Uptake of Same-Day Discharge for Patients Undergoing Robot-Assisted Radical Prostatectomy in the Michigan Urological Surgery Improvement Collaborative.

INTRODUCTION: Postoperative length of stay (LOS) after robot-assisted radical prostatectomy (RARP) is a potentially modifiable aspect of prostate cancer care. Our objective was to evaluate the use of same-day discharge (SDD) RARP and compare pre- and perioperative characteristics of these men with those who underwent hospitalization postoperatively. METHODS: Perioperative outcomes for patients undergoing RARP were evaluated from the Michigan Urological Surgery Improvement Collaborative (MUSIC) registry. Men were classified by hospital LOS: SDD, 1 day, and 2 days. Practice and surgeon-level variation of SDD and the change in SDD use over time were assessed. The primary outcome was 30-day readmission after RARP. RESULTS: We identified 10,249 men undergoing RARP in MUSIC from 2018 to 2022. Most patients had 1-day LOS (79.6%), with 2.8% undergoing SDD. The proportion of patients undergoing RARPs with SDD rose from 0.6% in 2018 to 1.2% in 2019 and 4.4% for 2020 to 2022. At least one SDD was performed in 12 of 28 MUSIC practices (42.9%) and by 52 of 138 urologists (37.7%). In multivariable analysis, odds of 30-day readmission were not significantly different between patients .undergoing SDD and LOS 1 day (OR: 1.72, 95% CI: 0.92-3.22, P = .090). Limitations include retrospective, registry-based observational study with nonuniform utilization of SDD. CONCLUSIONS: Although more patients have undergone SDD after RARP beginning in 2018, rates across Michigan have remained < 5% annually. Importantly, patients undergoing SDD RARP did not experience significantly more readmissions compared to hospitalized patients. SDD appears safe and feasible for select patients who are motivated by this approach.

Recovery of Social Continence and Sexual Function in Men With High-risk Prostate Cancer After Radical Prostatectomy: Results From a Statewide Collaborative.

OBJECTIVES: To examine post-operative urinary and sexual functional outcomes for men with high-risk prostate cancer (HRPCa) who underwent radical prostatectomy (RP) within the Michigan Urological Surgery Improvement Collaborative (MUSIC). METHODS: We identified patients who underwent RP for HRPCa in MUSIC between 2014 and 2023. HRPCa was defined according to American Urological Association criteria. Patients completed Expanded Prostate Cancer Index Composite (EPIC-26) pre-RP and 3-, 6-, 12-, and 24-months postoperatively. Primary outcomes included social continence, defined as 0-1 pads used daily; and recovery of sexual function, defined as the ability to achieve erections firm enough for intercourse. Multivariable and bivariate analyses were performed to identify factors associated with recovery of social continence and sexual function. RESULTS: Around 1323 patients were included in the post-RP urinary continence analysis and 422 men in the sexual function analysis. Fifty-eight percent and 86% of patients achieved social continence at 3- and 12-months post-RP, respectively. Continence recovery was associated with higher baseline EPIC-26 urinary continence scores (OR 1.10, per 5 points, 95% CI 1.06-1.15, P <.001), and negatively associated with increasing age (OR 0.78 per 5-year increase, 95% CI 0.71-0.85 P <.001). Fifteen percent of patients had recovery of sexual function at 12-month post-RP. On bivariate analysis, recovery of sexual function was associated with nerve-sparing at time of RP, lower pre-operative PSA, and not receiving post-RP ADT/RT. CONCLUSION: RP for HRPCa has acceptable rates of postoperative social continence. However, post-RP recovery of sexual function remains a challenge. This information has important implications for pre-operative counseling and post-operative follow-up for patients with HRPCa.

Current Perceptions, Practice Patterns, and Barriers to Adoption of Transperineal Prostate Biopsy Under Local Anesthesia.

