Prostate cancer assessment using MR elastography of fresh prostatectomy specimens at 9.4 T.

PURPOSE: Despite its success in the assessment of prostate cancer (PCa), in vivo multiparametric MRI has limitations such as interobserver variability and low specificity. Several MRI methods, among them MR elastography, are currently being discussed as candidates for supplementing conventional multiparametric MRI. This study aims to investigate the detection of PCa in fresh ex vivo human prostatectomy specimens using MR elastography. METHODS: Fourteen fresh prostate specimens from men with clinically significant PCa without formalin fixation or prior radiation therapy were examined by MR elastography at 500 Hz immediately after radical prostatectomy in a 9.4T preclinical scanner. Specimens were divided into 12 segments for both calculation of storage modulus (G' in kilopascals) and pathology (Gleason score) as reference standard. Sensitivity, specificity, and area under the receiver operating characteristic curve were calculated to assess PCa detection. RESULTS: The mean G' and SD were as follows: all segments, 8.74 ± 5.26 kPa; healthy segments, 5.44 ± 4.40 kPa; and cancerous segments, 10.84 ± 4.65 kPa. The difference between healthy and cancerous segments was significant with P ≤ .001. Diagnostic performance assessed with the Youden index was as follows: sensitivity, 69%; specificity, 79%; area under the curve, 0.81; and cutoff, 10.67 kPa. CONCLUSION: Our results suggest that prostate MR elastography has the potential to improve diagnostic performance of multiparametric MRI, especially regarding its 2 major limitations: interobserver variability and low specificity. Particularly the high value for specificity in PCa detection is a stimulating result and encourages further investigation of this method.

Helping Men Find Their Way: Improving Prostate Cancer Clinic Attendance via Patient Navigation.

Navigation programs aim to help patients overcome barriers to cancer diagnosis and treatment. Missed clinic appointments have undesirable effects on the patient, health system, and society, and treatment delays have been shown to result in inferior surgical cure rates for men with prostate cancer (CaP). We sought to measure the impact of patient navigation on CaP clinic adherence. Patient navigators contacted patients prior to their first encounter for known or suspected CaP between 7/1/2016 and 6/30/2017. Encounters from 7/1/2014 to 6/30/2015 were used as a historical control. Patient-variables were analyzed including age, health insurance status, home address, zip code, race, ethnicity, and referring primary care clinic. Encounter-level variables included diagnosis (categorized as known or suspected CaP), date of appointment, type of appointment [new vs. return], and provider. The associations between several factors including navigation contact and these variables with missed appointment were analyzed using generalized linear mixed effects multivariate logistic regression. A total of 2854 scheduled clinic encounters from 986 unique patients were analyzed. Patient navigation resulted in a lower missed appointment rate (8.8% vs. 13.9%, OR = 0.64, IQR 0.44-0.93, p = 0.02 on multivariable analysis). Lack of health insurance (OR = 13.18 [5.13-33.83]), suspected but not confirmed CaP diagnosis (OR = 7.44 [4.85-11.42]), and Black (1.97 [1.06-3.65]) or Hispanic (OR = 3.61 [1.42-9.16]) race, were associated with missed appointment. Implementation of patient navigation reduced missed appointment rates for CaP related ambulatory encounters. Identifying risk factors for missed appointment may aid in targeting navigation services to those most likely to benefit from this intervention.

Constructing and Pilot Testing a Novel Prostate Magnetic Resonance Imaging/Ultrasound Fusion Biopsy Phantom.

