Postmastectomy Radiation Research Articles

Single stage direct -to- implant breast reconstruction following mastectomy (The use of Ultrapro® Mesh)

BackgroundImmediate breast reconstruction (IBR) with direct to implant (DTI) is the preferred method of reconstruction by many surgeons and patients, however, acellular dermal matrix (ADM) and other synthetic meshes are expensive especially in low- and middle-income countries.Aim of the workTo evaluate the technique, indications, aesthetic outcomes, and short and long-term complications of DTI breast reconstruction performed with Ultrapro®, a low-cost alternative mesh to ADM and other synthetic meshes.MethodsOur study is a prospective cohort study that was conducted on 133 patients who experienced IBR following nipple-sparing mastectomy (NSM) or skin sparing mastectomy (SSM) using silicone implants and Ultrapro® mesh between December 2020 and December 2023. Techniques used were either sub-pectoral or pre-pectoral, evaluating aesthetic outcome, complication rate and patient satisfaction using breast Q questionnaire.ResultsWe included 133 patients (141 breasts) with a median age of 39 years. Mean duration of follow up: 20.364 ± 5.39 months. The sub-pectoral and the pre pectoral techniques were used for 80 breasts and 61 breasts respectively. We used the Ultrapro® mesh in all our patients. Smooth round silicone implants were used. The overall Major complications rate was 16.3%. 8 implants (5.7%) were lost within 6 months post-operatively while 2 implants were removed in the late post-operative period (after 6 months) one due to rupture and the other due to local recurrence.Capsular contracture Baker 3 and 4 was observed in 36 breasts (25%), 31 of them had post mastectomy radiotherapy treatment. 11 (7.8%) were managed by capsulotomies and re-insertion of the same implant.Radiotherapy was a significant risk factors for major complications and capsular contracture with p value of (0.01) and (0.0001) respectively.ConclusionDTI in properly selected patients offers excellent outcomes and patient satisfaction. The complication rate is low and improves with the experience of the surgeon. The Ultrapro® mesh is a safe, low-cost alternative to ADM or other synthetic meshes especially in low socioeconomic countries. Radiotherapy is a significant risk factor for major complications and capsular contractures.

Impact of Pre-pectoral Implant Placement and Radiation Modalities (Protons/Photons) in Mastectomy Patients undergoing Immediate Direct-to-Implant Breast Reconstruction

BackgroundFor breast cancer patients receiving mastectomy with direct-to-implant (DTI) immediate breast reconstruction, placing the implant in the pre-pectoral or subpectoral plane remains debatable; especially in settings of postmastectomy radiotherapy (PMRT). Materials/MethodsWe reviewed 3,039 patients who underwent mastectomy and reconstruction at our institution between 2005 and 2020. Patients receiving DTI with and without PMRT were included. PMRT was delivered either with photon (3D-conformal or VMAT) or proton therapy mainly with pencil beam scanning. All patients received conventional fractionation (50-50.4Gy in 25-28fractions). Primary endpoints were reconstruction complications defined as infection/necrosis requiring debridement; capsular-contracture requiring capsulotomy; absolute-reconstruction-failure entailing permanent removal of the implant without replacement (i.e: no salvage reconstruction) and overall-reconstruction-failure (removal of implant for any complication with and without salvage reconstruction). Different subgroups analyses were done. Results815 patients met inclusion criteria, with an overall median follow-up of 6.2 years. We found that there is no significant difference between pre-pectoral vs sub-pectoral for infection/necrosis (OR:1.5, p=0.3); capsular-contracture (OR:0.97, p=0.9); absolute-reconstruction-failure (OR:1.9, p=0.12) and overall-reconstruction-failure (OR:1.2, p=0.5). Findings were confirmed using both logistic regression, time-to-event analysis and multivariable analyses for the entire cohort and subgroups with and without PMRT. There was no significant difference between Protons and Photons in terms of infection/necrosis (OR:1.6, p=0.4) and absolute-reconstruction-failure (OR: 1.2, p=0.7), but significantly higher risks for capsular-contracture with protons (OR:4.4, p<0.001) and overall-reconstruction-failure when compared to photon(OR:2.0, p=0.05). We did not find significant correlation pattern between different dosimetry factors (Dmean, Dmax, volume in cc) in either reconstructed-chest-wall target or the skin structure, to reconstruction complications; whether for protons or photons patients. ConclusionFor patients receiving single-stage DTI reconstruction with and without PMRT, pre-pectoral implant placement had similar rates of complications and reconstruction failure compared to subpectoral reconstruction. Protons compared to Photons did not increase the risk of infection/necrosis but significantly increased capsular-contracture risks.

