Wall Skin Research Articles

Reliability of Chest Wall Perforator Flaps for Breast Reshaping following Massive Weight Loss

Abstract Background Breast deformity following massive weight loss poses a unique challenge inadequately managed by traditional methods. Patients also have considerable lateral and posterior upper trunk tissue surplus. Multiple studies have used chest wall flaps for auto-augmentation with mastopexy to tackle this problem. However, the outcome measures did not include any objective tools to assess the reliability of these flaps. Hence, in this study sono-mammography and breast anthropometric measurements are used for evaluation of the added volume and long-term sustainability of chest wall perforator flaps. Methodology Twenty massive weight loss patients with Pittsburgh Rating Scale score 2-3 underwent mastopexy with autologous augmentation through perforator flaps encompassing lateral chest wall skin. Outcome measures were breast volume, and the presence of fat necrosis on mammography, and direct breast anthropometry. Conclusion All patients showed a consistent increase in volume postoperatively and no fat necrosis in postoperative mammography, reflecting flap reliability over one year of follow-up. All postoperative anthropometric measurements showed improvement in the breast deformities addressed. Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Impact of the Stefan gusting on a bioconvective nanofluid with the various slips over a rotating disc and a substance-responsive species

This paper presents thorough computational and theoretical analyses of steady forced convective flow over a rotating disc submerged in a water-based nanofluid containing microorganisms. It delves into the examination of boundary layer flow characteristics of a viscous nanofluid, considering Stefan blowing effects and multiple slip conditions influenced by a magnetic field. Notably, the study accounts for novel aspects such as thermal radiation and both constructive and destructive chemical reactions. The movement of nanoparticles is elucidated based on thermophoresis and microscopic behaviors, while changes in volume fraction do not affect the thermo-physical properties of the nanofluid. To address the altered nonlinear set of differential equations, an effective numerical approach, the Keller-Box method, is implemented for critical and efficient solutions. These appropriate transformations are defined and applied. When compared to blowing suction, it shows a better enhancement in the rate of heat transfer, mass, and microorganisms. Some of the main observations are there is a decrease in wall skin friction in the directions of radial and tangential as magnetic field strength is increased. The evaluation of thermal boundary layer thickness and temperature is noted for the radiation parameter (Rd) improvement. The present analysis has applications in electromagnetic micro-pumps and nanomechanics. As to the applications in the science and engineering fields, technologies such as micro-electromechanical systems-based microfluidic devices and microfluidic-related technologies will be accepted.

Skin-friction measurements using oil-film interferometry in hypersonic transitional boundary layer flows

Skin-friction measurements in hypersonic transitional boundary layer (HTBL) flows on a flared cone at Mach 6 at zero angle of attack are obtained using oil-film interferometry (OFI). In addition, the amplitude evolution of instability waves is investigated using fast-response pressure sensors and Rayleigh-scattering flow visualization (RSFV). The connection between the skin-friction coefficient and near-wall dynamics during the whole transition process is illustrative and the underlying mechanism of the generation of the wall skin friction is revealed. There exist two peaks of skin-friction rise along the streamwise direction of the model. The first one is at the transitional region (denoted as FS) which is caused by the second-mode instability. The second one is at the region where the transition is completed (denoted as FT). The drastic growth of skin friction near the end of transition is mainly attributed to the rapid boundary-layer breakdown into small scales. It is found that the strong shear in the near-wall region in the quiet zone where dominant hairpin-shaped vortices evolved from the second modes can also cause a local skin-friction rise (denoted as FQ). Further investigations show that in the region between FS and FQ, there is a slight increase in the skin friction, which is associated with the growing low-frequency waves. The skin friction coefficient value decreases slowly after FT but does not reach the expected turbulent theoretical value by the end of the test domain, indicating that the development towards the completely turbulent boundary layer appears to be a gradual process.

