Preoperative CT angiography of the abdomen and pelvis is the gold standard for patients undergoing Deep Inferior Epigastric Perforator (DIEP) flap breast reconstruction (Pratt et al., Ann Plast Surg 69:3-9, 2012), with incidental findings in these scans varying from 13 to 74% (Hughes et al., Eur J Surg Oncol (EJSO) 42:59-63, 2016; Ho et al., J Plast Reconstr Aesthetic Surg 69:e97-e102, 2016). This study aimed to clarify the rate and nature of the incidental findings in a large single center cohort of patients undergoing DIEP flap breast reconstruction. An analysis of 1000 CT angiograms from 2013 to 2019 identified a risk rate of 23.5% for incidentalomas with the most commonly reported being liver cysts (3.6%), sclerotic bone lesions (3,3%), uterine fibroids (3%), spinal degenerative changes (2.6%), and ovarian cysts (2.5%). All findings were benign in nature, 2 cases (0.2%) required further invasive imaging, and in 1 case (0.1%) of ovarian cyst the procedure had to be delayed until further gynaecological consultation. To our knowledge, this is the largest cohort in literature. CT incidental findings (incidentalomas) remain common but rarely complicate the patient journey, even if further investigations are needed. Informing patients of the high chance (23.5%) of an abnormal finding on CTA should be a part of the consultation, acknowledging that the vast majority of incidentalomas are benign.

Background Radiotherapy before mastectomy and autologous free-flap breast reconstruction can avoid adverse radiation effects on healthy donor tissues and delays to adjuvant radiotherapy. However, evidence for this treatment sequence is sparse. We aimed to explore the feasibility of preoperative radiotherapy followed by skin-sparing mastectomy and deep inferior epigastric perforator (DIEP) flap reconstruction in patients with breast cancer requiring mastectomy. Methods We conducted a prospective, non-randomised, feasibility study at two National Health Service trusts in the UK. Eligible patients were women aged older than 18 years with a laboratory diagnosis of primary breast cancer requiring mastectomy and post-mastectomy radiotherapy, who were suitable for DIEP flap reconstruction. Preoperative radiotherapy started 3-4 weeks after neoadjuvant chemotherapy and was delivered to the breast, plus regional nodes as required, at 40 Gy in 15 fractions (over 3 weeks) or 42.72 Gy in 16 fractions (over 3.2 weeks). Adverse skin radiation toxicity was assessed preoperatively using the Radiation Therapy Oncology Group toxicity grading system. Skin-sparing mastectomy and DIEP flap reconstruction were planned for 2-6 weeks after completion of preoperative radiotherapy. The primary endpoint was the proportion of open breast wounds greater than 1 cm width requiring a dressing at 4 weeks after surgery, assessed in all participants. This study is registered with ClinicalTrials.gov, NCT02771938, and is closed to recruitment. Findings Between Jan 25, 2016, and Dec 11, 2017, 33 patients were enrolled. At 4 weeks after surgery, four (12.1%, 95% CI 3.4-28.2) of 33 patients had an open breast wound greater than 1 cm. One (3%) patient had confluent moist desquamation (grade 3). There were no serious treatment-related adverse events and no treatment-related deaths. Interpretation Preoperative radiotherapy followed by skin-sparing mastectomy and immediate DIEP flap reconstruction is feasible and technically safe, with rates of breast open wounds similar to those reported with post-mastectomy radiotherapy. A randomised trial comparing preoperative radiotherapy with post-mastectomy radiotherapy is required to precisely determine and compare surgical, oncological, and breast reconstruction outcomes, including quality of life. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd.

Introduction Post-mastectomy radiotherapy (PMRT) is recommended to women at high risk of local recurrence. There is a paucity of published work on the experience of women who undergo deep inferior epigastric perforator (DIEP) flap breast reconstruction in the context of requiring PMRT. The aim of the study was to explore and understand the patient experience of these women. Methods Purposive sampling was used to identify patients who had undergone an immediate reconstruction with PMRT and women who had undergone a delayed reconstruction after PMRT. Purposive sampling was used to identify and invite women to participate in the study. Semi-structured interviews were conducted using a grounded theory approach with a topic guide which was derived from relevant literature. Results Twenty women participated in the study. Ten women had undergone immediate reconstruction followed by PMRT and 10 women had undergone delayed reconstruction after PMRT. The results suggest that, regardless of the surgical pathway or the consequences of treatment, overall women were satisfied with the treatment decision they had made. Patients described the challenges around decision-making and their post-operative experience. However, patients were grateful to have had a breast reconstruction and in the most part happy with the treatment pathway they underwent. Conclusion The findings of this study suggest that women are motivated by a variety of factors when presented with the choice of immediate versus delayed breast reconstruction and can justify the treatment path they have taken. This study highlights the importance of discussing reconstruction options in terms of context of a person’s life and coping strategies. Patients appeared to use self-regulation in their behaviour to cope with their illness threat and decision-making. The women who chose delayed reconstruction were motivated by the delayed gratification of having a reconstruction that had not been subjected to PMRT.

