Tom Feng

Multiparametric magnetic resonance imaging localizes established extracapsular extension of prostate cancer

OBJECTIVE To define the accuracy of multiparametric magnetic resonance imaging (MP-MRI) for identifying focal and established extracapsular extension (ECE) in various zones of the prostate. METHODS Between 2010 and 2013, 342 patients underwent MP-MRI of the prostate (3T, no endorectal coil with axial perfusion and diffusion images). The findings of the images were reported as negative, suspicious, or positive for ECE by a single expert radiologist. Radical prostatectomy specimens were reviewed to confirm the size and the location of ECE and further defined as focal or established ECE. Established ECE included extension that was multifocal or involving more than 5 glands. The accuracy of MRI in localizing focal and established ECE to each zone of the prostate was determined. Regression analyses were performed to identify predictors of ECE. RESULTS We identified 112 patients who underwent prostate MP-MRI and radical prostatectomy. MRI findings considered suspicious or definite for ECE accurately predicted pathologic ECE (P<0.001). MP-MRI identified established ECE but not focal ECE. Sensitivity, specificity, positive predictive value, and negative predictive value of MP-MRI for established ECE were 70.7%, 90.6%, 57.1%, and 95.1%, respectively. MRI identified ECE to the left vs. right side as well as each zone of the prostate; however, sensitivity was lowest at the apex. On multivariate analysis, MRI was a significant predictor of ECE that was independent of prostate-specific antigen level, Gleason score, and clinical stage. CONCLUSION MP-MRI is useful for identifying established but not focal ECE in all zones of the prostate. MRI was a significant independent predictor of established ECE and may be a useful adjunct in staging prostate cancer.

Metformin Use and Risk of Prostate Cancer: Results from the REDUCE Study

The role of metformin in prostate cancer chemoprevention remains unclear. REDUCE, which followed biopsy-negative men with protocol-dictated PSA-independent biopsies at 2- and 4-years, provides an opportunity to evaluate the link between metformin use and prostate cancer diagnosis with minimal confounding from screening biases. In diabetic men from REDUCE, we tested the association between metformin use, use of other antidiabetic medications, versus no antidiabetic medication use, and prostate cancer diagnosis as well as prostate cancer grade (low-grade Gleason 4–6 and high-grade Gleason 7–10) using logistic regression. Of the 540 diabetic men with complete data, 205 (38%) did not report use of any antidiabetic medications, 141 (26%) reported use of at least one antidiabetic medication other than metformin, and 194 (36%) reported use of metformin. During the 4-year study, 122 men (23%) were diagnosed with prostate cancer. After adjusting for various clinical and demographic characteristics, we found that metformin use was not significantly associated with total (OR, 1.19; P = 0.50), low- (OR, 1.01; P = 0.96), or high-grade (OR, 1.83; P = 0.19) prostate cancer diagnosis. Likewise, there was no significant association between the use of non-metformin antidiabetic medications and prostate cancer risk in both crude (OR, 1.02; P = 0.95) and multivariable analysis (OR, 0.85; P = 0.56). Furthermore, the interactions between antidiabetic medication use and BMI, geographic location, coronary artery disease, smoking, and treatment group were not significant (all P > 0.05). Among diabetic men with a negative prestudy biopsy who all underwent biopsies largely independent of PSA, metformin use was not associated with reduced risk of prostate cancer diagnosis. Cancer Prev Res; 8(11); 1055–60. ©2015 AACR.

Preoperative Testing for Urethral Sling Surgery for Stress Urinary Incontinence: Overuse, Underuse and Cost Implications

PURPOSE We identify areas of overuse and underuse in the preoperative evaluation of patients undergoing mid urethral sling surgery. We also estimate the effect of overuse of preoperative testing on health care costs. MATERIALS AND METHODS We conducted a retrospective review of women who underwent sling surgery with or without concomitant prolapse repair between 2012 and 2013. Physician orders for preoperative electrocardiogram, chest x-ray, basic metabolic panel, complete blood count, coagulation studies and urinalysis were classified as appropriate or inappropriate based on summary guidelines from the American Academy of Family Physicians. The additional costs of inappropriate tests were estimated using the 2014 Medicare clinical laboratory and physician fee schedules. RESULTS A total of 101 women who underwent mid urethral sling surgery were identified and 346 preoperative tests were ordered. Overall 76% of coagulation profiles, 73% of complete blood counts, 47% of basic metabolic panels, 39% of chest x-rays and 21% of electrocardiograms ordered did not have an appropriate clinical indication. In addition, 6% of electrocardiograms, 22% of chest x-rays and 10% of urinalyses were not ordered despite an appropriate indication. The estimated charges of overused tests were

Prospective Pilot Trial to Evaluate a High Resolution Diffusion-Weighted MRI in Prostate Cancer Patients

1,844.15 for the cohort, or

Appendicovesical Fistula Following Transurethral Resection of Bladder Tumor With Mitomycin C

18 per patient. CONCLUSIONS Preoperative testing is overused as well as underused in patients undergoing sling surgery. The greatest variation occurred with the use of electrocardiograms, chest x-rays and urinalysis. Poor adherence to national guidelines leads to increased health care costs and warrants increased awareness in following evidence-based guidelines.