StrataXRT and Mepitel Film for preventing post-mastectomy acute radiation dermatitis in breast cancer: an intra-patient non-inferiority randomized clinical trial

StrataXRT and Mepitel Film for preventing post-mastectomy acute radiation dermatitis in breast cancer: an intra-patient non-inferiority randomized clinical trial

Revision Surgeries After Proton vs Photon Postmastectomy Radiation Therapy in Prepectoral Implant-Based Breast Reconstruction.

Postmastectomy radiation therapy (PMRT) improves disease-free survival in breast cancer but reduces aesthetic satisfaction. Proton PMRT has gained popularity due to fewer systemic complications. There is a lack of data regarding revision surgeries for pre-pectoral implant-based breast reconstruction (PP-IBBR) following radiation. To compare the revision surgeries in PP-IBBR with photon versus proton PMRT. A single-institution retrospective cohort study included breast cancer patients undergoing mastectomy and PP-IBBR with PMRT (January 2020-October 2022) The mean follow-up duration for the cohort was 1056.4 days (2.89 years). Revision surgeries evaluated were fat grafting, conversion to autologous flaps, implant replacement, implant removal, capsulectomy, and scar revision. 116 PP-IBBR were divided into two cohorts: photon (75, 64.66%) and proton (41, 35.34%) radiation cohorts. Overall corrective surgeries were higher with photon (27.5% overall; 32.4% photon vs 19.5% proton, p=0.132). The odds of any revision surgery were nearly double with photon (OR=1.98), and the conversion to an autologous flap was significantly more likely with photon (OR=4.55, p=0.025). Multivariable analysis showed an increased tendency for photon therapy patients to require any revision surgeries (OR=1.62, p=0.359), autologous flaps (OR=5.97, p=0.049), fat grafting (OR=1.52, p=0.664) and scar revision (OR=4.51, p=0.273). Compared to proton therapy, traditional photon therapy has a higher conversion rate to autologous flaps with PP-IBBR. Photon therapy had higher rates of overall revision surgeries, however not statistically significant. Proton therapy is safer, with fewer revision surgeries, warranting larger studies and broader utilization.

Dosimetric benefit and clinical feasibility of deep inspiration breath-hold and volumetric modulated arc therapy-based postmastectomy radiotherapy for left-sided breast cancer

To evaluate the dosimetric benefits and clinical feasibility of deep inspiratory breath-hold (DIBH) combined with volumetric modulated arc therapy (VMAT) in left-sided postmastectomy radiotherapy (PMRT). Eligible patients with left-sided breast cancer undergoing DIBH-based PMRT were prospectively included. Chest wall, supra/infraclavicular fossa, and/or internal mammary node irradiation (IMNI) were planned with a prescription dose of 43.5 Gy in 15 fractions. VMAT plans were designed on free breathing (FB)—and DIBH-CT to compare dosimetric parameters in heart, left anterior descending artery (LAD) and lung. Cone-beam computed tomography (CBCT) was performed before and after treatment to evaluate inter- and intra-fractional setup errors. Heart position and dose variations during treatment were estimated by fusing CBCT with DIBH-CT scans.Twenty patients were included with 10 receiving IMNI. In total, 193 pre-treatment and 39 pairs pre- and post-treatment CBCT scans were analyzed. The Dmean, Dmax, and V5−40 of the heart, LAD, and left lung were significantly lower in DIBH than FB (p < 0.05 for all), except for V5 of LAD (p = 0.167). The cardiopulmonary dosimetric benefits were maintained regardless of IMNI. The inter- and intra-fractional setup errors were < 0.3 cm; and the overall estimated PTV margins were < 1.0 cm. During treatment, the mean dice similarity coefficient of heart position and the mean ratio of heart Dmean between CBCT and DIBH-CT plans was 0.95 (0.88–1.00) and 100% (70.6–119.5%), respectively. DIBH-VMAT could effectively reduce the cardiopulmonary doses with acceptable reproducibility and stability in left-sided PMRT regardless of IMNI.

Autologous Breast Reconstruction and Radiotherapy: Consensus Report of the German-Speaking Society for Reconstructive Microsurgery (GSRM)

Autologous postmastectomy breast reconstruction is associated with favourable long-term clinical outcomes and superior patient-reported outcomes (PROMs) compared with implant-based reconstruction. However, adjuvant radiotherapy has traditionally been considered a relative contraindication to immediate flap-based reconstruction due to its unpredictable effects on the reconstructive outcome. While modern adjuvant postmastectomy radiotherapy (PMRT) has been able to significantly reduce acute and chronic radiation-induced complications, plastic surgeons still hesitate to offer immediate autologous reconstruction to patients expected to undergo adjuvant radiotherapy. More recently, evidence has emerged suggesting a paradigm shift in favour of immediate autologous reconstruction despite subsequent radiotherapy. At the 44th Annual Meeting of the German-speaking Society for Reconstructive Microsurgery (GSRM) in Bern, Switzerland, a workshop discussed the literature on PMRT and autologous breast reconstruction, aiming to establish consensus among the participants. Several areas of agreement were identified, including the goals of postmastectomy reconstruction, specifically the creation of a soft and sensitive breast symmetrical in shape and size to the unaffected breast via the safest procedure possible. The importance of preserving the maximum amount of native breast skin envelope through skin- and nipple-sparing approaches was emphasised. Finally, a consensus was reached that PMRT should no longer be considered a contraindication to immediate autologous breast reconstruction.

