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Radiation-Induced Lymphatic Injury: A Key Driver of Seroma Formation
Meeti Mehta
*1, Shayan M. Sarrami
2, Korrina Gidwani
1, Casey Zhang
1, Carolyn De La Cruz
21Department of Plastic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA; 2Department of Plastic Surgery, University of Pittsburgh, Pittsburgh, PA
Introduction
Radiation is a known risk factor of lymphedema but its damage on truncal lymphatics has never been assessed. Using ICG, damage can be visualized as dermal backflow or absent lymphatic flow following severe destruction. We analyzed the effects of radiation on chest lymphatics, exploring no flow zones and associated complications.
Methods
Breast cancer patients with suspected chest lymphedema who received ICG lymphography were included. Patients were grouped by radiation therapy. Zones of no lymphatic flow were recorded using ICG. Breast cancer treatment data was collected. Multivariate analysis evaluated radiation, no flow zones, and breast complications, controlling for other treatments and BMI.
Results
173 hemi-trunks (95 patients) were assessed. Patients had radiation (42%), mastectomy (79%), chemotherapy (65%), and axillary dissection (27%). Zones of no lymphatic flow were more common in the radiation vs non-radiation group (79% vs 63%, p=0.03). Most no flow zones were in inferior mastectomy flaps, correlating with clinical findings. On multivariate analysis, radiation increased the odds of absent lymphatic flow by 158% (OR 2.58, p=0.03).
Breast complications were more frequent in the radiation vs non-radiation group (52% vs 28%, p=0.002), including infection (26.0% vs 13.0%, p=0.048) and seroma (37.0% vs 19.0%, p=0.014). When controlling for confounders, radiation increased the odds of seroma by 162% (OR 2.62, p=0.02). When controlling for radiation and other confounders, diffuse and absent lymphatic flow increased the risk of seroma by 31% compared to less severe dermal backflow patterns (OR 1.31, p=0.04).
Conclusion
Radiation is associated with zones of absent lymphatic flow, reflecting severe lymphatic damage and stasis. These zones are correlated with increased risk of seroma, and radiation independently increases seroma risk. This suggests that radiation-induced lymphatic disruption is a critical factor in seroma formation, highlighting the need for targeted interventions to mitigate radiation-associated complications in breast cancer patients.
