Comparison of subjective, objective and patient-reported cosmetic outcomes between accelerated partial breast irradiation and whole breast radiotherapy: a prospective propensity score-matched pair analysis

Background To compare the early cosmetic outcomes after whole breast radiotherapy (WBRT) and accelerated partial breast irradiation (APBI) by various cosmetic assessment methods. Materials/methods APBI was delivered using multiplane interstitial brachytherapy as per standard guidelines. Majority of women in WBRT cohort received hypo-fractionated external beam radiotherapy using bitangential portals and mega-voltage photons along with sequential boost to the tumor bed. Single cross-sectional assessment (18-36 months post-treatment completion) of the breast cosmesis was done by RO, SO and the patient using the modified Harvard scale and by photographic assessment using the BCCT.core software. The two cohorts were propensity score-matched using menopausal status, size of surgical cavity, size of tumor in greatest dimension, median number of lymph nodes dissected, treatment with adjuvant chemotherapy and treatment with hormonal therapy. Results A total of 64 APBI patients were matched with 99 WBRT patients of the entire cohort of 320. At a median follow-up of 25 months, cosmetic results were significantly better for APBI as compared to WBRT cohort by all methods of evaluation (excellent/good: RO:75% vs 38.4%, p = 0.0001; SO: 54.7% vs 37.4%, p = 0.009; patient: 87.5% vs 58.6%, p = 0.001 and BCCT: 73.4% vs 51.6%, p = 0.001). Individual parameters that were significantly better in APBI cohort included size and shape of breast as well as location and shape of NAC. Better results for individual BCCT parameters (pLBC, pBRE, pBAD) were also seen. Conclusions Overall cosmetic outcomes as well as individual subdomains are significantly better with APBI as compared to WBRT by all methods of assessment of cosmesis when matched for various factors.