Predictors of poor cosmesis in breast cancer patients treated with adjuvant whole breast radiation therapy plus high-dose-rate interstitial brachytherapy boost after breast conservation surgery

Abstract

To identify patient, tumor, and treatment-related factors, which predict cosmesis in breast cancer survivors treated with adjuvant whole breast irradiation (WBI) plus high-dose-rate (HDR) multicatheter interstitial brachytherapy (MIBT) boost after breast conservation surgery.Material and methods: At least 12 months after completion of radiotherapy, cosmetic outcomes were measured both objectively with BCCT.core software (using a front view digital photograph), and subjectively according to Harvard's criteria. MIBT dose fractionation regimen was 13.6 Gy/4 fractions (bid). To evaluate the correlation between cosmetic scores and dose-volume histogram (DVH) parameters, WBI and MIBT plans were retrospectively analyzed, and ipsilateral skin and breast biologically equivalent dosimetric indices were recorded (α/β = 3 Gy). A multivariate ordinal logistic regression model was used for statistical analysis.Results: Twenty-eight consecutive patients were enrolled into this study. The median time from completion of radiation therapy to cosmesis scoring was 18 months. In evaluation with BCCT.core software, no patient was scored as excellent. Cosmesis was good in 18%, fair in 50%, and poor in 32% of patients. According to Harvard's scale, 10.5% of patients had excellent cosmesis, and 43%, 28.5%, and 18% of patients had good, fair, and poor scores, respectively. In univariate analysis, patients with higher absolute MIBT V 29Gy (cc), those treated with irradiation of regional lymphatics (odds ratio ≈ 5), and patients with larger breast volumes had statistically significant lower Harvard's scores. In the multivariate model, none of the mentioned factors remained statistically significant, except for a trend for poorer cosmesis in patients with higher absolute MIBT V 29Gy (p-value = 0.066).Conclusions: Based on the results of this study, MIBT breast V 29Gy , regional nodal irradiation, and larger breast volumes are the potential factors, which could predict cosmesis.

Thermally boosted interstitial high-dose-rate brachytherapy in high-risk early-stage breast cancer conserving therapy — large cohort long-term results

“…The paper presents retrospective data on good to excellent CO in 74.9% (group A) and 79.1% (group B), p = 0.32. The interpretation may be difficult as different researchers use different tools for assessing the cosmesis, also in terms of prospective or retrospective scenarios, still searching for eventual poor cosmesis predictors [ 38 ]. However, TB did not worsen CO in our cohort, and the above-mentioned patient selection (larger breast cups were easier qualified) might not significantly influence, yet slightly improve the score.…”