Background: Radiotherapy (RT) prior to mastectomy and autologous reconstruction spares healthy donor tissues the adverse effect of radiation, avoiding delay to adjuvant RT due to post-operative healing. However, little is known regarding the surgical safety of RT sequence reversal in this setting. We investigated the feasibility of microvascular anastomosis and surgical safety of deep inferior epigastric perforator (DIEP) breast reconstruction after neoadjuvant radiotherapy (NRT).Methods: PRADA was a multi-centre, non-randomized, observational study in the United Kingdom. Eligible participants were aged 18 years or older, requiring mastectomy either for extensive disease or for positive margins following attempted breast conserving surgery, and requiring PMRT and deemed suitable for a DIEP flap reconstruction. NRT was commenced 2-6 weeks following completion of neoadjuvant chemotherapy (NACT) and intention for surgery within 6 weeks of completion of NRT. Data was prospectively captured on demographic and clinicopathological variables, treatment schedules and timelines, and perioperative complications. Oncological outcomes including loco-regional recurrence (LRR), overall survival (OS) and disease-free survival (DFS) were recorded. The primary outcome was the open wound rate, and the primary end point was the rate of open breast wounds requiring a dressing 4 weeks following surgery. Findings: Between 26th January 2016 and 11th December 2017, 33 patients receiving immediate DIEP breast reconstruction after NRT were enrolled. Median time from NRT completion to surgery was 19·0 days with all completing surgery within 6 weeks of NRT (range=12-39). Microvascular anastomosis was successfully achieved in all patients and there were no DIEP flap failures. In three cases immediate revision anastomosis was required at the index surgery. There were two unplanned returns to the operating room: one <24hrs to assess a congested DIEP flap; the second at 4 weeks for debridement of mastectomy skin flap necrosis and split skin graft. At 4 weeks there was an open wound rate of 12·1% (4/33). After median follow up of 23 months (range 2-41), none had LRR, four had distant metastatic relapses and there were two breast cancer related deaths, with OS 93·9% and DFS 87·8%.Interpretation: NRT prior to mastectomy with immediate DIEP flap reconstruction is technically feasible with rates of mastectomy skin flap necrosis and open wounds analogous to those observed following post-mastectomy radiotherapy. An appropriately powered randomized trial of NRT compared to conventional PMRT is needed to determine more precisely the surgical, oncological, and quality of life outcomes of breast reconstruction.Clinical Trial Registration Details: Registered with clinical trials.gov [NCT02771938].Funding Information: NIHR Imperial BCR, the CR:UK Imperial Centre and the Royal Marsden Hospital.Declaration of Interests: PTRT reports personal fees from Stryker Surgical and Cytoveris. JH reports personal fees from Stryker Surgical. All other authors declare no competing interests.Ethics Approval Statement: Local Regional Ethical Committee (LREC) approval was obtained for the Primary Radiotherapy And DIEP flAp (PRADA) study [15/LO/1071].

We have previously published our venous thromboembolism (VTE) rates in patients undergoing breast reconstruction with the deep inferior epigastric artery perforator (DIEP) flap.1 This 5-year retrospective review (January 2010 – December 2014) highlighted 5 cases of postoperative VTE (all symptomatic pulmonary embolism (PE)) in 667 patients providing an overall VTE rate of 0.75%.1 Although this rate was low in our series and comparable with other published literature, VTE is a recognised complication that, although life-threatening, is potentially preventable.

