Application of 131I-MIBG scintigraphy in diagnosis of pheochromocytoma / 中国医学影像技术

ABSTRACT

Objective To assess the clinical value of 131I-metaiodobenzylguanidine (MIBG) scintigraphy in pheochromocytoma. Methods A total of 430 patients with clinically suspected pheochromocytoma underwent 131I-MIBG whole body scintigraphy, 326 among them underwent B-ultrasound, 400 for CT and 77 for MR examination respectively. While 178 among them were diagnosed with pathology and the others were diagnosed clinically. Results Of all the patients, 108 were diagnosed pheochromocytoma, including 89 131I-MIBG scan positive and 19 negative. The sensitivity, specificity and accuracy of 131I-MIBG were 82.41%, 100% and 95.70%, respectively. 131I-MIBG scan detected 90.00% of unilateral adrenal, 45.45% of bilateral adrenal, 85.71% of ectopic and 66.67% of malignant lesions, respectively. The proportion of patients with positive 131I-MIBG scan increased from 20.69% in all patients to 35.15% in patients with clinical symptoms and positive conventional imaging (at least one of B-ultrasonography, CT or MR was positive) and 64.58% in those with clinical symptoms, positive conventional imaging, and elevated 24 h urinary catacholamines. In 59 patients with adrenal incidentaloma, 8 were scan-positive and all had confirmed pheochromocytoma, while 2 of scan-negative patients also had confirmed pheochromocytoma. Conclusion 131I-MIBG scintigraphy is the first choice for the diagnosis of both adrenal and extra-adrenal pheochromocytoma. However, it is inappropriate to take this method as the initial screening approach.