Clinical Applications of Machine Learning for Urolithiasis and Benign Prostatic Hyperplasia: A Systematic Review

INTRODUCTION

Previous systematic reviews related to machine learning (ML) in urology often overlooked the literature related to endourology. Therefore, we aim to conduct a more focused systematic review examining the use of ML algorithms for benign prostatic hyperplasia (BPH) or urolithiasis. In addition, we are the first group to evaluate these articles using the STREAM-URO framework.

METHODS

Searches of MEDLINE, Embase, and the Cochrane CENTRAL databases were conducted from inception through July 12, 2021. Keywords included those related to ML, endourology, urolithiasis, and BPH. Two reviewers screened the citations that were eligible for title, abstract and full-text screening, with conflicts resolved by a third reviewer. Two reviewers extracted information from the studies, with discrepancies resolved by a third reviewer. The data collected was then qualitatively synthesized by consensus. Two reviewers evaluated each article according to the STREAM-URO checklist with discrepancies resolved by a third reviewer.

RESULTS

After identifying 459 unique citations, 63 articles were retained for data extraction. Most articles consisted of tabular (n=32) and computer vision (n=23) tasks. The two most common problem types were classification (n=40) and regression (n=12). In general, most studies utilized neural networks as their ML algorithm (n=36). Among the 63 studies retrieved, 58 were related to urolithiasis and five focused on BPH. The urolithiasis studies were designed for outcome prediction (n=20), stone classification (n=18), diagnostics (n=17), and therapeutics (n=3). The BPH studies were designed for outcome prediction (n=2), diagnostics (n=2), and therapeutics (n=1). On average, the urolithiasis and BPH articles met 13.8 (SD 2.6), and 13.4 (4.1) of the 26 STREAM-URO framework criteria, respectively.

CONCLUSIONS

The majority of the retrieved studies successfully helped with outcome prediction, diagnostics, and therapeutics for both urolithiasis and BPH. While ML shows great promise in improving patient care, it is important to adhere to the recently developed STREAM-URO framework to ensure the development of high-quality ML studies.

Aquablation Treatment for Benign Prostate Hyperplasia: Current Standardized Procedure

The following video Atlas summary reviews all technical elements of the standardized setup, robotic execution, aquablation procedure, and hemostasis for efficient rapid benign prostate hyperplasia treatment.

The Prevalence of Nocturnal Polyuria in the United States: Results from the Epidemiology of Nocturnal Polyuria Study

BACKGROUND

The prevalence of nocturnal polyuria (NP), which is passing large volumes of urine during the main sleep period, has been investigated primarily in middle-aged to older men. There is thus a gap in the NP evidence base for women and for younger individuals.

OBJECTIVE

To estimate the prevalence of nocturia due to NP in the USA.

DESIGN, SETTING, AND PARTICIPANTS

This large epidemiologic study used a US population-representative sample of men and women aged ≥30 yr to assess the prevalence of NP (NCT04125186).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Consenting participants completed an online survey (Lower Urinary Tract Symptoms Tool and comorbidities). All who reported two or more voids per night and 100 random respondents each reporting no or one void per night were asked to complete a 3-d bladder diary. Two NP definitions were used: nocturnal urine production >90 ml/h (NUP90) and Nocturnal Polyuria Index >0.33 (NPI33). Crude and population-adjusted prevalence results were calculated from completed diaries for the following subgroups by sex and age: idiopathic NP; NP with overactive bladder (NP-OAB) or bladder outlet obstruction (NP-BOO; men only); NP associated with other comorbidities; and no NP (did not meet the NPI33 or NUP90 definition).