OBJECTIVE: To assess perceptions, practice patterns, and barriers to adoption of transperineal prostate biopsy (TPBx) under local anesthesia. METHODS: Providers from Michigan urological surgery improvement collaborative (MUSIC) and Pennsylvania urologic regional collaborative (PURC) were administered an online survey to assess beliefs and educational needs regarding TPBx. Providers were divided into those who performed or did not perform TPBx. The MUSIC and PURC registries were queried to assess TPBx utilization. Descriptive analytics and bivariate analysis determined associations between provider/practice demographics and attitudes. RESULTS: Since 2019, TPBx adoption has increased more than 2-fold to 7.0% and 16% across MUSIC and PURC practices, respectively. Of 350 urologists invited to participate in a survey, a total of 91 complete responses were obtained with 21 respondents (23%) reported performing TPBx. Participants estimated the learning curve was <10 procedure for TPBx performers and non-performers. No significant association was observed between learning curve and provider age/practice setting. The major perceived benefits of TPBx were decreased risk of sepsis, improved cancer detection rate and antibiotic stewardship. The most commonly cited challenges to implementation included access to equipment and patient experience. Urologists performing TPBx reported learning curve as an additional barrier, while those not performing TPBx reported duration of procedure. CONCLUSION: Access to equipment and patient experience concerns remain substantial barriers to adoption of TPBx. Dissemination of techniques utilizing existing equipment and optimization of local anesthetic protocols for TPBx may help facilitate the continued adoption of TPBx.

Does Urologist-level Utilization of Active Surveillance for Low-risk Prostate Cancer Correspond with Utilization of Active Surveillance for Small Renal Masses?

Active surveillance (AS) for prostate cancer (CaP) or small renal masses (SRMs) helps in limiting the overtreatment of indolent malignancies. Implementation of AS for these conditions varies substantially across individual urologists. We examined the Michigan Urological Surgery Improvement Collaborative (MUSIC) registry to assess for correlation of AS between patients with low-risk CaP and patients with SRM managed by individual urologists. We identified 27 urologists who treated at least ten patients with National Comprehensive Cancer Network low-risk CaP and ten patients with SRMs between 2017 and 2021. For surgeons in the lowest quartile of AS use for low-risk CaP (<74%), 21% of their patients with SRMs were managed with AS, in comparison to 74% of patients of surgeons in the highest quartile (>90%). There was a modest positive correlation between the surgeon-level risk-adjusted proportions of patients managed with AS for low-risk CaP and for SRMs (Pearson correlation coefficient 0.48). A surgeon's tendency to use AS to manage one low-risk malignancy corresponds to their use of AS for a second low-risk condition. By identifying and correcting structural issues associated with underutilization of AS, interventions aimed at increasing AS use may have effects that influence clinical tendencies across a variety of urologic conditions. PATIENT SUMMARY: The use of active surveillance (AS) for patients with low-risk prostate cancer or small kidney masses varies greatly among individual urologists. Urologists who use AS for low-risk prostate cancer were more likely to use AS for patients with small kidney masses, but there is room to improve the use of AS for both of these conditions.

Can MRI Help Inform Which Men With a History of Multifocal High-Grade Prostatic Intraepithelial Neoplasia or Atypical Small Acinar Proliferation Remain at an Elevated Risk for Clinically Significant Prostate Cancer?

PURPOSE: We investigated the association of MRI findings in men with a previous diagnosis of atypical small acinar proliferation (ASAP) or multifocal high-grade intraepithelial neoplasia (HGPIN) with pathologic findings on repeat biopsy. MATERIALS AND METHODS: We retrospectively reviewed patients with ASAP/multifocal HGPIN undergoing a repeat biopsy in the Michigan Urological Surgery Improvement Collaborative registry. We included men with and without an MRI after the index biopsy demonstrating ASAP/multifocal HGPIN but before the repeat biopsy. Men with an MRI prior to the index biopsy were excluded. We compared the proportion of men with ≥ GG2 CaP (Grade Group 2 prostate cancer) on repeat biopsy among the following groups with the χ2 test: no MRI, PIRADS (Prostate Imaging-Reporting and Data System) ≥ 4, and PIRADS ≤ 3. Multivariable models were used to estimate the adjusted association between MRI findings and ≥ GG2 CaP on repeat biopsy. RESULTS: Among the 207 men with a previous diagnosis of ASAP/multifocal HGPIN that underwent a repeat biopsy, men with a PIRADS ≥ 4 lesion had a higher proportion of ≥ GG2 CaP (56%) compared with men without an MRI (12%, P < .001). A lower proportion of men with PIRADS ≤ 3 lesions had ≥ GG2 CaP (3.0%) compared with men without an MRI (12%, P = .13). In the adjusted model, men with a PIRADS 4 to 5 lesion had higher odds (OR: 11.4, P < .001) of ≥ GG2 CaP on repeat biopsy. CONCLUSIONS: MRI is a valuable diagnostic tool to triage which men with a history of ASAP or multifocal HGPIN on initial biopsy should undergo or avoid repeat biopsy without missing clinically significant CaP.

