Equilibrium Radionuclide Ventriculography in the Assessment of Cardiotoxicity of Chemotherapy and Chemoradiotherapy in Patients with Breast Cancer

BACKGROUND: Multidrug chemotherapy increases the efficacy of the treatment, but at the same time rises its cardiotoxicity. The majority of cardiac complications are caused by anthracyclines. Radiation therapy may intensify cardiotoxicity. The aim of this study was to determine early changes of cardiac function using radionuclide ventriculography in patients with breast cancer and to compare the toxicity of AC and AT chemotherapy programs.MATERIAL AND METHODS: The study included 71 patients with breast cancer between the ages of 38 and 71 years. All patients after surgery were qualified for chemotherapy, and for 37 (52%) of them subsequent irradiation treatment was planned. Patients received chemotherapy according to the scheme: AC - 47 patients (66%) and AT -24 patients (34%). Patients were irradiated using a photon beam (4 to 6 MeV) and an electron beam (6-15 MeV). In all patients, before and six months after the treatment, radionuclide ventriculography was performed.RESULTS: In all 71 patients a reductions in left ventricular ejection fraction (EF) and in peak filling rate (PFR) as well as an increase in the end-systolic and end-diastolic volumes (ESvol, EDvol) were observed. AC chemotherapy, where cumulative anthracycline dose was higher, significantly decreased left ventricular ejection fraction and PFR and increased ESvol. After AT chemotherapy the EF reduction proved to be smaller. Radiotherapy did not significantly lower the value of EF as compared to the group of patients who underwent chemotherapy.CONCLUSIONS: Radionuclide ventriculography is a useful method of evaluating the cardiotoxicity of the treatment. Early indicators of myocardial damage are EF, PFR, ESvol and EDvol. AC chemotherapy, where the average cumulative dose of anthracyclines was higher, caused more cardiotoxic effects than AT chemotherapy.Applying additional radiotherapy did not significantly increase the cardiotoxicity of the treatment.