Geometric and dosimetric evaluation for breast and regional nodal auto-segmentation structures.

The accuracy of artificial intelligence (AI) generated contours for intact-breast and post-mastectomy radiotherapy plans was evaluated. Geometric and dosimetric comparisons were performed between auto-contours (ACs) and manual-contours (MCs) produced by physicians for target structures. Breast and regional nodal structures were manually delineated on 66 breast cancer patients. ACs were retrospectively generated. The characteristics of the breast/post-mastectomy chestwall (CW) and regional nodal structures (axillary [AxN], supraclavicular [SC], internal mammary [IM]) were geometrically evaluated by Dice similarity coefficient (DSC), mean surface distance, and Hausdorff Distance. The structures were also evaluated dosimetrically by superimposing the MC clinically delivered plans onto the ACs to assess the impact of utilizing ACs with target dose (Vx%) evaluation. Positive geometric correlations between volume and DSC for intact-breast, AxN, and CW were observed. Little or anti correlations between volume and DSC for IM and SC were shown. For intact-breast plans, insignificant dosimetric differences between ACs and MCs were observed for AxNV95% (p=0.17) and SCV95% (p=0.16), while IMNV90% ACs and MCs were significantly different. The average V95% for intact-breast MCs (98.4%) and ACs (97.1%) were comparable but statistically different (p=0.02). For post-mastectomy plans, AxNV95% (p=0.35) and SCV95% (p=0.08) were consistent between ACs and MCs, while IMNV90% was significantly different. Additionally, 94.1% of AC-breasts met ΔV95% variation<5% when DSC>0.7. However, only 62.5% AC-CWs achieved the same metrics, despite AC-CWV95% (p=0.43) being statistically insignificant. The AC intact-breast structure was dosimetrically similar to MCs. The AC AxN and SC may require manual adjustments. Careful review should be performed for AC post-mastectomy CW and IMN before treatment planning. The findings of this study may guide the clinical decision-making process for the utilization of AI-driven ACs for intact-breast and post-mastectomy plans. Before clinical implementation of this auto-segmentation software, an in-depth assessment of agreement with each local facilities MCs is needed.

Smooth Operator: Nanotextured Breast Tissue Expanders Are Associated with Lower Rates of Capsular Contracture

Background: Continuous research on breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) has introduced a focus on surface texturizations and a shift towards smooth breast devices, yet outcomes comparing the complication profiles of differently textured tissue expanders (TEs) remain conflicting. The study aim was to compare the complication profile of a new nanotextured and MRI-compatible TE to micro- and macrotextured TEs and to identify possible predictors for complications. Methods: A retrospective analysis of women undergoing expander-based breast reconstruction after mastectomy between January 2016 and March 2022 was conducted. The primary endpoint was the development of capsular contracture. Possible predictors were analyzed in a mixed-effects model using the least absolute shrinkage and selection operator (LASSO). Moreover, a comparison of complications and an evaluation of predictors were carried out. Results: A total of 147 breasts, encompassing 82 nanotextured, 43 microtextured and 22 macrotextured TEs, were analyzed. Breasts with nanotextured TEs were less likely to develop capsular contracture overall (OR, 0.12; 95%CI 0.05–0.28, p &lt; 0.001). Post-mastectomy radiotherapy (PMRT) was identified as a predictor for capsular contracture (OR, 4.67; 95%CI 1.86–11.71, p &lt; 0.001). Breasts with nanotextured TEs showed a higher rate of seroma, but lower rates of malposition and pain. Predictors for developing postoperative complications included higher mastectomy weight (p = 0.008). Conclusions: Breasts with nanotextured TEs exhibited the lowest rate of capsular contracture compared to micro- and macrotextured TEs. Together with its MRI-compatibility and improved oncologic follow-up, the nanotextured TE seems to be a favorable device for expander-based breast reconstruction.