Building a Roadmap for Surveillance of Renal Masses Using a Modified Delphi Method to Help Achieve Consensus.

OBJECTIVE: To establish a consensus for initial evaluation and follow-up of patients on active surveillance (AS) for T1 renal masses (T1RM). METHODS: A modified Delphi method was used to gather information about AS of T1RM, with a focus on patient selection, timing/type of imaging modality, and triggers for intervention. A consensus panel of Michigan Urological Surgery Improvement Collaborative-affiliated urologists who routinely manage renal masses was formed. Areas of consensus (defined >80% agreement) about T1RM AS were established iteratively via 3 rounds of online questionnaires. RESULTS: Twenty-six Michigan Urological Surgery Improvement Collaborative urologists formed the panel. Consensus was achieved for 321/587 scenarios (54.7%) administered through 124 questions. Life expectancy, age, comorbidity, and renal function were most important for patient selection, with life expectancy ranking first. All tumors <3 cm and all patients with life expectancy <1 year were considered appropriate for AS. Appropriateness also increased with elevated perioperative risk, increasing tumor complexity, and/or declining renal function. Consensus was for multiphasic axial imaging initially (contrast CT for GFR >60 or MRI for GFR >30) with first repeat imaging at 3-6 months and subsequent imaging timing determined by tumor size. Consensus was for chest imaging for tumors >3 cm initially and >5 cm at follow up. Renal biopsy was not felt to be a requirement for entering AS, but useful in several scenarios. Consensus indicated rapid tumor growth as an appropriate trigger for intervention. CONCLUSION: Our consensus panel was able to achieve areas of consensus to help define a clinically useful and specific roadmap for AS of T1RM and areas for further discussion where consensus was not achieved.

Upgrading on Per Protocol versus For Cause surveillance prostate biopsies: An opportunity to decreasing the burden of active surveillance.

BACKGROUND: Most prostate cancer (PC) active surveillance (AS) protocols recommend "Per Protocol" surveillance biopsy (PPSBx) every 1-3 years, even if clinical and imaging parameters remained stable. Herein, we compared the incidence of upgrading on biopsies that met criteria for "For Cause" surveillance biopsy (FCSBx) versus PPSBx. METHODS: We retrospectively reviewed men with GG1 PC on AS in the Michigan Urological Surgery Improvement Collaborative (MUSIC) registry. Surveillance prostate biopsies obtained 1 year after diagnosis were classified as either PPSBx or FCSBx. Biopsies were retrospectively deemed FCSBx if any of these criteria were met: PSA velocity > 0.75 ng/mL/year; rise in PSA > 3 ng from baseline; surveillance magnetic resonance imaging (MRI) (sMRI) with a PIRADS ≥ 4; change in DRE. Biopsies were classified PPSBx if none of these criteria were met. The primary outcome was upgrading to ≥GG2 or ≥GG3 on surveillance biopsy. The secondary objective was to assess for the association of reassuring (PIRADS ≤ 3) confirmatory or surveillance MRI findings and upgrading for patients undergoing PPSBx. Proportions were compared with the chi-squared test. RESULTS: We identified 1773 men with GG1 PC in MUSIC who underwent a surveillance biopsy. Men meeting criteria for FCSBx had more upgrading to ≥GG2 (45%) and ≥GG3 (12%) compared with those meeting criteria for PPSBx (26% and 4.9%, respectively, p < 0.001 and p < 0.001). Men with a reassuring confirmatory or surveillance MRI undergoing PPSBx had less upgrading to ≥GG2 (17% and 17%, respectively) and ≥GG3 (2.9% and 1.8%, respectively) disease compared with men without an MRI (31% and 7.4%, respectively). CONCLUSIONS: Patients undergoing PPSBx had significantly less upgrading compared with men undergoing FCSBx. Confirmatory and surveillance MRI seem to be valuable tools to stratify the intensity of surveillance biopsies for men on AS. These data may help inform the development of a risk-stratified, data driven AS protocol.

Guideline Compliance Regarding Chest Imaging of Suspicious cT1 Renal Masses in MUSIC-KIDNEY.