RESULTS AND LIMITATIONS

Among the 10,190 respondents who completed the survey, the mean age was 54.4 yr (range 30-95); 3,339 reported two or more nocturnal voids and 1,763 completed the 3-d diary (response rate 49.3%). The adjusted overall NP prevalence was 31.5% among men and 38.5% among women using the NPI33 definition, and 23.8% among men and 18.1% among women using NUP90. The adjusted idiopathic NP prevalence was lower among men (NPI33: 5.2%; NUP90: 1.4%) than among women (NPI33: 9.8%; NUP90: 4.0%). The prevalence of idiopathic NP decreased with age as NP associated with other possible causes increased with age in men (most common, BOO) and women (most common, OAB).

CONCLUSIONS

This is the first population-based study of NP prevalence to include men, women, and young adults. NP is common; a multifactorial etiology should be considered, particularly as age increases.

PATIENT SUMMARY

In this population-based US study, we examined the frequency of nighttime urination among men and women aged ≥30 y and older. We found that nighttime urination is common among men and women. Many conditions can lead to increased nighttime urination as people age.

Patient and caretaker satisfaction with the PureWick system

INTRODUCTION

The BD PureWick System (PureWick) allows for non-invasive management of urinary incontinence (UI) by using a low-pressure suction to wick urine from an external catheter into a collection canister. The purpose of this study was to assess satisfaction of using PureWick for management of UI in the outpatient setting based on patient and caregiver feedback.

MATERIALS AND METHODS

Patients and caregivers utilizing PureWick completed an online questionnaire between August and October 2020. Factors evaluated included demographics, satisfaction, recommendations, and claims using multiple choice questions, checklists, 6-point Likert Scale, and open-ended questions. Patient and caregiver responses were compared using the independent samples t-test and z-test.

RESULTS

Of the 119 patients and 205 caregivers completing the questionnaire, > 80% indicated satisfaction, comfort benefits, continued future use, and likelihood of recommendation despite > 70% reporting increased expense compared to diapers. Additionally, > 20% indicated sleep benefits. Compared to patients, caregivers found PureWick easier to use (3% vs. 20%, p < 0.001) and associated with less perceived UTI and skin infections (7% vs. 17%, p = 0.008). Claims, using the 6-point Likert Scale, with mean ratings ≥ 5 included PureWick being easy to set up, empty, clean, and, compared to diapers, requiring leaving the bed less to use the bathroom. Caregivers gave higher ratings than patients to claims on PureWick being easy to set up and allowing for feelings of increased rest the morning after use.

CONCLUSIONS

Patients and caregivers using PureWick in the outpatient setting reported convenience in managing UI, intended future use, and more satisfaction in comparison to adult diapers.

Where Is Research in the Era of Electronic Health Records?

IntroductionData extraction from electronic health records (EHRs) for use in clinical research continues to be labor-intensive and to offer little benefit over traditional paper chart reviews. This is largely due to poor integration of EHR systems with hospital process flow, which still relies heavily on traditional paperwork as a means of documentation. DiscussionNew methods in data collection through mobile applications have streamlined data entry through better data standardization and improved overall data quality. However, mobile applications address only a portion of the problem. Data entry errors and legacy integration will continue to be an issue when there are changes between practitioners with different EHR systems. The combination of a mobile application with the cloud platform has been applied in multiple specialties to monitor recovery and patient-reported outcomes. ConclusionMobile applications along with a virtual cloud environment to host data provide a reasonable solution for consolidating patient data and can accelerate population research.

Rare complications of pessary use: A systematic review of case reports

Introduction

Pessaries are desirable for its overall safety profiles. Serious complications have been reported; however, there is little summative evidence. This systematic review aimed to consolidate all reported serious outcomes from pessaries usage to better identify and counsel patients who might be at higher risk of developing these adverse events.

Methods

We performed a systematic literature review using search terms such as ‘prolapse’, ‘stress urinary incontinence’ and ‘pessary or pessaries or pessarium’ on PubMed, Embase and CINAHL. A total of 36 articles were identified. Patient‐level data were extracted from case reports to further describe complications on an individual level.

