Cylinder Insertion Research Articles

Numerical analysis of heat transfer and flow dynamics in a pipe with square extruded bluff cylinder inserts

This paper presents the computational study of convective heat transfer enhancement and entropy generation performance by using bluff cylinder. A two-dimensional numerical simulation is executed successfully on thermo-hydraulic transport characteristics for a square extruded bluff cylinder placed inside duct. The test fluid, air (Pr 0.707), is used for the experiment. The turbulent SST scheme is engaged for the simulation. The simulation is accomplished with the aim to achieve an understanding of physical performance and activities of the thermo-fluidic flow inside the channel fitted with bluff body at 15D spacing from the inlet under constant temperature conditions at wall. The simulation is done to cover cross flow encompassing both laminar as well as turbulent flow regime in the range of Reynolds number (Re) up to 1×105 and inlet intensities from 5% to 40%. The effects of outlet temperature and Nusselt number is esteemed and considered. No ideal Re has been detected which could reduce the total entropy generation. It is highly promising to be executed in the practical relevance like power and energy industry.

Applications of Computational Fluid Dynamics in The Design and Rehabilitation of Nonstandard Vertical Slot Fishways

Vertical slot fishways are increasingly common structures for the passage of a wide variety of migratory fish and contribute to the maintenance of fish diversity in fragmented rivers. These structures are designed with several geometric arrangements and, consequently, flow patterns through them can be shaped to present suitable characteristics for the fish species. To aid in the design of vertical slot fishways, a three-dimensional numerical model was used to simulate the flow for different geometric configurations. An existing vertical slot fishway with nonstandard dimensions was initially modeled and validated. This geometry was used as a reference design. Modifications to the reference design, such as the insertion of cylinders, changes in the baffle shape and position of the vertical slots, as possible rehabilitation measures, were proposed and tested. In summary, five different designs were evaluated with several slopes, totaling 17 geometries. Hydraulic parameters, flow patterns, maximum velocities, velocity fields and turbulence kinetic energy in the pools were analyzed. The results indicate that the maximum velocity values were between 9% and 68% higher than those obtained by the theoretical equation. This indicates that maximum velocities can be underestimated for nonstandard vertical slot fishways if a simplified evaluation is conducted. The insertion of cylinders in the region close to the slot reduces the maximum velocity up to 8.2%. The positioning of the vertical slots on alternating sides increases the maximum values of turbulence kinetic energy and the regions subjected to higher values. However, this configuration provided greater energy dissipation and reduction of velocities by up to 27%. Thus, modifications in nonstandard vertical slot fishways can be useful in future design or rehabilitation of existing structures in order to provide velocities and turbulence more friendly for a higher number of fish species.

Experimental studies on the compound thermo-hydraulic characteristics in a 3D inner finned tube with porous copper fiber inserts

A novel easy-to-manufacture porous copper fiber sintered cylinder insert (PCFSCI) is designed to enhance the convective heat transfer performance in a three-dimensional inner finned tube (3D-IFT). The compound heat transfer enhancement of the PCFSCI and 3D inner fins is investigated at the Reynolds number ranging from 3921 to 14,290. The results show that the combination of PCFSCI and 3D-IFT creates a synergistic effect and a maximum performance evaluation criterion (PEC) value of 2.29. Moreover, the effect of porosity, diameter and spacing of the PCFSCI on heat transfer performance is investigated. The results show that the Nusselt number and friction factor increase with the decrease of porosity. The PCFSCI with a diameter of 8 mm presents a better PEC than PCFSCI with diameters of 12 mm and 10 mm. The spacing has a slight effect on the PEC, but a great influence on the Nusselt number and friction factor. These phenomena can be attributed to the fluid mixing between the core flow and the flow in the annular region, as well as the local vortexes and the changing of velocity gradient produced in the annular region.

