Searchable abstracts of presentations at key conferences in endocrinology
Endocrine Abstracts (2023) 98 C31 | DOI: 10.1530/endoabs.98.C31

NANETS2023 Clinical – Nuclear Medicine/Interventional Radiology/Imaging (24 abstracts)

High-specific-activity iodine-131-meta-iodo-benzylguanidine for the treatment of advanced pheochromocytoma and paraganglioma: a real-world study

Ruaa Al-Ward 1,2,3 , Vania Balderrama Brondan 1 , Sahar Sawani 1,2 , Roland Bassett 4 , Guofan Xu 5 , Steven G. Waguespack 1 , Jeena Varghese 1 , Mouhammed Amir Habra 1 , Yang Lu 5 & Camilo Jimenez 1


1Department of Endocrine Neoplasia and Hormonal Disorders, The University of Texas, MD Anderson Cancer Center, Houston, TX; 2Section of Endocrinology, Diabetes and Metabolism, Baylor College of Medicine, Houston, TX; 3Department of Neuroendocrinology, Diabetes and Metabolism, Methodist Hospital, Houston, TX; 4Department of Biostatistics, The University of Texas, MD Anderson Cancer Center; 5Department of Nuclear Medicine, The University of Texas, MD Anderson Cancer Center


Background: Metastatic pheochromocytomas and paragangliomas are rare neuroendocrine tumors with limited treatment options. We studied the efficacy and safety of off-label High-Specific-Activity I-131-meta-iodobenzylguanidine (HSA-I-131-MIBG) in routine clinical practice.

Methods: This is a retrospective cohort study. The primary endpoint is objective response rate (ORR) as per RECIST v1.1. Secondary endpoints are blood pressure control, safety, overall and progression free survival rates, duration of response, and correlations with genetic background.

Results: 25 patients were studied. 62% were men. Median age at the time of treatment was 43 years (range 18-82). 68% had hormonally active tumors.52% previously received antineoplastic treatment. 60% received two doses of HSA-I-131-MIBG. Median duration of follow up was 19 months (2-61). 24 patients were evaluable for radiographic response. The ORR was 33%, including two patients with complete response (CR). The disease control rate (DCR) was 83%. Median time to response was 12.5 months (95% CI, 4.6 to 25.1). Twelve patients had sporadic disease; ORR was 25% and DCR was 92%. Twelve patients had hereditary disease (SDHB, VHL, RET); ORR was 42%, DCR was 75%. Two SDHB carriers achieved CR. Plasma metanephrines normalized in 27%, improved by at least 50% in 45%. 16 patients had hypertension; blood pressure normalized leading to discontinuation of antihypertensive therapy in 56% of patients with hormonally active tumors and hypertension. The most common adverse events were grade I/II nausea/vomiting and transient bone marrow suppression. One patient developed premature ovarian failure. Grade III/IV myelosuppression was seen in 28% of patients. One patient had a fatal pneumonitis (probably related) and 1 patient had grade 5 gastrointestinal bleeding (not related).

Conclusion: HSA 131-I-MIBG is associated with a high DCR regardless of underlying genetic mutation. Severe adverse events are mainly transient and correctable bone marrow insufficiencies.

Abstract ID 23706

Article tools

My recent searches

No recent searches.