Prostate-specific membrane antigen (PSMA) is a transmembrane protein with significantly increased expression in the cells and metastases of prostate carcinoma (CaP). PSMA-expression correlates with higher serum levels of prostate-specific antigen (PSA) and a higher Gleason score (GS). This finding has led to the development of novel imaging modalities such as 68Ga-/18F-labeled PSMA positron emission tomography/computed tomography (PET/CT) and positron emission tomography/magnetic resonance imaging (PET/MRI). This article reviews the literature pertaining to various new imaging technologies for the management of CaP. PSMA positron emission tomography/computed tomography appears to be an excellent diagnostic tool, that may drastically impact the management of a large number of patients with primary and recurrent CaP.

Purpose: During ureteroscopy ureteral balloon dilation may be necessary to allow for passage of endoscopic instruments or access sheaths. We assessed the efficacy and complications associated with ureteral balloon dilation.Materials and Methods: We retrospectively reviewed the records at 2 institutions from 2000 to 2012 to identify patients who underwent ureteral balloon dilation during ureteroscopic treatment of upper tract stones. An 18Fr balloon dilator was used in all cases. Patients with documented ureteral stricture, radiation therapy or urothelial cancer were excluded from analysis. Primary outcomes were the stone-free rate, operative complications, balloon dilation failure and the postoperative ureteral stricture rate. Complications were divided into intraoperative and postoperative groups according to the Satava and Clavien-Dindo classifications, respectively.Results: A total of 151 patients fulfilled study criteria. Median followup was 12 months. The stone-free rate was 72% and median time to first postoperative imaging was 2.8 months. Balloon dilation failed in only 8 patients (5%). Eight intraoperative ureteral perforations (5%) were identified, which were managed by a ureteral stent in 7 patients and a percutaneous tube in 1. Endoscopic re-treatment was required in 4 patients with Satava 2b postoperative complications. The postoperative complication rate was 8% (11 cases). A single ureteral stricture was attributable to balloon dilation.Conclusions: In this contemporary review balloon dilation of the ureter before endoscopic treatment of stone disease was associated with a high success rate and few complications. Ureteral balloon dilation may decrease the need for a secondary procedure in patients undergoing ureteroscopy to manage proximal ureteral and intrarenal stones.

PURPOSEA novel ball tip (BT) holmium laser fiber has recently been developed, which features a modified rounded tip. The modification is purported to aid in insertion and minimize damage to the ureteroscope working channel. We evaluated this laser fiber with regard to stone comminution, tip degradation, insertional force into the ureteroscope, and impact on ureteroscope deflection.MATERIALS AND METHODSA 242 μm BT fiber and a standard flat tip (SF) fiber were compared. Four kilojoules was delivered to a BegoStone over a constant surface area using settings of 0.2/50, 0.6/6, 0.8/8, and 1 J/10 Hz. Fiber tip degradation was measured at 1 and 4 kJ. Ureteroscope deflection was measured with the Olympus URF-P5, URF-P6, and URF-V. Insertion force into a 270° angled ureteroscope sheath model was measured.RESULTSA sample size of five fibers was used for each comminution energy setting. Comminution increased with pulse energy without significant difference between fibers. No significant differences in tip degradation were observed. Both fibers reduced deflection (10°-30°) in all ureteroscopes without significant differences between fibers. Four new fibers paired with new sheath models were used to test insertion force. The BT insertion forces were approximately one-third of the SF. One SF fiber caused significant damage to the sheath and could not be advanced completely.CONCLUSIONSThe BT fiber has comparable comminution, tip degradation, and ureteroscope deflection performance compared with the SF fiber while exhibiting reduced insertion force within an aggressively deflected working sheath. The new tip design is likely protective of the working channel without loss of performance.

