All oncology nursing literature states that a MUGA scan must be obtained prior to initiating cardiotoxic chemotherapies such as doxorubicin (Adriamycin, Doxil, Rubex). However, none of the literature I have read discusses a time frame. When should the scan be obtained? Does this time frame differ in patients who have had prior paclitaxel (Abraxane, Taxol) or doxorubicin? We had a patient who was given weekly Taxol and one cycle of Doxil before she was started on Adriamycin. The physician decided the echocardiogram obtained about 5 months prior was sufficient enough to initiate chemotherapy. Nursing disagreed and insisted on obtaining a MUGA scan prior to administering the Adriamycin. The patient also had a mechanical aortic valve, indicating that she had had past heart issues. Since the patient was morbidly obese, the dose of Adriamycin was quite high and the physician insisted on not capping the dose because of her obesity. Should the dose have been capped? The patient ended up waiting a few days for the test to be done and to receive the new chemotherapy. Needless to say, no one—patient, physician, nurses—was happy with the process. — Nancy Gerum
As I see it the two main issues in your inquiry are how promptly the pretreatment ejection fraction (EF) should be determined and what impact prior paclitaxel and liposomal doxorubicin should have on future doxorubicin in the nonpegylated form. In regard to the first issue, prestudy or clinical trial acceptability is that the study utilized to determine the EF should be within 6 weeks of starting the therapy and may be repeated prior to each treatment to determine if continuation is appropriate. The same testing procedure (eg, MUGA scan or echocardiogram) should be used each time the EF is determined to allow for more accurate comparisons. In regard to the second issue, I know of no recommendations regarding the taxane and paclitaxel which would impact on subsequent doxorubicin dosing, but in general the total calculated dose of either liposomal and/or nonliposomal doxorubicin should be capped at a maximum of 550 mg/m2. — Donald Fleming, MD