The EORTC 22922/10925 trial investigating regional nodal irradiation in stage I-III breast cancer: Outcomes according to locoregional and systemic therapies

The EORTC 22922/10925 trial aimed to investigate the impact on overall survival (OS) of elective internal mammary and medial supraclavicular (IM-MS) radiation therapy (RT) in breast cancer stage I–III. Surgery for the primary tumour and axillary lymph nodes, chest wall RT, boost RT after whole breast RT in breast conserving therapy (BCT), RT to operated axilla, and systemic therapy were per physician’s preference. The aim of the current analysis is to assess breast cancer outcomes according to different locoregional and systemic therapy used in the trial. Material/MethodsData with a median follow-up of 15.7 years were extracted from the trial’s case report forms. Kaplan-Meier curves of disease-free and OS and cumulative incidence curves of breast cancer events were produced. An exploratory analysis of the effect of the type of locoregional and systemic therapy on breast cancer outcomes was conducted using the Cox model or the Fine & Gray model accounting for competing risks, both models being adjusted for baseline patient and disease characteristics and treatment. The significance level was set at 5 %, 2-sided. ResultsOf the 4,004 patients included, 625 (16%) did not receive any postoperative systemic therapy, 1,185 (30%) received endocrine therapy only, 994 (25%) chemotherapy only, and 1,200 (30%) both chemotherapy and endocrine therapy, without differences between the randomisation arms.Administration and type of therapy was associated with age, menopausal status, clinical T- and N-stage and ER status (p < 0.0001). Local control was better with mastectomy (with/without postmastectomy RT) as compared to BCT, but mastectomy was associated with more distant metastasis (DM) as first event. Similarly, DM as first event occurred more in the BCT group that received a boost as compared to no boost and in those who received RT to the lower axillary level. IM-MS RT reduced significantly regional recurrences and improved disease-free survival in a sensitivity stratified analysis. OS was worse with mastectomy as compared to BCT and with irradiation of the axilla but better with sentinel node dissection and adjuvant combined chemo and hormonal therapy. ConclusionDifferent components of therapy influenced the site of first event. IM-MS RT improved outcomes in different breast cancer outcomes were most probably related that the group were balanced due to the trial arms and stratification methods.

Protective role of transforming growth factor-Β3 (TGF-Β3) in the formation of radiation-induced capsular contracture around a breast implant: In vivo experimental study

Postmastectomy radiotherapy causes capsular contracture due to fibroproliferation of the capsular tissue around the implant. In fibrosis, unlike normal wound healing, structural and functional disorders are observed in the tissues caused by excessive/irregular accumulation of extracellular matrix proteins. It has been reported that transforming growth factor-β3 (TGF-β3) prevents and reverses fibrosis in various tissues or provides scarless healing with its antifibrotic effect. Additionally, TGF-β3 has been shown to reduce fibrosis in radiotherapy-induced fibrosis syndrome. However, no study in the literature investigates the effects of exogenously applied TGF-β3 on capsular contracture in aesthetic or reconstructive breast implant application. TGF-β3, which has a very short half-life, has low bioavailability with parenteral administration. Within the scope of this study, free TGF-β3 was loaded into the nanoparticles to increase its low bioavailability and extend its duration of action by providing controlled release. The aim of this study is to investigate the preventive/improving effects of radiation induced capsular contracture using chitosan film formulations containing TGF-β3 loaded poly(lactic-co-glycolic acid)-b-poly(ethylene glycol) (PLGA-b-PEG) nanoparticles in implant-based breast reconstruction. In the characterization studies of nanoparticles, the particle size and zeta potential of the TGF-β3-loaded PLGA-b-PEG nanoparticle formulation selected to be used in the treatment group were found to be 123.60 ± 2.09 nm and −34.87 ± 1.42 mV, respectively. The encapsulation efficiency of the formulation was calculated as 99.91 %. A controlled release profile was obtained in in vitro release studies. Chitosan film formulations containing free TGF-β3 or TGF-β3-loaded PLGA-b-PEG nanoparticles were used in in vivo studies. In animal studies, rats were randomly distributed into 6 groups (n = 8) as sham, implant, implant + radiotherapy, implant + radiotherapy + chitosan film containing unloaded nanoparticles, implant + radiotherapy + chitosan film containing free TGF-β3, implant + radiotherapy + chitosan film containing TGF-β3 loaded nanoparticle. In all study groups, a 2 cm incision was made along the posterior axillary line at the thoracic vertebral level in rats to reach the lateral edge of the latissimus dorsi. The fascial attachment to the chest wall was then bluntly dissected to create a pocket for the implants. In the treatment groups, the wound was closed after films were placed on the outer surface of the implants. After administering prophylactic antibiotics, rats were subjected to irradiation with 10 Gy photon beams targeted to each implant site. Each implant and the surrounding excised tissue were subjected to the necessary procedures for histological (capsule thickness, cell density), immunohistochemical, and biochemical (α-SMA, vimentin, collagen type I and type III, TGF-β1 and TGF-β3: expression level/protein level) examinations. It was determined that the levels of TGF-β1 and TGF-β3 collagen type III, which decreased as a result of radiotherapy, were brought to the control level with free TGF-β3 film and TGF-β3 nanoparticle film formulations. Histological analyses, consistent with biochemical analyses, showed that thick collagen and fibrosis, which increased with radiotherapy, were brought to the control level with free TGF-β3 film and TGF-β3 nanoparticle film treatments.In biochemical analyses, the decrease in thick collagen was compatible with the decrease in the collagen type I/type III ratio in the free TGF-β3 film and TGF-β3 nanoparticle film groups. Changes in protein expression show that TGF-β3 loaded nanoparticles are more successful than free TGF-β3 in wound healing. In line with these results and the literature, it is thought that the balance of TGF-β1 and TGF-β3 should be maintained to ensure scarless wound healing with no capsule contracture.