INTRODUCTION: Multiple urological societies recommend chest imaging for suspicious renal masses using chest x-ray or CT as clinically indicated. The purpose of chest imaging is to assess for thoracic metastasis at the time of renal mass diagnosis. Ideally, imaging use and type are commensurate with risk related to tumor size and clinical stage. We examined current practice patterns with chest imaging compliance in the state of Michigan and implemented clinician education and value-based reimbursement incentivization on guideline adherence. METHODS: MUSIC (Michigan Urological Surgery Improvement Collaborative)-KIDNEY (Kidney mass: Identifying and Defining Necessary Evaluation and therapY) is a statewide initiative focusing on quality improvement for patients with cT1 renal masses. Data regarding chest imaging in MUSIC and panel discussion occurred at an in-person MUSIC meeting in October 2019. Adherence to chest imaging guidelines was made a value-based reimbursement metric at the triannual MUSIC meeting in January 2020. Adherence was defined as optional in renal masses <3 cm (CT not indicated), recommended in renal masses 3-5 cm (chest x-ray preferred), and required in renal masses >5 cm (CT preferred). The MUSIC registry was queried for percentage of patients receiving chest imaging by type. Factors associated with adherence were assessed. RESULTS: There was significant practice-level variation in chest imaging rates across the 14 contributing practices, ranging from 11% to 68%. Compliance with MUSIC guidelines for chest imaging during evaluation of T1 renal masses was 81.8% overall, with only 61.8% of patients with masses >5 cm meeting the guideline requiring imaging with preference for CT. Factors associated with increased adherence included larger tumor size (T1b vs T1a) and solid (vs cystic or indeterminate) tumor (P < .05 for each). Prior to value-based reimbursement introduction, 46.7% of patients underwent imaging of either type, compared to 49.0% post-intervention. Imaging rates only slightly increased in masses >5 cm (58.3% before value-based reimbursement vs 61.2% after, P = .56) and 3-5 cm (50.0% before value-based reimbursement vs 56.2% after, P = .0585). CONCLUSIONS: Chest imaging guideline adherence during the initial evaluation of cT1 renal masses is acceptable, particularly given that most masses are <3 cm, for which metastatic risk is low. However, despite consensus from major urological societies regarding imaging for masses >4-5 cm, imaging rates were low across MUSIC. After educational and value-based reimbursement incentive initiation, rates of imaging for 3-5-cm and >5-cm masses changed only slightly. There remains significant practice variability and room for improvement.

Practice Patterns Regarding Female Reproductive Organ-Sparing and Nerve-Sparing Radical Cystectomy Among Urologic Oncologists in the United States.

BACKGROUND: Female reproductive organ-sparing (ROS) and nerve-sparing radical cystectomy (RC) techniques have been shown to be oncologically safe and to improve sexual function outcomes among select patients with organ-confined disease. We sought to characterize practice patterns regarding female ROS and nerve-sparing RC among US urologists. PATIENTS AND METHODS: We conducted a cross-sectional survey of members of the Society of Urologic Oncology to assess provider-reported frequency of ROS and nerve-sparing RC in premenopausal and postmenopausal patients with non-muscle-invasive bladder cancer that failed intravesical therapy or clinically localized muscle-invasive bladder cancer. RESULTS: Among 101 urologists, 80 (79.2%) reported that they routinely resect the uterus/cervix, 68 (67.3%) the neurovascular bundle, 49 (48.5%) the ovaries, and 19 (18.8%) a portion of the vagina when performing RC in premenopausal patients with organ-confined disease. When asked about changes to approach in postmenopausal patients, 71 participants (70.3%) reported that they were less likely to spare the uterus/cervix, 44 (43.6%) were less likely to spare the neurovascular bundle, 70 (69.3%) were less likely to spare the ovaries, and 23 (22.8%) were less likely to spare a portion of the vagina. CONCLUSION: We identified significant gaps in adoption of female ROS and nerve-sparing RC techniques for patients with organ-confined disease, despite evidence that ROS and nerve-sparing techniques are oncologically safe and can optimize functional outcomes in select patients. Future efforts should improve provider training in and education about ROS and nerve-sparing RC to improve postoperative outcomes among female patients.

The Use and Short-term Outcomes of Active Surveillance in Men With National Comprehensive Cancer Network Favorable Intermediate-risk Prostate Cancer: The Initial Michigan Urological Surgery Improvement Collaborative Experience.

