Posted: Wednesday, November 2, 2022
Heejoo Ko, BS, of The Catholic University of Korea, and colleagues suggested that axillary-lateral thoracic vessel juncture doses of less than 35 Gy may prevent lymphedema from developing in patients with breast cancer who undergo less-extensive axillary surgery. Additionally, the researchers proposed their study’s dose constraints may be incorporated into future prospective protocols to further investigate the impact of axillary treatment. These findings were presented at the 2022 American Society for Radiation Oncology (ASTRO) Annual Meeting (Abstract 104).
The study analyzed women with breast cancer who were treated with multimodal therapies. All patients were given axillary-lateral thoracic vessel juncture doses. Dose-volume histogram parameters were assessed.
A total of 1,488 women were included in the study. At the 5-year follow-up, the cumulative incidence of lymphedema development was 6.8%. The risk of patients developing lymphedema increased for each 10-Gy increment in the axillary-lateral thoracic vessel juncture mean dosage. The random survival forest model predicted the risk for developing lymphedema was higher when axillary-lateral thoracic vessel juncture dose-volume histogram parameters were integrated into the model with a c-index of 0.91 (P < .001). The most significant indicators for a patient’s risk of developing lymphedema were surgical extent followed by the mean dose to the axillary-lateral thoracic vessel juncture. Additionally, in the decision tree model developed with a hierarchic classification and regression tree, the 5-year follow-up lymphedema risk was significantly elevated in patients with a mean dose of axillary-lateral thoracic vessel juncture greater than 35 Gy compared with patients who had fewer than six sampled lymph nodes (12.8% vs. 1.0%, P < .001).
Disclosure: Ms. Ko reported no conflicts of interest.