The significance of risk stratification through nomogram-based assessment in determining postmastectomy radiotherapy for patients diagnosed with pT1 − 2N1M0 breast cancer

ObjectiveTo explore the high-risk factors affecting the prognosis of pT1 − 2N1M0 patients after mastectomy, establish a nomogram prediction model, and screen the radiotherapy benefit population.MethodThe clinical data of 936 patients with pT1 − 2N1M0 who underwent mastectomy in the fourth hospital of Hebei Medical University from 2010 to 2016 were retrospectively analyzed. There were 583 patients received postmastectomy radiotherapy(PMRT), and 325 patients without PMRT. Group imbalances were mitigated using the propensity score matching (PSM) method, and the log-rank test was employed to compare overall survival (OS) and disease-free survival (DFS) between the cohorts. The efficacy of PMRT across various risk groups was evaluated using a nomogram model.ResultThe median follow-up period was 98 months, Patients who received PMRT demonstrated significantly improved 5-year and 8-year OS and DFS compared to those who did not (P < 0.001). Multivariate analysis revealed that age, primary tumor site, positive lymph node, stage, and Ki-67 level independently influenced OS, while age, primary tumor site, and stage independently affected DFS. PMRT drastically enhanced OS in the high-risk group (P = 0.001), but did not confer benefits in the low-risk and intermediate risk groups (P = 0.057, P = 0.099). PMRT led to a significant improvement in disease-free survival (DFS) among patients in the intermediate and high-risk groups (P = 0.036, P = 0.001), whereas the low-risk group did not experience a significant benefit (P = 0.475).ConclusionAge ≤ 40 years, tumor located in the inner quadrant or central area, T2 stage, 2–3 lymph nodes metastasis, and Ki67 > 30% were the high-risk factors affecting the prognosis of this cohort of patients. In OS nomogram, patients with a risk score of 149 or higher who received PMRT exhibited improved OS. Similarly, in DFS nomogram, patients with a risk score of 123 or higher who received PMRT demonstrated enhanced DFS.

How Effective is Deep Inspiration Breath Hold in Minimizing Cardiac Doses During Hybrid Radiotherapy Treatment for Left-Sided Breast Cancer with Comprehensive Regional Nodes?

In the context of left breast cancer radiotherapy, long term cardiopulmonary toxicity has been well-documented, significant efforts have been undertaken to mitigate such toxicity by using 4D gating, deep inspiration breath-hold(DIBH) and active breath control(ABC) techniques. To evaluate and compare the cardio-pulmonary radiation doses incurred during postmastectomy radiotherapy (PMRT) in two distinct breathing conditions such as DIBH and Free Breathing (FB), with a specific focus on the left chest wall with comprehensive regional nodal irradiation. A prospective dosimetric study was conducted on 15 patients who received adjuvant loco-regional radiotherapy of chest-wall (CW), supraclavicular fossa(SCF), and internal mammary region(IMC), with or without axilla. Two sets of planning CT scans were taken in DIBH and FB conditions. The dosimetric difference between DIBH CT and FB CT plans analyzed using Wilcoxon signed-rank test, employing SPSS software version 21.0. Comparison of DIBH and FB parameters for target coverage revealed a statistically significant advantage with DIBH in SCF(D95, V90, p<0.017) and IMC(D98, V90 & V95, p<0.03). Dosimetric characteristics of heart and LAD exhibited statistically significant lower doses with DIBH (V20, V25, and Dmean, p<0.001) compared to FB plans. Lung doses were similar with no discernible advantage of one technique over the other. Other OARs such as contralateral breast (p=0.027) and esophagus (p=0.001) received lower doses with the DIBH technique while the spinal cord (p=0.691) and thyroid(p=0.496) showed no significant difference. Maximum heart distance (p= 0.001), central lung distance (p= 0.011) and Haller index (p= 0.001) exhibited statistical significance between the two techniques, whereas chest wall separation showed no significant statistical difference (p=0.629). DIBH demonstrates a substantial reduction in cardiac and LAD doses compared to the FB technique. This study underscores the efficacy of DIBH as a viable strategy for mitigating cardiac and LAD radiation doses in left-sided breast cancer patients undergoing PMRT of chest wall with comprehensive regional nodes.