MHD peristaltic two-phase Williamson fluid flow, heat and mass transfer through a ureteral tube with microliths: Electromagnetic therapy simulation

The ureter typically experiences a frequency of one to five peristaltic contractions per minute. However, it is important to note that these contractions can be disrupted by various physical and mechanical irritants. Ionic contents in the urine make it electrically conducting and responsive to electromagnetic body forces. MHD can be deployed in bio magnetic therapy to control or mitigate symptoms associated with peristaltic pumping in the urinary system. This article therefore focuses on the hydromagnetic effects on flow patterns of urine with debris (monoliths). The mechanism of urine flow is largely coordinated by the kidneys. The flow inside the ureter is interrupted by microliths, which are generated by the sedimentation of excretory products. To simulate this, a two-phase formulation is adopted, comprising the electromagnetic urological viscous fluid phase and the particulate phase for solid grains. The peristaltic propulsion of two-phase liquid in the ureter is simulated as a sinusoidal wave propagation of incompressible non-Newtonian fluid. The Williamson viscoelastic model is deployed for the rheology. Heat transfer is also included with Soret thermo-diffusion and viscous heating effects. Long wave and low Reynolds number approximations are employed based on lubrication theory. The mass, momentum, energy and concentration conservation equations with associated boundary conditions are rendered non-dimensional via appropriate scaling transformations. A numerical solution is achieved via BVP4C MATLAB quadrature. Graphical visualizations of the velocity, temperature and concentration (solid grains) are given for the influence of suspension parameter ( ζ ), Hartmann number (M), Prandtl number (Pr), Weissenburg number (We), particle volume fraction (C), Eckert number (Ec), Soret number (Sr), Schmidt number (Sc). The novelty of the present work is therefore the simultaneous consideration of a generalized two-phase model, wall slip, non-Newtonian characteristics, cross diffusion, viscous dissipation, mass diffusion, magnetic body force and curvature effects in peristaltic urological transport, which has not been undertaken previously. The detailed simulations reveal that the flow velocity is reduced due to the presence of solid particles and the channel curvature, in comparison to the flow in an unobstructed channel devoid of solid particles. Enhancing the hydrodynamic slip parameter speeds up the movement of particles and fluid near the channel walls, boosts wall skin friction, raises pressure difference in the pumping area, and amplifies bolus magnitudes.The rise in peristaltic pumping results in a reduction in solid particle concentration, which is significant phenomena.This theoretical approach may aid in treating conditions such as Urinary Tract Infections (UTIs). The computations effectively demonstrate that significant manipulation of urological pumping characteristics can be achieved with an electromagnetic field. Some new features of two-phase ureteral dynamics are highlighted as relevant to magnetic therapy techniques, which may be beneficial to clinicians.

A Distant Fasciocutaneous Chest Wall Skin Flap for Necrotic Finger Post Reimplantation: A Case Report

The hand is often compromised by scars or potentially necrotic wounds. Complete loss of index finger will result in impairment of 20% of hand and 11% of whole-person. One of the most influential factors in consideration of tissue loss are defect size, site, depth, and orientation. In our case study, a 16-year-old male presented with sensations of tingling and pain in his finger subsequent to an accidental laceration. Examination revealed a necrotic wound located on the distal phalanx of the index finger, accompanied by mild atrophy and discoloration. Subsequently, the patient underwent graft harvesting from the right chest wall flap, followed by primary closure of the donor site on the right chest wall. Upon a three-month follow-up, the patient expressed satisfaction, demonstrating proficient daily activities despite the injury being localized to the left hand. Utilizing a chest wall flap is less prevalent than employing regional or free flaps. Anterior chest wall flaps are specifically crafted on the anterolateral chest wall or within the infraclavicular region. The choice of a chest wall flap was determined to offer a less cumbersome graft and aligns with the patient's preference. The main goal of soft tissue reconstruction is to restore functionality, encompassing tasks such as exploration, sensation, and manipulation of objects, while simultaneously preserving the original length. Nonetheless, achieving this goal remains a complex challenge. Keywords: Necrotic finger, Reimplantation, Chest Wall Skin Flap, Soft Tissue Reconstruction

Investigation of the effect of bolus on skin dose in breast cancer treatment with tomotherapy and LINAC radiotherapy devices

