Impact of 123I-MIBG Scintigraphy on Clinical Decision-Making in Pheochromocytoma and Paraganglioma

Dipti Rao; Anouk van Berkel; Ianthe Piscaer; William F Young; Lucinda Gruber; Timo Deutschbein; Martin Fassnacht; Felix Beuschlein; Ariadni Spyroglou; Aleksander Prejbisz; Katarzyna Hanus; Graeme Eisenhofer; Massimo Manelli; Letizia Canu; Jacques W M Lenders; Irina Bancos; Henri J L M Timmers

doi:10.1210/jc.2018-02355

Impact of 123I-MIBG Scintigraphy on Clinical Decision-Making in Pheochromocytoma and Paraganglioma

J Clin Endocrinol Metab. 2019 Sep 1;104(9):3812-3820. doi: 10.1210/jc.2018-02355.

Authors

Dipti Rao¹, Anouk van Berkel¹, Ianthe Piscaer¹, William F Young², Lucinda Gruber³, Timo Deutschbein⁴, Martin Fassnacht^{4

5}, Felix Beuschlein^{6

7}, Ariadni Spyroglou⁶, Aleksander Prejbisz⁸, Katarzyna Hanus⁸, Graeme Eisenhofer⁹, Massimo Manelli¹⁰, Letizia Canu¹⁰, Jacques W M Lenders^{1

9}, Irina Bancos², Henri J L M Timmers¹

Affiliations

¹ Department of Internal Medicine, Radboud University Medical Centre, Nijmegen, Netherlands.
² Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Mayo Clinic, Rochester, Minnesota.
³ Mayo Clinic School of Graduate Medical Education, Internal Medicine, Mayo Clinic, Rochester, Minnesota.
⁴ Department of Internal Medicine I, Division of Endocrinology and Diabetes, University Hospital, University of Würzburg, Würzburg, Germany.
⁵ Comprehensive Cancer Center Mainfranken, University of Würzburg, Würzburg, Germany.
⁶ Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany.
⁷ Klinik für Endokrinologie, Diabetologie und Klinische Ernährung, Universitätsspital Zürich, Zurich, Switzerland.
⁸ Department of Hypertension, Institute of Cardiology, Warsaw, Poland.
⁹ Department of Medicine III and Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Carl Gustav, Technische Universität Dresden, Dresden, Germany.
¹⁰ Endocrinology Unit, Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy.

PMID: 30822354
DOI: 10.1210/jc.2018-02355

Abstract

Context: Cross-sectional imaging with CT or MRI is regarded as a first-choice modality for tumor localization in patients with pheochromocytoma and paraganglioma (PPGL). 123I-labeled metaiodobenzylguanidine (123I-MIBG) is widely used for functional imaging but the added diagnostic value is controversial.

Objective: To establish the virtual impact of adding 123I-MIBG scintigraphy to CT or MRI on diagnosis and treatment of PPGL.

Design: International multicenter retrospective study.

Intervention: None.

Patients: Two hundred thirty-six unilateral adrenal, 18 bilateral adrenal, 48 unifocal extra-adrenal, 12 multifocal, and 26 metastatic PPGL.

Main outcome measures: Patients underwent both anatomical imaging (CT and/or MRI) and 123I-MIBG scintigraphy. Local imaging reports were analyzed centrally by two independent observers who were blinded to the diagnosis. Imaging-based diagnoses determined by CT/MRI only, 123I-MIBG only, and CT/MRI combined with 123I-MIBG scintigraphy were compared with the correct diagnoses.

Results: The rates of correct imaging-based diagnoses determined by CT/MRI only versus CT/MRI plus 123I-MIBG scintigraphy were similar: 89.4 versus 88.8%, respectively (P = 0.50). Adding 123I-MIBG scintigraphy to CT/MRI resulted in a correct change in the imaging-based diagnosis and ensuing virtual treatment in four cases (1.2%: two metastatic instead of nonmetastatic, one multifocal instead of single, one unilateral instead of bilateral adrenal) at the cost of an incorrect change in seven cases (2.1%: four metastatic instead of nonmetastatic, two multifocal instead of unifocal and one bilateral instead of unilateral adrenal).

Conclusions: For the initial localization of PPGL, the addition of 123I-MIBG scintigraphy to CT/MRI rarely improves the diagnostic accuracy at the cost of incorrect interpretation in others, even when 123I-MIBG scintigraphy is restricted to patients who are at risk for metastatic disease. In this setting, the impact of 123I-MIBG scintigraphy on clinical decision-making appears very limited.