Impact of Tumor Location on Aesthetic Outcomes in Oncoplastic Breast-Conserving Surgery: A Retrospective Comparison of Three Acellular Dermal Matrix Techniques

<b>Background/Objectives</b>: Oncoplastic breast-conserving surgery (OBCS) with acellular dermal matrix (ADM) has gained prominence in contemporary breast cancer management, yet evidence-based guidelines for selecting optimal ADM techniques based on the tumor location remain undefined. This investigation evaluated the impact of the tumor quadrant location and ADM application methodology on aesthetic outcomes, patient satisfaction, and postoperative complications following OBCS. <b>Methods</b>: This retrospective comparative analysis examined 229 patients who underwent OBCS with immediate ADM-based volume replacement (2020-2022) utilizing three distinct techniques: the diced ADM with sheet technique (n = 102), the diced ADM with paste-type micronized technique (n = 70), or the diced ADM-only technique (n = 57). The outcomes were stratified by tumor location (superomedial, superolateral, inferomedial, and inferolateral) and evaluated using validated physician-assessed aesthetic scores (four-point scale), patient satisfaction metrics, and comprehensive complication profiling with 24-month minimum follow-up. <b>Results</b>: The tumor quadrant location significantly influenced aesthetic outcomes across all techniques (<i>p</i> < 0.001), with superolateral quadrants demonstrating superior results (3.5 ± 0.4). In the superomedial quadrant, the diced ADM with paste-type micronized technique yielded significantly higher aesthetic scores than the diced ADM-only technique (3.2 ± 0.5 vs. 2.8 ± 0.6, <i>p</i> = 0.032, Cohen's d = 0.71). In the superolateral quadrant, the diced ADM-only technique achieved superior outcomes compared with the diced ADM with sheet technique (3.6 ± 0.4 vs. 3.4 ± 0.5, <i>p</i> = 0.020, d = 0.44). For inferomedial defects, the diced ADM with sheet technique demonstrated significant advantages over the diced ADM-only technique (2.9 ± 0.7 vs. 2.7 ± 0.7, <i>p</i> = 0.005, d = 0.29). A consistent discrepancy between physician and patient assessments was observed, particularly in medial quadrant reconstructions (mean difference: 0.2 points, <i>p</i> = 0.003). <b>Conclusions</b>: The optimal ADM technique varied significantly by tumor location. The diced ADM with paste-type micronized technique demonstrated superior outcomes in superomedial defects, the diced ADM with sheet technique provided essential structural support for inferomedial reconstructions, and the diced ADM-only technique achieved excellent results with reduced material requirements in superolateral locations. These findings provide preliminary evidence that may guide quadrant-specific ADM technique selection in OBCS, potentially enhancing aesthetic outcomes, patient satisfaction, and resource utilization.