Cumulative cancer locations on prostate biopsy and active surveillance outcomes in the MRI era.

BACKGROUND: To validate the use of a cumulative cancer locations (CCLO) score, a measurement of tumor volume on biopsy, and to develop a novel magnetic resonance imaging (MRI)-informed CCLO (mCCLO) score to predict clinical outcomes on active surveillance (AS). METHODS: The CCLO score is a sum of uniquely involved sextants with prostate cancer on diagnostic + confirmatory biopsy. The mCCLO score incorporates MRI findings into the CCLO score. Participants included 1284 individuals enrolled on AS between 1994 and 2022, 343 of whom underwent prostate MRI. The primary outcome was grade reclassification (GR) to grade group ≥2 disease; the secondary outcome was receipt of definitive treatment. RESULTS: Increasing CCLO and mCCLO risk groups were associated with higher risk of GR and undergoing definitive treatment (both p < 0.001). On multivariable analysis, increasing mCCLO score was associated with higher risk of GR and receipt of definitive treatment (hazard ratios [HRs] per 1-unit increase: 1.26 [95% confidence interval [CI]: 1.12-1.41] and 1.21 [95% CI: 1.07-1.36], respectively). The model using mCCLO score to predict GR (c-index: 0.671; 95% CI: 0.621-0.721) performed at least as well as models using the number of cores positive for cancer (0.664 [0.613-0.715]; p = 0.7) and the maximum percentage of cancer in a core (0.641 [0.585-0.696]; p = 0.14). CONCLUSIONS: The CCLO score is a valid, objective metric to predict GR and receipt of treatment in a large AS cohort. The ability of the MRI-informed mCCLO to predict GR is on par with traditional metrics of tumor volume but is more descriptive and may benefit from greater reproducibility. The mCCLO score can be implemented as a shorthand, informative tool for counseling patients about whether to remain on AS.

Clinical Significance of Perineural Invasion in Men With Grade Group 1 Prostate Cancer on Active Surveillance.

PURPOSE: We aimed to evaluate the clinical significance of perineural invasion in men on active surveillance for Grade Group 1 prostate cancer. MATERIALS AND METHODS: We identified 1,969 men with Grade Group 1 prostate cancer and at least 1 follow-up biopsy. A time-dependent Cox model and a logistic regression model were used to assess the association between biopsy-detected perineural invasion and grade reclassification (defined as the detection of Grade Group ≥2 prostate cancer on a surveillance biopsy), and adverse pathology (defined as Grade Group ≥3 ± seminal vesicle invasion ± lymph node involvement) at radical prostatectomy, respectively. RESULTS: The 198 men with perineural invasion detected during active surveillance had lower rates of grade reclassification-free survival than those without perineural invasion (P < .001). On multivariable analysis perineural invasion was significantly associated with grade reclassification (HR 3.25, 95% CI 2.54-4.16, P < .001); an association that persisted in the multiparametric magnetic resonance imaging subset. At radical prostatectomy, men with biopsy-detected perineural invasion had more extraprostatic extension than men without perineural invasion (Relative Risk 1.71, 95% CI 1.15-2.56). However, on multivariable analysis biopsy-detected perineural invasion was not associated with adverse pathology (OR 0.68, 95% CI 0.27-1.68, P = .40) and these patients did not exhibit more biochemical recurrence at 5 years (P > .05). CONCLUSIONS: Perineural invasion during active surveillance was associated with grade reclassification. At radical prostatectomy biopsy-detected perineural invasion patients exhibited more extraprostatic extension but biopsy-detected perineural invasion was not independently associated with more adverse pathology. In addition, these patients did not have more biochemical recurrence during follow-up. Perineural invasion should not preclude Grade Group 1 patients from active surveillance but they may warrant more stringent monitoring.

Identifying Men Who Can Remain on Active Surveillance Despite Biopsy Reclassification to Grade Group 2 Prostate Cancer.