BackgroundThe transverse upper gracilis (TUG) flap provides a good alternative to the gold standard DIEP in breast reconstruction. However, flap volume estimates are subjective, making preoperative planning potentially challenging.Study aimTo derive a reliable, accurate, and reproducible mathematical algorithm for the preoperative calculation of TUG flap volumes.Materials and MethodsNineteen consecutive patients with 30 TUG flaps were prospectively included. On the assumption that the TUG flap resembles two isosceles prisms, the formula of the volume of a prism was used to calculate their preoperative flap weights. These were then intraoperatively compared to the actual flap weights. A regression equation was calculated from the correlation analysis of 10 random flaps. This was then applied to the remaining 20 flaps to assess for improved reliability and weight prediction accuracy.ResultsThe prism volume equation used to clinically calculate flap volumes was: Geometric flap weight = (h1bT)/2+ (h2bT)/2, (h = height, b = base, T = flap thickness); all in centimetres. Geometric and actual flap weights were found to be significantly correlated (r2 = 0.977) generating the following regression formula: predicted TUG weight = 0.924 × geometric weight + 26.601. When this was applied to the remaining 20 flaps, no significant difference was found (p = 0.625) between predicted and actual flap weights, demonstrating an increased accuracy of predicting flap volume.ConclusionThe proposed formula provides the clinician with a more accurate and reliable estimation of available TUG flap volume and may potentially aid with preoperative planning and patient consultations.

Introduction: Surgical guidelines have been altered in light of the SARS-CoV-2-pandemic. In March 2020, these guidelines advised against all breast reconstruction in the United Kingdom with the aim of protecting patients and resources. As breast reconstruction is regarded as integral to breast cancer recovery, rapid but safe reintroduction is a priority. We present a study that describes how breast reconstruction was reintroduced and benchmark peri-operative outcomes during the first wave recovery phase in a large UK Cancer Centre. Methods: Local audit committee approval (ID: BR_2021_169). Prospective cohort study of patients undergoing autologous or implant +/- Acellular Dermal Matrix (ADM) breast reconstruction between June 1st and August 31st, 2020. We defined a composite primary outcome to include positivity for COVID-19, adverse pulmonary outcomes, clinically manifest thromboembolism or mortality. Results: Fifty breasts were reconstructed in 42 patients (62% autologous; 38% implant-based). This represents a 40% reduction in activity when compared with the same timeframe for 2019. All tested negative for COVID-19 based at pre-operative clinical screening and by RT-PCR swabs for COVID-19 RNA 72 hours prior to surgery. No patients were diagnosed with COVID-19, experienced adverse pulmonary or clinically manifest thromboembolic outcomes or died within 30-days post-operatively. There were no cases of flap or implant loss and the return-to-theatre rate was 2%. Conclusions: Our data show that both autologous and implant-breast reconstruction can be performed safely with low risk of post-operative COVID-19 infection when performed within a COVID-19-protected pathway and should continue to be offered to women undergoing mastectomy at this time.

Preoperative CT angiography of the abdomen and pelvis is the gold standard for patients undergoing Deep Inferior Epigastric Perforator (DIEP) flap breast reconstruction (Pratt et al., Ann Plast Surg 69:3–9, 2012), with incidental findings in these scans varying from 13 to 74

Introduction: Evaluation of aesthetics after breast reconstruction is challenging. In the absence of an objective measurement, panel assessment is widely adopted. Heterogeneity of scales and poor internal consistency make comparison difficult. Development and validation of an expert panel scale using a Delphi consensus process is described. It was designed specifically for use as the gold standard for development of an objective evaluation tool using 3-Dimensional Surface Imaging (3D-SI). Materials and methods: 20 items relating to aesthetic assessment were identified for consideration in the Delphi consensus process. Items were selected for inclusion in the definitive panel scale by iterative rounds of voting according to importance, consensus discussion, and a final vote. The Delphi-derived scale was tested on a clinical research series for intra- and inter-panellist, and intra-panel reliability, and correlation with Patient Reported Outcome Measures (PROMs). Results: 61 surgeons participated in the Delphi process. Oncoplastic and plastic surgeons were represented. The Delphi-derived scale included symmetry, volume, shape, position of breast mound, nipple position, and a global score. Intra-panellist reliability ranged from poor to almost perfect (w kappa<0to0.86), inter-rater reliability was fair (ICC range 0.4-0.5) for individual items and good (ICC0.6) for the global score, intra-panel reliability was moderate to substantial (w kappa 0.4-0.7), and correlation with PROMs was moderate (r = 0.5p < 0.01). Conclusions: The Delphi-derived panel evaluation is at least as good as other scales in the literature and has been developed specifically to provide expert evaluation of aesthetics after breast reconstruction. The logistical constraints of panel assessment remain, reinforcing the need to develop an objective evaluation method. (C) 2020 The Authors. Published by Elsevier Ltd.