Vaginal Brachytherapy for Stage I-II Non-endometrioid Endometrial Cancer Using a Low-dose Scheme

To evaluate outcomes for women with FIGO stage I-II non-endometrioid endometrial adenocarcinoma treated with adjuvant vaginal brachytherapy (VB) using a low-dose scheme with or without adjuvant chemotherapy (CT). We retrospectively identified 122 women with FIGO stage I-II non-endometrioid endometrial cancer (serous carcinoma [SC], clear cell carcinoma [CC], mixed histology [MH, endometrioid and SC or CC components], carcinosarcoma [CS]) who received VB to 24 Gy in 6 fractions from 2005 – 2017. Dose was prescribed to the cylinder surface of the full vaginal length. CT imaging was performed prior to each fraction to confirm cylinder diameter and insertion depth. Women with < 6 months follow-up from VB completion were excluded (n = 16). Rates of vaginal relapse (VR), pelvic relapse (PR), distant metastasis including para-aortic relapse (DM), recurrence-free survival (RFS) and overall survival (OS) were estimated using the Kaplan-Meier method. Univariate analyses (UVA) were performed using logrank test or Cox proportional hazards. Multivariable analyses (MVA) using Cox proportional hazards modeling with backwards selection was used to identify independent predictors of RFS. Characteristics of the 106 eligible patients are summarized in Table 1. At a median follow up of 49 months (r, 9 – 119) from surgery, 26 women developed recurrence at a median of 39 months (r, 12 – 119), and 14 died of disease. The 5-year rates of VR, PR, DM, RFS and OS were: 7%, 8%, 21%, 74% and 83%, respectively. On UVA, age, histology, lymphovascular invasion (LVI), stage and %MMI were associated with RFS (all p < 0.05). By histology, the 5-year RFS rates were 77%, 68%, 88% and 56% for SC, CC, MH and CS, respectively (p = 0.046). On MVA including stage, histology and LVI, only stage remained significantly associated with RFS (hazard ratio [HR] 2.8 [95%CI: 0.96 – 7.39] for IB vs IA; HR 4.9 for II vs IA [95%CI: 1.34 – 14.77]; p=0.018). 5-year PR was higher for women with CS compared to other high-risk histologies (20% vs 6%; p = 0.017), while VR and DM did not significantly differ. Clinical outcomes for patients with early-stage, non-endometrioid endometrial cancer varied significantly by histologic subtype. Women with CS had significantly higher rates of pelvic relapse after VB, compared to those with other high-risk histologies.Abstract TU_19_3509: Table 1Univariate PAge (med, range)66 yr (40-93)0.029BMI (med, range)28 (20-53)0.352FIGO 2009 Stage IA IB II80% (85) 14% (15) 6% (6)0.004Histology Serous carcinoma (SC) Clear cell carcinoma (CC) Mixed histology (endometrioid and SC/CC) Carcinosarcoma (CS)47% (50) 10% (11) 27% (29) 15% (16)0.046No. of pelvic LN (med, range)13 (0-44)0.560No. of para-aortic LN (med, range)0 (0-14)0.788%MMI (med, range)10% (0-99)0.044LVI13% (14)0.001Positive pelvic washings12% (13)0.100Adjuvant chemotherapy SC CC MH CS75% (79) 90% (45) 73% (8) 63% (10) 55% (16)0.197Patterns of failure Vaginal Pelvic Distant Combined local-regional & distant6% (6) 7% (7) 20% (21) 7% (7)NA Open table in a new tab

Survey on the Contemporary Management of Intraoperative Urethral Injuries During Penile Prosthesis Implantation

