Mayo Clinic Logo Lymphedema apparently is an incurable, chronic swelling of tissue caused by damage to lymph nodes sustained during breast cancer radiation. Patients undergoing breast cancer can now be prevented from lymphedema, or at least the following tidbit suggests so. Radiation oncologists from Mayo Clinic assert that integrating single photon emission computed tomography (SPECT) with the computerized tomography (CT) scans during breast cancer radiotherapy can provide patients with substantial protection against lymphedema.

The ongoing prospective cohort study comprises 30 women diagnosed with early-stage, low-risk breast cancer. All the participants had completed surgery to remove tumors and scheduled for radiotherapy to the affected breast. Patients were registered with either no positive lymph nodes or had only micrometastasis to lymph nodes. Hence radiation to lymph nodes in the armpit may not be beneficial for these patients. Scientists merged SPECT scans with the CT images that are possibly employed in radiation treatment planning. The technology presumably points out the precise region where critical lymph nodes are under the armpit. Even though a person can probably have up to 62 lymph nodes under the arm, only a few are responsible for that function.

Andrea Cheville, M.D., a consultant in Physical Medicine and Rehabilitation at Mayo Clinic in Rochester, Minn., who specializes in lymphedema management and the study’s lead investigator, quoted, “In an effort to deliver therapeutic doses of radiation to the breast, lymph nodes under the arm are innocent bystanders that often are irrevocably harmed. Minimizing harm to these nodes during breast cancer treatment is the most effective way we have seen to reduce women’s risk of developing lymphedema. Lymphedema is a critical concern of breast cancer survivors, so developing a more individualized approach to irradiation is greatly needed.”

The two treatment plans designed for each patient were a standard plan and the one seemingly put to use for lymph node sparing based on the SPECT-CT scans. Lymph node radiation was then compared between the plans and significant reductions in radiation to critical lymph nodes within the SPECT-CT-adapted plans were noted. With the help of SPECT-CT images, all the critical lymph nodes in the patients were possibly observed. 65 percent of these nodes were apparently located within the standard radiation treatment fields, if they were not blocked. Among the 25 patients with at least one critical lymph node within the radiation treatment field, at least some blocking may be possible.

The number of lymph nodes receiving a moderate dose of radiation was allegedly decreased from 26 percent to 4 percent with blocking. Lymphedema development may take a couple of years and study patients will be evaluated. Up till now no incidence of lymphedema has been reported. The technique of locating critical lymph nodes and blocking them from radiation seems to be most useful for patients in need of surgical lymph nodes removal without radiation. Patients’ risk of developing lymphedema apparently is 50 percent without blocking, and measures that preserve the function of their lymphatic systems can assure long-term quality of life.

The study was presented at the 33rd Annual CTRC-AACR San Antonio Breast Cancer Symposium.