Abstract Background - Involvement of internal mammary lymph nodes (IMLN) in early breast cancer (EBC) leads to an upstaging of the disease anatomically. Unrecognized involvement of IMLNs leading to under-staging and under-treatment has been a hypothesis of studies demonstrating worse outcomes for medial tumours. Since surgery for removal of IMLNs is associated with high morbidity and radical surgical excision does not improve survival, surgical excision of IMLNs is not part of routine EBC treatment. Recent NCCN guidelines recommend IMLN irradiation for high risk EBC patients to reduce mortality. Metastasis to IMLNs may have a different impact on prognosis and management according to whether detected at the time of primary diagnosis, or later. Aims - The primary aim was to document the incidence of IMLN involvement in an EBC cohort - who underwent autologous deep inferior epigastric perforator (DIEP) flap reconstruction with unplanned sampling of 1 or more IMLNs - to ascertain the incidence of IMLN involvement. Our secondary aim was to ascertain whether IMLN involvement had an impact on management and/or prognosis. Materials and methods -We analyzed retrospectively collected data from a prospectively maintained database of patients who underwent DIEP flap reconstruction at the Royal Marsden Hospital, from April 2006 to March 2018. We used Freeman - Halton extension for Fisher’s test to assess association of IMN involvement with overall survival. Results - Of the 1471 women who underwent free flap reconstruction (1729 flaps) during this time period, 300 with EBC had their IMLNs sampled at the time of DIEP surgery. Of these, 36 had metastasis to their IMLN (incidence of 12%). The median age was 47 years and mean follow up was 34.5 months. Based on timing from initial diagnosis, 17 women had immediate DIEP flap reconstruction, 9 had delayed reconstruction (mean time from primary surgery 25 months) and 10 had reconstruction after mastectomy for loco-regional recurrence (7 at time of mastectomy for recurrence, 3 delayed). We compared outcomes for these 3 groups. Of these 36 patients, 19 had no preoperative staging and were staged only after they were found to have involved IMLNs. Four (2 in the delayed and 2 in the reconstruction after local recurrence group) of these 19 were found to have more widespread metastatic disease. Apart from these 4, based on IMLN involvement, treatment was altered in 17 others (total 21/36, 58.3%) - 8/17 in the immediate group, 7/9 in the delayed group and 2/8 for DIEP after local recurrence. The commonest alteration in treatment was addition of IMLN chain RT in 7 followed by change in endocrine therapy in 5; three had both. One patient who underwent immediate reconstruction had a negative SLN and had systemic adjuvant chemotherapy based solely on the involved IMLN. At a median follow up of 14 months, 12 patients (all either delayed or after local recurrence) of 19 relapsed with metastatic disease and 8 of them died due to disease progression. The local recurrence group had the highest rate of cancer-related mortality (p value < 0.0001) Conclusion - IMLN involvement leads to upstaging of the disease resulting in more significant change in treatment in those undergoing delayed autologous reconstruction. Local recurrence carries the worst prognosis. Staging prior to delayed DIEP surgery purely for reconstruction should be based on risk (from primary diagnosis) and all patients planned for DIEP reconstruction after local recurrence should undergo appropriate pre-operative staging investigations. Multivariate survival analysis using Cox’ proportional hazards model for those with involved versus uninvolved IMLNs to ascertain their prognostic significance will also be reported. Citation Format: Pooja Padmanabhan, Tania Policastro, Natalie To, Jennifer E Rusby, Stuart E James, Paul A Harris, Peter A Barry. The relevance of internal mammary lymph nodes found during autologous breast reconstruction [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-08-44.

