Arvin K. George

Prostate Cancer: Interobserver Agreement and Accuracy with the Revised Prostate Imaging Reporting and Data System at Multiparametric MR Imaging

PURPOSE To evaluate accuracy and interobserver variability with the use of the Prostate Imaging Reporting and Data System (PI-RADS) version 2.0 for detection of prostate cancer at multiparametric magnetic resonance (MR) imaging in a biopsy-naïve patient population. MATERIALS AND METHODS This retrospective HIPAA-compliant study was approved by the local ethics committee, and written informed consent was obtained from all patients for use of their imaging and histopathologic data in future research studies. In 101 biopsy-naïve patients with elevated prostate-specific antigen levels who underwent multiparametric MR imaging of the prostate and subsequent transrectal ultrasonography (US)-MR imaging fusion-guided biopsy, suspicious lesions detected at multiparametric MR imaging were scored by five readers who were blinded to pathologic results by using to the newly revised PI-RADS and the scoring system developed in-house. Interobserver agreement was evaluated by using κ statistics, and the correlation of pathologic results with each of the two scoring systems was evaluated by using the Kendall τ correlation coefficient. RESULTS Specimens of 162 lesions in 94 patients were sampled by means of transrectal US-MR imaging fusion biopsy. Results for 87 (54%) lesions were positive for prostate cancer. Kendall τ values with the PI-RADS and the in-house-developed scoring system, respectively, at T2-weighted MR imaging in the peripheral zone were 0.51 and 0.17 and in the transitional zone, 0.45 and -0.11; at diffusion-weighted MR imaging, 0.42 and 0.28; at dynamic contrast material-enhanced MR imaging, 0.23 and 0.24, and overall suspicion scores were 0.42 and 0.49. Median κ scores among all possible pairs of readers for PI-RADS and the in-house-developed scoring system, respectively, for T2-weighted MR images in the peripheral zone were 0.47 and 0.15; transitional zone, 0.37 and 0.07; diffusion-weighted MR imaging, 0.41 and 0.57; dynamic contrast-enhanced MR imaging, 0.48 and 0.41; and overall suspicion scores, 0.46 and 0.55. CONCLUSION Use of the revised PI-RADS provides moderately reproducible MR imaging scores for detection of clinically relevant disease.

Improving Detection of Clinically Significant Prostate Cancer: Magnetic Resonance Imaging/Transrectal Ultrasound Fusion Guided Prostate Biopsy

PURPOSE Given the limitations of prostate specific antigen and standard biopsies for detecting prostate cancer, we evaluated the cancer detection rate and external validity of a magnetic resonance imaging/transrectal ultrasound fusion guided prostate biopsy system used at the National Institutes of Health. MATERIALS AND METHODS We performed a phase III trial of a magnetic resonance imaging/transrectal ultrasound fusion guided prostate biopsy system with participants enrolled between 2012 and 2013. A total of 153 men consented to the study and underwent 3 Tesla multiparametric magnetic resonance imaging with an endorectal coil for clinical suspicion of prostate cancer. Lesions were classified as low or moderate/high risk for prostate cancer. Magnetic resonance imaging/transrectal ultrasound fusion guided biopsy and standard 12-core prostate biopsy were performed and 105 men were eligible for analysis. RESULTS Mean patient age was 65.8 years and mean prostate specific antigen was 9.5 ng/ml. The overall cancer detection rate was 62.9% (66 of 105 patients). The cancer detection rate in those with moderate/high risk on imaging was 72.3% (47 of 65) vs 47.5% (19 of 40) in those classified as low risk for prostate cancer (p<0.05). Mean tumor core length was 4.6 and 3.7 mm for fusion biopsy and standard 12-core biopsy, respectively (p<0.05). Magnetic resonance imaging/transrectal ultrasound fusion guided biopsy detected prostate cancer that was missed by standard 12-core biopsy in 14.3% of cases (15 of 105), of which 86.7% (13 of 15) were clinically significant. This biopsy upgraded 23.5% of cancers (4 of 17) deemed clinically insignificant on 12-core biopsy to clinically significant prostate cancer necessitating treatment. CONCLUSIONS Magnetic resonance imaging/transrectal ultrasound fusion guided biopsy can improve prostate cancer detection. The results of this trial support the external validity of this platform and may be the next step in the evolution of prostate cancer management.

The Comparison of Three Renal Tumor Scoring Systems: C-Index, P.A.D.U.A., and R.E.N.A.L. Nephrometry Scores

BACKGROUND AND PURPOSE The centrality-index (C-Index), preoperative aspects and dimensions used for anatomic (P.A.D.U.A.) classification, and radius.exophyic/endophytic.nearness.anterior/posterior.location (R.E.N.A.L.) nephrometry schemes were developed as standardized scoring systems (SS) to quantify anatomic characteristics of kidney tumors. The objective of this study was to establish reliability and assess relationships between these three SS and perioperative and postoperative variables. PATIENTS AND METHODS A retrospective chart review was performed in 101 patients who underwent laparoscopic partial nephrectomy. The nephrometry schemes were correlated with intraoperative and postoperative parameters using Spearman correlations. In addition, interobserver reliability was assessed on 50 of the patients by interclass correlations comparing the scores assigned by two residents and one fellow who reviewed preoperative CT studies of these patients. RESULTS The interobserver correlation was 0.84 for the C-Index, 0.81 for the P.A.D.U.A., and 0.92 for the R.E.N.A.L. scoring systems, demonstrating excellent interobserver reliability. All three SS were significantly associated with warm ischemia time (WIT) (C-Index, P=-0.44; P.A.D.U.A., P=0.25; R.E.N.A.L., P=0.32) and percent change in creatinine level (C-Index, P=- 0.33; P.A.D.U.A., P=0.37; R.E.N.A.L., P=0.37). There were no significant associations between any of the three SS assessed and the occurrence of complications, operative time, or estimated blood loss. No significant correlation was found between the P.A.D.U.A. and R.E.N.A.L. SS and length of stay; however, C-Index did show a significant relationship for patients with lower scores having longer hospital stays (P=-0.21). CONCLUSIONS All three scoring systems demonstrated reliability among observers and represent novel methods of quantitatively describing renal tumors. They were all associated with WIT, percent change in creatinine level, and tumor size. They did not, however, correlate with any other perioperative parameters investigated. At this time, these SS provide a common language for describing renal tumors.