You have accessJournal of UrologyStone Disease: New Technology II1 Apr 2014PD37-04 BALL-TIP HOLMIUM LASER FIBER: IN VITRO STONE COMMINUTION AND FIBER TIP DEGRADATION Richard Shin, Jaclyn Lautz, Fernando Cabrera, Zachariah Goldsmith, Nicholas Kuntz, Ramy Youssef, Andreas Neisius, Charles Scales, Michael Ferrandino, Pei Zhong, Walter Simmons, Glenn Preminger, and Michael Lipkin Richard ShinRichard Shin More articles by this author , Jaclyn LautzJaclyn Lautz More articles by this author , Fernando CabreraFernando Cabrera More articles by this author , Zachariah GoldsmithZachariah Goldsmith More articles by this author , Nicholas KuntzNicholas Kuntz More articles by this author , Ramy YoussefRamy Youssef More articles by this author , Andreas NeisiusAndreas Neisius More articles by this author , Charles ScalesCharles Scales More articles by this author , Michael FerrandinoMichael Ferrandino More articles by this author , Pei ZhongPei Zhong More articles by this author , Walter SimmonsWalter Simmons More articles by this author , Glenn PremingerGlenn Preminger More articles by this author , and Michael LipkinMichael Lipkin More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.2022AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Advancing a standard laser fiber through a fully deflected ureteroscope can result in significant damage to the delicate working channel, resulting in significant repair costs. A new ball-tip holmium laser fiber (Flexiva TracTip - Boston Scientific) was designed to atraumatically pass through a deflected ureteroscope. We evaluated the stone comminution capabilities and tip degradation of this fiber in an in vitro model. METHODS A 200 μm ball-tip (BT) fiber and standard fiber (SF) (Flexiva - Boston Scientific) were compared by delivering energy to a Begostone over a constant surface area controlled by a stage controller and 3 dimensional positioning system. Laser settings were 0.2J/50Hz, 0.6J/6Hz, 0.8J/8Hz, and 1J/10Hz. Fiber tip degradation was measured at 1 kJ and 4 kJ of delivered energy. Fiber-stone contact was adjusted every 1 kJ to account for any loss in length. Comminution efficiency was determined by measuring stone weight loss following lithotripsy at each energy setting. ANOVA or Kruskal Wallace test was used for multiple groups, and post hoc tests with Bonferroni correction were then applied (t-test, Wilcoxon). RESULTS A total of 5 virgin fibers were used to test each condition. Tip degradation by 1 kJ with all energy settings and 4 kJ at 0.2J/50Hz was minimal for both fibers without significant differences. By 4 kJ, tip degradation was less overall for the BT and maximal for the SF at 1J/10Hz (Table). Comminution was found to increase with pulse energy for both BT and SF fibers up to the 0.8J/8Hz setting (p < 0.003). No significant differences were found between 0.8J/8Hz and 1J/10Hz or between BT and SF fibers at any energy setting (Figure). CONCLUSIONS The ball-tip fiber exhibits similar comminution efficiency to a standard holmium laser fiber with minimal tip degradation at clinically relevant laser settings in our in vitro model. The new tip design may provide an advantage in access maneuverability without loss of performance. Further in vivo studies are warranted to validate these objective findings. Standard fiber (SF) and ball-tip (BT) fiber tip degradation at 1 kJ and 4 kJ (Median with IQR) Setting Energy SF tip degradation (mm) BT tip degradation (mm) P value 0.2J/50Hz 1 kJ 0 (-0.1 - 0.03) -0.02 (-0.05 - 0.02) 1 4 kJ 0 (-0.12 - 0.06) 0.07 (0.01 - 0.1) 0.207 0.6J/6Hz 1 kJ 0 (-0.08 - 0.05) 0 (-0.05 - 0.1) 0.747 4 kJ 0.16 (0.1 - 0.2) 0.15 (0.02 - 0.56) 0.599 0.8J/8Hz 1 kJ 0.05 (0 - 0.08) 0.1 (0 - 0.1) 0.576 4 kJ 0.25 (0.23 - 0.28) 0.1 (0.03 - 0.23) 0.112 1J/10Hz 1 kJ 0 (-0.05 - 0) 0.05 (0.02 - 0.1) 0.084 4 kJ 0.3 (0.2 - 1.35) 0.08 (0 - 0.2) 0.036 © 2014FiguresReferencesRelatedDetailsCited byKronenberg P and Traxer O (2018) Lithotripsy Performance of Specially Designed Laser Fiber TipsJournal of Urology, VOL. 195, NO. 5, (1606-1612), Online publication date: 1-May-2016. Volume 191Issue 4SApril 2014Page: e947 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Richard Shin More articles by this author Jaclyn Lautz More articles by this author Fernando Cabrera More articles by this author Zachariah Goldsmith More articles by this author Nicholas Kuntz More articles by this author Ramy Youssef More articles by this author Andreas Neisius More articles by this author Charles Scales More articles by this author Michael Ferrandino More articles by this author Pei Zhong More articles by this author Walter Simmons More articles by this author Glenn Preminger More articles by this author Michael Lipkin More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

OBJECTIVE To determine organ-specific doses (ODs) and effective dose (ED) for digital tomosynthesis (DT) and compare it with our institutional renal stone protocol noncontrast computed tomography (NCCT).METHODS A validated anthropomorphic male phantom was placed supine on a digital GE Definium 8000 radiological scanner. Thermoluminescent dosimeters were placed in 256 locations and used to measure OD. A routine DT study was performed consisting of 2 scout images and 1 tomographic sweep in a 14.2-degree arc over the phantom. Software is used to recreate a series of coronal images from the sweep. ODs were determined as the sum of the doses for the study. Equivalent doses were calculated by multiplying OD with the appropriate tissue weighting factor. ED is the summation of the equivalent doses. OD and ED were determined in a similar fashion (using dosimeters) for a renal stone protocol NCCT and doses were compared.RESULTS ODs for DT are significantly lower compared with NCCT. The ED for NCCT is 3.04 +/- 0.34 mSv. The calculated ED for DT is 0.87 +/- 0.15 mSv (2 scouts at 0.17 mSv and 0.14 mSv and 1 sweep at 0.56 mSv), P < .0001.CONCLUSION DT exposes patients to substantially less radiation than NCCT. This is particularly true for radiation-sensitive organs. Further studies are needed to compare the sensitivity and specificity of DT as compared with NCCT. However, its low overall radiation dose makes it an ideal study for the follow-up of recurrent stone formers in the office setting. (C) 2014 Elsevier Inc.

