[Localization of pheochromocytomas by scintigraphy with meta-iodobenzyl guanidine. Comparison with computed x-ray...

Meta-iodobenzylguanidine was synthesized, radiolabelled with I 131 or I 123 and injected to 28 controls and 7 patients totalling 13 foci of pheochromocytoma. The tumour was located in one adrenal gland in 3 cases, in both adrenal glands in 1 case, and between the aorta and the vena cava in 1 case; 2 were malignant with metastases. Scintigraphy was negative in all controls, whereas all pheochromocytomas were clearly demonstrated 24 h after injection, except one regarded as non functional due to necrosis. By comparison, CT readily showed the tumour in 7 cases, showed it only thanks to scintigraphic guidance in 4 cases and failed in 2 cases. It is concluded that scintigraphy with meta-iodobenzylguanidine provides a safe and reliable means of locating a wide range of pheochromocytomas.