Full bladder, empty rectum? Revisiting a paradigm in the era of adaptive radiotherapy.

BACKGROUND AND PURPOSE: Many patients find it challenging to comply with instructions regarding rectum and bladder filling during pelvic radiotherapy. With the implementation of online adaptive radiotherapy, the reproducibility of organ volumes is no longer a prerequisite. This study aims to analyze the sparing of the bladder and the posterior rectum wall (PRW) in conditions of full versus empty bladder and rectum. METHODS: 280 fractions from 14 patients with prostate cancer who underwent adaptive radiotherapy using the Varian Ethos system were analyzed post-hoc. Various metrics for the bladder and PRW were correlated with respect to organ volume. RESULTS: Our analysis quantitatively confirms the advantage of a full bladder during radiotherapy, as metrics V48Gy and V40Gy significantly inversely correlate with bladder filling for each patient individually. While bladder volume did not show a gradual decrease over the course of radiotherapy, it was observed to be higher during planning CT scans compared to treatment sessions. A full rectum condition either significantly improved (in 2 out of 7 patients) or at least did not impair (in 5 out of 7 patients) PRW sparing, as represented by the V30Gy metric, when patients were compared individually. The average V30Gy across all patients demonstrated a significant improvement in PRW sparing for the full rectum condition, with a [Formula: see text]-value of 0.039. CONCLUSION: Despite the implementation of adaptive therapy, maintaining a high bladder filling remains important. However, the recommendation for rectum filling can be abandoned, as reproducibility is not critical for adaptive radiotherapy and no dosimetric advantage per se is associated with an empty rectum. Patients may even be encouraged not to void their bowels shortly before treatment, as long as this is tolerated over the treatment session.

A-Mode Ultrasound Bladder Volume Estimation Algorithm Based on Wavelet Energy Ratio Adaptive Denoising.

Assessing bladder function is pivotal in urological health, with bladder volume a critical indicator. Traditional devices, hindered by high costs and cumbersome sizes, are being increasingly supplemented by portable alternatives; however, these alternatives often fall short in measurement accuracy. Addressing this gap, this study introduces a novel A-mode ultrasound-based bladder volume estimation algorithm optimized for portable devices, combining efficient, precise volume estimation with enhanced usability. Through the innovative application of a wavelet energy ratio adaptive denoising method, the algorithm significantly improves the signal-to-noise ratio, preserving critical signal details amidst device and environmental noise. Ultrasonic echoes were employed to acquire positional information on the anterior and posterior walls of the bladder at several points, with an ellipsoid fitted to these points using the least squares method for bladder volume estimation. Ultimately, a simulation experiment was conducted on an underwater porcine bladder. The experimental results indicate that the bladder volume estimation error of the algorithm is approximately 8.3%. This study offers a viable solution to enhance the accuracy and usability of portable devices for urological health monitoring, demonstrating significant potential for clinical application.

A Novel Three-Point Localization Method for Bladder Volume Estimation.

The measurement of bladder volume is crucial for the diagnosis and treatment of urinary system diseases. Ultrasound imaging, with its non-invasive, radiation-free, and repeatable scanning capabilities, has become the preferred method for measuring residual urine volume. Nevertheless, it still faces some challenges, including complex imaging methods leading to longer measurement times and lower spatial resolution. Here, we propose a novel three-point localization method that does not require ultrasound imaging to calculate bladder volume. A corresponding triple-element ultrasound probe has been designed based on this method, enabling the ultrasound probe to transmit and receive ultrasound waves in three directions. Furthermore, we utilize the Hilbert Transform algorithm to extract the envelope of the ultrasound signal to enhance the efficiency of bladder volume measurements. The experiment indicates that bladder volume estimation can be completed within 5 s, with a relative error rate of less than 15%. These results demonstrate that this novel three-point localization method offers an effective approach for bladder volume measurement in patients with urological conditions.

Postpartum urinary retention in women undergoing instrumental delivery: A cross-sectional analytical study.