Fat Grafting and Prepectoral Prosthetic Reconstruction with Polyurethane-Covered Implants: Protective Role against Adjuvant Radiotherapy.

Background/Objectives: Breast cancer treatment increasingly incorporates immediate prepectoral prosthetic reconstruction after conservative mastectomy, including nipple-sparing (NSMs) and skin-sparing mastectomies (SSMs). Although recent data from the literature show that postmastectomy radiotherapy (PMRT) after prepectoral reconstruction presents good clinical results, with reduction in capsular contracture and implant migration, compared to the traditional submuscular technique, these patients have higher rates of long-term complications when compared with nonradiated patients. This study evaluates the protective effects of autologous fat grafting to reduce long-term radiotherapy-induced complications in breast cancer patients submitted for prepectoral reconstruction with polyurethane-covered (PU) implants. Methods: A pilot study with two parallel cohorts of patients undergoing an NSM or SSM followed by PMRT was conducted. Patients were randomly assigned to either of the two groups to ensure homogeneity. One cohort underwent autologous fat grafting sessions, individually tailored based on periodic evaluations by the principal investigator (PI), M. Salgarello, at least six months after PMRT. The control group received standard clinical follow-ups without fat grafting. Inclusion criteria ensured participants were disease-free, non-smokers, and had a LENT-SOMA score within 2. Results: Preliminary findings indicate significant differences between the groups, with improved outcomes observed in patients undergoing tailored lipofilling. Specifically, these patients experienced a notable reduction in capsular contracture severity and reported higher satisfaction with the aesthetic results compared to the control group. Conclusions: Autologous fat grafting, customized per patient by the PI based on ongoing evaluations, appears to mitigate some adverse effects of radiotherapy in prepectoral breast reconstruction, suggesting a viable option for enhancing surgical outcomes in irradiated patients. Further research is needed to substantiate these findings and evaluate long-term benefits.

Radiation hepatitis after postmastectomy radiation therapy for early breast cancer: difficult to differentiate from drug-induced liver injury caused by abemaciclib.

Abemaciclib (ABM) is recommended for adjuvant endocrine therapy in hormone receptor-positive, human epidermal growth factor receptor type 2-negative early breast cancer (EBC) patients at high risk of recurrence. Here, we present a case of radiation hepatitis challenging to differentiate from drug-induced liver injury during ABM treatment. The patient, a woman in her 40s, underwent right mastectomy, axillary dissection, and postmastectomy radiation therapy (PMRT) after neoadjuvant chemotherapy for EBC. Subsequently, she received ABM as adjuvant endocrine therapy. Despite suspending ABM due to Grade 3 leukopenia, she developed Grade 3 hepatic dysfunction upon cessation. Based on the dynamic contrast-enhanced computed tomography, we diagnosed the cause of liver dysfunction as radiation hepatitis. Spontaneous improvement allowed us to resume ABM treatment. Clinicians may need to consider radiation hepatitis as a potential cause of hepatic dysfunction in patients who underwent PMRT, along with drug-induced liver injury.

Hypofractionated vs Conventionally Fractionated Postmastectomy Radiation After Implant-Based Reconstruction