Results

Overall median age of the patients was 82 years (range 62–98). The most frequent complications were vesicovaginal fistula (25%, n = 9/36), rectovaginal fistula (19%, n = 7/36), vaginal impaction (11%, n = 4/36) and vaginal evisceration of small bowel through vaginal vault (8%, n = 3/36). In the vesicovaginal fistula cohort, none of the patients had a history of radiation, and two had histories of total abdominal hysterectomy (22%). In the rectovaginal fistula cohort, one patient had a history of pelvic radiation for rectal squamous cell carcinoma, and another had a history of chronic steroid use for rheumatoid arthritis. No other risk factors were reported in the other groups. Ring and Gellhorn were the most represented pessary types among the studies, 16 (44%) and 12 (33%), respectively. No complications were reported with surgical and non‐surgical treatment of the complications.

Conclusion

Pessaries are a reasonable and durable treatment for POP with exceedingly rare reports of severe adverse complications. The ideal candidate for pessary should have a good self‐care index. Studies to determine causative factors of the more serious adverse events are needed; however, this may be difficult given the long follow‐up that is required.

Use of the penile cuff test to diagnose bladder outlet obstruction: A systematic review and meta-analysis

PURPOSE

Among noninvasive modalities for assessing bladder outlet obstruction (BOO), the penile cuff test (PCT) is the most used in clinical practice. The purpose of this review was to evaluate the performance of PCT in diagnosing and managing BOO.

MATERIALS AND METHODS

PubMed, Scopus, CINAHL, Embase, Cochrane Library, and Web of Science were searched for studies investigating use of PCT for BOO. Studies evaluating diagnostic parameters, inter-observer agreements, or treatment outcomes using PCT were included. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol was followed (PROSPERO ID: CRD42022300047). A proportional meta-analysis was done for diagnostic accuracy proportions. The Egger's and the Begg-Mazumdar rank-correlation tests were used to assess publication bias. Risk of bias was assessed using the Gradings of Recommendations, Assessment, Development, and Evaluations (GRADE) criteria.

RESULTS

Of the 272 articles retrieved, 17 were included in qualitative synthesis and meta-analysis was performed on five studies (comprising 448 patients). Two studies evaluating inter-observer agreement demonstrated 95% agreement and five studies evaluating procedures reported a 66%-80% surgical success rate on obstructed patients using PCT. From the proportional meta-analysis, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 0.85 (95% CI 0.71-0.95) 0.78 (95% CI 0.67-0.87), 0.74 (95% CI 0.52-0.91), and 0.87 (95% CI 0.73-0.96), respectively. Publication bias was noted for PPV but not for sensitivity, specificity, or NPV. Based on the GRADE criteria, there were two low, six moderate, and nine high-quality studies.

CONCLUSIONS

PCT performs sufficiently in diagnosing and managing BOO. However, due to variability in obstruction criteria assessment, more studies comparing diagnostic criteria are warranted.

Micro-cost analysis of single-use vs. reusable cystoscopy in a single-payer healthcare system

Introduction: Single-use flexible diagnostic cystoscopy has recently been developed with comparable functionality to reusable cystoscopes. Prior studies have demonstrated considerable upfront costs of reusable cystoscopy. The objective of this study was to compare costs of reusable cystoscopy to single-use cystoscopy in a single-payer, socialized healthcare system. Methods: A retrospective micro-cost analysis of reusable cystoscopy in a combined inpatient and outpatient setting at a single institution was performed. The cost analysis was divided into capital, maintenance, reprocessing, and labor. Annual costs were averaged over two fiscal years. Costs were amortized over 5- and 10-year basis as appropriate. The results were compared to theoretical costs of single-use cystoscopes. Results: There were 3415 annual average cystoscopy cases with 171 cases per reusable cystoscope. The capital, maintenance, reprocessing, and labor costs of reusable cystoscopy are $96 000, $99 867, $247 855, and $65 317, respectively. The total annual costs per case for reusable and single-use cystoscopy are $149.06 and $245.57, respectively. The costs of reusable cystoscopy decrease with the number of procedures per year and intersect the costs of single-use cystoscopes at 1265 procedures per year. All costs are CAD. Conclusions: The cost-effectiveness of reusable cystoscopes is dependent on cystoscopy volume due to considerable upfront costs. Single-use cystoscopes are more cost-effective if the total number of cases performed is less than 1265 per year. Additional investigation into the cost-effectiveness of single-use cystoscopes as supplements in the outpatient setting or primary endoscopes in inpatient/emergency settings should be performed.