PURPOSE: Men on active surveillance with Grade Group 1 prostate cancer who reclassify to Grade Group 2 on surveillance biopsy often leave active surveillance. We aimed to identify subgroups of men who can safely remain on active surveillance despite preoperative reclassification to Grade Group 2. MATERIALS AND METHODS: We studied 249 active surveillance patients with surveillance biopsies classified as Grade Group 1 or Grade Group 2 who underwent radical prostatectomy. Perineural invasion, cancer volume, linear length and maximum percentage of Gleason pattern 4, and prostate-specific antigen density were evaluated. Radical prostatectomy adverse pathology was defined by any of: pN1; ≥pT3; ≥Grade Group 2 with ≥20% Gleason pattern 4; intraductal carcinoma; large cribriform glands. RESULTS: A multivariable logistic regression model incorporating prostate-specific antigen density and perineural invasion stratified radical prostatectomy adverse pathology risk among Grade Group 1 and Grade Group 2 active surveillance patients. 57% (39/68) of Grade Group 1 men reclassified to Grade Group 2 while on active surveillance had favorable radical prostatectomy pathology. Those without biopsy perineural invasion and with low prostate-specific antigen density were more likely to have favorable radical prostatectomy pathology. CONCLUSIONS: Most Grade Group 1 men who enter active surveillance and subsequently reclassify to Grade Group 2 have favorable findings at radical prostatectomy and can remain on active surveillance. Among patients reclassified to Grade Group 2, those with low prostate-specific antigen density and without perineural invasion had the lowest risk of radical prostatectomy adverse pathology, comparable to (or below) that of Grade Group 1 patients who were not reclassified to Grade Group 2 preoperatively. Prostate-specific antigen density and perineural invasion stratify risk in active surveillance patients reclassified to Grade Group 2 and, if concordant with other clinicopathological and radiographic findings, can enable more patients to remain on active surveillance. Reclassification to Grade Group 2 alone should not disqualify men from remaining on active surveillance.

Multiparametric magnetic resonance imaging to characterize cabotegravir long-acting formulation depot kinetics in healthy adult volunteers.

AIM: Cabotegravir long-acting (LA) intramuscular (IM) injection is being investigated for HIV preexposure prophylaxis due to its potent antiretroviral activity and infrequent dosing requirement. A subset of healthy adult volunteers participating in a Phase I study assessing cabotegravir tissue pharmacokinetics underwent serial magnetic resonance imaging (MRI) to assess drug depot localization and kinetics following a single cabotegravir LA IM targeted injection. METHODS: Eight participants (four men, four women) were administered cabotegravir LA 600 mg under ultrasonographic-guided injection targeting the gluteal muscles. MRI was performed to determine injection-site location in gluteal muscle (IM), subcutaneous (SC) adipose tissue and combined IM/SC compartments, and to quantify drug depot characteristics, including volume and surface area, on Days 1 (≤2 hours postinjection), 3 and 8. Linear regression analysis examined correlations between MRI-derived parameters and plasma cabotegravir exposure metrics, including maximum observed concentration (Cmax ) and partial area under the concentration-time curve (AUC) through Weeks 4 and 8. RESULTS: Cabotegravir LA depot locations varied by participant and were identified in the IM compartment (n = 2), combined IM/SC compartments (n = 4), SC compartment (n = 1) and retroperitoneal cavity (n = 1). Although several MRI parameter and exposure metric correlations were determined, total depot surface area on Day 1 strongly correlated with plasma cabotegravir concentration at Days 3 and 8, Cmax and partial AUC through Weeks 4 and 8. CONCLUSION: MRI clearly delineated cabotegravir LA injection-site location and depot kinetics in healthy adults. Although injection-site variability was observed, drug depot surface area correlated with both plasma Cmax and partial AUC independently of anatomical distribution.

Prostate MRI Qualification: AJR Expert Panel Narrative Review.