INTRODUCTION: Women undergoing instrumental delivery are known to be at higher risk of urinary retention, which can lead to long-term complications such as voiding dysfunction. Nulliparous women undergo a pronounced and sudden change in the perineum due to stretching during delivery, which may add to the perineal trauma from an episiotomy, increasing the risk of urinary retention. We aim to study the incidence and risk factors associated with postpartum urinary retention in women undergoing instrumental delivery. MATERIAL AND METHODS: Pregnant women who had an instrumental delivery after 37 weeks of gestation at JIPMER, Puducherry, India, between January 2017 and June 2017 were included in the study. Postpartum urinary retention was defined as the inability to void spontaneously or ultrasonographic documentation of post-void residual volume of >150 mL, 6 hours after delivery. Demographic factors, clinical profile and follow-up of these patients were noted. Multivariate logistic regression analysis was performed to assess the risk factors associated with urinary retention and was presented as adjusted odds ratios (OR) with 95% confidence intervals (CI). RESULTS: Postpartum urinary retention was noted in 124 (20.6%) women undergoing instrumental delivery. Overt and covert urinary retention occurred in 2.3% and 18.3%, respectively. After adjusting for other risk factors, nulliparity (adjusted OR = 4.05, 95% CI 2.02-8.12 compared with multiparity) and prolonged second stage (OR = 3.96, 95% CI 1.53-10.25) compared with suspected fetal compromise as an indication for instrumental delivery was associated with increased risk of postpartum urinary retention. Interaction was noted between parity and episiotomy on the occurrence of postpartum urinary retention (P = .010). Among nulliparous women, those with episiotomy (adjusted OR = 6.10, 95% CI 2.65-14.04) have higher odds of developing postpartum urinary retention compared with those without episiotomy. CONCLUSIONS: Approximately one of five (20.6%) women undergoing instrumental delivery developed postpartum urinary retention. Among women undergoing instrumental delivery, episiotomy increased the chances of developing postpartum retention in nulliparous but not multiparous women. Prolonged second stage as an indication for instrumental delivery also increased the chances of retention. Future studies are needed to define the cutoff for diagnosis and to evaluate the long-term effects of covert postpartum urinary retention, as well to study the effect of episiotomy on development of postpartum urinary retention in women undergoing instrumental delivery.

Reduction of Bladder Volume after BCG Immunotherapy.

Bacillus Calmette-Guérin (BCG) immunotherapy is the most effective treatment for carcinoma in situ and high-risk non-muscle invasive bladder cancer (NMIBC). However, it can also provoke diverse side effects. We found 1 patient with a significantly and rapidly reduced bladder volume after the instillation of BCG. Few such cases and corresponding treatments have been reported. We speculated that the tuberculosis infection existed, so antitubercular therapy was given. After a 3-month oral intake of rifampicin, isoniazid, and ofloxacin, the volume of bladder returned to normal and the voiding symptoms disappeared. This case indicated that the reduction of bladder volume caused by BCG instillation could be treated with antitubercular therapy. Prompt and accurate diagnosis was important for the management.

Forward-Looking Ultrasound Wearable Scanner System for Estimation of Urinary Bladder Volume.

Accurate measurement of bladder volume is an important tool for evaluating bladder function. In this study, we propose a wearable bladder scanner system that can continuously measure bladder volume in daily life for urinary patients who need urodynamic studies. The system consisted of a 2-D array, which included integrated forward-looking piezoelectric transducers with thin substrates. This study aims to estimate the volume of the bladder using a small number of piezoelectric transducers. A least-squares method was implemented to optimize an ellipsoid in a quadratic surface equation for bladder volume estimation. Ex-vivo experiments of a pig bladder were conducted to validate the proposed system. This work presents the potential of the approach for wearable bladder monitoring, which has similar measurement accuracy compared to the commercial bladder imaging system. The wearable bladder scanner can be improved further as electronic voiding diaries by adding a few more features to the current function.

Simple calculation using anatomical features on pre-treatment verification CT for bladder volume estimation during radiation therapy for rectal cancer.

BACKGROUND: Despite detailed instruction for full bladder, patients are unable to maintain consistent bladder filling during a 5-week pelvic radiation therapy (RT) course. We investigated the best bladder volume estimation procedure for verifying consistent bladder volume. METHODS: We reviewed 462 patients who underwent pelvic RT. Biofeedback using a bladder scanner was conducted before simulation and during treatment. Exact bladder volume was calculated by bladder inner wall contour based on CT images (Vctsim). Bladder volume was estimated either by bladder scanner (Vscan) or anatomical features from the presacral promontory to the bladder base and dome in the sagittal plane of CT (Vratio). The feasibility of Vratio was validated using daily megavoltage or kV cone-beam CT before treatment. RESULTS: Mean Vctsim was 335.6 ± 147.5 cc. Despite a positive correlation between Vctsim and Vscan (R2 = 0.278) and between Vctsim and Vratio (R2 = 0.424), Vratio yielded more consistent results than Vscan, with a mean percentage error of 26.3 (SD 19.6, p < 0.001). The correlation between Vratio and Vctsim was stronger than that between Vscan and Vctsim (Z-score: - 7.782, p < 0.001). An accuracy of Vratio was consistent in megavoltage or kV cone-beam CT during treatment. In a representative case, we can dichotomize for clinical scenarios with or without bowel displacement, using a ratio of 0.8 resulting in significant changes in bowel volume exposed to low radiation doses. CONCLUSIONS: Bladder volume estimation using personalized anatomical features based on pre-treatment verification CT images was useful and more accurate than physician-dependent bladder scanners. TRIAL REGISTRATION: Retrospectively registered.