Rezum to the rescue: Early outcomes of Rezum on patients with recurrent lower urinary tract symptoms after surgical interventions for benign prostatic enlargement

We aim to report the short-term outcomes of patients undergoing Rezum as a re-treatment intervention for recurrent lower urinary tract symptoms after prior surgical treatment for benign prostate enlargement. Data from two institutions for baseline International Prostatic Symptom Score with Quality of life item, prostate size, and maximum flow-rate was acquired. Patients were assessed 3-month post-treatment. Outcomes were compared with unpaired t-tests and Fisher's exact tests. Nineteen patients were included. Prior surgical interventions included transurethral resection of the prostate (31.6%, n = 6), Urolift (26.3%, n = 5), transurethral bladder neck incision (15.8%, n = 3), prostate artery embolization (10.5%, n = 2), transurethral needle ablation, greenlight photovaporization of prostate and Rezum (5.3%, n = 1 each). Median age was 69.0 years (IQR 14; range 59-87 years) with a median prostate volume of 65.0 ml (IQR 63; range 22-160 ml). The median time to Rezum treatment was 48 months (IQR 78; range 9-240 months). 63.1% (n = 12) were re-started on benign prostatic enlargement medication and 36.8% (n = 7) had recurrent bothersome symptoms before re-treatment with Rezum. At 3-month follow up, median International Prostatic Symptom Score decreased from 23 to 9 (p < 0.001) and Quality of life from 4 to 2 (p < 0.001). Median maximum flow-rate improved after treatment from 8.6 to 14.8 ml/s (p < 0.001). None of the patients were required to restart medication for benign prostate enlargement.

Rezūm therapy for ≥ 80 ml benign prostatic enlargement: a large, multi-center cohort study

OBJECTIVE

The purpose of this study was to evaluate the efficacy and safety of Rezūm therapy in benign prostatic hyperplasia (BPH) patients with prostates ≥ 80 ml.

METHODS

A prospective registry was established at two high-volume Canadian centers. Patients had baseline medical history documented, and uroflowmetry and questionnaires recorded over 12 months.

RESULTS

83 patients (median age: 69.2 years, IQR 63.2, 74.8) with a prostate size ≥ 80 ml were included. Median prostate volume was 100.0 ml (IQR 88.5, 115.0) and 65% had a median lobe. 21 patients had prior urinary retention. Median number of injections was 13 (IQR 11, 15). Median catheterization length was 9 days (IQR 7, 14). IPSS improved by 24%, 57%, and 59% at 1, 3, and 12 months, respectively (p<0.001). QoL scores improved by 27%, 56%, and 70% at these same timepoints (p<0.001). Qmax improved by 55% at 3 months (p=0.002) and 59% at 12 months, and PVR improved by 58% at 3 months (p=0.006). BPHII scores improved by 57% at 3 months and 71% at 12 months. IIEF-15 scores improved by 15% at 6 months, and MSHQ-EjD function scores improved by 22.4% at 1 month. 3 (3.6%) men observed reduced/anejaculation. No Clavien-Dindo events ≥ Grade III occurred.

CONCLUSION

This study demonstrates for the first-time safety and efficacy of Rezum in large glands >80mL. IPSS improved by 59% and QoL improved by 70% at 12 months. Objective maximum flow measures improved at 12 months by 59%, while erectile and ejaculatory function remained preserved.