Prostate MRI is now established as a first-line investigation for individuals presenting with suspected localized or locally advanced prostate cancer. Successful delivery of the MRI-directed pathway for prostate cancer diagnosis relies on high-quality imaging as well as the interpreting radiologist's experience and expertise. Radiologist certification in prostate MRI may help limit interreader variability, optimize outcomes, and provide individual radiologists with documentation of meeting predefined standards. This AJR Expert Panel Narrative Review summarizes existing certification proposals, recognizing variable progress across regions in establishing prostate MRI certification programs. To our knowledge, Germany is the only country with a prostate MRI certification process that is currently available for radiologists. However, prostate MRI certification programs have also recently been proposed in the United States and United Kingdom and by European professional society consensus panels. Recommended qualification processes entail a multifaceted approach, incorporating components such as minimum case numbers, peer learning, course participation, continuing medical education credits, and feedback from pathology results. Given the diversity in health care systems, including in the provision and availability of MRI services, national organizations will likely need to take independent approaches to certification and accreditation. The relevant professional organizations should begin developing these programs or continue existing plans for implementation.

Transperineal Prostate Biopsy Improves the Detection of Clinically Significant Prostate Cancer among Men on Active Surveillance.

PURPOSE: Transperineal prostate biopsy offers improved sampling of the anterior prostate compared to the transrectal approach. The objective of this study was to determine if transperineal prostate biopsy is associated with an increased incidence of cancer upgrading among men on active surveillance for very low or low risk prostate cancer. MATERIALS AND METHODS: Our active surveillance registry was queried to identify patients who underwent a surveillance biopsy following the introduction of transperineal prostate biopsy at our institution. Patients were dichotomized by the type of biopsy performed. The baseline characteristics and rates of cancer upgrading were compared between groups. RESULTS: Between November 2017 and June 2020, 790 men with very low or low risk prostate cancer underwent a surveillance biopsy. In total, 59 of 279 men (21.2%) in the transperineal prostate biopsy group were upgraded to grade group ≥2 as compared to 75 of 511 (14.7%) in the transrectal biopsy group (p=0.01). Among patients who were upgraded to grade group ≥2, 26 of 59 (44%) had grade group ≥2 detected in the anterior/transition zone with transperineal prostate biopsy compared to 14 of 75 (18.7%) with transrectal biopsy (p=0.01). Additionally, 17 of 279 men (6.1%) who underwent transperineal prostate biopsy were upgraded to grade group ≥3 vs 17 of 511 (3.3%) who underwent transrectal biopsy (p=0.05). After adjusting for age, prostate specific antigen density, use of magnetic resonance imaging, and number of prior transrectal biopsies, transperineal prostate biopsy was significantly associated with upgrading to grade group ≥2 (OR 1.49, 95% CI 1.11-2.19, p=0.01). CONCLUSIONS: Among men on active surveillance for very low or low risk prostate cancer, transperineal prostate biopsy was associated with an increased likelihood of upgrading to clinically significant prostate cancer. This is likely due to improved sampling of the anterior prostate with the transperineal approach.

Magnetic Resonance Imaging-Guided Transurethral Ultrasound Ablation of Prostate Cancer.

PURPOSE: Magnetic resonance imaging-guided transurethral ultrasound ablation uses directional thermal ultrasound under magnetic resonance imaging thermometry feedback control for prostatic ablation. We report 12-month outcomes from a prospective multicenter trial (TACT). MATERIALS AND METHODS: A total of 115 men with favorable to intermediate risk prostate cancer across 13 centers were treated with whole gland ablation sparing the urethra and apical sphincter. The co-primary 12-month endpoints were safety and efficacy. RESULTS: In all, 72 (63%) had grade group 2 and 77 (67%) had NCCN® intermediate risk disease. Median treatment delivery time was 51 minutes with 98% (IQR 95-99) thermal coverage of target volume and spatial ablation precision of ±1.4 mm on magnetic resonance imaging thermometry. Grade 3 adverse events occurred in 9 (8%) men. The primary endpoint (U.S. Food and Drug Administration mandated) of prostate specific antigen reduction ≥75% was achieved in 110 of 115 (96%) with median prostate specific antigen reduction of 95% and nadir of 0.34 ng/ml. Median prostate volume decreased from 37 to 3 cc. Among 68 men with pretreatment grade group 2 disease, 52 (79%) were free of grade group 2 disease on 12-month biopsy. Of 111 men with 12-month biopsy data, 72 (65%) had no evidence of cancer. Erections (International Index of Erectile Function question 2 score 2 or greater) were maintained/regained in 69 of 92 (75%). Multivariate predictors of persistent grade group 2 at 12 months included intraprostatic calcifications at screening, suboptimal magnetic resonance imaging thermal coverage of target volume and a PI-RADS™ 3 or greater lesion at 12-month magnetic resonance imaging (p <0.05). CONCLUSIONS: The TACT study of magnetic resonance imaging-guided transurethral ultrasound whole gland ablation in men with localized prostate cancer demonstrated effective tissue ablation and prostate specific antigen reduction with low rates of toxicity and residual disease.