BackgroundIntraoperative urethral injury is an uncommon event during the placement of a penile prosthesis, and alternative management strategies have been proposed with continuation of implantation after urethral injury. AimTo evaluate surgeon practices in the management of intraoperative urethral injury. MethodsAn online survey was sent to the society listservs of the Genitourinary Reconstructive Surgeons (GURS) and the Sexual Medicine Society of North America (SMSNA). Physicians were queried on their fellowship training, experience with penile prosthesis implantation, and management of urethral injuries during prosthesis placement. The response data were analyzed using SAS 9.4 (SAS Institute, Cary, NC, USA). The χ2 test and Fisher exact test were used to determine associations between variables. OutcomesSurvey responses. Results131 survey responses were analyzed. Of the responders, 41.2% were GURS fellowship trained, 19.1% were SMSNA trained, 30.5% were non-fellowship trained, and 9.2% were trained in other fellowships. 25.4% of participants performed more than 50 implantations per year, 37.7% performed 20 to 50 per year, and 36.9% performed fewer than 20 per year. Urethral injury during prosthesis implantation was uncommon, with 26.2% reporting 0 injury, 58.5% reporting 1 to 3 injuries, and 15.4% reporting more than 3 career injuries. Injuries were most commonly encountered during corporal dilation (71.1%) compared with corporal exposure (12.5%) or penile straightening maneuvers (7.0%). There was no statistically significant difference with aborting or continuing implantation among GURS-trained, SMSNA-trained, other fellowship-trained, and non–fellowship-trained surgeons. Of all responders, 55% would abort the procedure after distal urethral injury, whereas 45% would continue the procedure with unilateral or bilateral insertion of cylinders. Patient factors that increased likelihood of terminating the procedure in the case of urethral injury included immunosuppression, spinal cord injury, and clean intermittent catheterization dependence. Clinical ImplicationsA urethral injury during penile prosthesis implantation might not mandate termination of the procedure despite classic teaching. Strengths and LimitationsThe strength of this study is that it provides difficult to obtain epidemiologic data on the frequency and management of this clinically significant injury. Limitations include the inherent biases from a survey-based study including response bias and recall bias. The survey response rate could not be obtained. ConclusionUrethral injury during penile prosthesis implantation is a rare but clinically significant risk of the procedure, with many variations in management of the injury. Termination and delayed implantation might not be necessary after injury, although long-term outcome data are difficult to obtain.Sexton SJ, Granieri MA, Lentz AC. Survey on the Contemporary Management of Intraoperative Urethral Injuries During Penile Prosthesis Implantation. J Sex Med 2018;15:576–581.

Thermal and friction characteristics of a circular tube fitted with perforated hollow circular cylinder inserts

The objective of the present work is to measure the heat transfer and pressure drop in a circular tube integrated with the perforated hollow circular cylinder (PHCC) inserts with air as the working medium. The experiments are performed with PHCC inserts of three different diameter ratios (DR = 0.5, 0.65, and 0.8) and three perforation index (PI = 8%, 16%, and 24%) in a circular tube turbulent flow regime, where the Reynolds number is varied from 6000 to 27,000. A fixed value of pitch ratio (PR = 2) is considered in all the experiments. The experimental results demonstrated that the Nusselt number (Nu) and friction factor (f) are increased with the decrease of pitch ratio. The results also reveal that the heat transfer rate in the tube fitted with PHCC inserts is significantly increased with the corresponding marginal increase in pressure drop. In the range of the present work, heat transfer rate and friction factor are obtained to be around 150–230% and 160–450% higher than those of the plain tube values, respectively. Thermal enhancement factor (TEF) in the present study is in the range of 1.21–1.47 with a maximum value for DR = 0.65 and PI = 8%, respectively. In addition, the empirical correlations for the Nusselt number and friction factor are also developed, based on the experimental data.

