[Comparison of MIBG scintigraphy and computerized tomography in the localization of pheochromocytomas]

Ninety-nine patients suspected of having pheochromocytoma were studied with MIBG scintigraphy and in 92 of them were studied with computed tomography. In 49 patients, the diagnosis was ruled out, in 3 patients it remained doubtful, and in 47 patients it was confirmed. Two patients had epinephrine--and/or norepinephrine--non-secreting tumors and 45 had secreting pheochromocytomas. In these latter patients, there were 4 scintigraphic false-negatives, all intra-adrenal, and 4 computed tomography false-negatives, 3 extra-adrenal and 1 intra-adrenal. For about 80% of the patients and/or the tumor sites, both methods were thus in agreement. They were complementary in the remaining 20%. The advantage of scintigraphy is to screen the whole body with high specificity and to locate extra-adrenal sites or metastases of pheochromocytoma with better accuracy than computed tomography. The limits of scintigraphy are the possibility of false-negatives in around 10% of patients whereas computed tomography visualizes more than 95% of intra-adrenal tumors.