S14
Track-Topic
ESTRO 2026
phase II APBI study (ACTRN12613000551796) and a historical control arm of the STARS (TROG 08.06) study. APBI patients received 34 Gy in 10 fractions to the partial breast via HDR multiplanar catheters, whereas STARS patients received whole breast treatment using a tangential external-beam radiotherapy technique. Patients were screened against predefined inclusion criteria: age ≥ 50 years; unifocal tumour ≤ 30 mm in maximal dimension; clear surgical margins defined as no tumour on ink; no lymphovascular invasion; no extensive intraductal component; no lymph-node involvement; hormone- receptor positive; and human epidermal growth factor receptor 2 (HER2) negative. Standardised digital photographs at baseline, 1 year, and 3 years post- treatment were assessed using the BCCT.core software to classify cosmetic outcomes as excellent/good (EG) or fair/poor (FP) based on breast asymmetry, colour, and scar visibility. Only patients with complete photographic datasets were included the analysis. Statistical analyses included chi - square tests for between - group comparisons and McNemar’s test for within - group changes over time. Results: 116 patients from the APBI trial and 96 patients from the STARS trial met the inclusion criteria. In total, 348 APBI and 288 STARS photographs were available for analysis. At baseline, 83% of APBI and 84% of WBRT patients had EG cosmesis. At 1 year, EG rates were 82% versus 76%, and at 3 years, 81% versus 74% for the APBI and WBRT arms, respectively. There was no statistically significant difference observed in overall cosmetic outcomes (EG versus FP) between the APBI and STARS cohorts at any time point. The proportion of patients with EG cosmesis, however, significantly declined from baseline to 1 year (p=0.046) and baseline to 3 years (p=0.0412) in the STARS arm, whereas this remained stable for the APBI cohort. Conclusion: Global cosmetic outcomes are equivalent at baseline, 1 year and 3 years following breast conservation treatment with APBI versus whole breast irradiation. APBI maintains stable and durable cosmetic outcomes through 3 years following breast conserving surgery, whereas WBRT is associated with a statistically significant decline in cosmetic quality over time. Keywords: cosmesis, outcomes References: Jaime S. Cardoso and M. J. Cardoso, "Towards an Intelligent Medical System for the Aesthetic Evaluationof Breast Cancer Conservative Treatment", doi:10.1016/j.artmed.2007.02.007, Artificial
features (e.g., age 40–49 years, tumour 2.1–3.0 cm, close margins, focal LVI, ER-negative, invasive lobular histology, or selected DCIS) was permitted after multidisciplinary review and documentation. Kaplan– Meier estimates were generated for ipsilateral breast tumour recurrence (IBTR), locoregional recurrence- free survival (LRRFS), distant metastasis-free survival (DMFS), event-free survival (EFS), and overall survival (OS) at 5 and 10 years; first failure patterns and causes of death were recorded. Results: Overall, 210 patients were analysed. The 10-year IBTR rate was 2.58% (5 events). LRRFS was 96.46% at 5 years (95% CI, 92.69–98.30) and 94.62% at 10 years (89.62–97.25; 9 events). DMFS was 97.14% at both 5 and 10 years (95% CI, 93.20–98.81; 5 events). EFS at 5 years was 92.74% (95% CI, 88.00–95.66; 17 events). OS was 96.84% at 5 years (95% CI, 92.46–98.69) and 95.95% at 10 years (95% CI, 91.04–98.19; 6 deaths). First failures were local (n=5), regional including nodes (n=4), and distant (n=5). Conclusion: Within an ASTRO-aligned framework prioritizing “Suitable” patients and allowing carefully vetted “Cautionary” cases, IORT at Chung Shan Medical University Hospital achieved low IBTR and durable 5- /10-year LRRFS, DMFS, and OS. These data support IORT as a pragmatic option for appropriately selected early breast cancer patients. Propensity-matched and multicentre studies, including subgroup analyses by ASTRO category, are planned. Keywords: IORT, PBI, Long-term results Accelerated partial breast irradiation using interstitial multicatheter high-dose-rate brachytherapy: A comparative analysis of long term cosmesis Lincoln Dinh 1 , Lauren Moses 1 , George Cosman 1 , Peter Graham 1 , Andrej Bece 1 , Gina Hesselberg 1 , Lois Browne 1 , Yaw Sinn Chin 1,2 1 Department of Radiation Oncology, St George Hospital, Sydney, Australia. 2 UNSW Medicine, University of New South Wales, Sydney, Australia Proffered Paper 3836 Purpose/Objective: To compare long-term cosmetic outcomes of accelerated partial breast irradiation (APBI) using a multi-catheter interstitial high-dose-rate brachytherapy technique with whole-breast external beam radiotherapy (WBRT) following breast conserving surgery. Material/Methods: A comparative analysis was performed using photographs from two separate prospective trials, a
Made with FlippingBook - Share PDF online