Alteration of myocardial metaiodobenzylguanidine uptake after treatment of phaeochromocytoma and neuroblastoma

Abstract

The relationships between changes in myocardial uptake of metaiodobenzylguanidine (MIBG) and those in circulating catecholamines and cardiac function after treatment of phaeochromocytoma and neuroblastoma were evaluated. Iodine-123 or iodine-131 MIBG scintigraphy was performed before and after surgical resection and/or chemotherapy for primary tumours in nine patients with phaeochromocytoma and 13 patients with neuroblastoma. Changes in myocardial MIBG uptake after treatment were estimated by the heart-to-upper mediastinum (H/M) uptake ratios on the images obtained 24 h after MIBG injection, which were compared with serum levels of noradrenaline (NA) and adrenaline (A). Cardiac function was assessed by echocardiography, with measurements of the left ventricular ejection fraction (LVEF). Before treatment, eight patients with phaeochromocytoma and three with neuroblastoma showed poor myocardial MIBG uptake, with highly elevated circulating NA and A. Echocardiography, however, did not show cardiac dysfunction in these patients with the exception of two patients with phaeochromocytoma. With normalization of NA and A levels after treatment, all of these patients except for the two with persistent cardiac dysfunction showed restoration of myocardial MIBG uptake. The H/M ratios increased significantly after treatment in both patient groups, i.e. with phaeochromocytoma and with neuroblastoma (P<0.0001 and P<0.05, respectively), and these ratios correlated inversely with circulating NA and A before and after treatment. By contrast, there was no significant correlation between H/M ratios and LVEF in these two groups. These results indicate that suppression of myocardial MIBG uptake usually may not be related to cardiac dysfunction and may be reversible following normalization of excess catecholamine levels after treatment in patients with neuroadrenergic tumours. However, the suppression may persist in the presence of catecholamine-induced cardiac dysfunction. The assessment of myocardial MIBG uptake can be a helpful adjunct in monitoring the normalization of circulating catecholamine levels and also in identifying the presence of cardiac dysfunction in treated patients with neuroadrenergic tumours.

Cardiac Uptake-1 Inhibition by High Circulating Norepinephrine Levels in Patients with Pheochromocytoma

“…Reports that patients with high circulating norepinephrine concentrations due to pheochromocytoma can have decreased myocardial MIBG-derived radioactivity, however, have called this view into question. [7][8][9] In the present study, we show that myocardial 6-[…”

“…Reports that patients with high circulating norepinephrine concentrations due to pheochromocytoma can have decreased myocardial MIBG-derived radioactivity, however, have called this view into question. [7][8][9] In the present study, we show that myocardial 6-[18 F]fluorodopamine-derived radioactivity decreased when plasma norepinephrine levels were markedly elevated in patients with pheochromocytoma. We included data from 3 patients evaluated before and after treatment for pheochromocytoma to assess the reversibility of uptake-1 inhibition by high plasma norepinephrine levels.…”

“…[7][8][9] In addition, infusion of high doses of norepinephrine in rats leads to decreased uptake and increased washout of […”

Remarkable Improvement of Myocardial Metaiodobenzylguanidine Uptake After Surgery in a Patient with Pheochromocytoma

“…1,2 Improvement of myocardial MIBG uptake has been observed in treated patients with pheochromocytoma, 3,4 although the mechanism of the improvement remains unclear. We report a patient with pheochromocytoma whose myocardial MIBG uptake markedly improved within a short time after surgical resection of the tumor.…”

Biomarkers for the early detection of cancer treatment induced cardiotoxicity

“…The relationship between myocardial 123 I-mIBG uptake and circulating catecholamines has been shown in adult patients with pheochromocytoma. 188,189 However, data correlating cardiac 123 I-mIBG uptake and catecholamine levels in neuroblastoma patients are limited and do not include adjustment for age-specific changes in normal patients. 189 Recently, reference values for cardiac 123 I-mIBG uptake in children were published.…”