Abstract Background - Involvement of internal mammary lymph nodes (IMLN) in early breast cancer (EBC) leads to an upstaging of the disease anatomically. Unrecognized involvement of IMLNs leading to under-staging and under-treatment has been a hypothesis of studies demonstrating worse outcomes for medial tumours. Since surgery for removal of IMLNs is associated with high morbidity and radical surgical excision does not improve survival, surgical excision of IMLNs is not part of routine EBC treatment. Recent NCCN guidelines recommend IMLN irradiation for high risk EBC patients to reduce mortality. Metastasis to IMLNs may have a different impact on prognosis and management according to whether detected at the time of primary diagnosis, or later. Aims - The primary aim was to document the incidence of IMLN involvement in an EBC cohort - who underwent autologous deep inferior epigastric perforator (DIEP) flap reconstruction with unplanned sampling of 1 or more IMLNs - to ascertain the incidence of IMLN involvement. Our secondary aim was to ascertain whether IMLN involvement had an impact on management and/or prognosis. Materials and methods -We analyzed retrospectively collected data from a prospectively maintained database of patients who underwent DIEP flap reconstruction at the Royal Marsden Hospital, from April 2006 to March 2018. We used Freeman - Halton extension for Fisher’s test to assess association of IMN involvement with overall survival. Results - Of the 1471 women who underwent free flap reconstruction (1729 flaps) during this time period, 300 with EBC had their IMLNs sampled at the time of DIEP surgery. Of these, 36 had metastasis to their IMLN (incidence of 12%). The median age was 47 years and mean follow up was 34.5 months. Based on timing from initial diagnosis, 17 women had immediate DIEP flap reconstruction, 9 had delayed reconstruction (mean time from primary surgery 25 months) and 10 had reconstruction after mastectomy for loco-regional recurrence (7 at time of mastectomy for recurrence, 3 delayed). We compared outcomes for these 3 groups. Of these 36 patients, 19 had no preoperative staging and were staged only after they were found to have involved IMLNs. Four (2 in the delayed and 2 in the reconstruction after local recurrence group) of these 19 were found to have more widespread metastatic disease. Apart from these 4, based on IMLN involvement, treatment was altered in 17 others (total 21/36, 58.3%) - 8/17 in the immediate group, 7/9 in the delayed group and 2/8 for DIEP after local recurrence. The commonest alteration in treatment was addition of IMLN chain RT in 7 followed by change in endocrine therapy in 5; three had both. One patient who underwent immediate reconstruction had a negative SLN and had systemic adjuvant chemotherapy based solely on the involved IMLN. At a median follow up of 14 months, 12 patients (all either delayed or after local recurrence) of 19 relapsed with metastatic disease and 8 of them died due to disease progression. The local recurrence group had the highest rate of cancer-related mortality (p value &lt; 0.0001) Conclusion - IMLN involvement leads to upstaging of the disease resulting in more significant change in treatment in those undergoing delayed autologous reconstruction. Local recurrence carries the worst prognosis. Staging prior to delayed DIEP surgery purely for reconstruction should be based on risk (from primary diagnosis) and all patients planned for DIEP reconstruction after local recurrence should undergo appropriate pre-operative staging investigations. Multivariate survival analysis using Cox’ proportional hazards model for those with involved versus uninvolved IMLNs to ascertain their prognostic significance will also be reported. Citation Format: Pooja Padmanabhan, Tania Policastro, Natalie To, Jennifer E Rusby, Stuart E James, Paul A Harris, Peter A Barry. The relevance of internal mammary lymph nodes found during autologous breast reconstruction [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-08-44.

Introduction: Many reconstructive surgeons are reluctant to offer immediate, autologous reconstruction if women are likely to receive post-mastectomy radiotherapy (PMRT). This is due to historical evidence of higher rates of complications as well as poorer aesthetic outcomes. This multicentre trial evaluates the feasibility and safety of offering radiotherapy prior to mastectomy and immediate DIEP flap reconstruction (ClinicalTrials.gov Identifier: NCT02771938).

Introduction: Evaluation of reconstructive aesthetics is challenging. In the absence of a gold standard, panel assessment is a widely adopted method. Heterogeneity and poor internal consistency renders comparison challenging. We describe the development of an expert panel method using a Delphi Consensus Model.

Introduction: For patients with locally advanced node-positive disease requiring post-mastectomy radiotherapy (PMRT), integrating breast reconstruction poses challenges. Irradiating autologous tissue may cause fibrosis, fat necrosis, shrinkage and longitudinal degradation of symmetry. Many patients are denied immediate breast reconstruction (IMBR). An approach to avoid flap irradiation is neoadjuvant radiotherapy (NRT) to the tumour-bearing breast prior to mastectomy and IMBR. The aim of this study was to evaluate the safety of this approach.