Postmastectomy radiation therapy (PMRT) improves local-regional disease control and patient survival. Hypofractionation (HF) regimens have comparable efficacy and complication rates with improved quality of life compared with conventional fractionation (CF) schedules. However, the use of HF after mastectomy in patients undergoing breast reconstruction has not been prospectively examined. To compare HF and CF PMRT outcomes after implant-based reconstruction. This randomized clinical trial assessed patients 18 years or older undergoing mastectomy and immediate expander or implant reconstruction for breast cancer (Tis, TX, or T1-3) and unilateral PMRT from March 8, 2018, to November 3, 2021 (median [range] follow-up, 40.4 [15.4-63.0] months), at 16 US cancer centers or hospitals. Analyses were conducted between September and December 2023. Patients were randomized 1:1 to HF or CF PMRT. Chest wall doses were 4256 cGy for 16 fractions for HF and 5000 cGy for 25 fractions for CF. Chest wall toxic effects were defined as a grade 3 or higher adverse event. The primary outcome was the change in physical well-being (PWB) domain of the Functional Assessment of Cancer Therapy-Breast (FACT-B) quality-of-life assessment tool at 6 months after starting PMRT, controlling for age. Secondary outcomes included toxic effects and cancer recurrence. Of 400 women (201 in the CF arm and 199 in the HF arm; median [range] age, 47 [23-79] years), 330 patients had PWB scores at baseline and at 6 months. There was no difference in the change in PWB between the study arms (estimate, 0.13; 95% CI, -0.86 to 1.11; P = .80), but there was a significant interaction between age group and study arm (P = .03 for interaction). Patients younger than 45 years had higher 6-month absolute PWB scores if treated with HF rather than CF regimens (23.6 [95% CI, 22.7-24.6] vs 22.0 [95% CI, 20.7-23.3]; P = .047) and reported being less bothered by adverse effects (mean [SD], 3.0 [0.9] in the HF arm and 2.6 [1.2] in the CF arm; P = .02) or nausea (mean [SD], 3.8 [0.4] in the HF arm and 3.6 [0.8] in the CF arm; P = .04). In the as-treated cohort, there were 23 distant (11 in the HF arm and 12 in the CF arm) and 2 local-regional (1 in the HF arm and 1 in the CF arm) recurrences. Chest wall toxic effects occurred in 39 patients (20 in the HF arm and 19 in the CF arm) at a median (IQR) of 7.2 (1.8-12.9) months. Fractionation was not associated with chest wall toxic effects on multivariate analysis (HF arm: hazard ratio, 1.02; 95% CI, 0.52-2.00; P = .95). Fewer patients undergoing HF vs CF regimens had a treatment break (5 [2.7%] vs 15 [7.7%]; P = .03) or required unpaid time off from work (17 [8.5%] vs 34 [16.9%]; P = .02). In this randomized clinical trial, the HF regimen did not significantly improve change in PWB compared with the CF regimen. These data add to the increasing experience with HF PMRT in patients with implant-based reconstruction. ClinicalTrials.gov Identifier: NCT03422003.

346 Current practice pattern of postmastectomy hypofractionated radiotherapy: A revolution in management

346 Current practice pattern of postmastectomy hypofractionated radiotherapy: A revolution in management

Radiotherapy Trends and Variations in Invasive Non-metastatic Breast Cancer Treatment in the Netherlands: A Nationwide Overview From 2008 to 2019

AimsThis nationwide study provides an overview of trends and variations in radiotherapy use as part of multimodal treatment of invasive non-metastatic breast cancer in the Netherlands in 2008–2019. Materials and MethodsWomen with invasive non-metastatic breast cancer were selected from the population-based Netherlands Cancer Registry. Treatments trends were presented over time. Factors associated with (1) boost irradiation in breast-conserving therapy and (2) regional radiotherapy instead of axillary lymph node dissection (ALND) in N+ disease were identified using multilevel logistic regression analyses. ResultsRadiotherapy use increased from 61% (2008) to 70% (2016), caused by breast-conserving therapy instead of mastectomy, increased post-mastectomy radiotherapy, and increased regional radiotherapy (32% in 2011 to 61% in 2019) instead of ALND in N+ disease. Omission of radiotherapy after breast-conserving surgery (BCS) in 2016–2019 (4–9%, respectively), mainly in elderly, decreased overall radiotherapy use to 67%. Radiotherapy treatment was further de-escalated by decreased boost irradiation in breast-conserving therapy (66% in 2011 to 37% in 2019) and partial (1% in 2011 to 6% in 2019) instead of whole breast irradiation following BCS. Boost irradiation was associated with high-risk features: younger age (OR>75 vs <50:0.04, 95%CI:0.03–0.05), higher grade (OR grade III vs I:11.46, 95%CI:9.90–13.26) and residual disease (OR focal residual vs R0-resection:28.08, 95%CI:23.07–34.17). Variation across the country was found for both boost irradiation use (OR South vs North:0.58, 95%CI:0.49–0.68), and regional radiotherapy instead of ALND (OR Southwest vs North:0.55, 95%CI:0.37–0.80). ConclusionOverall radiotherapy use increased in 2008–2016, while a decreasing trend was observed after 2016, caused by post-BCS radiotherapy omission. Boost irradiation in breast-conserving therapy became omitted in low-risk patients, and regional radiotherapy use increased as an alternative for ALND in N+ disease.

The impact of adjuvant radiotherapy for cosmetic results after immediate breast reconstruction based on the tissue expander and permanent implant