PURPOSE: National Comprehensive Cancer Network favorable intermediate-risk prostate cancer is a heterogeneous disease with varied oncologic and survival outcomes. We describe the Michigan Urological Surgery Improvement Collaborative's experience with the use of active surveillance and the short-term oncologic outcomes for men with favorable intermediate-risk prostate cancer.Materials and Methods:We reviewed the Michigan Urological Surgery Improvement Collaborative registry for men diagnosed with favorable intermediate-risk prostate cancer from 2012-2020. The proportion of men with favorable intermediate-risk prostate cancer managed with active surveillance was calculated by year of diagnosis. For men selecting active surveillance, the Kaplan-Meier method was used to estimate treatment-free survival. To assess for the oncologic safety of active surveillance, we compared the proportion of patients with adverse pathology and biochemical recurrence-free survival between men undergoing delayed radical prostatectomy after a period of active surveillance with men undergoing immediate radical prostatectomy. RESULTS: Of the 4,275 men with favorable intermediate-risk prostate cancer, 1,321 (31%) were managed with active surveillance, increasing from 13% in 2012 to 45% in 2020. The 5-year treatment-free probability for men with favorable intermediate-risk prostate cancer on active surveillance was 73% for Gleason Grade Group 1 and 57% for Grade Group 2 disease. More men undergoing a delayed radical prostatectomy had adverse pathology (46%) compared with immediate radical prostatectomy (32%, P < .001), yet short-term biochemical recurrence was similar between groups (log-rank test, P = .131). CONCLUSIONS: The use of active surveillance for men with favorable intermediate-risk prostate cancer has increased markedly. Over half of men with favorable intermediate-risk prostate cancer on active surveillance remained free of treatment 5 years after diagnosis. Most men on active surveillance will not lose their window of cure and have similar short-term oncologic outcomes as men undergoing up-front treatment. Active surveillance is an oncologically safe option for appropriately selected men with favorable intermediate-risk prostate cancer.

The added influence of genomics and post-MRI confirmatory biopsy results to MRI results alone on medical decision making for men with favorable risk prostate cancer being considered for active surveillance.

BACKGROUND: We examined how the results of genomic classifier (GC) or post-magnetic resonance imaging confirmatory biopsy (pMRI-CBx) influenced management strategy for men with an MRI considering active surveillance (AS). METHODS: We reviewed the Michigan Urological Surgery Improvement Collaborative registry for men with favorable-risk prostate cancer. Among men with an MRI after the diagnostic biopsy (n = 1162) a subset also had GC (n = 126) or pMRI-CBx (n = 309). Results of MRI, GC, and pMRI-CBx were deemed reassuring (RA) or non-reassuring (Non-RA). We assess the association of the combination of test results obtained with the selection of AS. Proportions were compared with the Fisher's exact test. Multivariable logistic regression models were fit for an association of test results with the selection of AS. RESULTS: The results of pMRI-CBx tended to influence management decisions greater than that of GC, especially in situation where testing results were discordant with the MRI result. Fewer men with a RA MRI and non-RA pMRI-CBx where managed with AS compared with RA MRI alone (31% vs. 86%, p < 0.001). non-RA genomics did not seem to have the same influence on management as non-RA pMRI-CBx as a similar proportion of men with RA MRI and non-RA genomics were managed with AS compared with RA MRI alone (85% vs. 86%, p = 0.753). More men with non-RA MRI and RA pMRI-CBx were managed with AS compared with non-RA MRI alone (89% vs. 40%, p < 0.001). Alternatively, a similar proportion of men with non-RA MRI and RA genomics were managed with AS compared with non-RA MRI alone (42% vs. 40%, p > 0.999). In the multivariable models, pMRI-CBx results influenced the decision for AS versus treatment. CONCLUSIONS: In men with newly diagnosed prostate cancer and an MRI, the additional information provided by pMRI-CBx influenced the decision of AS versus treatment, while the addition of GC results were less influential.

Pelvic Lymph Node Dissection at Radical Prostatectomy for Intermediate Risk Prostate Cancer: Assessing Utility and Nodal Metastases Within a Statewide Quality Improvement Consortium.

