MUGA Heart Scan
MUGA heart scan for breast cancer chemotherapy is an important test for many breast cancer patients. The test is conducted to determine the ability of the heart to pump blood. The operating doctor may perform a multigated acquisition test (MUGA) prior to the chemotherapy treatment as well as after the treatment during follow-ups.
Need for the Test
One of the common drugs used for chemotherapy treatment for breast cancer patients is anthracycline. This drug therapy is particularly used when the cancer is detected at an early stage. Anthracyclines have cardiotoxic properties, which means they can be harmful for the health of the heart. Any damage to the heart muscle may expose the patient to the risk of heart failure even many years after the chemotherapy treatment has been completed.
Therefore, if the patient is a candidate for treatment with anthracyclines, it is recommended to perform a MUGA heart scan before, during and after the treatment. This test evaluates the heart’s capability to pump blood before and after the chemotherapy treatment. It also helps to examine the size of the lower heart chambers or the ventricles that hold blood in the heart. If the flow of blood shows any signs of abnormality, the MUGA scan can reveal the trouble.
If the results of the MUGA heart scan are normal, it indicates that the heart is functioning normally in terms of efficient pumping of blood all through the body. A result of 45 percent or higher is considered to be a normal result. A result below this limit may be an indication of inefficient pumping of blood by the heart, arterial blockages, damage to the heart valve, or other abnormalities. MUGA helps to detect such abnormalities during the course of the chemotherapy treatment. In such a situation, the physician may choose to cut back the dosage of anthracyclines, or stop the drug entirely and consider alternative drugs to continue with chemotherapy.
Conditions that may Affect Results
Under certain conditions, the results of MUGA heart scan for breast cancer chemotherapy patients may not be accurate, or may prevent the test altogether. If the patient is pregnant, the doctor may have to consider his options because the MUGA scan involves a minor exposure to radiation. This exposure may not harm an adult, but it may interfere with the baby’s development. If the patient is obese, or suffers from a rapid or irregular heartbeat, or is undergoing certain heart medications, or has had nuclear testing in the recent past, it may impact the accuracy of MUGA scan results.
As a standard precaution that most doctors observe, patients who are detected with any heart abnormality prior to the chemotherapy treatment, may not be administered anthracycline based treatment altogether.
Cancer.net: “MUGA Scan – What to Expect” (Retrieved on Nov. 12, 2010) - https://www.cancer.net/patient/All+About+Cancer/Cancer.Net+Feature+Articles/Treatments%2C+Tests%2C+and+Procedures/MUGA+Scan%E2%80%94What+to+Expect
Kpsantaclaracancercare.org: “MUGA Scan or Gated Scan” (Retrieved on Nov. 12, 2010) - https://kpsantaclaracancercare.org/clinical_services/med_imaging/nuc_med/muga.php