Imaging Utilization for the Staging of Clinically Localized Prostate Cancer

Prostate Cancer

RiU_Apr2011_p61-64.qxd 4/13/11 10:54 AM Page 63 Prostate Cancer Imaging Utilization for the Staging of Clinically Localized Prostate Cancer Reviewed by Stacy Loeb, MD, Alan W. Partin, MD, PhD The James Buchanan Brady Urological Institute, Department of Urology, The Johns Hopkins Medical Institutions, Baltimore, MD [Rev Urol. 2011;13(1):63-64 doi: 10.3909/riu0518] © 2011 MedReviews®, LLC or prostate cancer staging, the National Comprehensive Cancer Network currently recommends computed tomography (CT) or magnetic resonance imaging (MRI) for patients with clinical stage  T3 disease or clinical stage T1-2 disease with a nomogram probability of lymph node involvement  20%.1 Bone scan is recommended for a prostate-specific antigen (PSA)  20 ng/mL (clinical stage T1) or PSA  10 ng/mL (clinical stage T2), a Gleason score  8, and clinical stage  T3 or symptoms. According to the American Urological Association, bone scans are typically not necessary for patients with a prediagnostic PSA  20 ng/mL. However, it is reasonable to consider a bone scan for clinical stage  T3 disease or a Gleason score  8 even if the PSA level is  10 ng/mL. Similarly, CT or MRI can be considered for locally advanced disease, a Gleason score  8, or a PSA  20 ng/mL.2 Several recent studies have examined utilization trends for imaging of clinically localized prostate cancer. In this article, we review this evidence to help elucidate how well staging guidelines are being followed in contemporary practice. F Contemporary Trends in Imaging Test Utilization for Prostate Cancer Staging: Data from the Cancer of the Prostate Strategic Urologic Research Endeavor Cooperberg MR, Lubeck DP, Grossfeld GD, et al. J Urol. 2002;168:491-495. Cooperberg and colleagues evaluated imaging use in 4966 men from CaPSURE, an observational database of men diagnosed with prostate cancer at multiple sites in the United States. Among men diagnosed from 1995 to 2001 with complete data on stage, the researchers examined imaging use between the time of diagnosis and treatment. Comparing the intervals before and after 1997, bone scan use decreased from 58.5% to 18.6% (P  .0001) and crosssectional imaging decreased from 27.4% to 11.6% (P  .0001) in low-risk disease (PSA  10 ng/mL, Gleason  7, and cT1 or T2a). In intermediate-risk (PSA 10.1-15 ng/mL, Gleason 7, or cT2b), there were also significant decreases in the use of bone scan (67.5%-50.9%) and cross-sectional imaging (34.0%-16.3%) between the two intervals (P  .0001). Of concern in high-risk patients (PSA  15 ng/mL, Gleason  7 or cT3/T4), for whom a staging workup is recommended, bone scan decreased from 77.5% to 68.9% (P  .0013) and cross-sectional imaging decreased from 40.5% to 22.4% (P  .0001). On multivariable analysis, imaging utilization was significantly associated with risk group (most common in highrisk), race (higher in white and black than Latino), location (higher in East), insurance type (higher in Medicare  supplemental than in Veterans Affairs), and the type of treatment ultimately received (highest in those who subsequently underwent cryotherapy). With regard to low-risk disease, the results of this study were encouraging by suggesting declining rates in the use of unnecessary imaging studies by the end of the study interval in 2001. By contrast, this study also suggested continued underutilization of appropriate imaging for the staging of high-risk patients to rule out occult metastases prior to treatment. Unnecessary Imaging for the Staging of Low-Risk Prostate Cancer Is Common Lavery HJ, Brajtbord JS, Levinson AW, et al. Urology. 2011;77:274-278. Since the report by Cooperberg and associates, a more recent study of Medicare beneficiaries with multiple malignancies suggested an increase in overall utilization of imaging studies in prostate cancer, but was not stratified by stage.3 The objective of the new study by Lavery and colleagues was to follow-up on these findings by specifically evaluating whether imaging is overutilized in contemporary low-risk patients. To do this, the authors retrospectively identified 677 patients with low-risk disease (PSA  10 ng/mL and biopsy Gleason score  6) who underwent robotic prostatectomy from 2005 to 2010. Although imaging is not recommended for these patients according to the guidelines, 328 (48%) underwent at least one imaging study prior to surgery (CT, MRI, or bone scan), 30% had two imaging studies, and 3% had all three. Of the 264 CT scans performed, 96% were negative, and none of the patients in this series had lymph node metastases in the final pathology. Of the 241 bone scans, 91% were negative. Suspicious findings on either CT and/or bone scan prompted additional imaging studies in 27 patients, none of which altered clinical management. VOL. 13 NO. 1 2011 REVIEWS IN UROLOGY 63 RiU_Apr2011_p61-64.qxd 4/13/11 10:54 AM Page 64 Prostate Cancer continued The authors highlighted the irony that pathologic nodal staging via pelvic lymphadenectomy is frequently deferred in low-risk patients, yet imaging continues to be overutilized in this population. This is problematic because radiographic studies are associated with potential health risks (contrast nephropathy, nephrogenic systemic fibrosis, and unnecessary radiation exposure), as well as significant cost. For example, in this population, Lavery and coauthors estimated that preoperative imaging for 328 patients resulted in an excess charge of $644,392, which was nearly identical to the Medicare reimbursement of $654,507 for 328 robotic prostatectomies. Although these 64 VOL. 13 NO. 1 2011 REVIEWS IN UROLOGY findings reflect a single institution and may not be generalizable to other populations, they suggest an ongoing issue with overutilization of unnecessary imaging for lowrisk prostate cancer patients. References 1. 2. 3. National Comprehensive Cancer Network. Clinical Practice Guidelines in Oncology, version 2011. http://www.nccn.org/professionals/physician_gls/pdf/ prostate.pdf. Accessed January 14, 2011. Greene KL, Albertsen PC, Babaian RJ, et al. Prostate specific antigen best practice statement: 2009 update. J Urol. 2009;182:2232-2241. Dinan MA, Curtis LH, Hammill BG, et al. Changes in the use and costs of diagnostic imaging among Medicare beneficiaries with cancer, 1999-2006. JAMA. 2010;303:1625-1631.