Anthracyclines are used extensively in therapy of several types of human cancer where long-term survival and cure are common, such as haematological malignancies and paediatric cancers. They are now increasingly used also in adjuvant therapy of breast cancer, because the results of some trials suggest that anthracycline-containing combinations are associated with better survival than non-anthracycline-containing regimens (Early Breast Cancer Trialists' Collaborative Group, 1998). These trials have, however, only limited follow-up of a few years. Cardiotoxicity is a wellestablished side-effect of anthracyclines, and subclinical cardiotoxicity of adjuvant and other curative therapies might manifest only several decades after treatment when the myocardial reserves start to decrease in old age. This might counterbalance the shortterm absolute survival benefit associated with anthracyclinecontaining regimens over CMF (cyclophosphamide, 5-fluorouracil and methotrexate), which is only about 3% at 5 years of follow-up according to the meta-analysis (Early Breast Cancer Trialists' Collaborative Group, 1998). Cardiotoxicity of anthracyclines may be reduced by low-peak therapies, such as anthracyclines given as long infusions (Legha et al, 1982). A novel iron-chelating agent, dexrazoxane, has reduced anthracycline-associated cardiotoxity in several randomized trials, and apart from one study, it has not reduced response rates (Green, 1998).High-dose chemotherapy is used increasingly in therapy of breast cancer both in the US and Europe (Antman et al, 1997;Grathwohl et al, 1997). In the USA, breast cancer is the most common indication for high-dose chemotherapy given with the support of either bone marrow or peripheral blood stem cell rescue at present (Antman et al, 1997). It is currently highly controversial whether high-dose chemotherapy is superior to conventional-dose chemotherapy either in the adjuvant or the metastatic setting, but several controlled trials are currently in progress to resolve the issue. Favourable results have been obtained with adjuvant highdose therapy in phase II studies (Peters, 1996), and many breast cancer patients with a high risk of relapse are now given high-dose therapy. However, besides its efficacy, the long-term risks of highdose therapy are unsettled. Little is known about the subclinical cardiac toxicity related to high-dose adjuvant therapy, which might be of great importance for the long-term survivors from cancer.Endomyocardial biopsy is the most reliable method to diagnose anthracycline-induced cardiotoxicity. However, a non-invasive method of indium-111 monoclonal antimyosin antibody scintigraphy has been shown to be highly sensitive for detecting cardiac damage. The method is capable for detecting even small areas of myocardial damage or necrosis in a variety of diseases Verna et al, 1995;Astorri et al, 1996;Ballester et al, 1997aBallester et al, , 1997bBengel et al, 1997; Schutz et al, 1997). Moreover, it may be the only non-invasive method currently available for detection o...