MP25-19 SURVEY ON THE CONTEMPORARY MANAGEMENT OF INTRAOPERATIVE URETHRAL INJURIES DURING PENILE PROSTHESIS IMPLANTATION

You have accessJournal of UrologySexual Function/Dysfunction: Surgical Therapy I1 Apr 2017MP25-19 SURVEY ON THE CONTEMPORARY MANAGEMENT OF INTRAOPERATIVE URETHRAL INJURIES DURING PENILE PROSTHESIS IMPLANTATION Stephanie J. Sexton, Michael A. Granieri, and Aaron C. Lentz Stephanie J. SextonStephanie J. Sexton More articles by this author , Michael A. GranieriMichael A. Granieri More articles by this author , and Aaron C. LentzAaron C. Lentz More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.769AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Intraoperative urethral injury is an uncommon event during the placement of an inflatable penile prosthesis (IPP) with an estimated incidence of up to 3%. The conventional teaching is to perform primary repair, place a transurethral catheter, and abort the procedure. Recently, alternative management strategies have been proposed with continuation of the implant following urethral injury. The objective of this study is to evaluate surgeon management of urethral injury during IPP and determine if fellowship training influences practice. METHODS An online survey was sent to the society listservs of the Genitourinary Reconstructive Surgeons (GURS) and The Sexual Medicine Society of North America (SMSNA). Physicians were queried on their fellowship training, experience with IPP and urethroplasty, IPP surgical approach, and management of urethral injuries during IPP implantation. The response data was analyzed using SAS 9.4 (SAS Institute Inc., Cary, NC). Chi-squared test and Fisher's exact test were used to determine associations between variables. RESULTS There were a total of 131 survey responses. Of the responders, 41.2% were GURS fellowship trained, 19.1% were SMSNA trained, 30.5% were non-fellowship trained, and 9.2% trained in other fellowships. 25.4% of participants perform >50 IPPs per year, while 37.7% perform 20-50 and 36.9% perform fewer than 20 per year. Urethral injury during IPP implantation was uncommon, with 26.2% reporting 0 injuries, 58.5% reporting 1-3 injuries, and 15.4% reporting >3 career injuries. Injuries were most commonly encountered during corporal dilation (71.1%), compared to corporal exposure (12.5%), or penile straightening maneuvers (7.0%). There was no statistically significant difference with aborting or continuing implantation among GURS, SMSNA, and/or non-fellowship trained surgeons. Of all responders, 55% abort the procedure after distal urethral injury, while 45% continue the procedure with unilateral or bilateral insertion of cylinders. For those who chose to abort the procedure, the next implant was attempted in <6 weeks in 9.3%, 6-12 weeks in 45.7%, and >12 weeks in 41.1%. Patient factors that increased likelihood of aborting procedure in the case of urethral injury included immunosuppression, spinal cord injury, and clean intermittent catheterization-dependence. CONCLUSIONS Urethral injury during IPP implantation is a rare but established risk of the procedure. Fellowship training does not appear to have an effect on intraoperative management of this injury. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e318 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Stephanie J. Sexton More articles by this author Michael A. Granieri More articles by this author Aaron C. Lentz More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Thermo-hydraulic characteristics of laminar flow in a circular tube with porous metal cylinder inserts

Based on periodic surface models, a novel type of porous metal cylinder inserts (PMCIs) was designed in this work to improve heat transfer. The thermo-hydraulic performance of laminar flow was numerically studied on a circular tube with PMCIs. The effect of porosity, pore types, spacer length and clearance on the heat transfer performance was investigated. Liquid water was used as the working fluid. The numerical results show that the Nusselt number increases by 2.15–7.17 times the value of the plain tube, while the friction factor is augmented by 5.98–11.68 times. The performance evaluation criterion (PEC) value is 1.2–3.16. The computation results indicate that the Nusselt number and friction factor increase with the decrease in spacer length. Moreover, the effect of porosity on the thermo-hydraulic performance is also investigated. The results show that better PEC values of the tube can be obtained with smaller porosity. The effect of pore types on the heat transfer performance is also reported. Besides these findings, it indicates that the clearance is very sensitive to the heat transfer performance. The better heat transfer performance of the tube can be obtained with larger clearance. Compared with other inserts, the novel PMCIs can transfer more heat than other inserts under the same pumping power which can guide us to optimize heat exchanges.

Boundary layer redevelops with mesh cylinder inserts for heat transfer enhancement

In this paper, mesh cylinder inserts were adopted to enhance the convective heat transfer in a circular tube. The effect of open area rate (P=0.1mm, P=0.2mm, P=0.4mm), inlet closed type, spacer length (S/D=50/12, S/D=75/12, S/D=100/12) and insert length (L/D=25/12, L/D=50/12, L/D=100/12) on heat transfer performance were numerically investigated at the Reynolds number of 280–1800. The results show that mesh cylinder inserts has an excellent heat transfer performance in the laminar regime. It was mainly due to the high Nu number produced by boundary layer redevelopment at the inlet and the complex flow at the annular region also contributes to the high heat transfer rate. The excellent heat transfer performance is obtained at the cost of high flow resistance. To avoid sharply increase in the flow resistance, a small hole is cut in the closed inlet of mesh cylinder inserts, which can greatly decrease the friction factor without sharply decrease the heat transfer rate. The open area rate has little impact on the heat transfer rate and the best heat transfer performance is resulted from inserts with P=0.2mm. Heat transfer performance of mesh cylinder inserts is also affected by the spacer length, insert length. A relatively long spacer length (S/D=100/12) and a short insert length (L/D=25/12) are recommended in the design of heat exchanger in this work.