You have accessJournal of UrologyUrodynamics/Incontinence/Female Urology: Basic Research I1 Apr 2014MP1-16 STRIKING DOSE- AND TIME-DEPENDENCE OF RADIATION CYSTITIS IN THE RAT: WEEKLY CYSTOMETRIC EVALUATION UP TO NINE WEEKS AFTER PELVIC IRRADIATION Nicholas J. Kuntz, Matthew O. Fraser, Danielle J. Degoski, Abhay A. Singh, Paul C. Dolber, and Andrew C. Peterson Nicholas J. KuntzNicholas J. Kuntz More articles by this author , Matthew O. FraserMatthew O. Fraser More articles by this author , Danielle J. DegoskiDanielle J. Degoski More articles by this author , Abhay A. SinghAbhay A. Singh More articles by this author , Paul C. DolberPaul C. Dolber More articles by this author , and Andrew C. PetersonAndrew C. Peterson More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.114AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Radiation therapy (RT) is a common treatment for prostate cancer and other pelvic malignancies. Radiation cystitis (PRC) occurs frequently and is characterized by acute irritative voiding symptoms and chronic hemorrhagic cystitis. We describe the development of a rat model designed to test novel therapeutic strategies for prevention and treatment of PRC. METHODS Female SD rats (n=24) received specially fabricated chronic bladder catheters positioned to better maintain the natural position of the bladder for the duration of the experiments (up to 9 weeks) and tunneled subcutaneously to the midscapular region for ready access. One week after catheter implant, the animals received single dose pelvic RT with either 0, 5, 10 or 20 Gy using a small-field biological irradiator (X-RAD 225Cx, Precision X-Ray, Inc.) with a 42 collimator (Exp1) or 0, 20, 30 and 40 Gy with a 2.52 collimator (Exp2). Every week for 4 or 9 weeks thereafter, resp., conscious restrained cystometry was performed with infusion of normal saline, and 300 and 500 mM KCl. The primary outcome measure was bladder capacity (BC) for each infusate at each interval. Data were analyzed using 2-Way RM ANOVA, p<0.05 was considered significant. RESULTS Statistical analysis revealed a marked and significant inverse relationship between radiation dose and BC for both sets. Exp1 - the 0 and 5 Gy doses had no effect. 10 Gy dose was also without effect until week 4, with ∼30% drop under saline. The 20 Gy dose resulted in a ∼50% reduction in BC by Week 1, that evolved to a ∼60% decrease by Week 4. KCl sensitivity was evident by Week 1 following 20 Gy, and BC was reduced ∼50% and ∼75% by 10 and 20 Gy, resp. by Week 4. Exp2 – KCL decreased BC at 3 and 4 weeks for 40 and 30 Gy by 87 and 70%, resp. BC under saline alone was reduced 65% by Week 6 for 40 Gy. CONCLUSIONS The results clearly support a dose-response relationship between radiation exposure and bladder physiology using serial cystometric evaluation ± intravesical KCl challenge. Intensity of effect was + and – related to RT intensity and field size, resp. These preliminary results set the stage for the development of therapeutic approaches directed toward the treatment and prevention of radiation cystitis. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e7 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Nicholas J. Kuntz More articles by this author Matthew O. Fraser More articles by this author Danielle J. Degoski More articles by this author Abhay A. Singh More articles by this author Paul C. Dolber More articles by this author Andrew C. Peterson More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

You have accessJournal of UrologyStone Disease: Basic Research I1 Apr 2014MP20-04 BALL-TIP HOLMIUM LASER FIBER MAY REDUCE FLEXIBLE URETEROSCOPE DAMAGE Richard Shin, Fernando Cabrera, Constandi Shami, Zachariah Goldsmith, Nicholas Kuntz, Ramy Youssef, Andreas Neisius, Charles Scales, Michael Ferrandino, Pei Zhong, Walter Simmons, Glenn Preminger, and Michael Lipkin Richard ShinRichard Shin More articles by this author , Fernando CabreraFernando Cabrera More articles by this author , Constandi ShamiConstandi Shami More articles by this author , Zachariah GoldsmithZachariah Goldsmith More articles by this author , Nicholas KuntzNicholas Kuntz More articles by this author , Ramy YoussefRamy Youssef More articles by this author , Andreas NeisiusAndreas Neisius More articles by this author , Charles ScalesCharles Scales More articles by this author , Michael FerrandinoMichael Ferrandino More articles by this author , Pei ZhongPei Zhong More articles by this author , Walter SimmonsWalter Simmons More articles by this author , Glenn PremingerGlenn Preminger More articles by this author , and Michael LipkinMichael Lipkin More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.726AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Lower pole renal stones present a challenge for retrograde laser lithotripsy. Holmium laser fiber passage can damage the working channel of a fully flexed ureteroscope. A recently released ball-tip laser fiber (TracTip - Boston Scientific) features a modified tip to reduce scope trauma. We compared ureteroscope deflection and insertion forces of this ball tip to a standard laser fiber. METHODS Ureteroscope deflection was measured using a 200 μm ball-tip (BT) and standard fiber (SF) (Flexiva - Boston Scientific) with two fiber optic and one digital ureteroscope (URF-P5, URF-P6, URF-V - Olympus). The ureteroscopes were flexed/extended empty and with each fiber for 4 consecutive runs. Deflection angle was measured using AutoCAD software. Insertion force was