A comprehensive analysis of clinical, quality of life, and cost-effectiveness outcomes of key treatment options for benign prostatic hyperplasia

Treatment options for men with moderate-to-severe lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) have variable efficacy, safety, and retreatment profiles, contributing to variations in patient quality of life and healthcare costs. This study examined the long-term cost-effectiveness of generic combination therapy (CT), prostatic urethral lift (PUL), water vapor thermal therapy (WVTT), photoselective vaporization of the prostate (PVP), and transurethral resection of the prostate (TURP) for the treatment of BPH. A systematic literature review was performed to identify clinical trials of CT, PUL, WVTT, PVP, and TURP that reported change in International Prostate Symptom Score (IPSS) for men with BPH and a prostate volume ≤80 cm³. A random-effects network meta‐analysis was used to account for the differences in patient baseline clinical characteristics between trials. An Excel-based Markov model was developed with a cohort of males with a mean age of 63 and an average IPSS of 22 to assess the cost-effectiveness of these treatment options at 1 and 5 years from a US Medicare perspective. Procedural and adverse event (AE)-related costs were based on 2021 Medicare reimbursement rates. Total Medicare costs at 5 years were highest for PUL ($9,580), followed by generic CT ($8,223), TURP ($6,328), PVP ($6,152), and WVTT ($2,655). The total cost of PUL was driven by procedural ($7,258) and retreatment ($1,168) costs. At 5 years, CT and PUL were associated with fewer quality-adjusted life years (QALYs) than WVTT, PVP, and TURP. Compared to WVTT, the incremental cost-effectiveness ratios (ICERs) for both TURP and PVP were above a willingness-to-pay threshold of $50,000/QALY (TURP: $64,409/QALY; PVP: $87,483/QALY). This study provides long-term cost-effectiveness evidence for several common treatment options for men with BPH. WVTT is an effective and economically viable treatment in resource-constrained environments.

Rezūm water vapor therapy for catheter-dependent urinary retention: a real-world Canadian experience

INTRODUCTION

This analysis reported outcomes of treating catheter-dependent urinary retention with Rezūm water vapor therapy.

MATERIALS AND METHODS

A prospective registry was established at two high-volume Canadian centers. Patients had baseline medical and benign prostatic hyperplasia (BPH) history documented. The subgroup of patients with refractory, catheter-dependent urinary retention was analyzed. The primary outcome was the proportion of patients who were spontaneously voiding and catheter-free at 6 months.

RESULTS

Sixteen patients (age: 68.7 years) with catheter-dependent urinary retention were treated with Rezūm. Average prostate volume was 84.4 mL and 75% had median lobe. All patients had at least one recent failed trial without catheter (TWOC) and 87.5% were on BPH oral therapy. Mean number of vapor injections was 14.5. Visibility and bleeding during procedure were assessed using a 5-point scale, and were rated as 1.4 and 1.3, respectively. Anesthesia was either intravenous propofol sedation (n = 13) or self-administered methoxyflurane inhaler (n = 3). Mean catheter duration until first planned TWOC was 28.4 days. Three patients needed catheter replacement due to initial failed TWOC. One patient was lost to follow up, one patient did not return at 1 month, and one patient did not return at 3 months. At 1 month, 13/14 patients were spontaneously voiding and catheter-free. At 3 months, 14/14 patients were spontaneously voiding, and at 6 months, 15/15 patients were spontaneously voiding and catheter-free (1 patient was lost to follow up).

CONCLUSIONS

Rezūm water vapor therapy can successfully treat catheter-dependent urinary retention after initial failed TWOC in an outpatient setting.

GreenLight photovaporization of the prostate in high-medical-risk patients: an analysis of the Global GreenLight Group (GGG) database

PURPOSE

We sought to characterize the adjusted outcomes of GreenLight photoselective vaporization of the prostate (PVP) in high-medical-risk (HMR) patients using data from the largest international database.

