High-dose cyclophosphamide-induced myocardial damage during BMT: assessment by positron emission tomography.

Despite its potential to cause myocardial damage, high-dose CY in doses up to 200 mg/kg is an integral part of preparative regimens for BMT. Conventional tests, such as an electrocardiogram or echocardiogram, have lacked sensitivity in prediction of cardiotoxicity in this patient population. We prospectively compared serial electrocardiograms and positron emission tomography scans before and after CY administration to investigate the possible changes in 13N-ammonia perfusion and 18F-2-deoxyglucose metabolism after CY administration in 12 consecutive patients undergoing BMT. Neither global nor regional changes in myocardial N-13 ammonia and 18-fluorodeoxyglucose were significant when compared with baseline studies and control studies (p < 0.05). In a single patient, however, a substantial increase in 13N-ammonia perfusion was seen in the inferior region simultaneously with electrocardiographic T wave inversions in the inferior leads. These changes may be due to alterations in myocardial blood flow or membrane permeability. PET scanning may be a useful adjunct in evaluating CY cardiotoxicity, although further investigations are needed to elucidate its role in clinical practice.