Scoping Review: Neoadjuvant Radiotherapy Prior to Mastectomy with Immediate DIEP Flap Reconstruction in Primary Invasive Breast Cancer

PROJECT OVERVIEW This scoping review will systematically map the published literature on neoadjuvant radiotherapy followed by immediate autologous breast reconstruction in women with primary invasive breast cancer, with emphasis on DIEP (Deep Inferior Epigastric Perforator) flap outcomes. WHY THIS QUESTION MATTERS Historically, the sequence has been: mastectomy first, then radiotherapy months later once the surgical site heals, and reconstruction happens even later in separate operations. This takes 6-12 months total. But recent studies—the PRADA feasibility trial (Thiruchelvam 2022) and the PreMRT RCT (Schaverien 2024) being the most important—have shown something different might be possible. What if you gave radiotherapy first, then did mastectomy and reconstruction all in one surgery? Theoretically, patients could go from diagnosis to completion in 4-5 months instead of a year. The catch: we don't actually know if this works as well as the traditional approach. The literature is spread across different journals, different authors use different outcome measures, and when studies do report results, they often lump together different types of reconstruction (DIEP, TRAM, latissimus) without separating the data. So it's not clear whether this sequence is actually better, worse, or just different. WHAT I'M MAPPING OUT I want to systematically find and review everything published from 2010 to 2026 that reports outcomes from this reversed sequence—neoadjuvant radiotherapy followed immediately by autologous reconstruction, especially DIEP. This isn't a meta-analysis—I'm not combining statistics. It's a scoping review, which means I'm mapping the landscape of what's out there, what we actually know, what we don't know, and where the gaps are that future research should fill. The key questions I'm tracking: - How does the tumor respond to neoadjuvant radiotherapy? - Does the flap survive? What complications actually happen in practice? - Are patients satisfied with how their breast looks and feels? - Is their quality of life better, worse, or the same compared to traditional sequences? - When studies separate DIEP data specifically, how do the outcomes look? The literature I'll be looking at ranges from small case reports (usually the unusual cases) all the way up to randomized controlled trials. The problem is that many studies lump all autologous flaps together without separating results by flap type, which obscures what's specific to DIEP. This matters clinically because DIEP is the gold standard for autologous reconstruction. It achieves 97-98% flap survival rates, has the lowest serious complication rates (