OBJECTIVE: To assess which patients with intermediate-risk PCa would benefit from a pelvic lymph node dissection (PLND) across the Michigan Urological Surgery Improvement Collaborative, given the discrepancy in recommendations. AUA guidelines for localized prostate cancer (PCa) state that PLND is indicated for patients with unfavorable intermediate-risk and high-risk PCa and can be considered in favorable intermediate-risk patients. NCCN guidelines recommend PLND when risk for nodal disease is ≥2%. METHODS: Data regarding all robot-assisted radical prostatectomy (RARP) (March 2012-October 2020) were prospectively collected, including patient, and surgeon characteristics. Univariate and multivariate analyses of PLND rate and lymph node involvement (LN+) were performed. RESULTS: Among 8,591 men undergoing RARP for intermediate-risk PCa, 80.2% were performed with PLND (n = 6883), of which 2.9% were LN+ (n = 198). According to the current AUA risk stratification system, 1.2% of favorable intermediate-risk PCa and 4.7% of unfavorable intermediate-risk PCa demonstrated LN+. There were also differences in the LN+ rates among the subgroups of favorable (0.0%-1.3%), and unfavorable (3.5%-5.0%) categories. Additional factors associated with higher LN+ rates include ≥50% cores positive, ≥35% involvement at any core, and unfavorable genomic classifier result, none of which contribute to the favorable/unfavorable subgroups. CONCLUSION: These data support PLND at RARP for all patients with unfavorable intermediate-risk PCa. Our data also indicate patients with favorable intermediate-risk prostate cancer at greatest risk for LN+ are those with ≥50% cores positive, ≥35% involvement at any core, and/or unfavorable genomic classifier result.

Patient Preferences and Treatment Decisions for Prostate Cancer: Results From A Statewide Urological Quality Improvement Collaborative.

OBJECTIVES: To examine the relationship between influential factors and treatment decisions among men with newly diagnosed prostate cancer (PCa). METHODS: We identified men in the Michigan Urological Surgery Improvement Collaborative registry diagnosed with localized PCa between 2018-2020 who completed Personal Patient Profile-Prostate. We analyzed the proportion of active surveillance (AS) between men who stated future bladder, bowel, and sexual problems (termed influential factors) had "a lot of influence" on their treatment decisions versus other responses. We also assessed the relationship between influential factors, confirmatory testing results and choice of AS. RESULTS: A total of 509 men completed Personal Patient Profile-Prostate. Treatment decisions aligned with influential factors for 88% of men with favorable risk and 49% with unfavorable risk PCa. A higher proportion of men who identified bladder, bowel and sexual concerns as having "a lot of influence" on their treatment decision chose AS, compared with men with other influential factors, although not statistically significant (44% vs 35%, P = .11). Similar results were also found when men were stratified based on PCa risk groups (favorable risk: 78% vs 67%; unfavorable risk: 17% vs 9%, respectively). Despite a small sample size, a higher proportion of men with non-reassuring confirmatory testing selected AS if influential factors had "a lot of influence" compared to "no influence" on their treatment decisions. CONCLUSION: Men's concerns for future bladder, bowel, and sexual function problems, as elicited by a decision aid, may help explain treatment selection that differs from traditional clinical recommendation.

Development of a Novel Scoring System Quantifies Opportunities to Reduce Surgery for Benign Renal Neoplasms: A Retrospective Quality Improvement Analysis within the MUSIC-KIDNEY Collaborative.

PURPOSE: Nonmalignant pathology has been reported in 15% to 20% of surgeries for cT1 renal masses. We seek to identify opportunities for improvement in avoiding surgery for nonmalignant pathology. MATERIALS AND METHODS: MUSIC-KIDNEY started collecting data in 2017. All patients with cT1 renal masses who had partial or radical nephrectomy for nonmalignant pathology were identified. Category for improvement (none-0, minor-1, moderate-2 or major-3) was independently assigned to each case by 5 experienced kidney surgeons. Specific strategies to decrease nonmalignant pathology were identified. RESULTS: Of 1,392 patients with cT1 renal masses 653 underwent surgery and 74 had nonmalignant pathology (11%). Of these, 23 (31%) cases were cT1b. Radical nephrectomy was performed in 17 (22.9%) patients for 5 cT1a and 12 cT1b lesions. Only 6 patients had a biopsy prior to surgery (5 oncocytoma, 1 unclassified renal cell carcinoma). Review identified 25 cases with minor (34%), 26 with moderate (35%) and 10 with major (14%) quality improvement opportunities. Overall 17% of cases had no quality improvement opportunities identified (12 partial nephrectomy, 1 radical nephrectomy). CONCLUSIONS: Review of patients with cT1 renal masses who underwent surgery for nonmalignant pathology revealed a significant number of cases in which this outcome may have been avoided. Approximately half of cases had moderate or major quality improvement opportunities, with radical nephrectomy for nonmalignant pathology being the most common reason. Our data indicate a lowest achievable and acceptable rate of nonmalignant pathology to be 1.9% and 5.4%, respectively. Avoiding interventions for nonmalignant pathology, particularly radical nephrectomy, is an important focus of quality improvement efforts. Strategies to decrease unnecessary interventions for nonmalignant pathology include greater use of repeat imaging, renal mass biopsy and surveillance.