METHODS

Data were obtained from the Global GreenLight Group (GGG) database which pools data of eight high-volume, experienced surgeons, from a total of seven international centers. Eligible study participants underwent GreenLight PVP using the XPS-180 W system between 2011 and 2019. HMR patients were defined as patients with ASA III or greater and were compared to non-HMR patients. Analyses were adjusted for patient age and prostate volume.

RESULTS

In the HMR group, patients on average were older and had smaller prostates than the non-HMR control group. Compared to non-HMR patients, transfusions occurred more frequently (2.6% vs. 0.14%, p < 0.01) and the odds of readmission were elevated [OR 2.0, (95% CI 1.4-2.8, p < 0.01)] among HMR patients. Twelve months postoperatively, HMR patients experience greater improvement in QoL than the control group [+ 0.54 (95% CI 0.07-1.0, p = 0.02)]. PVR also decreased 93.1 ml more in HMR than in non-HMR patients after 12 months (95% CI 33.6-152.6, p < 0.01).

CONCLUSION

We found that GreenLight PVP is safe and effective in improving functional outcomes in higher-risk patients with severe systemic disease compared to their lower-risk counterparts. Though absolute risks remain low, GreenLight PVP is associated with higher odds of transfusion and readmission in the high-risk cohort. The findings of our study reaffirm current guidelines that propose PVP as a viable treatment option for HMR patients.

A Community-Based Education Program for Overactive Bladder in a Predominantly Minority Older Female Population: A Pilot Study

Introduction

Knowledge gaps regarding available treatment and social stigmatization are barriers to care in patients with overactive bladder (OAB). We assessed the feasibility of an OAB education program targeting older community-dwelling females.

Methods

Community-dwelling women over 55 years old were recruited. Eligible participants underwent an education program covering continence-promotion strategies. The Overactive Bladder Questionnaire-Short Form and Short Form-12 were completed at baseline, 1 week, 3 months, and 6 months post-intervention to measure symptom bother and condition-specific and general quality of life (QoL). Data were analyzed using a linear mixed-effects model for repeated measures.

Results

Thirty-seven female patients with OAB symptoms at baseline were assessed with the majority from Latino/Hispanic or Black/African American ethnic/racial backgrounds. For our youngest subgroup (≤68 years old), significant improvements were observed at 3 and 6 months compared to 1 week post-intervention for symptom bother (3 months, −22.75, p = 0.006; 6 months, −25.76; p = 0.001) and condition-specific and health-related QoL subscale scores for concern (3 months, +23.76, p = 0.006; 6 months, +22.15, p = 0.011) and social interaction (3 months, +21.11, p = 0.017; 6 months, +20.51; p = 0.021). For all age subgroups, improvements in general QoL measures for mental health were seen at 3 and 6 months compared to baseline (3 months, +7.57, p = 0.02; 6 months, +6.70; p = 0.048).

Conclusions

Statistically significant improvements in symptom bother, condition-specific, and general QoL measures were observed following an OAB education program pilot study in a predominantly minority female population. Further studies are needed to support efficacy and optimize program design.

I Can't Get No Satisfaction: Patient-reported Outcomes After Different Treatment Options for Lower Urinary Tract Symptoms

Effective clinical management of benign prostatic obstruction is determined by the ability to address lower urinary tract symptoms as measured via patient-reported outcomes (PROs). Minimally invasive surgical therapies (MISTs) offer better erectile or ejaculatory side effects and potentially faster recovery time in comparison to transurethral resection of the prostate (TURP). Premature excitement for MISTs derives from prospective sham-controlled trials with several years of follow-up data. Currently there is a lack of randomized controlled trials that directly compare MISTs to TURP and of a clearer definition of treatment failure. These types of studies are important in comparing efficacy between treatments. In head-to-head comparison, TURP yields the most robust improvement in PROs when compared to MISTs. At best, MISTs may achieve equivalent urological symptom-relief profiles to TURP; however, noninferiority assessments are needed. MISTs are potentially advantageous for their side-effect profiles and lower complication rates, but consistency in reporting these data is needed. PATIENT SUMMARY: We looked at the current data on patient-reported outcomes after each type of treatment for lower urinary tract symptoms. We found that the efficacy of these procedures is difficult to compare given the lack of direct studies comparing new options to the standard procedure. We can only conclude that the standard procedure, transurethral resection of the prostrate, will provide the best relief of voiding symptoms as reported by patients.

