Fig. 1.

A 45-year-old patient with malignant pheochromocytoma had abdominal mass adjacent to aorta (white arrow): a, b before and c, d after first ¹³¹I-MIBG therapy (7.4 GBq). The objective and scintigraphic responses were not observed after the first ¹³¹I-MIBG therapy (non-PD). e, f Repeated ¹³¹I-MIBG therapy (total 66.0 GBq) decreased the size of mass (white arrow) and uptake of metastases. He is still alive 74 months after first ¹³¹I-MIBG therapy without progression of disease. The scintigraphy was obtained at 24 h after injection of ¹²³I-MIBG [b (111 MBq), d (111 MBq), and f (222 MBq)]