PI-RADS Committee Position on MRI Without Contrast Medium in Biopsy-Naive Men With Suspected Prostate Cancer: Narrative Review.

The steadily increasing demand for diagnostic prostate MRI has led to concerns regarding the lack of access to and the availability of qualified MRI scanners and sufficiently experienced radiologists, radiographers, and technologists to meet the demand. Solutions must enhance operational benefits without compromising diagnostic performance, quality, and delivery of service. Solutions should also mitigate risks such as decreased reader confidence and referrer engagement. One approach may be the implementation of MRI without the use gadolinium-based contrast medium (bipara-metric MRI), but only if certain prerequisites such as high-quality imaging, expert interpretation quality, and availability of patient recall or on-table monitoring are mandated. Alternatively, or in combination, a clinical risk-based approach could be used for protocol selection, specifically, which biopsy-naive men need MRI with contrast medium (multiparametric MRI). There is a need for prospective studies in which biopsy decisions are made according to MRI without contrast enhancement. Such studies must define clinical and operational benefits and identify which patient groups can be scanned successfully without contrast enhancement. These higher-quality data are needed before the Prostate Imaging Reporting and Data System (PI-RADS) Committee can make evidence-based recommendations about MRI without contrast enhancement as an initial diagnostic approach for prostate cancer workup.

Utility of multiparametric magnetic resonance imaging in the risk stratification of men with Grade Group 1 prostate cancer on active surveillance.

OBJECTIVE: To assess if the adoption of multiparametric magnetic resonance imaging (mpMRI) in active surveillance (AS) has improved the identification of occult higher-grade prostate cancer (PCa). PATIENTS AND METHODS: We retrospectively identified men from the Johns Hopkins AS registry enrolled since 2013 (year of mpMRI adoption) with Grade Group (GG) 1 PCa and who underwent a single mpMRI. Men in this group were dichotomised by the presence (n = 207) or absence (negative mpMRI, n = 225) of one or more lesions with a Prostate Imaging-Reporting and Data System (PI-RADS) score of ≥ 3. Both groups were compared to a third cohort of men with GG1 PCa enrolled in AS prior to 2013 (pre-mpMRI era, n = 669). The risk of upgrading to GG ≥ 2 PCa on follow-up biopsies (performed with or without MRI targeting) was evaluated among the groups using survival analysis. RESULTS: Men in both mpMRI groups underwent a median (interquartile range [IQR]) of 2 (2-3) biopsies separated by a median (IQR) interval of 13 (12-16) months, whereas men in the pre-MRI era underwent a median (IQR) of 3 (2-5) biopsies, separated by a median (IQR) interval of 12 (12-14) months. The 2- and 4-year upgrade-free survival rates were 93% and 83%, 74% and 59%; and, 87% and 76% for the negative mpMRI, PI-RADS ≥ 3, and pre-mpMRI-era groups, respectively (P < 0.001). On multivariable analysis, both mpMRI groups had significantly different risk of upgrading compared to pre-mpMRI-era group (negative mpMRI group: hazard ratio [HR] 0.61, 95% confidence interval [CI] 0.39-0.95, P = 0.03; PI-RADS ≥ 3 group: HR 1.96, 95% CI 1.36-2.82, P < 0.001). CONCLUSIONS: mpMRI improves the risk stratification of men on AS and should be used to aid enrolment and monitoring decisions.