In postmastectomy radiation therapy (PMRT), it is important that the chest wall skin is included in the target volume and receives an adequate dose. This study aims to investigate the effect of bolus on skin dose in breast cancer treatment with Tomotherapy and LINAC radiotherapy devices and to examine the accuracy of the surface dose calculated by treatment planning system (TPS) with thermoluminescence dosimetry (TLD). Female Alderson Rando Phantom's chest wall is virtually divided into 9 regions. Computed tomography (CT) images of the phantom were obtained with a section thickness of 3 mm. Two plans, with and without bolus, were created for each of the helical tomotherapy (HT), intensity-modulated radiotherapy (IMRT) and field-in-field (FiF) techniques. A bolus thickness of 0.5 cm was used for all bolus plans. Doses calculated from TPSs were obtained for 88 predetermined points on the chest wall. After irradiation, doses measured with TLDs were obtained. The effect of bolus use on the chest wall surface was examined. The increase in surface dose due to bolus use was 50.35%, 55.35% and 68.56% for HT, IMRT and FiF techniques in TPS, respectively. This increase in TLD measurements was 58.18%, 30.90% and 46.31% for HT, IMRT and FiF techniques, respectively. The best agreement between TPS and TLD doses for bolus and non-bolus plans was found in the HT technique. The difference between TPS and TLD doses decreased within the three treatment techniques due to bolus use. Since the chest wall skin cannot receive the required dose in IMRT and FiF techniques, bolus use is recommended until acute skin reactions occur. There is no need to use a bolus for the HT technique.

Experimental study of the effects of isolated roughness elements on the stability and transition of a hypersonic boundary layer on a flat plate

Surface roughness elements on hypersonic vehicles can cause early boundary layer transition, increasing wall skin friction and heat flux and affecting aircraft range and thermal protection systems. Accurate prediction of the transition caused by these roughness elements is crucial for the design of hypersonic vehicles. In this work, wind tunnel experiments on isolated roughness-induced boundary layer transition at Ma = 6 are conducted. Infrared thermography and high-frequency pressure sensors are utilized to investigate the effects of different roughness element configurations (cylindrical, diamond, ramp) on the hypersonic boundary layer instability and transition. The experimental results show that all three roughness elements can effectively enhance the generation of second mode waves and promote boundary layer transition. Compared to smooth surfaces, they exhibit similar frequency band range, faster growth, and earlier saturation. Among them, the ramp roughness element most effectively triggers the boundary layer transition, with a relatively small heat flux increase. Furthermore, bispectral analysis illustrates that all three roughness elements undergo self-interactions that lead to spectral broadening, ultimately resulting in boundary layer transitions.

An MHD boundary layer flow of Casson fluid due to a moving wedge analyzed by the Bernoulli wavelet method

AbstractThe current study adopts a Bernoulli wavelet technique to explore the magnetohydrodynamic (MHD) boundary layer flow of a Casson fluid through a wedge. A nanofluid across a wedge has been investigated for its stable laminar MHD flow, heat, and mass transport characteristics. By choosing worthwhile non‐dimensional parameters, the governing boundary layer equation is reformed into a dimensionless Falkner–Skan equation. The consequent nonlinear equation is addressed via the Bernoulli wavelet method. For a range of different values of the physical parameters, the nature of the boundary layer flow is visually observed. Fluid velocity rises with rise in the values of Casson parameter, wedge parameter, and magnetic parameter. Local wall skin friction increases with increase in wedge parameter and magnetic parameter values. To ensure the accuracy of the findings, local wall skin friction is estimated and tested with other techniques that are already reported in the existing research.

Herpes zoster, complicated with thoracic wall phlegmon in a patient with HIV-infection: a case report

Herpes zoster is often associated with HIV infection. The article presents a clinical case of herpes zoster, complicated by the thoracic wall phlegmon in a 41-year-old male infected with HIV. Dissection and debridement of the phlegmon were performed. Antibacterial and pain relief therapy, start of antiretroviral therapy and treatment of the concomitant diseases were carried out. The residual thoracic wall skin and soft tissue defect on the site of the phlegmon was healed with surgery.Conclusions. Secondary manifestations of HIV infection present with the diversity of symptoms and severe clinical performance. Herpes zoster may be complicated with the purulent inflammation of surrounding tissue in the patients with HIV-infection. A multidisciplinary approach to the diagnosis and treatment of such patients is required.