Validity of bladder volume measurement by ultrasound in women postpartum.

INTRODUCTION: Vaginal birth increases the risk of urinary retention and overdistention of the bladder. To avoid unnecessary discomfort by catheterization, it is preferable to use ultrasound for diagnosis of these conditions. The aim of this study was to determine the validity of transabdominal ultrasound and a portable ultrasound system, Biocon-700, to measure bladder volume in women postpartum. METHODS: Fifty women were included in this method comparison study. Within 48 h of giving birth, their bladder volume was measured in randomized order with both transabdominal ultrasound and Biocon-700. After urination, participants were scanned with Biocon-700 to measure residual bladder volume, and finally the bladder was emptied by catheterization. The total bladder volume was calculated as the voided volume plus the catheterized volume. RESULTS: Biocon-700 measured 43.4 ml ± 117.4 ml (mean ± SD) lower than the total bladder volume, while volumes measured by transabdominal ultrasound were 117.8 ml ± 110.0 ml (mean ± SD) lower. Linear regression showed significant proportional bias in both methods. The Biocon-700 could detect a residual bladder volume > 150 ml with a positive predictive value of 66.7% and a negative predictive value of 100%. CONCLUSIONS: Neither transabdominal ultrasound nor the portable ultrasound system, Biocon-700, can be used to measure bladder volume precisely after vaginal delivery. However, both ultrasound methods can be used as screening tools to prevent overdistention of the bladder, and Biocon-700 can furthermore be used to screen women for a residual bladder volume > 150 ml.

Intra- and inter-rater reliability of post-void residual bladder volume with ultrasound.

INTRODUCTION AND HYPOTHESIS: The purpose of the present study was to test the intra- and inter-rater reliability of the measurement of post-void residual bladder volume using ultrasound. METHODS: Two evaluators performed three measurements of the height, width, and length of the empty bladder using ultrasound. The voiding residual volume was calculated using the equation: volume = length × width × height × 0.52. Intraclass correlations (ICC) were calculated considering: ICC ≥ 0.75 excellent, 0.40 ≤ ICC < 0.75 satisfactory, and ICC <0.40 poor, with a significance level of 5% and analysis of confidence intervals (95% CI). RESULTS: Twenty women participated, with an average age of 27.95 ± 3.15 years. The inter-rater ICCs for height, width, and length were 0.96 (CI 0.89-0.98), 0.88 (CI 0.71-0.95), and 0.84 (CI0.60-0.94) respectively. For the intra-rater ICCs, the values were 0.97 (CI 0.95-0.99), 0.98 (CI 0.96-0.99), and 0.97 (CI 0.94-0.99) for evaluator 1 and 0.99 (CI 0.97-0.99), 0.97 (CI 0.94-0.99), and 0.95 (CI 0.90-0.98) for evaluator 2, for height, width, and length, respectively. The residual inter-test volume was 0.96 (CI 0.90-0.99) and the intra-test volume was 0.99 (CI 0.97-0.99). All analyses presented p < 0.0001. CONCLUSIONS: The intra- and inter-rater reliability for both the post-void residual volume and measurement of the bladder dimensions showed excellent agreement.

Proposal of a Lab Bench for the Unobtrusive Monitoring of the Bladder Fullness with Bioimpedance Measurements.