measured in a ureteroscope sheath positioned in a 270° curve. The BT and SF fibers were advanced using a stage controller and a strain gauge measured force. ANOVA test was used to compare multiple groups and t-test was used for intergroup comparison with a Bonferroni correction as applicable. RESULTS Both fibers caused reduced but equivalent reduction (10-30°) in ureteroscope flexion/extension in all three models with no statistical difference (Figure 1). Four virgin fibers and ureteroscope sheaths were used to test insertion force of each fiber. The maximum and average insertion force for the SF was 998 ±394 mN and 603 ±163 mN respectively. The BT insertion forces were approximately 1/3 of the SF; 304 ±31 mN maximum and 213 ±31 mN mean insertion force (p = 0.040, 0.025 respectively). One SF fiber caused significant damage to the sheath and could not be advanced completely (Figure 2). CONCLUSIONS The ball-tip fiber has markedly reduced force of insertion in a deflected ureteroscope without compromising maneuverability compared to a standard laser fiber. Minimal investment in the ball-tip fiber may result in cost savings by reducing working channel damage and increasing ureteroscope longevity. © 2014FiguresReferencesRelatedDetailsCited byKronenberg P and Traxer O (2018) Lithotripsy Performance of Specially Designed Laser Fiber TipsJournal of Urology, VOL. 195, NO. 5, (1606-1612), Online publication date: 1-May-2016. Volume 191Issue 4SApril 2014Page: e197 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Richard Shin More articles by this author Fernando Cabrera More articles by this author Constandi Shami More articles by this author Zachariah Goldsmith More articles by this author Nicholas Kuntz More articles by this author Ramy Youssef More articles by this author Andreas Neisius More articles by this author Charles Scales More articles by this author Michael Ferrandino More articles by this author Pei Zhong More articles by this author Walter Simmons More articles by this author Glenn Preminger More articles by this author Michael Lipkin More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Objective To evaluate whether body mass index (BMI) has an impact on the outcomes of tubeless percutaneous nephrolithotomy (PCNL). Patients and Methods We retrospectively reviewed patients who underwent tubeless PCNL at our institution from 2006 to 2011. Specifically, stone‐free rates, complications, and hospital length of stay (LOS) were assessed. Patients were divided into four groups based on BMI: <25, 25–29.9, 30–34.9 and ≥35 kg/m2. Baseline characteristics and outcomes were compared between BMI groups. Multivariable logistic regressions were used to evaluate the independent contribution of BMI as a predictor of outcomes. Results We identified 268 patients who fulfilled study requirements. The overall stone‐free and complication rates were 52.5% and 19.0%, respectively. Minor and severe complication comprised 10.4% and 8.6%, respectively. Univariate and multivariable analyses showed no association between BMI and stone‐free or complication rates. However, patients with a normal BMI had significantly higher transfusion rates (P = 0.005), and were significantly more likely to have a prolonged LOS (≥2 days), when compared with an overweight BMI (P = 0.032) Conclusions BMI did not impact the stone‐free, or complication rates of tubeless PCNL. Normal BMI was found to be a risk factor for prolonged LOS, which may be due to an increase in clinically significant bleeding in this patient population. Tubeless PCNL appears to be a safe and effective procedure for the treatment of complex renal calculi, independent of BMI.

PURPOSE:Computerized tomography use increased exponentially in the last 3 decades, and it is commonly used to evaluate many urological conditions. Ionizing radiation exposure from medical imaging is linked to the risk of malignancy. We measured the organ and calculated effective doses of different studies to determine whether the dose-length product method is an accurate estimation of radiation exposure. MATERIALS AND METHODS:An anthropomorphic male phantom validated for human organ dosimetry measurements was used to determine radiation doses. High sensitivity metal oxide semiconductor field effect transistor dosimeters were placed at 20 organ locations to measure specific organ doses. For each study the phantom was scanned 3 times using our institutional protocols. Organ doses were measured and effective doses were calculated on dosimetry. Effective doses measured by a metal oxide semiconductor field effect transistor dosimeter were compared to calculated effective doses derived from the dose-length product. RESULTS:The mean±SD effective dose on dosimetry for stone protocol, chest and abdominopelvic computerized tomography, computerized tomography urogram and renal cell carcinoma protocol computerized tomography was 3.04±0.34, 4.34±0.27, 5.19±0.64, 9.73±0.71 and 11.42±0.24 mSv, respectively. The calculated effective dose for these studies Was 3.33, 2.92, 5.84, 9.64 and 10.06 mSv, respectively (p=0.8478). CONCLUSIONS:The effective dose varies considerable for different urological computerized tomography studies. Renal stone protocol computerized tomography shows the lowest dose, and computerized tomography urogram and the renal cell carcinoma protocol accumulate the highest effective doses. The calculated effective dose derived from the dose-length product is a reasonable estimate of patient radiation exposure.