RadioGraphics Update: PI-RADS Version 2.1-A Pictorial Update.

Editor's Note.-Articles in the RadioGraphics Update section provide current knowledge to supplement or update information found in full-length articles previously published in RadioGraphics. Authors of the previously published article provide a brief synopsis that emphasizes important new information such as technological advances, revised imaging protocols, new clinical guidelines involving imaging, or updated classification schemes. Articles in this section are published solely online and are linked to the original article.

PI-RADS Steering Committee: The PI-RADS Multiparametric MRI and MRI-directed Biopsy Pathway.

High-quality evidence shows that MRI in biopsy-naive men can reduce the number of men who need prostate biopsy and can reduce the number of diagnoses of clinically insignificant cancers that are unlikely to cause harm. In men with prior negative biopsy results who remain under persistent suspicion, MRI improves the detection and localization of life-threatening prostate cancer with greater clinical utility than the current standard of care, systematic transrectal US-guided biopsy. Systematic analyses show that MRI-directed biopsy increases the effectiveness of the prostate cancer diagnosis pathway. The incorporation of MRI-directed pathways into clinical care guidelines in prostate cancer detection has begun. The widespread adoption of the Prostate Imaging Reporting and Data System (PI-RADS) for multiparametric MRI data acquisition, interpretation, and reporting has promoted these changes in practice. The PI-RADS MRI-directed biopsy pathway enables the delivery of key diagnostic benefits to men suspected of having cancer based on clinical suspicion. Herein, the PI-RADS Steering Committee discusses how the MRI pathway should be incorporated into routine clinical practice and the challenges in delivering the positive health impacts needed by men suspected of having clinically significant prostate cancer.

Clinical, Pathological and Oncologic Findings of Radical Prostatectomy with Extraprostatic Extension Diagnosed on Preoperative Prostate Biopsy.

PURPOSE: Prostatic adenocarcinoma with extraprostatic extension detected on prostate needle biopsy is an uncommon finding. We describe clinical and pathological findings in a large cohort of patients with prostatic adenocarcinoma who were treated with radical prostatectomy and in whom extraprostatic extension was identified on prostate needle biopsy. MATERIALS AND METHODS: Using our institutional pathology database we identified 83 patients with prostatic adenocarcinoma and with extraprostatic extension on prostate needle biopsy between 2000 to 2018 who underwent radical prostatectomy and had clinical followup information. Clinical and pathological outcomes were examined. RESULTS: Of the 83 patients 54 (65%) presented with clinical stage T2 or greater disease. On biopsy 50 of the 83 patients (60%) had Grade Group 4-5 and 66 (81%) had perineural invasion. Extraprostatic extension was confirmed in the radical prostatectomy specimen in 81 of 83 cases (98%). At radical prostatectomy 49 of 83 patients (59%) had positive surgical margins, 37 (45%) had seminal vesicle invasion and 30 (37%) had lymph node involvement. Median followup after radical prostatectomy was 2 years. Overall 34 of 76 men (45%) received postoperative radiation a median of 1 year after radical prostatectomy and 8 (11%) received chemotherapy a median of 2 years after radical prostatectomy. The 3-year biochemical recurrence-free survival rate was 48.4% (95% CI 0.345-0.610) and the 3-year metastasis-free survival rate was 75.2% (95% CI 0.603-0.851). CONCLUSIONS: Patients in whom extraprostatic extension is detected on prostate needle biopsy almost always have extraprostatic disease and markedly adverse pathology findings at radical prostatectomy. Many of them experience biochemical recurrence and most will require multimodal therapy. These data can be useful to counsel such patients in regard to the treatment approach and the expected outcomes after surgery.

Combining Prostate Health Index density, magnetic resonance imaging and prior negative biopsy status to improve the detection of clinically significant prostate cancer.