(1) Background: millions of people, from children to the elderly, suffer from bladder dysfunctions all over the world. Monitoring bladder fullness with appropriate miniaturized textile devices can improve, significantly, their daily life quality, or even cure them. Amongst the existing bladder sensing technologies, bioimpedance spectroscopy seems to be the most appropriate one to be integrated into textiles. (2) Methods: to assess the feasibility of monitoring the bladder fullness with textile-based bioimpedance spectroscopy; an innovative lab-bench has been designed and fabricated. As a step towards obtaining a more realistic pelvic phantom, ex vivo pig's bladder and skin were used. The electrical properties of the fabricated pelvic phantom have been compared to those of two individuals with tetrapolar impedance measurements. The measurements' reproducibility on the lab bench has been evaluated and discussed. Moreover, its suitability for the continuous monitoring of the bladder filling has been investigated. (3) Results: although the pelvic phantom failed in reproducing the frequency-dependent electrical properties of human tissues, it was found to be suitable at 5 kHz to record bladder volume change. The resistance variations recorded are proportional to the conductivity of the liquid filling the bladder. A 350 mL filling with artificial urine corresponds to a decrease in resistance of 7.2%, which was found to be in the same range as in humans. (4) Conclusions: based on that resistance variation; the instantaneous bladder fullness can be extrapolated. The presented lab-bench will be used to evaluate the ability of textiles electrodes to unobtrusively monitor the bladder volume.

[Individual control of urine volume to improve stability of bladder volume in radiotherapy of urinary tumor].

OBJECTIVE: To explore the training mode of individual urine volume control, to take indi-vidual expected urine volume as the goal of bladder control in patients with urinary system tumors, and to improve the accuracy of bladder control during radiotherapy by active training of bladder receptivity. METHODS: Twenty-five patients of urinary system tumors were enrolled from May 2019 to September 2019, of whom, 21 patients had prostate cancer, and 4 had bladder cancer. Training of bladder filling started before CT simulation. The patients were required to take the individual bladder filling as the training goal, and the optimal bladder volume range was suggested to be 200－400 mL. After 2－4 weeks of training, the prescribed volume of the bladder was determined according to the patient's bladder receptivity. The volume of the bladder was measured by images of plain CT and images 8-minutes after intravenous contrast injection. The patient's bladder volume was measured using BladderScan before treatment. CBCT (Cone-beam CT) was performed, and bladder volume was measured before treatment. The bladder volume was measured again using BladderScan after treatment. RESULTS: The mean bladder volume of simulation (VCT01) was (262±130) mL, ranging from 78 mL to 505 mL. The mean self-evaluation bladder volume before radiotherapy (VEVA01) was (238±107) mL, ranging from 100 mL to 400 mL. The mean BladderScan measured volume before radiotherapy (VBVI01) was (253±123) mL, ranging from 60 mL to 476 mL. The mean cone-beam CT measured volume before radiotherapy (VCBCT) was (270±120) mL, ranging from 104 mL to 513 mL. There was a correlation between VEVA01 and VBVI01, VCT01 and VBVI01, VCT01, and VBVI01, and there was no significant difference in paired t-test. There was a correlation between differences of self-evaluation bladder volume before radiotherapy(VEVA01) and simulation CT (VCT01) and differences of self-evaluation bladder volume before radiotherapy (VEVA01) and cone-beam CT (VCBCT), and there was no significant difference in paired samples by t-test. CONCLUSION: During radiotherapy for urinary system tumors, such as prostate cancer and bladder cancer, with the assistance of BladderScan, the patients could try to hold their urine moderately according to their conditions, and individualized bladder prescription may be beneficial to achieve stable bladder volume during radiotherapy.

Impact of bladder volume on acute genitourinary toxicity in intensity modulated radiotherapy for localized and locally advanced prostate cancer.

BACKGROUND AND PURPOSE: To evaluate the effect of changes in bladder volume during high-dose intensity-modulated-radiotherapy (IMRT) of prostate cancer on acute genitourinary (GU) toxicity and prospectively evaluate a simple biofeedback technique for reproducible bladder filling with the aim of reducing acute GU toxicity. METHODS: One hundred ninety-three patients were trained via a biofeedback mechanism to maintain a partially filled bladder with a reproducible volume of 200-300 cc at planning CT and subsequently at each fraction of radiotherapy. We prospectively analyzed whether and to what extent the patients' ability to maintain a certain bladder filling influenced the degree of acute GU toxicity and whether cut-off values could be differentiated. RESULTS: We demonstrated that the ability to reach a reproducible bladder volume above a threshold volume of 180 cc and maintain that volume via biofeedback throughout treatment predicts for a decrease in acute GU toxicity during curative high-dose IMRT of the prostate. Patients who were not able to reach a partial bladder filling to that cut-off value and were not able to maintain a partially filled bladder throughout treatment had a significantly higher risk of developing ≥grade 2 GU acute toxicity. CONCLUSION: Our results support the hypothesis that a biofeedback training for the patient is an easy-to-apply, useful, and cost-effective tool for reducing acute GU toxicity in high-dose IMRT of the prostate. Patients who are not able to reach and maintain a certain bladder volume during planning and treatment-two independent risk factors-might need special consideration.