Background and Purpose: Struvite stones have been associated with significant morbidity and mortality, yet there has not been a report on the medical management of struvite stones in almost 20 years. We report on the contemporary outcomes of the surgical and medical management of struvite stones in a contemporary series.Patients and Methods: A retrospective review of patients who were treated with percutaneous nephrolithotomy (PCNL) for struvite stones at Duke University Medical Center between January 2005 and September 2012 identified a total of 75 patients. Of these, 43 patients had adequate follow-up and were included in this analysis. Stone activity, defined as either stone recurrence or stone-related events, and predictors of activity were evaluated after combined surgical and medical treatment.Results: The study included 43 patients with either pure (35%) or mixed (65%) struvite stones with a median age of 55 -15 years (range 21-89 years). The stone-free rate after PCNL was 42%. Stone recurrence occurred in 23% of patients. Postoperatively, 30% of patients had a stone-related event, while 60% of residual stones remained stable with no growth after a median follow-up of 22 months (range 6-67 mos). Kidney function remained stable during follow-up. Independent predictors of stone activity included the presence of residual stones > 0.4 cm 2, preoperative large stone burden (> 10 cm 2), and the presence of medical comorbidities (P< 0.05).Conclusions: Struvite stones can be managed safely with PCNL followed by medical therapy. The majority of patients with residual fragments demonstrated no evidence of stone growth on medical therapy. With careful follow-up and medical management, kidney function can be maintained and stone morbidity can be minimized. Initial large stone burden, residual stones after surgery, and associated medical comorbidities may have deleterious effect on stone recurrence or residual stone-related events.

You have accessJournal of UrologyStone Disease: Basic Research (I)1 Apr 20132076 SPECIFIC ORGAN DOSES UTILIZING A NEW TECHNIQUE FOR IMAGING NEPHROLITHIASIS: DIGITAL TOMOSYNTHESIS Andreas Neisius, Gaston M. Astroza, Nicholas J. Kuntz, Agnes J. Wang, Giao Nguyen, Chu Wang, Natalie Januzis, Amy M. Neville, Greta Toncheva, Ramy Youssef, Muhammad W. Iqbal, Michael N. Ferrandino, Terry T. Yoshizumi, Glenn M. Preminger, and Michael E. Lipkin Andreas NeisiusAndreas Neisius Durham, NC More articles by this author , Gaston M. AstrozaGaston M. Astroza Durham, NC More articles by this author , Nicholas J. KuntzNicholas J. Kuntz Durham, NC More articles by this author , Agnes J. WangAgnes J. Wang Durham, NC More articles by this author , Giao NguyenGiao Nguyen Durham, NC More articles by this author , Chu WangChu Wang Durham, NC More articles by this author , Natalie JanuzisNatalie Januzis Durham, NC More articles by this author , Amy M. NevilleAmy M. Neville Durham, NC More articles by this author , Greta TonchevaGreta Toncheva Durham, NC More articles by this author , Ramy YoussefRamy Youssef Durham, NC More articles by this author , Muhammad W. IqbalMuhammad W. Iqbal Durham, NC More articles by this author , Michael N. FerrandinoMichael N. Ferrandino Durham, NC More articles by this author , Terry T. YoshizumiTerry T. Yoshizumi Durham, NC More articles by this author , Glenn M. PremingerGlenn M. Preminger Durham, NC More articles by this author , and Michael E. LipkinMichael E. Lipkin Durham, NC More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.2495AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Digital tomosynthesis (DT) is a novel imaging technique for the evaluation of patients of with nephrolithiasis. It consists of a plain abdominal radiograph (KUB) and one tomographic sweep. Software is used to recreate a series of coronal images from the tomographic sweep. We determined organ specific dose and effective dose (ED) for DT and compared it to our institutional “low dose” non contrast computed tomography (NCCT). METHODS A validated anthropomorphic male phantom was placed supine on a GE Definium 8000 CT scanner. High sensitivity metal oxide semiconductor field effect transistors (MOSFET) dosimeters were placed at 20 organ locations and used to measure organ doses (OD). A routine DT study was performed consisting of two KUB (scout) images and one tomographic sweep in a 60 degree arc over the phantom. OD were determined as the sum of the doses for the study. Equivalent doses were calculated by multiplying OD and the appropriate tissue weighting factor. ED was calculated by the summation of the equivalent doses. OD and ED were determined in a similar fashion for a renal stone protocol NCCT and the doses were compared. RESULTS Specific organ doses for DT (2 scouts and 1 tomographic sweep) and NCCT are shown in the table. The ED for NCCT is 3.04 (±0.34) mSv. The calculated ED for digital tomosynthesis is 0.54 (±0.07) mSv (2 scouts at 0.10mSv and 0.08mSv + 1 sweep at 0.36mSv), p=0.0002. CONCLUSIONS Digital tomosynthesis exposes patients to substantially less radiation than NCCT. This is particularly true for radiation sensitive organs. Further studies are needed to compare the sensitivity and specificity of DT as compared to NCCT. However, its low overall radiation dose make it an ideal study for the follow up of the recurrent stone former in the office setting. Table. Exemplary organ doses (OD) from NCCT (stone protocol) compared to DT Organs NCCT (+/− SD) Digital tomosynthesis (+/− SD) p value Skin entrance 7.23 (+/−0.51) mGy 9.69 (+/−0.43) mGy 0.0031 Lungs 3.05 (+/−1.26) mGy 6.40 (+/−0.61) mGy 0.0143 Red bone marrow 3.2 (+/−0.1) mGy 0.81 (+/−0.15) mGy < 0.0001 Testes 5.17 (+/−3.73) mGy 0.12 (+/−0.21) mGy 0.0793 Liver 4.28 (+/−0.24) mGy 4.26 (+/−4.07) mGy 0.9960 Kidney 5.18 (+/−0.47) mGy 2.10 (+/−1.16) mGy 0.0130 © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e852 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Andreas