RT Journal Article SR Electronic T1 Efficacy and Safety of High-Specific-Activity 131I-MIBG Therapy in Patients with Advanced Pheochromocytoma or Paraganglioma JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 623 OP 630 DO 10.2967/jnumed.118.217463 VO 60 IS 5 A1 Daniel A. Pryma A1 Bennett B. Chin A1 Richard B. Noto A1 Joseph S. Dillon A1 Stephanie Perkins A1 Lilja Solnes A1 Lale Kostakoglu A1 Aldo N. Serafini A1 Miguel H. Pampaloni A1 Jessica Jensen A1 Thomas Armor A1 Tess Lin A1 Theresa White A1 Nancy Stambler A1 Stuart Apfel A1 Vincent A. DiPippo A1 Syed Mahmood A1 Vivien Wong A1 Camilo Jimenez YR 2019 UL http://jnm.snmjournals.org/content/60/5/623.abstract AB Patients with metastatic or unresectable (advanced) pheochromocytoma and paraganglioma (PPGL) have poor prognoses and few treatment options. This multicenter, phase 2 trial evaluated the efficacy and safety of high-specific-activity 131I-meta-iodobenzylguanidine (HSA 131I-MIBG) in patients with advanced PPGL. Methods: In this open-label, single-arm study, 81 PPGL patients were screened for enrollment, and 74 received a treatment-planning dose of HSA 131I-MIBG. Of these patients, 68 received at least 1 therapeutic dose (∼18.5 GBq) of HSA 131I-MIBG intravenously. The primary endpoint was the proportion of patients with at least a 50% reduction in baseline antihypertensive medication use lasting at least 6 mo. Secondary endpoints included objective tumor response as assessed by Response Evaluation Criteria in Solid Tumors version 1.0, biochemical tumor marker response, overall survival, and safety. Results: Of the 68 patients who received at least 1 therapeutic dose of HSA 131I-MIBG, 17 (25%; 95% confidence interval, 16%–37%) had a durable reduction in baseline antihypertensive medication use. Among 64 patients with evaluable disease, 59 (92%) had a partial response or stable disease as the best objective response within 12 mo. Decreases in elevated (≥1.5 times the upper limit of normal at baseline) serum chromogranin levels were observed, with confirmed complete and partial responses 12 mo after treatment in 19 of 28 patients (68%). The median overall survival was 36.7 mo (95% confidence interval, 29.9–49.1 mo). The most common treatment-emergent adverse events were nausea, myelosuppression, and fatigue. No patients had drug-related acute hypertensive events during or after the administration of HSA 131I-MIBG. Conclusion: HSA 131I-MIBG offers multiple benefits, including sustained blood pressure control and tumor response in PPGL patients.