Faculty Bibliography

PURPOSE: To assess the utility of apparent diffusion coefficient (ADC) values obtained from diffusion-weighted imaging (DWI) in distinguishing high-grade bladder cancer with and without metastatic disease. MATERIALS AND METHODS: Seventeen patients with histologically confirmed high-grade bladder cancer who underwent pelvic magnetic resonance imaging (MRI) at 1.5T including DWI using b-values of 0, 400, and 800 sec/mm(2) were assessed. Histologic findings and follow-up imaging were used to establish the reference standard in terms of metastatic disease. Two radiologists independently recorded ADC of all lesions following a training session, with their results averaged. Mann-Whitney U-test, receiver operating characteristic (ROC) curve analysis and intraclass correlation coefficient (ICC) were used for data analysis. RESULTS: Metastatic disease was characterized as present or absent in eight and nine patients, respectively. ADC was significantly lower among cases with metastatic disease than among cases without metastatic disease, both within the entire cohort (1.07 +/- 0.18 x 10(-3) mm(2) /s vs. 1.45 +/- 0.22 x 10(-3) mm(2) /s; P = 0.002) and within the subset of patients with muscle-invasive tumor (1.06 +/- 0.19 x 10(-3) mm(2) /s vs. 1.45 +/- 0.23 x 10(-3) mm(2) /s; P = 0.017). Area under the ROC curve for identifying metastatic disease using ADC was 0.944, with optimal threshold of 1.21 x 10(-3) mm(2) /s, which was associated with a sensitivity of 87.5%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 90.0%. Interreader agreement for ADC was excellent (ICC = 0.91). CONCLUSION: In this preliminary study, ADC was significantly different between cases of high-grade urothelial carcinoma of the bladder with and without metastatic disease. These results may have value in assessing the metastatic potential of patients with localized high-grade tumors of the bladder. J. Magn. Reson. Imaging 2012;. (c) 2012 Wiley Periodicals, Inc.

Purpose: To retrospectively assess the relationships between a number of magnetic resonance (MR) imaging features and growth rate of solid renal masses in patients undergoing active surveillance. Materials and Methods: This retrospective study was institutional review board approved, with waiver of informed consent. This study was HIPAA compliant. Forty-four patients (mean age, 70 years +/- 13 [standard deviation]; 31 men, 13 women) with 47 solid renal masses measuring at least 1 cm who underwent two contrast material-enhanced MR imaging studies at least 3 months apart were included. The initial MR imaging study was evaluated independently by two radiologists for an array of imaging features, with differences resolved by consensus. Later, the two readers in consensus measured tumor volume on the first and last study to calculate tumor doubling time (DT). Associations between MR imaging features and DT were assessed by using generalized estimating equations and mixed model analyses. Interreader agreement was assessed with k coefficients. Results: kappa coefficients ranged from 0.62 to 0.92. Mean DT of the 47 masses was 530 days. Five (11%) masses decreased in size. Twenty-five of 47 masses were classified as slow growing on the basis of a DT of more than 2 years. There was significantly slower growth among masses showing homogeneity on T2-weighted images (P = .036) and a nearly significant slower growth rate among masses showing homogeneity on postcontrast images (P = .065) and hypointensity on T2-weighted images (P = .074). There was a significant correlation between initial volume and growth rate among lesions larger than 3 cm (r = 0.79, P = .041) but not among smaller lesions (r = -0.02, P = .911). Multivariate analysis identified age (odds ratio = 0.92, P = .015) and homogeneity on T2-weighted images (odds ratio = 4.47, P = .037) as independent predictors of slow growth. Conclusion: The results suggest MR imaging features may have a role in predicting growth rate of solid renal masses during active surveillance. (c) RSNA, 2012 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11111074/-/DC1.

BACKGROUND: Prostate cancer (PCa) racial disparity studies typically focus on survival differences after curative treatment. The authors of this report hypothesized that comparing mortality rates between African American (AA) and Caucasian American (CA) patients who deferred primary treatment for clinically nonmetastatic PCa may provide a better assessment of the impact of race on the natural course of PCa. METHODS: The pathology database of the New York Veterans Administration Medical Center (VAMC), an equal access-of-care facility, was searched for patients with biopsy-proven PCa. Inclusion criteria included 1) no evidence of metastatic disease or death within 3 years after diagnosis, 2) no primary treatment, and 3) a minimum of 5 years of follow-up for survivors. RESULTS: In total, 518 patients met inclusion criteria between 1990 and 2005. AA patients were younger (P = .02) and had higher median prostate-specific antigen (PSA) levels (P = .001) at the time of diagnosis compared with CA patients. In a multivariate model, higher Gleason score and PSA level were associated with increased mortality (P = .001 and P = .03, respectively), but race was not a predictor of death from PCa. CONCLUSIONS: The current data suggested that race did not have a major impact on survival in patients with PCa who deferred primary treatment for clinically nonmetastatic disease. Cancer 2011. (c) 2011 American Cancer Society

Study Type - Diagnostic (validating cohort) Level of Evidence 1b What's known on the subject? and What does the study add? Nadir Ultrasensitive PSA levels has some value for predicting BCR following RD. AccuPSA assays lower limit of PSA quantification of <0.01 pg/ml greatly enhances sensitivity and specificity of nadir PSA to predict BCR following RP. Our pilot study shows an AccuPSA of 3 pg/ml has a sensitory and specificity of 100% and 75% respectively for predicting 5 year BCR following RP. OBJECTIVES * To conduct a proof of concept study to evaluate a novel digital single molecule immunoassay (AccuPSA(TM) ) that detects prostate-specific antigen (PSA) a thousandfold more sensitively than current PSA detection methods. * To determine the ability of the AccuPSA(TM) assay to predict 5-year biochemical recurrence (BCR)-free survival after radical prostatectomy (RP). PATIENTS AND METHODS * A total of 31 frozen serum specimens were obtained from specimen logs maintained at New York University Langone Medical Center and the Johns Hopkins University School of Medicine on men who had undergone RP. Those men without evidence of BCR had a minimum of 5 years' PSA follow-up. * In all cases, preoperative and pathological information were available, as was a serum specimen 3-6 months after RP, with a PSA level of <0.1 ng/mL measured by conventional PSA methods at the time of serum collection. * Specimens were tested using the AccuPSA(TM) method. * A Cox proportional hazard model and Kaplan-Meier analysis were used to determine whether AccuPSA(TM) predicted the risk of BCR. RESULTS * Overall, 11/31 (35.5%) men developed BCR. * Mean AccuPSA(TM) nadir levels were significantly different (P < 0.001) between the non-BCR group (2.27 pg/mL) and the BCR group (46.99 pg/mL). * Using a multivariate Cox proportional hazard model, AccuPSA(TM) nadir level was a significant predictor of BCR-free survival (P < 0.01). * Kaplan-Meier analysis of up to 5 years follow-up showed that 100% of men with AccuPSA(TM) nadir values <3 pg/mL did not develop BCR, whereas 62.5% of men with values >3 pg/mL developed BCR (P= 0.00024). * The sensitivity, specificity, positive predictive value and negative predictive value of the AccuPSA(TM) method was 100%, 75%, 69% and 100%, respectively. CONCLUSIONS * AccuPSA(TM) assay predicts 5-year BCR- free survival after RP. * Identifying a reliable predictor of BCR soon after RP has important implications for frequency of PSA testing, selection of candidates for adjuvant therapy, and reassuring a large subset of men that they are not at risk of recurrence. * Larger studies are needed to validate these findings