RT Journal Article SR Electronic T1 Diagnostic Performance of 124I-Metaiodobenzylguanidine PET/CT in Patients with Pheochromocytoma JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 869 OP 874 DO 10.2967/jnumed.121.262797 VO 63 IS 6 A1 Weber, Manuel A1 Schmitz, Jochen A1 Maric, Ines A1 Pabst, Kim A1 Umutlu, Lale A1 Walz, Martin A1 Herrmann, Ken A1 Rischpler, Christoph A1 Weber, Frank A1 Jentzen, Walter A1 Theurer, Sarah A1 Poeppel, Thorsten D. A1 Unger, Nicole A1 Fendler, Wolfgang P. YR 2022 UL http://jnm.snmjournals.org/content/63/6/869.abstract AB 123/131I-metaiodobenzylguanidine (MIBG) scintigraphy has shown a high specificity for imaging pheochromocytoma and paraganglioma, but with low sensitivity because of low spatial resolution. 124I-MIBG PET may be able to overcome this limitation and improve the staging of patients with (suspected) pheochromocytoma. Methods: We analyzed the sensitivity, specificity, and positive and negative predictive values of 124I-MIBG PET in 43 consecutive patients with suspected (recurrence of) pheochromocytoma using histopathologic (n = 25) and clinical validation (n = 18) as the standard of truth. Furthermore, we compared the detection rate of 124I-MIBG PET versus contrast-enhanced (CE) CT on a per-patient and per-lesion basis in 13 additional patients with known metastatic malignant pheochromocytoma. Results: 124I-MIBG PET/CT was positive in 19 (44%) of 43 patients with suspected pheochromocytoma. The presence of pheochromocytoma was confirmed in 22 (51%) of 43. 124I-MIBG PET/CT sensitivity, specificity, and positive and negative predictive values were 86%, 100%, 100%, and 88%, respectively. 124I-MIBG PET was positive in 11 (85%) of 13 patients with malignant pheochromocytoma. Combined 124I-MIBG PET and CE CT detected 173 lesions, of which 166 (96%) and 118 (68%) were visible on 124I-MIBG PET and CE CT, respectively. Conclusion: 124I-MIBG PET detects pheochromocytoma with high accuracy at initial staging and a high detection rate at restaging. Future assessment of 124I-MIBG PET for treatment guidance, including personalized 131I-MIBG therapy, is warranted.