[Usefulness of 123I-MIBG myocardial SPECT in patients with hematologic malignancies with chemotherapeutic agent-induced cardiomyopathy].

In 59 patients with hematologic malignancy undergoing chemotherapy regimens including adriamycin (ADR), myocardial imaging was performed by SPECT with 123I-metaiodobenzylguanidine (MIBG) to detect cardiac sympathetic nerve abnormalities. SPECT imaging was performed 20 min and 4 hr after intravenous injection of 123I-MIBG, and the washout rate (WR) for the entire left ventricle was calculated. Then the relationship of the WR to the total dose of ADR, the left ventricular ejection fraction, and the frequency of arrhythmias was evaluated. It was found that the WR was related to the total dose of ADR, suggesting that it is a useful parameter for cardiac sympathetic nerve damage. As the WR increased, the frequency of ventricular arrhythmias also increased. The WR was usually normalized 3-6 months after the discontinuation of ADR. In patients with a WR > or = 50%, however, prolonged follow-up was required. In conclusion, the WR on 123I-MIBG myocardial SPECT scans may be useful as a parameter for predicting cardiac toxicity requiring the discontinuation of ADR or dose reduction.