Histological comparison between predictive value of preoperative 3-T multiparametric MRI and 68 Ga-PSMA PET/CT scan for pathological outcomes at radical prostatectomy and pelvic lymph node dissection for prostate cancer.

OBJECTIVE: To evaluate the ability of preoperative multiparametric magnetic resonance imaging (mpMRI) and a gallium-68 prostate-specific membrane antigen positron emission tomography/computed tomography (68 Ga-PSMA PET/CT) scan to predict pathological outcomes and also identify a group of men with a <5% risk of histological pelvic lymph node metastasis (LNM) at pelvic lymph node dissection (PLND) performed during a robot-assisted laparoscopic radical prostatectomy (RALP) for prostate cancer. We then aimed to compare these results to known risk calculators for LNM, including the Cancer of the Prostate Risk Assessment (CAPRA) score, Memorial Sloan Kettering Cancer Centre (MSKCC) and Briganti nomograms. PATIENTS AND METHODS: Between July 2014 and September 2019 only men who had both a preoperative mpMRI and staging 68 Ga-PSMA PET/CT at our institution followed by a RALP with PLND referred to a single specialist uropathology laboratory were considered for inclusion. The data were collected retrospectively prior to February 2019 and in a prospective manner thereafter. A model was built to allocate probabilities of the men with a negative 68 Ga-PSMA PET/CT scan having a <5% risk of histologically LNM at RALP based on the preoperative radiological staging. RESULTS: A total of 233 consecutive men met the inclusion criteria of which 58 men (24.9%) had a LNM identified on PLND histology. The median (range) International Society of Urological Pathology (ISUP) Grade was 5 (1-5) and the median (range) prostate-specific antigen level was 7.4 (1.5-72) ng/mL. The median (range) number of resected lymph nodes was 16 (1-53) and the median (range) number of positive nodes identified on histology was 2 (1-22). Seminal vesicle invasion on mpMRI was more common in node-positive men than in the absence of LNM (31% vs 12%). The maximum standardised uptake value of the primary tumour on 68 Ga-PSMA PET/CT was higher in men with LNM (median 9.2 vs 7.2, P = 0.02). Suspected LNM were identified in 42/233 (18.0%) men with 68 Ga-PSMA PET/CT compared with 22/233 (9.4%) men with mpMRI (P = 0.023). The positive and negative predictive value for 68 Ga-PSMA PET/CT was 66.7% and 84.3% respectively, compared to 59.1% and 78.7% for mpMRI. A predictive model showed only two men (4.2%) with a negative preoperative 68 Ga-PSMA PET/CT would be positive for a histological LNM if they are ISUP Grade < 5 and Prostate Imaging-Reporting and Data System (PI-RADS) <5; or ISUP Grade 5 with PI-RADS < 4. An inspection of three additional variables: CAPRA score, MSKCC and Briganti nomograms did not improve the predictive probability for this group. However, of the 61 men with ISUP Grade 4-5 malignancy and also a PI-RADS 5 mpMRI, 20 (32.8%) men had a microscopic LNM despite a negative preoperative 68 Ga-PSMA PET/CT. CONCLUSION: Preoperative 68 Ga-PSMA/PET CT was more sensitive in identifying histological pelvic LNM than 3-T mpMRI. Men with a negative 68 Ga-PSMA PET/CT have a lower risk of LNM than predicted with CAPRA scores or MSKCC and Briganti nomograms. We identified that the combination of a negative preoperative 68 Ga-PSMA PET/CT, ISUP biopsy Grade <5 and PI-RADS <5 prostate mpMRI, or an ISUP Grade 5 with PI-RADS <4 on mpMRI was associated with a <5% risk of a LNM. The addition of CAPRA scores, MSKCC and Briganti nomograms did not improve the predictive probability within this model. Conversely, men with ISUP Grade 4-5 malignancy associated with a PI-RADS 5 prostate mpMRI had a >30% risk of microscopic LNM despite a negative preoperative 68 Ga-PSMA PET/CT and this high-risk group would appear suitable for an extended PLND at the time of a radical prostatectomy.

Analysis of invoked slips while wearing flip-flops in wet and dry conditions: Does alternative footwear alter slip kinematics?

Minimal footwear has become more ubiquitous; however, it may increase slip severity. This study specifically examined the slipping kinematics of flip-flop sandals. Invoked slips from standing were evaluated in dry and wet tile, and a unique wet footbed + wet tile condition, with 40, 50, and 60% bodyweight (BW) committed to the slipping foot. Water did not alter peak slip velocity (PV) at 40% BW, but PV increased with greater slip-foot force on wet tile by ~1 m/s. Interestingly, when floor-contact was lost during the slip, the flip-flops could come off the heel. This decoupling occurred most often when both the tile and footbed were either dry or wet. Given that both decoupling and greater PV were observed on wet tile, slipping in flip-flops under wet conditions may have more serious consequences. The results highlight that slips may occur at both the foot-flip-flop, and flip-flop-tile interfaces.

MRI-guided in-bore biopsy for prostate cancer: what does the evidence say? A case series of 554 patients and a review of the current literature.

PURPOSE: To review our experience with MRI-guided in-bore prostate biopsy (MRGB) and present a review of the literature on MRGB. METHODS: A retrospective review of patients presenting for MRGB between 2013 and 2018. Diagnostic and biopsy MRI scans were reviewed to collect data on scan dates, procedure times, characteristics of MRI targets (PI-RADS™ score, target size, ADC value and location). A review of the literature on MRGB for the period 2013-2018 was performed. RESULTS: 607 targets in 554 men were biopsied. Overall and significant cancer detection rate were 80% and 55% at a patient level, and 76 and 59% at the target level, respectively. Prostate cancer (CaP) detection in men with prior negative biopsy was 60% while 50% of men on active surveillance were upgraded to clinically significant disease (CSD). Lesion location did not predict for presence of CaP or CSD. PI-RADS™ score, age and PSAD were predictors of CSD at biopsy on multivariate analysis. Literature review identified 23 reports reporting on MRGB cohorts (~ 4000 patients). Overall cancer detection ranged from 23 to 74% and CSD in 63% overall. CaP detection in PI-RADS™ 3 targets was substantially lower in our series and the literature than for PI-RADS™ 4-5 targets. CONCLUSIONS: MRGB in PI-RADS™ 3-5 targets yields high rates of cancer diagnosis. High detection rates are also seen in men with prior negative biopsy and AS cohorts. PI-RADS™ score, age and PSAD can reliably predict CSD detection. The number of published series is small and the role of MRGB in PI-RADS™ 3 targets needs further study.