Definitive radiation therapy is the preferred treatment for many men with prostate cancer. Several modalities are used for radiation treatment delivery, including 3-dimensional conformal radiation therapy, intensity-modulated radiation therapy, proton beam therapy, stereotactic body radiation therapy, high-dose-rate prostate brachytherapy, and low-dose-rate prostate brachytherapy. This article reviews technologic advances that have enhanced radiation delivery and describes contemporary radiation treatment techniques for prostate cancer.
Radiation Therapy Modalities in Prostate Cancer
Thomas J. Pugh, Bao-Ngoc Nguyen, James E. Kanke, Jennifer L. Johnson, and Karen E. Hoffman
Variation in National Use of Long-Term ADT by Disease Aggressiveness Among Men With Unfavorable-Risk Prostate Cancer
Vinayak Muralidhar, Paul J. Catalano, Gally Reznor, Brandon A. Mahal, Toni K. Choueiri, Christopher J. Sweeney, Neil E. Martin, Clair J. Beard, Yu-Wei Chen, Michelle D. Nezolosky, Karen E. Hoffman, Felix Y. Feng, Quoc-Dien Trinh, and Paul L. Nguyen
Background: The current NCCN Clinical Practice Guidelines in Oncology for Prostate Cancer recommend long-term androgen deprivation therapy (ADT) for all men with high-risk prostate cancer treated with external-beam radiation therapy (EBRT). We determined whether the use of long-term ADT varied by the recently defined subcategories of high-risk disease (favorable, other, and very high) versus unfavorable intermediate-risk disease. Methods: We identified 5,524 patients with unfavorable-risk prostate cancer diagnosed from 2004 to 2007 and managed with EBRT using the SEER-Medicare linked database. Patients were stratified by risk group: unfavorable intermediate-risk, favorable high-risk (previously defined and validated as clinical stage T1c, Gleason score of 4 + 4 = 8, and prostate-specific antigen [PSA] level <10 ng/mL, or clinical stage T1c, Gleason score of 6, and PSA level >20 ng/mL), very-high-risk (clinical stage T3b–T4 or primary Gleason pattern 5), or other high risk (ie, neither favorable nor very high). We used multivariable competing risks regression to estimate the rates of long-term (≥2 years) ADT by group. Results: Men with favorable high-risk prostate cancer were significantly less likely to receive long-term ADT than those with other high-risk disease (15.4% vs 24.6%, adjusted hazard ratio [AHR], 0.68; 95% CI, 0.60–0.76; P<.001), and similarly likely as those with unfavorable intermediate-risk disease (AHR, 1.10; 95% CI, 0.99–1.23; P=.087). Other high-risk disease was less likely to receive long-term ADT than very high-risk cancer (24.6% vs 30.8%; AHR, 0.83; 95% CI, 0.74–0.93; P=.002). Conclusions: Despite current guidelines, patients with EBRT-managed high-risk prostate cancer received significantly different rates of long-course ADT based on subclassification. Our results suggest that oncologists view these patients as a heterogeneous group with favorable high-risk cancer warranting less aggressive therapy than other high-risk or very high-risk disease.
Impact of a Clinical Trial Initiative on Clinical Trial Enrollment in a Multidisciplinary Prostate Cancer Clinic
Lydia T. Madsen, Deborah A. Kuban, Seungtaek Choi, John W. Davis, Jeri Kim, Andrew K. Lee, Delora Domain, Larry Levy, Louis L. Pisters, Curtis A. Pettaway, John F. Ward, Christopher Logothetis, and Karen E. Hoffman
Clinical oncology trials are hampered by low accrual rates, with fewer than 5% of adult patients with cancer treated on study. Clinical trial enrollment was evaluated at The University of Texas MD Anderson Cancer Center's Multidisciplinary Prostate Cancer Clinic (MPCC) to assess whether a clinical trial initiative, introduced in 2006, impacted enrollment. The trial initiative included posting trial-specific information in clinic, educating patients about appropriate clinical trial options during the treatment recommendation discussion, and providing patients with trial-specific educational information. The investigators evaluated the frequency of clinical trial enrollment for men with newly diagnosed prostate cancer seen in the MPCC from 2004 to 2008. Logistic regression evaluated the impact of patient characteristics and the clinical trial initiative on trial enrollment. The median age of the 1370 men was 64 years; 32% had low-risk, 49% had intermediate-risk, and 19% had high-risk disease. Overall, 74% enrolled in at least one trial and 29% enrolled in more than one trial. Trial enrollment increased from 39% before the initiative (127/326) to 84% (880/1044) after the trial initiative. Patient enrollment increased in laboratory studies (from 25% to 80%), quality-of-life studies (from 10% to 26%), and studies evaluating investigational treatments and systemic agents (from 6% to 15%) after the trial initiative. In multivariate analysis, younger men (P<.001) and men seen after implementation of the clinical trial initiative (P<.001) were more likely to enroll in trials. Clinical trial enrollment in the MPCC was substantially higher than that seen nationally in adult patients with cancer, and enrollment rates increased after the introduction of a clinical trial initiative.