Use of serial multiparametric magnetic resonance imaging in the management of patients with prostate cancer on active surveillance

INTRODUCTION We evaluated the performance of multiparametric prostate magnetic resonance imaging (mp-MRI) and MRI/transrectal ultrasound (TRUS) fusion-guided biopsy (FB) for monitoring patients with prostate cancer on active surveillance (AS). MATERIALS AND METHODS Patients undergoing mp-MRI and FB of target lesions identified on mp-MRI between August 2007 and August 2014 were reviewed. Patients meeting AS criteria (Clinical stage T1c, Gleason grade ≤ 6, prostate-specific antigen density ≤ 0.15, tumor involving ≤ 2 cores, and ≤ 50% involvement of any single core) based on extended sextant 12-core TRUS biopsy (systematic biopsy [SB]) were included. They were followed with subsequent 12-core biopsy as well as mp-MRI and MRI/TRUS fusion biopsy at follow-up visits until Gleason score progression (Gleason ≥ 7 in either 12-core or MRI/TRUS fusion biopsy). We evaluated whether progression seen on mp-MRI (defined as an increase in suspicion level, largest lesion diameter, or number of lesions) was predictive of Gleason score progression. RESULTS Of 152 patients meeting AS criteria on initial SB (mean age of 61.4 years and mean prostate-specific antigen level of 5.26 ng/ml), 34 (22.4%) had Gleason score ≥ 7 on confirmatory SB/FB. Of the 118 remaining patients, 58 chose AS and had at least 1 subsequent mp-MRI with SB/FB (median follow-up = 16.1 months). Gleason progression was subsequently documented in 17 (29%) of these men, in all cases to Gleason 3+4. The positive predictive value and negative predictive value of mp-MRI for Gleason progression was 53% (95% CI: 28%-77%) and 80% (95% CI: 65%-91%), respectively. The sensitivity and specificity of mp-MRI for increase in Gleason were also 53% and 80%, respectively. The number needed to biopsy to detect 1 Gleason progression was 8.74 for SB vs. 2.9 for FB. CONCLUSIONS Stable findings on mp-MRI are associated with Gleason score stability. mp-MRI appears promising as a useful aid for reducing the number of biopsies in the management of patients on AS. A prospective evaluation of mp-MRI as a screen to reduce biopsies in the follow-up of men on AS appears warranted.

Off‐clamp versus complete hilar control laparoscopic partial nephrectomy: comparison by clinical stage

Study Type – Therapy (case series)

Perioperative outcomes of off‐clamp vs complete hilar control laparoscopic partial nephrectomy

Whats known on the subject? and What does the study add?

Accuracy and agreement of PIRADSv2 for prostate cancer mpMRI: A multireader study

Multiparametric MRI (mpMRI) improves the detection of clinically significant prostate cancer, but is limited by interobserver variation. The second version of theProstate Imaging Reporting and Data System (PIRADSv2) was recently proposed as a standard for interpreting mpMRI. To assess the performance and interobserver agreement of PIRADSv2 we performed a multi‐reader study with five radiologists of varying experience.

Image-guided percutaneous renal cryoablation: Preoperative risk factors for recurrence and complications

Whats known on the subject? and What does the study add?

Multiparametric Magnetic Resonance Imaging and Image-Guided Biopsy to Detect Seminal Vesicle Invasion by Prostate Cancer

OBJECTIVES To evaluate the correlation between multiparametric prostate MRI (MP-MRI) suspicion for seminal vesicle invasion (SVI) by prostate cancer (PCa) and pathology on MRI/ultrasound (US) fusion-guided biopsy. PATIENTS AND METHODS From March 2007 to June 2013, 822 patients underwent MP-MRI at 3 Tesla and MRI/US fusion-guided biopsy. Of these, 25 patients underwent targeted biopsy of the seminal vesicles (SVs). In six patients, bilateral SVI was suspected, resulting in 31 samples. MP-MRI findings that triggered these SV biopsies were scored as low, moderate, or high suspicion for SVI based on the degree of involvement on MRI. Correlative prostate biopsy and radical prostatectomy (RP) pathology were reviewed by a single genitourinary pathologist. RESULTS At the time of MP-MRI, the median age was 64 years with a median prostate-specific antigen of 10.74 ng/mL. Of the 31 SV lesions identified, MP-MRI suspicion scores of low, moderate, and high were assigned to 3, 19, and 9 lesions, respectively. MRI/US fusion-guided biopsy detected SVI in 20/31 (65%) of cases. For the four patients who underwent RP after a preoperative assessment of SVI, biopsy pathology and RP pathology were concordant in all cases. CONCLUSIONS As this technology becomes more available, MP-MRI and MRI/US fusion-guided biopsy may play a role in the preoperative staging for PCa. Future work will determine if improved preoperative staging leads to better surgical outcomes.

Comparison of magnetic resonance imaging and ultrasound (MRI-US) fusion-guided prostate biopsies obtained from axial and sagittal approaches

To compare cancer detection rates and concordance between magnetic resonance imaging and ultrasound (MRI‐US) fusion‐guided prostate biopsy cores obtained from axial and sagittal approaches.