Neisius Durham, NC More articles by this author Gaston M. Astroza Durham, NC More articles by this author Nicholas J. Kuntz Durham, NC More articles by this author Agnes J. Wang Durham, NC More articles by this author Giao Nguyen Durham, NC More articles by this author Chu Wang Durham, NC More articles by this author Natalie Januzis Durham, NC More articles by this author Amy M. Neville Durham, NC More articles by this author Greta Toncheva Durham, NC More articles by this author Ramy Youssef Durham, NC More articles by this author Muhammad W. Iqbal Durham, NC More articles by this author Michael N. Ferrandino Durham, NC More articles by this author Terry T. Yoshizumi Durham, NC More articles by this author Glenn M. Preminger Durham, NC More articles by this author Michael E. Lipkin Durham, NC More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

You have accessJournal of UrologyStone Disease: Evaluation & Medical Management (I)1 Apr 20132094 TREATMENT RESPONSE IN STONE PATIENTS WITH GOUTHY DIATHESIS STRATIFIED BY BODY MASS INDEX Gastón Astroza, Andreas Neisius, Matvey Tsivian, Muhammad Iqbal, Nicholas Kuntz, Ramy Youssef, Glenn Preminger, and Michael Lipkin Gastón AstrozaGastón Astroza Durham, NC More articles by this author , Andreas NeisiusAndreas Neisius Durham, NC More articles by this author , Matvey TsivianMatvey Tsivian Durham, NC More articles by this author , Muhammad IqbalMuhammad Iqbal Durham, NC More articles by this author , Nicholas KuntzNicholas Kuntz Durham, NC More articles by this author , Ramy YoussefRamy Youssef Durham, NC More articles by this author , Glenn PremingerGlenn Preminger Durham, NC More articles by this author , and Michael LipkinMichael Lipkin Durham, NC More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.2003AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Hypocitraturia (hypocit) and gouthy diathesis (GD) are common metabolic abnormalities in patients with urolithiasis. Since different physiologic pathways may be associated with GD in obese and non-obese patients we hypothesized that therapeutic response to treatment with potassium citrate (KCit) could differ by body mass index (BMI). METHODS We performed a retrospective review of patients with urolithiasis who had undergone metabolic evaluation from 2001-2011. Patients with hypocit/GD defined as urinary citrate ≤500mg and urinary pH≤5.6, respectively, who were treated with KCit were included. Metabolic data from 24 hour urine collections was recorded at baseline, 3, 6, 9, 12, 18, 24 and 36 months. The cohort was divided into 4 groups based on BMI: BMI<25kg/m2, II: BMI 25-29.9, III: BMI 30-34.9 and IV: BMI≥35kg/m2. Metabolic data was compared between groups at baseline and subsequent visits. We compared urinary pH and citrate both in absolute values and the relative change in these parameters from baseline, as well as the rate at which patients required an increase of KCit. Fisher's exact and rank sum tests were used for comparisons. Trend analyses were performed using Cochran-Armitage and Cuzick's tests. RESULTS A total of 3166 patients with urolithiasis who had undergone metabolic evaluation were identified, of which 125 had both hypocit/GD. Median patient age was 61 (52-68) yrs, 80 (64%) were males and median BMI was 30.4kg/m2 (26.1-35.0). Urine pH increased from 5.4 (5.2-5.5) to 6.0 (5.5-6.6) at first follow up (p<0.001). Similarly, citrate levels rose from 247mg/d (125-355) to 534 (318-728) (p<0.001). The median change in pH on KCit treatment was 0.7 (0.2-1.2). PH values and their absolute change from baseline were lower as BMI increased (p≤0.001). Similarly, an association between increasing BMI category and lower urinary citrate levels was accompanied by a significant trend indicating lower absolute changes in citrate with increasing BMI (p≤0.001). KCit doses and therapy modifications were increased more frequently among higher BMI groups being 9% for normal weight and overweight, 17% for obese and 38% for morbidly obese patients (p=0.002). Overall, pH and citrate levels normalized in 61% and 51% with no apparent differences between the BMI groups. CONCLUSIONS In patients with hypocit/GD, KCit appears to be less effective at raising pH as BMI increases and more frequent dose adjustments are needed in obese patients. Obese patients with hypocit/GD treated with KCit require close follow up with repeat 24 hour urine collections to ensure adequate response. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e859 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Gastón Astroza Durham, NC More articles by this author Andreas Neisius Durham, NC More articles by this author Matvey Tsivian Durham, NC More articles by this author Muhammad Iqbal Durham, NC More articles by this author Nicholas Kuntz Durham, NC More articles by this author Ramy Youssef Durham, NC More articles by this author Glenn Preminger Durham, NC More articles by this author Michael Lipkin Durham, NC More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Radiation therapy is the first choice for treatment of many pelvic visceral cancers. Two forms are currently employed, external beam radiation and brachytherapy. In the case of the former, ionizing radiation is directed at the afflicted organ and, in the latter, pellets of radioactive material are implanted at cancer lesion sites. The therapeutic mechanism of action is indirect (via reactive oxygen species) and direct damage to DNA of cancer cells. In non-replicating cells, this is not necessarily a lethal event, and DNA repair mechanisms may be utilized to repair the damaged DNA and maintain the terminally differentiated cells. In the case of cancers, where the cells are rapidly replicating and doing so before DNA repair mechanisms are able to correct the radiationinduced damage, this damage results in death of the cells during mitosis and thus elimination of the cancer.