Mechanisms and characteristics of wall skin friction reduction by boundary layer injection under hypervelocity inflow conditions

In this paper, the influences of boundary layer injection on skin friction reduction are numerically studied using Reynolds-averaged Navier-Stokes equations. The methodology is first validated by comparing the numerical results with the existing experimental data. Studies on the effects of inert gas boundary layer injection reveal that boundary layer injection forms a gas film cooling effect, which reduces skin friction through low viscosity and low temperature effects. However, the enhancement of turbulence in the boundary layer by the jet weakens this effect For fuel boundary layer injection, boundary layer combustion creates a low-density environment in the boundary layer, reducing the momentum transport of the fluid to the wall and significantly enhancing the drag reduction effect. Based on this, the drag reduction effect of boundary layer combustion is found to decrease significantly under mainstream heat release conditions, mainly due to the large-scale heat release in the outer edge of the boundary layer, which puts the fluid in a high-temperature and high-pressure state as a whole, and boundary layer combustion cannot establish a “barrier” for momentum transport in a low-density region.

Radical resection and reconstruction of a large sternal chondrosarcoma

Introduction. Primary malignant tumors of the sternum are rare, with chondrosarcoma being the most common primary malignant tumor of the chest. The gold standard in treatment is surgical treatment with wide resection margins, where the rigidity of the chest wall must be ensured, with protection of internal organs with satisfactory lung function. Case outline. We present a 67-year-old patient in whom previous computed tomography and magnetic resonance imaging examinations confirmed a tumor mass involving the sternum with the associated ribs, with involvement of the soft tissues above. First, sternum resection was performed with partial resection of the associated ribs and soft tissues. Reconstruction and stabilization of the chest wall were achieved with two layers of polypropylene mesh and methyl methacrylate bone cement with antibiotics. We reconstructed the primary soft tissue defect with a combination of a large local fasciocutaneous flap raised from the abdomen and a smaller sliding flap from the chest. The secondary defect was reconstructed by wide undermining of the skin in the area of the anterior abdominal wall and a small Thiersch-type free skin graft. In the postoperative period, the flaps were vital, but there was necrosis of the free skin graft. That defect was closed secondary thanks to bandaging. Respiratory function was preserved. Conclusion. Surgical treatment is the main treatment for sternal chondrosarcoma. With an adequate preoperative and intraoperative approach, it is necessary to enable good postoperative oncological outcomes with the achievement of chest rigidity and satisfactory respiratory status.

Numerical Simulation of Supersonic Turbulent Separated Flows Based on k–ω Turbulence Models with Different Compressibility Corrections

The accurate prediction of supersonic turbulent separated flows involved in aerospace vehicles is a great challenge for current numerical simulations. Based on the k–ω equations, several different compressibility corrections are incorporated in turbulence models to improve their prediction capabilities. Two benchmark test cases, namely the ramped cavity and the compression corner, are adopted for the numerical validation. Detailed comparisons between simulations and experiments are conducted to evaluate the effect of compressibility corrections on turbulence models. The computed results indicate that compressibility corrections have a significant impact on turbulence model performance. The compressibility correction, considering the effects of both dilatation dissipation and pressure dilatation, is suitable for the prediction of compressible free shear layers, but it may have a negative impact on the prediction of low-speed flows in the near-wall region due to the severe underprediction of the wall skin friction coefficient. In comparison, the compressibility correction only considering the effects of dilatation dissipation is conservative, with decreased predictability of free shear layers in supersonic flows, although it improves the predictions of the original models without corrections.

Computation of non-Newtonian quadratic convection in electro-magneto-hydrodynamic (EMHD) duct flow with temperature-dependent viscosity

Motivated by novel developments in smart non-Newtonian thermal duct systems, a theoretical study has been presented in this article for electro-magneto-hydrodynamic (EMHD) buoyancy-driven flow of a fourth-grade viscoelastic fluid in a vertical duct with quadratic convection. The viscosity of the fourth-grade fluid model is assumed to be temperature-dependent, and the Reynolds exponential model is deployed. Viscous heating and Joule dissipation effects are included. The duct comprises a pair of parallel electrically insulated vertical flat plates located a finite distance apart. Via suitable scaling transformations, a nonlinear boundary value problem is derived for the momentum and heat transport. A homotopy perturbation method (HPM) solution is obtained coded in Mathematica symbolic software. There is a considerable enhancement in wall skin friction with an increment in fourth-grade fluid parameter, Brinkman number, electrical field parameter, thermal buoyancy parameter, and quadratic thermal convection parameter. However, skin friction is strongly reduced with a rise in variable viscosity parameter, Hartmann (magnetic) number, and electromagnetic heat generation to conduction ratio. Nusselt number magnitudes are elevated with increase in variable viscosity parameter, thermal buoyancy parameter, and quadratic thermal convection parameter, whereas they are significantly suppressed with increment in fourth-grade fluid parameter, Brinkman number, and Hartmann magnetic number.