Serum cholesterol and risk of lower urinary tract symptoms progression: Results from the Reduction by Dutasteride of Prostate Cancer Events study

Objectives High-resolution prostate imaging may allow for detection of subtle changes in tumor size, decrease the reliance on biopsies, and help define tumor boundaries during ablation. This pilot clinical trial evaluates a novel high-resolution prostate MRI for detection of small, biopsy-proven prostate tumors. Methods Our team developed a software that can be loaded on any modern MRI to generate high resolution diffusion-weighted imaging sequences (HR-DWI), which were compared to standard diffusion-weighted imaging sequence (S-DWI) in a prospective pilot trial in active surveillance patients. HR-DWI captures the entire volume of the prostate rather than sections, reducing streaking artifacts and geometric distortions. Multiple shots, rather than single shots, are used to differentiate signal and noise, enhancing resolution. All images were read by two radiologists. The primary outcome was the percent of biopsy-proven zones seen in 17 patients. The trial was powered to detect discordant proportions of 0.04 and 0.40 at one-sided alpha = 0.05. Results The resolution was defined using standard phantoms. HR-DWI produced a 5-fold improvement in spatial resolution when compared to S-DWI. Multiparametric (MP)-MRI incorporating S-DWI was useful for predicting biopsy results (AUC 0.72, Fishers exact p < 0.001); however, using HR-DWI allowed MP-MRI to be more highly predictive of biopsy results (AUC 0.88, Fishers exact p < 0.001). AUC for MP-MRI incorporating HR-DWI was significantly larger than MP-MRI incorporating S-DWI (p = 0.002). MP-MRI with HR-DWI had a sensitivity of 95.7% and identified tumor in 22 of 23 zones proven to have cancer on biopsy. In contrast, MP-MRI with S-DWI had a sensitivity of 60.9% and only identified 14 of 23 biopsy-positive zones (p = 0.004). Conclusion We developed a novel DWI and evaluated its improved resolution in a clinical setting. This technology has many potential applications and should be evaluated in future clinical trials as a patient management tool.

PSA predicts development of incident lower urinary tract symptoms: results from the REDUCE study

Appendicovesical fistula is a rare entity, with only 116 cases reported to date. It is an uncommon form of enterovesical fistula and often associated with a history of appendicitis. It can present as pneumaturia, fecaluria, and recurrent urinary tract infections, not unlike symptoms of enterovesical fistulas. We present a novel case of appendicovesical fistula developing after transurethral resection of bladder tumor and instillation of mitomycin C. Treatment included laparoscopic appendectomy and bladder repair.

Equipment, Setup, and Troubleshooting for Basic and Advanced Urodynamics

To determine if cholesterol is a risk factor for the development of lower urinary tract symptoms in asymptomatic men.

The Use of Fluoroscopy

BackgroundThe relationship between baseline prostate-specific antigen (PSA) and development of lower urinary tract symptoms (LUTS) in asymptomatic and mildly symptomatic men is unclear. We sought to determine if PSA predicts incident LUTS in these men.MethodsA post-hoc analysis of the 4-year REDUCE study was performed to assess for incident LUTS in 1534 men with mild to no LUTS at baseline. The primary aim was to determine whether PSA independently predicted incident LUTS after adjusting for the key clinical variables of age, prostate size, and baseline International prostate symptom score (IPSS). Incident LUTS was defined as the first report of medical treatment, surgery, or sustained clinically significant symptoms (two IPSS >14). Cox proportional hazards, cumulative incidence curves, and the log-rank test were used to test our hypothesis.ResultsA total of 1534 men with baseline IPSS <8 were included in the study cohort. At baseline, there were 335 men with PSA 2.5–4 ng/mL, 589 with PSA 4.1–6 ng/mL, and 610 with PSA 6–10 ng/mL. During the 4-year study, 196 men progressed to incident LUTS (50.5% medical treatment, 9% surgery, and 40.5% new symptoms). As a continuous variable, higher PSA was associated with increased incident LUTS on univariable (HR 1.09, p = 0.019) and multivariable (HR 1.08, p = 0.040) analysis. Likewise, baseline PSA 6–10 ng/mL was associated with increased incident LUTS vs. PSA 2.5–4 ng/mL in adjusted models (HR 1.68, p = 0.016). This association was also observed in men with PSA 4.1–6 ng/mL vs. PSA 2.5–4 ng/mL (HR 1.60, p = 0.032).ConclusionsMen with mild to no LUTS but increased baseline PSA are at increased risk of developing incident LUTS presumed due to benign prostatic hyperplasia.

Multiparametric MRI Improves Accuracy of Clinical Nomograms for Predicting Extracapsular Extension of Prostate Cancer

Urodynamics (UDS) is a set of functional tests of the lower urinary tract and is used to aid in the diagnosis of voiding disorders. Multiple options for UDS equipment exist with the main categories being simple (single-channel) versus complex (multichannel) UDS. Other variations include types of catheters used, fluid-based versus air systems, addition of fluoroscopy for video-UDS, software, and data storage. All of these considerations, in addition to the fact that the acquisition of urodynamics equipment can be costly, make it imperative that the clinician have some basic knowledge and understanding of the options available for UDS equipment. Furthermore, insight into the most efficient setup and how to troubleshoot common problems is invaluable for the clinician preparing to perform UDS in the office. The primary aim of this chapter is to provide the clinician with information that will be helpful when choosing urodynamics equipment appropriate for his/her practice, basic instruction on how to set up the urodynamics system, and guidelines for troubleshooting equipment-related problems.