Background. One of the causes of complications in breast cancer patients after immediate breast reconstruction (IBR) is postmastectomy radiation therapy (PMRT).Aim. Retrospective analysis of the results of IBR, and evaluating the effect of PMRT on the frequency and type of complications.Materials and methods. Between 2015 and 2021, 798 patients underwent IBR with tissue expander or implant in N.N. Petrov National Medical Research Center of Oncology, Ministry of Health of Russia. PMRT was performed in 375 patients (group 1). The remaining 423 patients did not receive PMRT (group 2). Complications, including reconstructive failure (RF), Baker grade III/IV capsular contracture (CC), were recorded and analyzed.Results. Finally, cosmetic result analyzed in 521 patients. In 281 patients of PMRT group (group 1) IBR with expander or implant were performed in 144 and 137 cases, respectively. In the 240 patients without PMRT (group 2), IBR with expander was performed in 81 patients, with implant – in 159 cases. Pooled analysis revealed that overall rate of complications in the PMRT group was 33.8 % (in 95 of 281 patients), in non-irradiation patients – 22.9 % (in 55 of 240 patients), p &lt;0.01. In group 1, RF were recorded in 67 (23.8 %) patients, in group 2 – in 44 (18.3 %) patients, p &gt;0.05. CC in group 1 were detected in 28 (10 %) patients, in group 2 in 11 (4.6 %) patients, p &lt;0.05. In patients with permanent implants RF were detected in 21 (14.6 %) of irradiation patients and in 22 (13.8 %) non-irradiation patients (p &gt;0.2). On the contrary, CC were mentioned in 22 (16.1 %) of irradiated patient and in 8 (5 %) patients that didn’t receive PMRT, p &lt;0.005. After reconstruction with expander RF were diagnosed in 46 (31.9 %) patients after PMRT and in 22 (27.2 %) non-irradiation patients, p &gt;0.2. CC were observed in 6 (4.2 %) patients from PMRT group and in 3 (3.7 %) patients treated without PMRT, p &gt;0.2.Conclusion. PMRT in patients after IBR with simultaneous installation of a permanent implant is characterized by a decrease in the incidence of RF, but an increase in the incidence of CC.

Study on the Impact of Post-Mastectomy Radiotherapy on Immediate Breast Reconstruction and Complications: A Meta-Analysis

Background and objective: Immediate breast reconstruction not only reduces the number of surgeries for patients after mastectomy but also decreases psychological and physical trauma, making it increasingly popular. However, there is currently no consensus on the integration of post-mastectomy radiotherapy (PMRT) with reconstruction techniques. This review evaluates the impact of PMRT on complications following immediate breast reconstruction, providing guidance for clinical treatment decisions. Methods: PubMed, Web of Science, Embase, and other databases were searched for studies published in the past 15 years on outcomes of implant-based breast reconstruction in the context of radiotherapy to identify articles for analysis. RevMan 5.4 software was used to analyze the risks of seroma, infection, wound dehiscence, flap necrosis, implant exposure, capsule contracture, and reconstruction failure. Results: A total of 11 relevant studies were included, comprising 6323 cases of immediate breast reconstruction. It was found that breasts receiving postoperative irradiation had a significantly increased risk of complications, with statistically significant differences in seroma (P = 0.004), infection (P &lt; 0.00001), wound dehiscence (P = 0.04), implant exposure (P &lt; 0.00001), capsule contracture (P &lt; 0.00001), and reconstruction failure (P &lt; 0.00001). There was no statistically significant difference in flap necrosis (P = 0.88). Conclusion: The results indicate that postoperative radiotherapy significantly increases the risk of complications for patients undergoing immediate implant-based reconstruction. Preventive measures may be taken in advance with the assistance of healthcare providers if necessary.

Patient-Reported Outcomes and Complication Profiles of Implant-Based Breast Reconstruction in Patients With Postmastectomy Radiation Therapy.

This study aims to investigate the patient-reported outcomes (PROs) and complications of distinct implant-based breast reconstruction modality for patients with postmastectomy radiation therapy (PMRT). A retrospective review was conducted on breast cancer patients with stage II-III disease who performed implant-based breast reconstruction following with PMRT between September 2016 and April 2022. The patients were categorized into two matched groups: (1) patients receiving prepectoral breast reconstruction (PBR) or (2) subpectoral breast reconstruction (SBR) followed by PMRT. Following reconstruction, the patients were further compared for PMRT with the tissue expander (PMRT-TE) versus PMRT with permanent implant (PMRT-PI). PROs were measured with BREAST-Q questionnaire. Early and late complications were recorded and analyzed. A total of 55 eligible patients were recruited. Patients who underwent PBR reported significantly higher satisfaction with breasts scores (P = 0.003) compared with the SBR group. The PMRT-TE group had higher satisfaction with breasts (P = 0.001) but lower physical well-being (P = 0.029) scores compared with PMRT-PI group. Moreover, patients in SBR cohort had a higher risk of capsular contracture (Baker grade III or IV) (20.5% vs 6.3%) and implant dislocation (48.7% vs 12.5%) than patients in PBR cohort. Patients in PMRT-PI group had a slightly higher rate of capsular contracture (Baker grade III or IV) than PMRT-TE group (20.8% vs 12.9%). PBR was associated with lower rates of late complications, especially for implant dislocation, and higher satisfaction with breasts scores compared to SBR. In addition, compared to PMRT-TE with PMRT-PI, patients in PMRT-TE cohort reported superior PROs of satisfaction with breasts.