OBJECTIVE: To describe the design and build of a novel phantom for magnetic resonance imaging (MRI)/ultrasound (US) fusion biopsy and present pilot testing results from a multicenter urology resident training session. METHODS: We cast our phantom from polyvinylchloride-plastisol that features 10 mm and 5 mm blue clay tumors, a urethral lumen, and an echogenic capsule. T2-weighted images were acquired with a 3T MR750 scanner (GE Healthcare, Boston, MA). Fusion testing was performed on the bkFusion system (BK ultrasound, Peabody, MA) with MIM Symphony software (MIM, Cleveland, OH) and an 18-gauge Bard Monopty disposable gun (Bard, Murray Hill, NJ). Twenty residents from 6 urology programs in Chicago performed proctored user testing. RESULTS: The per phantom material cost was $12. The phantom was compatible with all necessary equipment to create a MRI/US fusion data set. MRI and US imaging characteristics were excellent with hypointense lesions. Image fusion was achieved through both end and side fire ultrasound probes. The phantom allowed for biopsies to be performed, and target lesion hits were confirmed by visual inspection of core samples. 38% (8/21) of urology resident pilot testing participants had previously performed a fusion biopsy. The mean postsession survey scores were (1-10 [best]): realism 9.0, usefulness 9.4, ease of use 9.1, ease of orientation 8.9, and overall experience 9.3. CONCLUSION: This simple and inexpensive phantom allows for training and accuracy testing of MRI/US fusion biopsy hardware and software platforms.

Determinants of Clinic Absenteeism: A Novel Method of Examining Distance from Clinic and Transportation.

Delayed treatment and non-adherence are associated with inferior prostate cancer (CaP) outcomes. Missed clinic appointments (MA) are one form of non-adherence that may be preventable. We conducted a retrospective cohort study of 1341 scheduled clinic encounters for men referred to an academic urology clinic for evaluation of known or suspected CaP. Driving distance and public transit times were calculated using a Google Distance Matrix API algorithm. Zip code level data regarding socioeconomic status was obtained from the 2013 American Community Survey. Logistic regression multivariate analysis was used to identify MA predictors. Of scheduled clinic encounters, 14% were missed. Public health insurance was associated with MA (Private insurance 10%, Public insurance 19%), (p < 0.01) Calendar month was associated with MA with December showing the highest rate (21.2%) and June the lowest (5.3%) rates. (p = 0.02) Appointments for suspected CaP were more likely to be missed (19.3%) than those for known CaP (10.5%), p < 0.01. Driving distance was inversely associated with rate of MA (CA median 11.8 miles, MA median 10.4 miles, p = 0.04) while public transit times were not (66.7 min for CA, 65.3 min for MA, p = 0.36). Men that missed appointments were from areas with lower household incomes and educational attainment. Patient encounter type, insurance status, and reason for referral remained significantly associated with MA after multivariable adjusted analysis. By computing public transit time to the clinic using a mapping engine, we present a novel way to measure this parameter for studies of urban health care.

Wide Variation in Radiation Exposure During Computerized Tomography.

OBJECTIVE: To determine the variance in computeed tomography (CT) radiation measured via dose-length product (DLP) and effective dose (ED) during stone protocol CT scans. METHODS: We retrospectively examined consecutive records of patients receiving stone protocol diagnostic CT scans (n = 1793) in 2010 and 2014 in our health system. Patient age, body mass index (BMI), and gender were recorded, along with the hospital, machine model, year, DLP, and ED of each scan. Multivariate regression was performed to identify predictive factors for increased DLP. We also collected data on head (n = 837) CT scans to serve as a comparison. RESULTS: For stone CT scans, mean patient age was 55.1 ± 18.4 years with no significant difference in age (P=.2557) or BMI (P=.1794) between 2010 and 2014. Gender, BMI, and machine model were independent predictors of radiation dosage (P < .0001). Within each BMI class, there was an inexplicable 6-fold variation in the ED for the same imaging test when comparing the lowest and highest CT dose patients. There was no significant change in DLP over time for stone CT scans, but head scan patients in 2014 received lower radiation doses than those in 2010 (P < .0001). Low-dose scans for renal colic (defined as <4 mSv) were underutilized. Substantial variation exists for head scan radiation doses. CONCLUSION: Our data demonstrate large variations in diagnostic CT radiation dosage. Such differences within a single institution suggest similar trends elsewhere, warranting more stringent dosage guidelines and regulations for diagnostic CT scans within institutions.