Radionuclide ejection fraction in doxorubicin cardiotoxicity.

Serial assessment of cardiac function by radionuclide ejection fraction (EF), using a "first-pass" technique, was performed prior to each dose in 292 patients receiving doxorubicin. Detailed analysis was undertaken in 98 patients, consisting of all 91 patients who had received greater than 200 mg/m2 and seven with risk factors (RFs) who had received between 100 and 200 mg/m2. Thirty-two patients had RFs and 66 had no risk factors (NRFs). RFs were: (a) cardiovascular disease, (b) mediastinal irradiation within 6 months of starting doxorubicin treatment, and (c) total doxorubicin dose greater than 550 mg/m2. The criteria for discontinuing doxorubicin were EF less than 0.40 in RF patients or less than 0.35 in NRF patients or decrease in EF of greater than or equal to 0.14 over three successive readings. In the NRF group, no patient met these criteria nor did any develop cardiac failure. In the RF group, discontinuation was indicated in eight patients: two stopped receiving doxorubicin at total doses of 730 mg/m2 and 680 mg/m2, respectively, and it was discontinued in the other six at total doses ranging from 120 to 420 mg/m2. Prior to the first dose of doxorubicin, all patients should have a baseline EF and assessment of RFs. An EF study is required before each subsequent dose in patients with RFs or with initial EF less than 0.45, but in the remaining patients, serial studies are not required until there is a cumulative dose of 450 mg/m2. Use of these guidelines and our criteria for discontinuation may prevent development of doxorubicin cardiotoxicity.