Effects of bladder shape on accuracy of measurement of bladder volume using portable ultrasound scanner and development of correction method.

AIMS: To compare the accuracy of using a bladder scanner to measure bladder volume through intermittent catheterization (IC) in patients and to introduce the Bladder Deformation Index (BDI) to develop a correction method. METHODS: Bladder volume was assessed by a nurse with the scanner. A second nurse catheterized the patient's bladder. A third nurse measured the urine volume in a 500-mL or 1000-mL graduated cylinder. RESULTS: Sixty one patients were included and 590 pairs of data were obtained. The mean bladder volume measured using a scanner and IC was (332.3 ± 156.1) mL and (339.1 ± 158.8) mL. The mean absolute difference was 30.8 mL. The correlation coefficient was 0.929. Patients were classified into 2 groups depending on whether they had undergone augmentation cystoplasty. The mean absolute difference was 109.2 and 20.4 mL. The correlation coefficient was 0.712 and 0.981. According to the BDI, bladders can be classified into 3 groups. The mean absolute difference was 21.9, 60.4, and 109.4 mL. The correlation coefficient was 0.970, 0.839, and 0.783. The linear regression equations of Grade I and Grade II were Y = 1.11X + 3.1 and Y = 0.76X + 161.5. CONCLUSIONS: The results showed that bladder shape plays a critical role in accuracy which is inversely associated with BDI. This degree of accuracy is sufficient; especially measurement adjusted using the linear regression equation in patients with high BDI. However, although the preliminary results of the study are promising, a large-scale prospective study should be needed to address the validation of the data in the future.

Evaluation of electrical impedance tomography for determination of urinary bladder volume: comparison with standard ultrasound methods in healthy volunteers.

BACKGROUND: Continuous non-invasive urinary bladder volume measurement (cystovolumetry) would allow better management of urinary tract disease. Electrical impedance tomography (EIT) represents a promising method to overcome the limitations of non-continuous ultrasound measurements. The aim of this study was to compare the measurement accuracy of EIT to standard ultrasound in healthy volunteers. METHODS: For EIT of the bladder a commercial device (Goe MF II) was used with 4 different configurations of 16 standard ECG electrodes attached to the lower abdomen of healthy participants. To estimate maximum bladder capacity (BCmax) and residual urine (RU) two ultrasound methods (US-Ellipsoid and US-L × W × H) and a bedside bladder scanner (BS), were performed at the point of urgency and after voiding. For volume reference, BCmax and RU were validated by urine collection in a weight measuring pitcher. The global impedance method was used offline to estimate BCmax and RU from EIT. RESULTS: The mean error of US-Ellipsoid (37 ± 17%) and US-L × W × H (36 ± 15%) and EIT (32 ± 18%) showed no significant differences in the estimation of BCmax (mean 743 ± 200 ml) normalized to pitcher volumetry. BS showed significantly worse accuracy (55 ± 9%). Volumetry of RU (mean 152.1 ± 64 ml) revealed comparable higher errors for both EIT (72 ± 58%) and BS (63 ± 24%) compared to US-Ellipsoid (54 ± 25%). In case of RU, EIT accuracy is dependent on electrode configuration, as the Stripes (41 ± 25%) and Matrix (38 ± 27%) configurations revealed significantly superior accuracy to the 1 × 16 (116 ± 62%) configuration. CONCLUSIONS: EIT-cystovolumetry compares well with ultrasound techniques. For estimation of RU, the selection of the EIT electrode configuration is important. Also, the development of an algorithm should consider the impact of movement artefacts. Finally, the accuracy of non-invasive ultrasound accepted as gold standard of cystovolumetry should be reconsidered.

Polypyrrole/Agarose Hydrogel-Based Bladder Volume Sensor with a Resistor Ladder Structure.