OBJECTIVES: To determine the performance of Prostate Health Index (PHI) density (PHID) combined with MRI and prior negative biopsy (PNB) status for the diagnosis of clinically significant prostate cancer (PCa). PATIENTS AND METHODS: Patients without a prior diagnosis of PCa, with elevated prostate-specific antigen and a normal digital rectal examination who underwent PHI testing prospectively prior to prostate biopsy were included in this study. PHID was calculated retrospectively using prostate volume derived from transrectal ultrasonography at biopsy. Univariable and multivariable logistic regression modelling, along with receiver-operating characteristic (ROC) curve analysis, was used to determine the ability of serum biomarkers to predict clinically significant PCa (defined as either grade group [GG] ≥2 disease or GG1 PCa detected in >2 cores or >50% of any one core) on biopsy. Age, PNB status and Prostate Imaging Reporting and Data System (PI-RADS) score were incorporated into the regression models. RESULTS: Of the 241 men who qualified for the study, 91 (37.8%) had clinically significant PCa on biopsy. The median (interquartile range) PHID was 0.74 (0.44-1.24); it was 1.18 (0.77-1.83) and 0.55 (0.38-0.89) in those with and without clinically significant PCa on biopsy, respectively (P < 0.001). On univariable logistic regression, age and PNB status were associated with clinically significant cancer. Of the tested biomarkers, PHID demonstrated the highest discriminative ability for clinically significant disease (area under the ROC curve [AUC] 0.78 for the univariable model). That continued to be the case in multivariable logistic regression models incorporating age and PNB status (AUC 0.82). At a threshold of 0.44, representing the 25th percentile of PHID in the cohort, PHID was 92.3% sensitive and 35.3% specific for clinically significant PCa; the sensitivity and specificity were 93.0% and 32.4% and 97.4% and 29.1% for GG ≥2 and GG ≥3 disease, respectively. In the 104 men who underwent MRI, PI-RADS score was complementary to PHID, with a PI-RADS score ≥3 or, if PI-RADS score ≤2, a PHID ≥0.44, detecting 100% of clinically significant disease. For that subgroup, of the biomarkers tested, PHID (AUC 0.90) demonstrated the highest discriminative ability for clinically significant disease on multivariable logistic regression incorporating age, PNB status and PI-RADS score. CONCLUSIONS: In this contemporary cohort of men undergoing prostate biopsy for the diagnosis of PCa, PHID outperformed PHI and other PSA derivatives in the diagnosis of clinically significant cancer. Incorporating age, PNB status and PI-RADS score led to even further gains in the diagnostic performance of PHID. Furthermore, PI-RADS score was found to be complementary to PHID. Using 0.44 as a threshold for PHID, 35.3% of unnecessary biopsies could have been avoided at the cost of missing 7.7% of clinically significant cancers. Despite these encouraging results, prospective validation is needed.

Influences for Gender Disparity in the Radiology Societies in North America.

OBJECTIVE: The objective of our study was to outline the gender distribution in leadership positions in the North American radiology societies. MATERIALS AND METHODS: A review of North American radiology societies was conducted to identify committee members and those holding leadership positions. The Scopus database was queried for research productivity metrics of these individuals. Gender, university affiliation, and academic rank were identified from departmental websites. The chi-square test was used to assess for differences in gender distribution, and nonparametric analyses were applied to determine gender differences in continuous variables. RESULTS: Of 2826 radiology society committee members, men outnumbered women 67.4% (n = 1906) to 32.6% (n = 920). There were 696 society leadership positions, of which men held 501 (72.0%) and women held 195 (28.0%) (p < 0.003). Additionally, 26.3% of all men held leadership positions compared with 21.2% of all women (p = 0.0032). Overall, men had a higher median h-index (14 [range, 0-113] vs 11 [range, 0-73]), number of publications (52 [range, 2-1264] vs 35 [range, 2-428]), and number of citations (880 [range, 0-54,813] vs 483.5 [range, 0-17,332]) than women (p < 0.001). Across university academic ranks of assistant and associate professor, research productivity metrics were similar between genders, but interestingly, female representation decreased with increasing academic rank. A higher proportion of men held a university rank of professor than women (39.5% vs 33.4%; p = 0.0017) with parity at the levels of assistant and associate professors. CONCLUSION: Gender disparity exists in the leadership positions in North American radiology societies. We have attempted to study the relationship between gender, academic rank, and h-index with leadership roles in these societies.