SU‐F‐T‐136: Breath Hold Lung Phantom Study in Using CT Density Versus Relative Stopping Power Ratio for Proton Pencil Beam Scanning System

Purpose:To evaluate mass density effects of CT conversion table and its variation in current treatment planning system of spot scanning proton beam using an IROC proton lung phantom for this study.Methods:A proton lung phantom study was acquired to Imaging and Radiation Oncology Core Houston (IROC) Quality Assurance Center. Inside the lung phantom, GAF Chromic films and couples of thermal luminescent dosimeter (TLD) capsules embedded in specified PTV and adjacent structures to monitor delivered dosage and 3D dose distribution profiles. Various material such as cork (Lung), blue water (heart), Techron HPV (ribs) and organic material of balsa wood and cork as dosimetry inserts within phantom of solid water (soft tissue). Relative stopping power (RLSP) values were provided. Our treatment planning system (TPS) doesn't require SP instead relative density was converted relative to water. However lung phantom was irradiated by planning with density override and the results were compared with IROC measurements. The second attempt was conducted without density override and compared with IROC's.Results:The higher passing rate of imaging and measurement results of the lung phantom irradiation met the criteria by IROC without density override. The film at coronal plane was found to be shift due to inclined cylinder insertion. The converted CT density worked as expected to correlate relative stopping power.Conclusion:The proton lung phantom provided by IROC is a useful tool to qualify our commissioned proton pencil beam delivery with TPS within reliable confidence. The relative mass stopping power ratios of materials were converted from the relative physical density relative to water and the results were satisfied.

Thermal characteristic of a laminar flow through a circular tube fitted with wire-net cylinder inserts

A novel type of porous media inserts, wire-net cylinder inserts, was developed to improve convection heat transfer in the present work. Heat transfer performance and pressure drop was numerically studied. Wire-net cylinder inserts with different spacer length (S/D=2.1, S/D=4.2, S/D=8.3) and different open area rate (OAR=0.33, 0.5 and 0.67) were investigated at the Reynolds number range of 290–2024. Liquid water was used as the working fluid. The results show that wire-net cylinder inserts have an excellent heat transfer performance in the laminar regime. This was mainly due to the increase in the velocity at the inlet and the high intensity of the fluid mixing between annular region and the core region. The open area rate has a great impact on the heat transfer rate. The best heat transfer rate resulting from inserts with P=0.2mm (OAR=0.5) is about 3.45 times that of smooth tube. The friction factor increases with the decrease in open area rate. Although inserts with P=0.4mm (OAR=0.67) have the lowest heat transfer rate, its friction factor is also the lowest. As a result, inserts with P=0.4mm achieve the best PEC values (performance evaluation criterion). Heat transfer performance of wire-net cylinder inserts is also affected by the spacer length. The heat transfer rate increases with the decrease in the spacer length. Although a short spacer length can result in a high friction factor, the PEC values are still very high. It is still valuable to adopt a short spacer length in the design of heat exchanger. Compared with other inserts, wire-net cylinder inserts are simple and can be fabricated easily at a low cost.

Heat transfer and pressure drop characteristics in a circular tube with mesh cylinder inserts

Heat transfer performance and pressure drop tests were conducted on a circular tube with mesh cylinder inserts. These inserts with different open area rate, 30, 60, and 120 pores per inch (PPI) were tested at Reynolds numbers between 4000 and 18,000. Tap water was used as the working fluid. A high heat transfer coefficient was obtained by using mesh cylinder inserts. The friction factor increases with increases in PPI. Optimal results were obtained for PPI=60. Heat transfer rates and friction factors were enhanced by 2.3–2.6 and 3.4–3.7 times, respectively, to those in the plain tube. Performance evaluation criterion (PEC) values were approximately 1.48–1.7. Numerical method is also employed to analyze the enhancement. The results show that the reason for the heat transfer enhancement is attributed to two factors. One is attributed to the velocity increase at the inlet. Another owes to the high turbulent intensity generated by inserting the mesh issue. Two factors work together to achieve a high heat transfer rate. Compared with other inserts, mesh cylinder inserts can transfer more heat for the same pumping power.