Dual solutions for the two-dimension copper oxide with silver (CuO–Αg) and zinc oxide with silver (ΖnO–Αg) hybrid nanofluid flow past a permeable shrinking sheet in a dusty fluid with velocity slip

PurposeThis paper aims to present dual solutions for the two-dimension copper oxide with silver (CuO–Ag) and zinc oxide with silver (ZnO–Ag) hybrid nanofluid flow past a permeable shrinking sheet in a dusty fluid with velocity slip.Design/methodology/approachThe governing partial differential equations for the two dust particle phases are reduced to the pertinent ordinary differential equations using a similarity transformation. Closed-form analytical solutions for the reduced skin friction and reduced Nusselt number, as well as for the velocity and temperature profiles, were presented, both graphically and in tables, under specific non-dimensional physical parameters such as the suction parameter, Prandtl number, slip parameter and shrinking parameter, which are also presented in both figures and tables.FindingsThe results indicate that for the shrinking flow, the wall skin friction is higher in the dusty fluid when compared with the clear (viscous) fluid. In addition, the effect of the fluid–particle interaction parameter to the fluid phase can be seen more clearly in the shrinking flow. Furthermore, multiple (dual, upper and lower branch solutions) are found for the governing similarity equations and the upper branch solution expanded with higher values of the suction parameter. It can be confirmed that the lower branch solution is unstable.Practical implicationsIn practice, the study of the stretching/shrinking flow is crucially important and useful. Both the problems of steady and unsteady flow of a dusty fluid have a wide range of possible applications in practice, such as in the centrifugal separation of particles, sedimentation and underground disposal of radioactive waste materials.Originality/valueEven though the problem of dusty fluid has been broadly investigated, very limited results can be found for a shrinking sheet. Indeed, this paper has succeeded to obtain analytically dual solutions. The stability analysis can be performed by following many published papers on stretching/shrinking sheets. Finally, the critical values and plotting curves for obtaining single or dual solution are successfully presented.

Abdominal Hypertension after Abdominal Plication in Postbariatric Patients: The Consequence in the Postoperative Recovery.

Background Abdominoplasty with abdominal plication increases intra-abdominal pressure (IAP) and has been previously associated with limited diaphragmatic excursion and respiratory dysfunctions. Many factors found in abdominoplasties and among postbariatric patients predispose them to a higher occurrence. This study aims to evaluate the impact of abdominal plication among postbariatric patients, assess whether the plication increases their IAP, and analyze how these IAP correlate to their postoperative outcome. Methods This prospective study was performed on all patients who underwent circumferential Fleur-De-Lis abdominoplasty. For this intended study, the IAP was measured by an intravesical minimally invasive approach in three stages: after the initiation of general anesthesia, after a 10-cm abdominal wall plication and skin closure, and 24 hours after the procedure. Results We included 46 patients, of which 41 were female and 5 were male. Before the bariatric procedure, these patients had an average maximum weight of 121.4 kg and an average maximum body mass index of 45.78 kg/m 2 ; 7 were grade I obese patients, 10 were grade II, and 29 were grade III. Only three patients were operated on with a gastric sleeve and 43 with gastric bypass. We presented six patients with transitory intra-abdominal hypertension in the first 24 hours, all of them from the grade I obesity group, the highest presented was 14.3 mm Hg. We presented 15% (7/46) of complication rates, which were only four seroma and five dehiscence; two patients presented both seroma and wound dehiscence. Conclusion Performing a 10-cm abdominal wall plication or greater represents a higher risk for intra-abdominal hypertension, slower general recovery, and possibly higher complication rate in patients who presented a lower degree of obesity (grade I) at the moment of the bariatric surgery.