Addressing Needs of Women Radiologists: Opportunities for Practice Leaders to Facilitate Change.

Women are, and have always been, underrepresented in radiology. This gender disparity must be addressed. Women bring a different perspective to the workplace; and their collaborative, empathetic, and compassionate approach to patient care and education is an asset that the radiology community should embrace and leverage. Radiologic organizations should focus on removing barriers to the entry of women physicians into radiology as a specialty and to their career advancement. Organizations should address bias, promote physician well-being, and cultivate a safe and positive work environment. Radiology leaders committed to increasing gender diversity and fostering an inclusive workplace have the opportunity to strengthen their organizations. This article outlines the key steps that practice leaders can take to address the needs of women in radiology: (a) marketing radiology to talented women medical students, (b) addressing recruitment and bias, (c) understanding and accommodating the provisions of the Family and Medical Leave Act of 1993 and the Fair Labor Standards Act for both trainees and radiologists in practice, (d) preventing burnout and promoting well-being, (e) offering flexible work opportunities, (f) providing mentorship and career advancement opportunities, and (g) ensuring equity. ©RSNA, 2018.

Use of Dynamic MRI of the Pelvic Floor in the Assessment of Anterior Compartment Disorders.

PURPOSE OF REVIEW: Approximately 25% of women in the USA suffer from pelvic floor disorders. Disorders of the anterior compartment of the pelvic floor, in particular, can cause symptoms such as incomplete urinary voiding, urinary incontinence, pelvic organ prolapse, dyspareunia, and pelvic pain, potentially negatively impacting a woman's quality of life. In some clinical situations, clinical exam alone may be insufficient, especially when patient's symptoms are in excess of their pelvic exam findings. In many of these patients, dynamic magnetic resonance imaging (dMRI) of the pelvic floor can be a valuable imaging tool allowing for comprehensive assessment of the entire pelvic anatomy and its function. RECENT FINDINGS: Traditionally, evaluation of the anterior compartment has been primarily through clinical examination with occasional use of urodynamic testing and ultrasound. In recent years, dMRI has continued to gain popularity due to its improved imaging quality, reproducibility, and ability to display the entire pelvic floor. Emerging evidence has also shown utility of dMRI in the postoperative setting. In spite of advances, there remains an ongoing discussion in contemporary literature regarding the accuracy of dMRI and its correlation with clinical examination and with patient symptoms. Dynamic pelvic MRI is a helpful adjunct to physical examination and urodynamic testing, particularly when a patient's symptoms are in excess of the physical examination findings. Evaluation with dMRI can guide preoperative and postoperative surgical management in many patients, especially in the setting of multicompartmental disorders. This review will summarize relevant pelvic floor anatomy and discuss the clinical application, imaging technique, imaging interpretation, and limitations of dMRI.

Dynamic Contrast Enhanced Magnetic Resonance Imaging Improves Classification of Prostate Lesions: A Study of Pathological Outcomes on Targeted Prostate Biopsy.

