Longitudinal impact of postmastectomy radiotherapy on arm lymphedema in patients with breast cancer: an analysis of serial changes in arm volume measured by infrared optoelectronic volumetry.

Abstract Background and purpose This study was conducted to evaluate the longitudinal impact of postmastectomy radiation therapy (PMRT) on persistent severe lymphedema (PSL) using arm volume measurements by an infrared optoelectronic volumetry. Materials and Methods Of the patients who underwent mastectomy between 2008 and 2016, we included 330 patients with secondary arm lymphedema. Percentage of excessive volume (PEV) of the arm were serially assessed using an optoelectronic volumetry 1, 3, 6, 12, 18, 24, 36, and 48 months after the lymphedema diagnosis (Tlymh_Dx). We defined PSL as 2 or more episodes of PEV ≥ 20%. Risk factors for PSL were evaluated using stepwise regression analyses. Results Patients who received PMRT (n=202, 61.2%) were more likely to have larger extent of axillary node dissection (AND), and frequent stage II/III lymphedema at Tlymh_Dx than those who did not receive PMRT (p Conclusion PMRT, especially RNI, was associated with a consistent increase in PEV in patients with arm lymphedema. Therefore, timely physical therapy is necessary for this patient population.