Chronic monitoring of bladder activity and urine volume is essential for patients suffering from urinary dysfunctions. However, due to the anatomy and dynamics of the bladder, chronic and precise monitoring of bladder activity remains a challenge. Here, we propose a new sensing mechanism that measures the bladder volume using a resistive ladder network with contact switches. Instead of measuring the impedance between the electrode continuously, the proposed sensor provides a digitized output ('on' or 'off') when the bladder volume reaches a certain threshold value. We present simple proof-of-concept sensors which compare the discrete-mode operation to the continuous-mode operation. In addition, by using multiple pairs of this contact-mode switch in a resistor ladder structure, we demonstrate monitoring of the bladder volume in four discrete steps using an idealized balloon and an ex vivo pig's bladder. We implemented the resistive ladder network using a conductive polypyrrole/agarose hydrogel composite which exhibits a Young's modulus comparable to that of the bladder wall. Compared to the continuous-mode operation, the proposed sensing mechanism is less susceptible to drift due to material degradation and environmental factors.

Non-invasive bladder volume measurement for the prevention of postoperative urinary retention: validation of two ultrasound devices in a clinical setting.

Ultrasound scanning of bladder volume is used for prevention of postoperative urinary retention (POUR). Accurate assessment of bladder volume is needed to allow clinical decision-making regarding the need for postoperative catheterization. Two commonly used ultrasound devices, the BladderScan® BVI 9400 and the newly released Prime® (Verathon Medical®, Bothell, WA, USA), with or without the 'pre-scan' option, have not been validated in clinical practice. The aim of this study was to assess the performance of these devices in daily clinical practice. Between June and September 2016 a prospective observational study was conducted in 318 surgical patients (18 years or older) who needed a urinary catheter perioperatively for clinical reasons. For acceptable performance, we required that the volume as estimated by the BladderScan® differs by no more than 5% from the actual urine volume after catheterization. The Schuirmann's two one-sided test was performed to assess equivalence between the BladderScan® estimate and catheterization. The BVI 9400® overestimated the actual bladder volume by + 17.5% (95% CI + 8.8 to + 26.3%). The Prime® without pre-scan underestimated by - 4.1% (95% CI - 8.8 to + 0.5%) and the Prime® with pre-scan underestimated by - 6.3% (95% CI - 11.6 to - 1.1%). This study shows that while both ultrasound devices were able to approximate current bladder volume, both BVI 9400® and Prime®-with and without pre-scan-were not able to measure the actual bladder volume within our predefined limit of ± 5%. Using the pre-scan feature of the Prime® did not further improve accuracy.

Does applying postoperative suprapubic catheterisation in urogynecology benefit patients?

PURPOSE: The aim of this study was to define groups of women that are at particular risk for postoperative voiding dysfunction (PVD) after surgery for stress urinary incontinence (SUI) and/or pelvic organ prolapse (POP) and to focus on the question if these specific groups would benefit from suprapubic catheter (SPC) insertion. Complications associated with SPC were identified. METHODS: Between 06/2005 and 01/2013, the medical records of N = 4463 patients who underwent POP and/or SUI surgery were reviewed for suprapubic bladder drainage, duration of suprapubic catheterisation and SPC associated complications. 35 women suffering from vesicovaginal (28) and urethrovaginal (7) fistulas at the same time span were enrolled additionally. RESULTS: The results obtained revealed that patients after isolated anterior colporrhaphy, isolated anterior colporrhaphy and TVT, isolated cystocele repair using mesh and TVT, as well as patients with concomitant posterior and/or middle compartment prolapse surgery are at increased risk of developing PVD. Thus, postoperative suprapubic bladder drainage is beneficial. Complications occurred in 4.9 % of patients who received an SPC: urinary tract infection (UTI) (35), catheter dislocation (21), infection at the catheter insertion (2) and small bowel perforation (1). For the patients treated for fistulas we noticed a complication rate related to SPC of 11.4 %: UTI (2) and small bowel perforation (2). CONCLUSIONS: Patients should be counselled about the risk of developing PVD after POP and/or SUI surgery and should be informed about postoperative bladder drainage options related to their surgery.

Collagen-1 Membrane for Replacing the Bladder Wall.