Heat transfer modification in an unsteady laminar boundary layer subject to free-stream traveling waves

A laminar, thermal boundary layer was forced computationally by free-stream, traveling-wave velocity fluctuations and the effects on the wall heat flux and skin friction were measured as a function of the phase speed of the disturbances and the streamwise location along the developing flow. The heat flux modification due to the flow forcing was significantly higher than the corresponding skin friction enhancement, and the dependence of these two transport properties on the phase speed was qualitatively different. The skin friction modification exhibited a maximum at an optimal phase speed, which was explained in terms of the overlap of two distinct viscous layers within the boundary layer. The heat flux modification did not exhibit this maximum, although evidence was found to suggest such a maximum may occur with sufficient boundary layer development. Because the magnitude of the wall heat-flux modification scales quadratically with wave amplitude, traveling wave disturbances pose significant challenges for thermal transport measurements in periodically perturbed environments, like turbomachinery, but also new opportunities for the control of heat transfer.

Surface Roughness in RANS Applied to Aircraft Ice Accretion Simulation: A Review

Experimental and numerical fluid dynamics studies highlight a change of flow structure in the presence of surface roughness. The changes involve both wall heat transfer and skin friction, and are mainly restricted to the inner region of the boundary layer. Aircraft in-flight icing is a typical application where rough surfaces play an important role in the airflow structure and the subsequent ice growth. The objective of this work is to investigate how surface roughness is tackled in RANS with wall resolved boundary layers for aeronautics applications, with a focus on ice-induced roughness. The literature review shows that semi-empirical correlations were calibrated on experimental data to model flow changes in the presence of roughness. The correlations for RANS do not explicitly resolve the individual roughness. They principally involve turbulence model modifications to account for changes in the velocity and temperature profiles in the near-wall region. The equivalent sand grain roughness (ESGR) approach emerges as a popular metric to characterize roughness and is employed as a length scale for the RANS model. For in-flight icing, correlations were developed, accounting for both surface geometry and atmospheric conditions. Despite these research efforts, uncertainties are present in some specific conditions, where space and time roughness variations make the simulations difficult to calibrate. Research that addresses this gap could help improve ice accretion predictions.

Structural uncertainty quantification of Reynolds-Averaged Navier–Stokes closures for various shock-wave/boundary layer interaction flows

Accurate prediction of Shock-Wave/Boundary Layer Interaction (SWBLI) flows has been a persistent challenge for linear eddy viscosity models. A major limitation lies in the isotropic representation of the Reynolds stress, as assumed under the Boussinesq approximation. Recent studies have shown promise in improving the prediction capability for incompressible separation flows by perturbing the Reynolds-stress anisotropy tensor. However, it remains uncertain whether this approach is effective for SWBLI flows, which involve compressibility and discontinuity. To address this issue, this study systematically quantifies the structural uncertainty of the anisotropy for oblique SWBLI flows. The eigenspace perturbation method is applied to perturb the anisotropy tensor predicted by the Menter Shear–Stress Transport (SST) model and reveal the impacts of anisotropy on the prediction of quantities of interest, such as separation and reattachment positions, wall static pressure, skin friction, and heat flux. The results demonstrate the potential and reveal the challenges of eigenspace perturbation in improving the SST model. Furthermore, a detailed analysis of turbulent characteristics is performed to identify the source of uncertainty. The findings indicate that eigenspace perturbation primarily affects turbulent shear stress, while the prediction error of the SST model is more related to turbulent kinetic energy.

Omission of Chest Wall/Scar Boost and Skin Bolus Does Not Increase Risk of Local Recurrence for Breast Cancer Patients