Background: The authors investigated aesthetic outcome and patient satisfaction in women who have undergone deep inferior epigastric artery perforator (DIEP) flap reconstruction in the setting of postmastectomy radiotherapy. Patients who underwent DIEP flap reconstruction without postmastectomy radiotherapy were the control group. Methods: Participants who had undergone DIEP flap reconstruction between September 1, 2009, and September 1, 2014, were recruited, answered the BREAST-Q, and underwent three-dimensional surface-imaging. A panel assessed the aesthetic outcome by reviewing these images. Results: One hundred sixty-seven women participated. Eighty women (48 percent) underwent immediate DIEP flap reconstruction and no postmastectomy radiotherapy; 28 (17 percent) underwent immediate DIEP flap reconstruction with postmastectomy radiotherapy; 38 (23 percent) underwent simple mastectomy, postmastectomy radiotherapy, and DIEP flap reconstruction; and 21 (13 percent) underwent mastectomy with temporizing implant, postmastectomy radiotherapy, and DIEP flap reconstruction. Median satisfaction scores were significantly different among the groups (p < 0.05). Post hoc comparison demonstrated that women who had an immediate DIEP flap reconstruction were significantly less satisfied if they had postmastectomy radiotherapy. In women requiring radiotherapy, those undergoing delayed reconstruction after a simple mastectomy were most satisfied, but there was no significant difference between the immediate DIEP flap and temporizing implant groups. Median panel scores differed among groups, being significantly higher if the immediate reconstruction was not subjected to radiotherapy. There was no significant difference in panel assessment among the three groups of women who had received radiotherapy. Conclusions: Patients who avoid having their immediate DIEP flap reconstruction irradiated are more satisfied and have better aesthetic outcome than those who undergo postmastectomy radiotherapy. In women requiring radiotherapy and who wish to have an immediate or “delayed-immediate” reconstruction, there were no significant differences in panel or patient satisfaction. Therefore, immediate DIEP flap reconstruction or mastectomy with temporizing implant then DIEP flap surgery are acceptable treatment pathways in the context of post-mastectomy radiotherapy.

Slim women are not always considered candidates for bilateral autologous breast reconstruction. The study aims to assess the volume considerations and complications of deep inferior epigastric perforator (DIEP) flap in bilateral breast reconstruction among slim patients.

Introduction: Evidence about the optimal sequence of post-mastectomy radiotherapy (PMRT) and DIEP reconstruction is lacking. Our aim was to explore the patient journey of DIEP reconstruction according to timing of radiotherapy.

Abstract Background: The need for post mastectomy radiotherapy (PMRT), may preclude reconstructive surgeons from offering patients immediate, autologous reconstruction. This is due to historical evidence suggesting high rates of short- and long-term complications as well as poorer aesthetic outcomes. As the indications for PMRT broaden this practice denies an ever-increasing number of women the benefit of an immediate reconstruction. Aim: This pilot study evaluates the safety of offering radiotherapy prior to mastectomy and immediate DIEP flap reconstruction. Methods: Women planned for neoadjuvant chemotherapy (NAcT), mastectomy (following unsuccessful breast conservation surgery (BCS) or upfront selection) and PMRT were offered a change in sequencing of RT at two academic breast surgery units in London, UK. Data was prospectively captured on 19 women, including: patient demographics, treatment details, tumour characteristics, oncological and post-operative outcomes. Operative parameters included unplanned return to theatre [RTT] <30 days, mastectomy skin flap necrosis, and evidence of wound infection at 5 days, 4 and 12 weeks post-operatively. All mastectomies, were performed by one of 3 breast surgeons (DH, FAM, DRL) using a circumareolar incisions with one patient undergoing a vertical pattern incision for skin reduction. Results: The cohort demonstrated a broad range of age, body mass index (BMI) and mastectomy weight [mean (range): age=46 years (28-72); BMI = 28.4 kg/m2 (23-37.6) and specimen weight=678gm (257-1040)]. The mean time from completion of NAcT to neoadjuvant radiotherapy (NART) was 31.1 days (9-49 days), and time from completion of NART to mastectomy and DIEP was 17.8 days (13-24 days). There was one unplanned RTT at 72 hours for an evacuation of haematoma, 1 revision of micro-vascular anastomosis, 1 clinical fat necrosis requiring formal excision and 1 wound debridement and primary closure for poor wound healing (vertical pattern skin reduction). There were no flap failures and no mastectomy envelope necrosis. With a mean follow-up of 16.2 months, there were no loco-regional recurrences, 5 distant relapses with mean presentation at 13.7 months and 2 breast-cancer related deaths at 13.9 and 22.2months respectively. Conclusion: This pilot study suggests that mastectomy and DIEP reconstruction is surgically feasible within 4 weeks of completing NART. In this small cohort of oncologically high-risk women with altered sequencing of RT we did not observe flap failure or post-mastectomy skin flap necrosis. A larger multicentre study with aesthetic assessment, PROMS and translational aspects is planned. Citation Format: Thiruchelvam P, Hadjiminas D, Cleator S, Wood S, Leff D, Jallali N, James S, MacNeill F. Neoadjuvant radiotherapy in mastectomy and immediate autologous free flap reconstruction. Findings from the primary radiotherapy and DIEP flap (PRADA) pilot study [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-14-07.