A neobladder-arterial fistula is a very rare complication following cystectomy, with only 1 previously reported case. Delay in diagnosis can be rapidly fatal and requires prompt intervention. We report the case of a 63-year-old male who developed massive hematuria, and was found to have a fistula between the right external iliac artery and Studer neobladder during emergent exploratory laparotomy. Treatment success relies on a high index of suspicion and may include open operative intervention.

You have accessJournal of UrologyStone Disease: Basic Research (II)1 Apr 20132304 IN VIVO STONE COMMINUTION PRODUCED BY A MODIFIED ACOUSTIC LENS FOR ELECTROMAGNETIC LITHOTRIPTERS Andreas Neisius, Nathan Smith, Nicholas J. Kuntz, Tim Schykowski, Gaston M. Astroza, Ramy Youssef, Muhammad W. Iqbal, Michael E. Lipkin, Michael N. Ferrandino, Walther N. Simmons, Glenn M. Preminger, and Pei Zhong Andreas NeisiusAndreas Neisius Durham, NC More articles by this author , Nathan SmithNathan Smith Durham, NC More articles by this author , Nicholas J. KuntzNicholas J. Kuntz Durham, NC More articles by this author , Tim SchykowskiTim Schykowski Durham, NC More articles by this author , Gaston M. AstrozaGaston M. Astroza Durham, NC More articles by this author , Ramy YoussefRamy Youssef Durham, NC More articles by this author , Muhammad W. IqbalMuhammad W. Iqbal Durham, NC More articles by this author , Michael E. LipkinMichael E. Lipkin Durham, NC More articles by this author , Michael N. FerrandinoMichael N. Ferrandino Durham, NC More articles by this author , Walther N. SimmonsWalther N. Simmons Durham, NC More articles by this author , Glenn M. PremingerGlenn M. Preminger Durham, NC More articles by this author , and Pei ZhongPei Zhong Durham, NC More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.2245AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The acoustic lens of a Siemens Modularis electromagnetic shock wave lithotripter has been further modified to reduce pre-focal cavitation while generating a pressure waveform and broad focal zone mimicking that of the Dornier HM3. In this study, we sought to determine the comminution efficiency of the modified lens following a clinical therapy regime and compared the results to comminution produce by the original lens in a swine model. METHODS Using the maximum energy level (E+ = 44 mJ) that is safe for lithotripsy (i.e., without formation of gross hematoma), we have compared stone comminution produced by the original and modified lenses in vivo using hard cylindrical Begostones of 5 x10 mm, surgically implemented in pig kidneys. A clinical protocol with a soft ramping scheme was used to deliver 3000 shock waves to each kidney using a pulse repetition frequency of 1.5 Hz, leading to a total accumulated energy of 112.84 J. Following lithotripsy, kidneys were harvested, dissected, all visible stone fragments were collected, dried and filtered with standard sieves with decreasing mesh size of 4, 2.8, and 2 mm, respectively. Final comminution efficiencies were determined by the percentage (by weight) of fragments less than 2 mm. An unpaired two-tailed student's t-test was used to compare fragmentation results. RESULTS At E+ = 44 mJ, the modified lens (12 renal units) showed a comminution efficiency of 72.8% (±21.4%) compared to 63.6% (±21.8%) for the original lens (10 renal units) overall, p= 0.058. When considering stones not trapped in the DJ loop and those with no spread >2cm, comminution efficiency was 88.8% (±10.9%) for the modified lens vs 54.1% (±23.3%) for the original lens, p=0.013. CONCLUSIONS With our latest lens modification the electromagnetic lithotripter demonstrates better stone comminution under a clinically relevant energy setting and treatment protocol when compared to the original lens. This lens modification could be retrofitted to most electromagnetic lithotripters, thereby improving efficiency of clinical stone fragmentation. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e944 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Andreas Neisius Durham, NC More articles by this author Nathan Smith Durham, NC More articles by this author Nicholas J. Kuntz Durham, NC More articles by this author Tim Schykowski Durham, NC More articles by this author Gaston M. Astroza Durham, NC More articles by this author Ramy Youssef Durham, NC More articles by this author Muhammad W. Iqbal Durham, NC More articles by this author Michael E. Lipkin Durham, NC More articles by this author Michael N. Ferrandino Durham, NC More articles by this author Walther N. Simmons Durham, NC More articles by this author Glenn M. Preminger Durham, NC More articles by this author Pei Zhong Durham, NC More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