The gut, vaginal, and urine microbiome in overactive bladder: a systematic review

INTRODUCTION AND HYPOTHESIS

The objective was to systemically review the current literature on the association of gut, vaginal, and urinary dysbiosis in female patients with overactive bladder (OAB).

METHODS

We performed a comprehensive literature search following the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) protocols for systematic reviews. In the EMBASE, CINAHL, and Medline databases, a search was conducted using key words such as "microbiome," "microbiota," "microflora," "overactive bladder," "urge," "gut," "vaginal." Articles were screened using the online tool www.covidence.org . Two independent reviewers screened studies at each stage and resolved conflicts together. We excluded papers that discussed pediatric patients and animal studies. In total, 13 articles met this criterion, which included 6 abstracts.

RESULTS

After identifying 817 unique references, 13 articles met the criteria for data extraction. Articles were published from 2017 to 2021. No study reported the same microbiota abundance, even in healthy individuals. Overall, there was a loss of bacterial diversity in OAB patients compared with controls. Additionally, the bacterial composition of the controls and OAB patients was not significantly different, especially if the urine was collected midstream. Overall, the composition of the microbiome is dependent on the specimen collection methodology, and the metagenomic sequencing technique utilized. OAB urine microbiome is more predisposed to alteration from the gut or vaginal influences than in controls.

CONCLUSIONS

Current evidence suggested a potential relationship among gut, vaginal, and urinary microbiome in OAB patients, but there are very limited studies.

Natural history of lower urinary tract symptoms among men undergoing stereotactic body radiation therapy for prostate cancer with and without a Rectal Hydrogel Spacer

PURPOSE

Stereotactic body radiation therapy (SBRT) is increasingly used for prostate cancer, but has morbidity as both the bladder and rectum are radiated during treatment. Our goal was to document and compare lower urinary tract symptoms (LUTS) among men who underwent SBRT with and without SpaceOAR hydrogel (Augmenix, Inc., Bedford, MA).

METHODS

We performed a retrospective analysis of 87 men (50 SpaceOAR and 37 non-SpaceOAR) who underwent SBRT. Primary outcomes were patient reported symptoms during radiation therapy, pharmacotherapy usage, and urologic and bowel survey scores up to 6-months post-SBRT.

RESULTS

78% of men were on α-inhibitors at the end of SBRT, an increase from 27.6% baseline usage (p < 0.001). Post-SBRT urinary frequency was more common in the non-SpaceOAR group versus the SpaceOAR group (68% versus 38%, p = 0.006), as was nocturia (35% vs. 8%, p = 0.002). Acute gastrointestinal symptoms did not differ. 58.8% of men were on α-inhibitors at 6-months of follow-up post-SBRT, an increase from 27.6% baseline usage (p < 0.001). Importantly, there was a difference of α-inhibitor use between non-SpaceOAR and SpaceOAR groups at the end of SBRT and at 1.5-, 3-, and 6-months follow up (86% vs. 53% [p = 0.002], 83% vs. 53% [p = 0.005], 72% vs. 49% [p = 0.038], respectively).

CONCLUSION

LUTS after SBRT remains a significant problem for men undergoing treatment for prostate cancer. LUTS affects men during and up to 6-months following SBRT. Owing to these increased LUTS, preemptive minimally invasive solutions and their mechanisms of protection, including the SpaceOAR, should be further investigated.