Do changes in interfraction organ at risk volume and cylinder insertion geometry impact delivered dose in high-dose-rate vaginal cuff brachytherapy?

PurposeWithin a multifraction high-dose-rate vaginal cuff brachytherapy course, we determined if individual variations in organ at risk (OAR) volume and cylinder insertion geometry (CIG) impacted dose and whether planned minus fractional (P − F) differences led to a discrepancy between planned dose and delivered dose. Methods and MaterialsWe analyzed vaginal cuff brachytherapy applications from consecutive patients treated with three fractions of 5 Gy after each undergoing a planning CT and three repeat fractional CTs (fCTs). Rectal and bladder D2ccs and volumes were recorded in addition to the x (in relationship to midplane) and y (in relationship to the table) angles of CIG. Paired t-tests and multiple regression analyses were performed. ResultsTwenty-seven patients were identified. In comparing the planning CT vs. mean fCT rectal volumes, bladder volumes, x angles, and y angles, only bladder volume was significantly different (planned volume higher, t = 2.433, p = 0.017). The cumulative mean planned OAR D2cc vs. delivered D2cc was only significantly different for the bladder (planned dose lower, t = −2.025, p = 0.053). Regression analysis revealed planned rectal D2cc (p < 0.0003) and a positive (posterior) y insertion angle (p = 0.015) to significantly impact delivered rectal D2cc. Additionally, P − F rectal volume (p = 0.037) was significant in determining rectal delivered dose. ConclusionsA more posterior y angle of insertion was found to increase rectal D2cc leading us to believe that angling the vaginal cylinder anteriorly may reduce rectal dose without significantly increasing bladder dose. Although attention should be paid to OAR volume and CIG to minimize OAR dose, the clinical significance of P − F changes remains yet to be shown.

Vaginal Cuff Underdosing Persists Despite Maximal Insertion Using MRI Guidance

Vaginal failures occur following cylinder-based vaginal brachytherapy (VB) for endometrial cancer, and it is unknown whether inadequate dosimetry contributes to these cancer recurrences. Advances in imaging have the potential to delineate the vaginal cuff (VC) from the surrounding tissue, allowing improved assessment of radiation coverage. We hypothesized that MRI would identify VC underdosing in a contemporary cohort of patients undergoing VB. A cohort of 32 patients with endometrial cancer who underwent VB was retrospectively analyzed. All cases were retrospectively replanned to treat 4 cm of VC to a dose of 7 Gy per fraction prescribed to 5 mm. Cylinders were inserted to the maximum extent tolerated and T2-weighted magnetic resonance imaging (MRI) images (T2WI) were used clinically to assess for air gaps between the cylinder and VC. Fifty-one T2WI from 25 patients were later analyzed for research purposes, to identify visibly evident areas of undistended VC, defined as VC at or near the apex that did not contact the cylinder. After identifying VC underdosing in many of the initial patients, steps were taken in subsequent patients to improve cylinder placement, such as using stackable cylinders to improve VC distention. We then analyzed an additional 26 MRIs on 7 patients to see if these changes would decrease the incidence of VC underdosing. T2WI revealed an undistended VC in 17 of 32 (53%) patients in the entire cohort (12 of 25 [48%] initial and 5 of 7 [71%] subsequent patients). There were volumes of VC that received less than 50% of the prescription dose in 13 of 32 (42%) patients. At least 2 mL of the VC received less than 50% of the prescription dose in 7 of 32 (22%) patients. The volume of VC that received less than half of the prescription dose ranged from 0.0 to 10.7 mL (mean 2.6 mL). In patients with undistended VC, the range of minimum dose to the VC was 0.71 to 5.46 Gy (mean 2.29 Gy) or 10% to 78% (mean 33%) of the prescription dose. We identified vaginal cuff underdosing in over half of our patients, with most of these patients having volumes of undistended vaginal cuff that received less than half of the prescription dose. Focused attempts to clinically optimize cylinder insertion did not impact underdosing. We observed that the maximum dimension was along the cranio-caudal axis in some patients or left-right/anterior-posterior axis in others, suggesting that surgical methods of vaginal cuff closure may be restricting access to the vaginal apex or that alternative applicators may be needed when the diameter of the apex is larger than the introitus, respectively. Additional follow-up will be needed to determine whether underdosing is associated with isolated vaginal cuff failure.