You have accessJournal of UrologyStone Disease: Basic Research (I)1 Apr 20132079 ENERGY AND PULSE REPETITION FREQUENCY DEPENDENT TISSUE INJURY PRODUCED BY A MODIFIED ACOUSTIC LENS FOR ELECTROMAGNETIC LITHOTRIPTERS Andreas Neisius, Nathan Smith, Nicholas J. Kuntz, Tim Schykowski, Gaston M. Astroza, Ramy Youssef, Muhammad W. Iqbal, Michael E. Lipkin, Michael N. Ferrandino, Michael R. Gustafson, Walther N. Simmons, Glenn M. Preminger, and Pei Zhong Andreas NeisiusAndreas Neisius Durham, NC More articles by this author , Nathan SmithNathan Smith Durham, NC More articles by this author , Nicholas J. KuntzNicholas J. Kuntz Durham, NC More articles by this author , Tim SchykowskiTim Schykowski Durham, NC More articles by this author , Gaston M. AstrozaGaston M. Astroza Durham, NC More articles by this author , Ramy YoussefRamy Youssef Durham, NC More articles by this author , Muhammad W. IqbalMuhammad W. Iqbal Durham, NC More articles by this author , Michael E. LipkinMichael E. Lipkin Durham, NC More articles by this author , Michael N. FerrandinoMichael N. Ferrandino Durham, NC More articles by this author , Michael R. GustafsonMichael R. Gustafson Durham, NC More articles by this author , Walther N. SimmonsWalther N. Simmons Durham, NC More articles by this author , Glenn M. PremingerGlenn M. Preminger Durham, NC More articles by this author , and Pei ZhongPei Zhong Durham, NC More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.2498AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The acoustic lens of a Siemens Modularis electromagnetic shock wave lithotripter has been further modified to reduce pre-focal cavitation while generating a pressure waveform and broad focal zone mimicking the Dornier HM3 electrohydraulic device. We sought to determine the threshold for the maximum acoustic energy which can be safely applied to a kidney under clinically relevant treatment protocols, and the dependency of tissue injury on pulse repetition frequency (PRF). METHODS Tissue injury (TI) produced by the original and modified lenses in a swine model were first evaluated starting from the highest output level to determine the threshold energy for safe lithotripsy. Thereafter, TI was assessed under an effective acoustic pulse energy for the leading compressive wave (E+)of 44 mJ. A clinical protocol with a soft ramping scheme was used to deliver 3000 shock waves to each kidney using a PRF of 1.0 and 1.5 Hz, leading to a total accumulated energy of 112.84 J. Following lithotripsy, kidneys were perfused, harvested, dehydrated, cast in paraffin wax, and sectioned. Photographic images were taken every 120 μm and analyzed to determine the functional renal volume (FRV) damage. RESULTS Gross subcapsular hematomas were produced by both the original and modified lenses at E+ of 51 mJ. Using E+ of 44 mJ, the modified lens showed quantatively macroscopic tissue injury (subcapsular hematoma) in 1/6 renal units (17%) in the 1.5 Hz group. No macroscopic tissue injury was detected in the 1.0 Hz group (0/6 renal units). After processing of the digitalized images TI was detected in 0.432 % (±0.51%) of the FRV (with a maximum level of 1.324% in the kidney with the gross hematoma) in the 1.5 Hz group and in 0.009% (±0.015%) of the FRV in the 1 Hz group (p=0.025), respectively. CONCLUSIONS This study demonstrates that the energy threshold for gross TI of the modified lens is comparable to the original lens. Our data further confirms that the initiation of TI depends on acoustic pulse energy, and the extent of TI depends on the total accumulated acoustic energy delivered to a kidney, as well as on PRF. Overall, our results suggest that a rational design of treatment strategies to minimize tissue injury in SWL is warranted. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e853 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Andreas Neisius Durham, NC More articles by this author Nathan Smith Durham, NC More articles by this author Nicholas J. Kuntz Durham, NC More articles by this author Tim Schykowski Durham, NC More articles by this author Gaston M. Astroza Durham, NC More articles by this author Ramy Youssef Durham, NC More articles by this author Muhammad W. Iqbal Durham, NC More articles by this author Michael E. Lipkin Durham, NC More articles by this author Michael N. Ferrandino Durham, NC More articles by this author Michael R. Gustafson Durham, NC More articles by this author Walther N. Simmons Durham, NC More articles by this author Glenn M. Preminger Durham, NC More articles by this author Pei Zhong Durham, NC More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...