octreotate ([.sup.177]Lu-DOTATATE) results in an increase of progression-free survival and quality of life in patients with progressive, well-differentiated neuroendocrine neoplasms (NENs). Objective: To study the effect of [.sup.177]Lu-DOTATATE in patients with carcinoid syndrome and radiologically stable or newly diagnosed disease treated solely for the purpose of symptom reduction. Design: Retrospective cohort study. Setting: Tertiary care hospital. Patients: Twenty-two patients with a metastatic midgut NEN, elevated urinary 5-hydroxyindolacetic acid excretion, and flushing and/or diarrhea despite treatment with a somatostatin analog, without documented disease progression. Intervention: PRRT with [.sup.177]Lu-DOTATATE (intended cumulative dose: 29.6 GBq) with a primary aim to reduce symptoms. Results: After PRRT, mean bowel movement frequency (BMF) decreased from 6.1 [+ or -] 3.4 to 4.6 [+ or -] 3.6 per day (P = 0.009). Flushes decreased from 4.3 [+ or -] 2.9 to 2.4 [+ or -] 2.7 flushes per day (P = 0.002). A decrease of BMF of more than 30% occurred in 47% of patients with baseline BMF of 4 or more (n = 17). In patients with [greater than or equal to]2 episodes of flushing a day (n = 15), 67% of patients had more than 50% decrease of daily flushing. A decrease in urinary 5-hydroxyindolacetic acid excretion of more than 30% was seen in 56% of patients. The European Organization for Research and Treatment of Cancer-Core Module diarrhea subscale score showed a trend toward improvement by an average of 16.7 [+ or -] 33.3 points (P = 0.11). Conclusion: PRRT with [.sup.177]Lu-DOTATATE effectively reduced diarrhea and flushing in patients with carcinoid syndrome and can be considered for symptomatic treatment of carcinoid syndrome insufficiently controlled with somatostatin analogs. Key Words: neuroendocrine tumor, PRRT, carcinoid syndrome