Description of the Baudet Surgical Technique and Introduction of a Systematic Method for Training Surgeons to Perform Male-to-Female Sex Reassignment Surgery.

Male-to-female sex reassignment surgery involves three main procedures, namely, clitoroplasty, new urethral meatoplasty and vaginopoiesis. Herein we describe the key steps of our surgical technique. Male-to-female sex reassignment surgery includes the following 14 key steps which are documented in this article: (1) patient installation and draping, (2) urethral catheter placement, (3) scrotal incision and vaginal cavity formation, (4) bilateral orchidectomy, (5) penile skin inversion, (6) dismembering of the urethra from the corpora, (7) neoclitoris formation, (8) neoclitoris refinement, (9) neovaginalphallic cylinder formation, (10) fixation of the neoclitoris, (11) neovaginalphallic cylinder insertion, (12) contouring of the labia majora and positioning the neoclitoris and urethra, (13) tie-over dressing and (14) compression dressing. The size and position of the neoclitoris, position of the urethra, adequacy of the neovaginal cavity, position and tension on the triangular flap, size of the neo labia minora, size of the labia majora, symmetry and ease of intromission are important factors when considering the immediate results of the surgery. We present our learning process of graduated responsibility for optimisation of these results. We describe our postoperative care and the possible complications. Herein, we have described the 14 steps of the Baudet technique for male-to-female sex reassignment surgery which include clitoroplasty, new urethral meatoplasty and vaginopoiesis. The review of each key stage of the procedure represents the first step of our global teaching process. 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.

SU-E-T-280: Dose Evaluation in Using CT Density Versus Relative Stopping Power for Pencil Beam Planning and Treating IROC Proton Phantom

Purpose: The purpose of this study is to evaluate any effects of converted CT density variation in treatment planning system (TPS) of spot scanning proton therapy with an IROC proton prostate phantom at our new ProteusOne Proton Therapy Center. Methods: A proton prostate phantom was requested from the Imaging and Radiation Oncology Core Houston (IROC), The University of Texas MD Anderson Cancer Center, Houston, TX, where GAF Chromic films and couples of thermo luminescent dosemeter (TLD) capsules in target and adjacent structures were embedded for imaging and dose monitoring. Various material such as PVC, PBT HI polystyrene as dosimetry inserts and acrylic were within phantom. Relative stopping power (SP) were provided. However our treatment planning system (TPS) doesn’t require SP instead relative density was converted relative to water in TPS. Phantom was irradiated and the results were compared with IROC measurements. The range of relative density was converted from SP into relative density of water as a new assigned material and tested. Results: The summary of TLD measurements of the prostate and femoral heads were well within 2% of the TPS and met the criteria established by IROC. The film at coronal plane was found to be shift in superior-inferior direction due to locking position of cylinder insert was off and was corrected. The converted CT density worked precisely to correlated relative stopping power. Conclusion: The proton prostate phantom provided by IROC is a useful methodology to evaluate our new commissioned proton pencil beam and TPS within certain confidence in proton therapy. The relative stopping power was converted into relative physical density relatively to water and the results were satisfied.

采用内插金属丝网管强化竖直蒸发管传热研究

基于蒸发管内流型与传热的内在关联，本文采用200目、孔隙尺寸为75微米的不锈钢金属丝网管作为内插物，通过金属丝网管对流型的调控来影响管内流动沸腾的换热特性；对比研究了普通光管及具有不锈钢金属丝网管作为内插物的蒸发管的传热特性，揭示了泡状流、弹状流、混块状流及环状流这四类典型流型条件下金属丝网管对管内流动沸腾传热的影响机理，为内插金属网管强化沸腾换热技术的应用奠定了科学依据。 Based on the relationship between the flow pattern and heat transfer in an evaporative tube, a stainless steel mesh cylinder of 200 ppi with a pore diameter of 75 μm was used as the insert to regulate the flow patter and enhance the heat transfer of flow boiling in the tube. A comparative study on the evaporative heat transfer was conducted for the bare tube and the tube with the mesh cylinder insert, respectively. In the flow regimes of bubbly flow, slug flow, churn flow and churn/annular flow, the influential mechanisms of the mesh tube on the flow boiling heat transfer were disclosed. The results of this paper will provide a scientific basis for the application of flow boiling heat transfer enhancement by the mesh cylinder insert.