We studied the possibility of using membrane fabricated from type 1 collagen isolated from cattle tissues (group 1) or porcine tissues (group 2) for replacement of the resected bladder wall defect in rabbits in order to retain functional volume of the organ. Satisfactory take of both types of collagen membranes with formation of competent anastomosis was observed. Histological studies revealed inflammatory process in the bladder wall at the site of contact with the implanted membrane (more pronounced in case of membranes from cattle tissues) that decreased by day 21 of the experiment. Bladder tissue ingrowth into the implant from was observed starting from day 14. The bladder capacity decreased in 7 days after surgery in both groups, presumably because of increasing tone of the organ wall resulting from surgical trauma and inflammation. In group 2, the bladder volume increased by day 14 after surgery and returned to normal by day 21, whereas in group 1 it remained below the control despite a trend to increase. These findings confirm good prospects of using collagen-1 membranes for plastic repair of the urinary bladder, the membranes from porcine collagen being more preferable.

[Comparison of Bladder Volume Measurement Accuracy between Portable Ultrasound Diagnostic Equipment and CBCT for Pelvic Prostate Radiotherapy].

PURPOSE: We evaluated the measurement accuracy of the CubeScan BioCon-900 (here after BioCon-900), a portable ultrasound imaging diagnostic device capable of measuring bladder volume, to determine if it can accurately assess bladder volume before intensity-modulated radiation therapy (IMRT) for prostate cancer. METHODS: Bladder volume was measured from kV-Cone Beam computed tomography (CBCT) images obtained immediately before the administration of IMRT for prostate cancer using Halcyon. The bladder volume measured from kV-CBCT images (23 patients, total number of scans: 139) immediately before the IMRT procedure was used as the reference value. The difference between the bladder volume measured by the BioCon-900 was then calculated. RESULTS: The bladder volume measured from kV-CBCT images was 117.5±49.4 cc. In contrast, the bladder volume obtained with BioCon-900 was 104.1±48.6 ml, resulting in an absolute mean difference of 18.4% and a correlation coefficient of 0.881. The measurements by BioCon-900 tended to be, on average, 11% smaller than the bladder volume measured by kV-CBCT imaging. CONCLUSION: kV-CBCT images demonstrated a strong positive correlation between bladder volume and bladder urine output obtained with BioCon-900. BioCon-900 can be used before kV-CBCT imaging to accurately and conveniently assess bladder volume.

A prospective comparative study on bladder volume measurement with portable ultrasound scanner and CT simulator in pelvic tumor radiotherapy.

OBJECTIVE: The consistency of bladder volume is very important in pelvic tumor radiotherapy, and portable bladder scanner is a promising device to measure bladder volume. The purpose of this study was to investigate whether the bladder volume of patients with pelvic tumor treated with radiotherapy can be accurately measured using the Meike Palm Bladder Scanner PBSV3.2 manufactured in China and the accuracy of its measurement under different influencing factors. METHODS: A total of 165 patients with pelvic tumor undergoing radiotherapy were prospectively collected. The bladder volume was measured with PBSV3.2 before simulated localization. CT simulated localization was performed when the bladder volume was 200-400ml. The bladder volume was measured with PBSV3.2 immediately after localization and recorded. The bladder volume was then delineated on CT simulation images and recorded. To compare the consistency of CT simulation bladder volume and bladder volume measured by PBSV3.2. To investigate the accuracy of PBSV3.2 in different sex, age, treatment purpose, and bladder volume. RESULTS: There was a significant positive correlation with bladder volume on CT and PBSV3.2 (r = 0.874; p < 0.001). The mean difference between CT measured values and PBSV3.2 was (-0.14 ± 50.17) ml. The results of the different variables showed that the overall mean of PBSV3.2 and CT measurements were statistically different in the age ≥ 65 years, bladder volumes > 400ml and ≤ 400ml groups (p = 0.028, 0.002, 0.001). There was no statistical significance between the remaining variables. The volume difference between PBSV3.2 measurement and CT was 12.87ml in male patients, which was larger than that in female patients 3.27ml. Pearson correlation analysis showed that the correlation coefficient was 0.473 for bladder volume greater than 400ml and 0.868 for bladder volume less than 400ml; the correlation coefficient of the other variables ranged from 0.802 to 0.893. CONCLUSION: This is the first large-sample study to evaluate the accuracy of PBSV3.2 in a pelvic tumor radiotherapy population using the convenient bladder scanner PBSV3.2 made in China. PBSV3.2 provides an acceptable indicator for monitoring bladder volume in patients with pelvic radiotherapy. It is recommended to monitor bladder volume with PBSV3.2 when the planned bladder volume is 200-400ml. For male and patients ≥ 65 years old, at least two repeat measurements are required when using a bladder scanner and the volume should be corrected by using a modified feature to improve bladder volume consistency.