For breast cancer patients receiving postmastectomy radiation (PMRT), little is known about the value of Chest Wall Boost (CWB) and Skin Bolus (SB) across different biological subtypes and patients with high-risk features. We reviewed 2,917 charts of breast cancer patients treated with mastectomy between 2000-2020 at our institution. Only patients treated with PMRT were included. Patients with and without reconstruction were included. Reconstruction types included autologous or single-stage-direct-implant or two stages expanders/implant. PMRT was delivered with 3D conformal technique using photons and conventional fractionation (50-50.4 Gy in 25-28 fractions). CWB using enface electrons and 3-5 mm SB applied every other day were delivered at the discretion of the physician. Primary objectives were locoregional failure (LF) rates between CWB and No CWB groups; SB and No SB groups. Different subgroup analyses exploring the benefits of CWB and SB in different biological subtypes, patients with lymphovascular invasion (LVI+), positive margins (PM) and nipple sparing mastectomy (NSM) were conducted. Secondary objectives were toxicity of CWB and SB on different reconstruction outcomes and PMRT side effects. Logistic and cox regressions were used. A total of 1,103 patients with an overall median follow-up of 7.8 years were available for analysis. Among the entire cohort, 55.4% received CWB, 76% received SB, 48% had LVI, 23% with PM, 41% with NSM, 67% with Luminal A, 15% with Luminal B, 7% with HER2 enriched and 11% with triple negative. The 10 years incidence of LF was 6.5% and 4.0% for CWB and NO CWB, respectively (HR 1.6, p = 0.1); and 5.6% and 5.1% for SB and NO SB respectively (HR 0.9, p = 0.8). Multivariable analysis of LF adjusted for LVI, ECE, grade, tumor size, number of malignant nodes, and biological subtype showed no association of CWB and SB with local control (HR:1.4, p = 0.2 and HR:0.9, p = 0.8), respectively. Subgroup analyses confirmed no association of CWB or SB with improved local control across different biological subtypes, (LVI+), PM and NSM patients. On multivariable level CWB significantly increased reconstruction complications (OR 2.3, p = 0.001, OR 1.7, p = 0.008) for infection/necrosis (I/N) and overall reconstruction failure (ORF), respectively; while SB did not (OR 1.1, p = 0.8, OR 1.0, p = 0.9) for I/N and ORF, respectively. 56 patients needed treatment break, 49 of them (87%) had SB. Both CWB and SB significantly increased the risk of higher grade radiation dermatitis (2-4) in the entire cohort OR 2.1 p = 0.01, and OR 2.3, p = 0.02 for CWB and SB, respectively. CWB and SB did not improve local control across different biological subtypes, patients with LVI, Positive Margins and NSM. CWB significantly increased reconstruction complications and SB increased treatment breaks and radiation dermatitis. These findings do not support routine usage of CWB and SB.

Quality Assurance in a Phase III, Multicenter, Randomized Trial of POstmastectomy radioThErapy in Node posiTive Breast Cancer with or without Internal mAmmary nodaL Irradiation (POTENTIAL): A Planning Dummy Run

To report the planning dummy run results of the POstmastectomy radioThErapy in Node posiTive breast cancer with or without Internal mAmmary nodaL irradiation (POTENTIAL) trial-a multicenter, randomized, phase 3 trial-to evaluate postmastectomy radiotherapy, with or without internal mammary nodal irradiation, for patients with high-risk breast cancer. All participating institutions were provided the contours of the dummy run case, and they generated radiotherapy (RT) plans per protocol guidelines. The plans were reviewed and feedback were provided by the quality assurance team, after which the institutions resubmitted revised plans. The information on beams arrangement, skin flash, inhomogeneity corrections, and protocol compliance was assessed both in the primary and final submission. Theplans from 26 institutions were included in the analysis. A number of major deviations were found in the primary submission, such as less strict constraint on organs at risk (OARs) V5Gy, and no application of chest wall skin flash. The protocol compliance rates of the dose coverage for the planning target volume of the chest wall (PTVcw), PTV of supra/infraclavicular fossa plus axilla levels I, II, III (PTVsc+ax), and PTV of the IMN region (PTVim) were all significantly improved in the final submission compared with those in the primary submission, which were 96.2% vs. 69.2%, 100% vs. 76.9%, and 88.4% vs. 53.8, respectively. For OARs, the protocol compliance rates of heart Dmean, left anterior descending coronary artery V40Gy, ipsilateral lung V5Gy, and stomach V5Gy were significantly improved. All major deviations were corrected and protocol compliance was significantly improved and of high level in the final submission. Moreover, the variations were reduced. Therefore, a planning dummy run was essential to guarantee good RT plan quality and inter-institutional consistency for multicenter trials.