A biological phantom for evaluation of CT image reconstruction algorithms.

In recent years, iterative algorithms have become popular in diagnostic CT imaging to reduce noise or radiation dose to the patient. The non-linear nature of these algorithms leads to non-linearities in the imaging chain. However, the methods to assess the performance of CT imaging systems were developed assuming the linear process of filtered backprojection (FBP). Those methods may not be suitable any longer when applied to non-linear systems. In order to evaluate the imaging performance, a phantom is typically scanned and the image quality is measured using various indices. For reasons of practicality, cost, and durability, those phantoms often consist of simple water containers with uniform cylinder inserts. However, these phantoms do not represent the rich structure and patterns of real tissue accurately. As a result, the measured image quality or detectability performance for lesions may not reflect the performance on clinical images. The discrepancy between estimated and real performance may be even larger for iterative methods which sometimes produce "plastic-like", patchy images with homogeneous patterns. Consequently, more realistic phantoms should be used to assess the performance of iterative algorithms. We designed and constructed a biological phantom consisting of porcine organs and tissue that models a human abdomen, including liver lesions. We scanned the phantom on a clinical CT scanner and compared basic image quality indices between filtered backprojection and an iterative reconstruction algorithm.

Long-term results of combined tunica albuginea plication and penile prosthesis implantation for severe penile curvature and erectile dysfunction.

Penile prosthesis implantation is the recommended treatment in patients with penile curvature and severe erectile dysfunction (ED) not responding to pharmacotherapy. Most patients with mild-to-moderate curvature can expect cylinder insertion to correct both ED and penile curvature. In patients with severe curvature and in those with persistent curvature after corporeal dilation and prosthesis placement, intraoperative penile “modelling” over the inflated prosthesis has been introduced as an effective treatment. We report for the first time the long-term results of a patient treated with combined penile plication and placement of an inflatable penile prosthesis.

SU‐C‐500‐02: Comparison of a Commercial Electronic Brachytherapy Source and Ir‐192/Co‐60 HDR Source for Endometrial and Cervical Cancers

Purpose: To evaluate the dosimetric differences between Iridium‐192, Co‐60 based HDR plans and plans generated by electronic brachytherapy source (EBS) for cervical and endometrial cancers. Material/Methods: Our institution uses volume based planning for each tandem and ovoid (T&amp;O) or vaginal cylinder insertion and treatment. We attempt to characterize the differences between the three sources (Ir‐192, Co‐60 and EBS). For vaginal cylinder cases, patients receive 6 Gy x3 prescribed to a depth 5 mm. For T&amp;O cases, the prescription is 8Gy x3 to point A. Organs at risk (OARs) contoured were rectum, bladder, sigmoid &amp; small bowel. Our planning protocol requires adjustment of source dwell times and positions to keep doses to the OARs below 70% of the prescription dose. For vaginal cylinder, dose coverage is optimized to a line drawn 5mm from the vaginal cylinder surface. This is a retrospective study of previously planned Ir‐192 treated patients. Results: There is no difference between the Co‐60 and Ir‐192 plans but plans generated using the EBS offer better sparing of OARs as evaluated using the dose to highest 2cc of the organ at risk but the differences are not statistically significant. However, there are significant differences in the DVH between EBS and the other two sources. There was a reduction of up to 50% between EBS and other two sources using v15%, v25%, v50% v75% (% of volume getting 15, 50, 75 percent of the prescription dose). Conclusion: All three sources are suitable for HDR Brachytherapy but the use of EBS can reduce the organ at risk dose while achieving similar dose coverage. Even though D2cc is the recommended dose volume point for HDR plans evaluation, V15%, V25%, V50% and V75% are also useful indicator of the plan quality as they characterize the lower dose region of the DVH curves more adequately