PURPOSE: PI-RADS™, version 2 stipulates that dynamic contrast enhanced imaging should be used to classify diffusion-weighted imaging score 3 peripheral zone lesions as PI-RADS score 3 (dynamic contrast enhanced imaging negative or nonenhancing) or 4 (dynamic contrast enhanced imaging positive or enhancing). However, to our knowledge it is unknown whether dynamic contrast enhanced imaging separates lesions into clinically meaningful pathological groups. We examined whether dynamic contrast enhanced imaging would improve the detection of clinically significant cancer. MATERIALS AND METHODS: We identified patients without a prior diagnosis of prostate cancer who underwent multiparametric magnetic resonance imaging-transrectal ultrasound fusion targeted biopsy of peripheral zone lesions with a diffusion-weighted imaging score of 3 or 4. Each lesion was grouped into 1 of 3 classifications, including group 1-diffusion-weighted imaging score 3/nonenhancing/PI-RADS score 3, group 2-diffusion-weighted imaging score 3/enhancing/PI-RADS score 4 or group 3-diffusion-weighted imaging score 4/PI-RADS score 4. We measured the rate of grade group 2 or greater pathology detected for each lesion group with subgroup analyses in patients with vs without prior negative systematic biopsy. RESULTS: We identified a total of 389 peripheral zone diffusion-weighted imaging score 3 or 4 lesions in 290 patients. The rate of grade group 2 or greater cancer on biopsy for group 1, 2 and 3 lesions was 8.9%, 21% and 36.5%, respectively (p <0.03). The rate of grade group 2 or greater pathology was higher in group 2 than group 1 lesions in patients with prior negative systematic prostate biopsy (28% vs 5.0%, p <0.001) but not in those without such a biopsy (16% vs 12%, p = 0.5). Group 3 lesions had a higher rate of grade group 2 or greater cancer than group 2 lesions in the biopsy naïve subgroup (46% vs 16%, p = 0.001). However, the rates were similar in patients with prior negative systematic prostate biopsy (27% vs 28%, p = 0.9). CONCLUSIONS: Diffusion-weighted imaging score 3 peripheral zone lesions were more likely to be clinically significant cancer (grade group 2 or greater) if they were dynamic contrast enhanced T1-weighted imaging positive. That was most apparent in patients with a prior negative systematic prostate biopsy. In such patients including a dynamic contrast enhanced sequence in multiparametric magnetic resonance imaging allowed for optimal lesion risk stratification.

MR Safe Robot, FDA Clearance, Safety and Feasibility Prostate Biopsy Clinical Trial.

Compatibility of mechatronic devices with the MR environment has been a very challenging engineering task. After over a decade of developments, we report the successful translation to clinical trials of our MR Safe robot technology. MrBot is a 6-degree-of-freedom, pneumatically actuated robot for transperineal prostate percutaneous access, built exclusively of electrically nonconductive and nonmagnetic materials. Its extensive pre-clinical tests have been previously reported. Here, we present the latest technology developments, an overview of the regulatory protocols, and technically related results of the clinical trial. The FDA has approved the MrBot for the biopsy trial, which was successfully performed in 5 patients. With no trajectory corrections, and no unsuccessful attempts to target a site, the robot achieved an MRI based needle targeting accuracy of 2.55 mm. To the best of our knowledge, this is the first robot approved by the FDA for the MR environment. The results confirm that it is possible to perform safe and accurate robotic manipulation in the MRI scanner, and the development of MR Safe robots is no longer a daunting technical challenge.

Association between breast cancer, breast density, and body adiposity evaluated by MRI.

OBJECTIVE: Despite the lack of reliable methods with which to measure breast density from 2D mammograms, numerous studies have demonstrated a positive association between breast cancer and breast density. The goal of this study was to study the association between breast cancer and body adiposity, as well as breast density quantitatively assessed from 3D MRI breast images. METHODS: Breast density was calculated from 3D T1-weighted MRI images. The thickness of the upper abdominal adipose layer was used as a surrogate marker for body adiposity. We evaluated the correlation between breast density, age, body adiposity, and breast cancer. RESULTS: Breast density was calculated for 410 patients with unilateral invasive breast cancer, 73 patients with ductal carcinoma in situ (DCIS), and 361 controls without breast cancer. Breast density was inversely related to age and the thickness of the upper abdominal adipose layer. Breast cancer was only positively associated with body adiposity and age. CONCLUSION: Age and body adiposity are predictive of breast density. Breast cancer was not associated with breast density; however, it was associated with the thickness of the upper abdominal adipose layer, a surrogate marker for body adiposity. Our results based on a limited number of patients warrant further investigations. KEY POINTS: • MRI breast density is negatively associated with body adiposity. • MRI breast density is negatively associated with age. • Breast cancer is positively associated with body adiposity. • Breast Cancer is not associated with MRI breast density.