Dramatic Polarization in Genitourinary Expert Opinions Regarding the Clinical Utility of Advanced Imaging Technologies in Prostate Cancer

Abstract

Advanced imaging technologies are already incorporated in national guidelines for treatment of prostate cancer (PCa), however opinions of North American genitourinary (GU) experts regarding inclusion of technologies such as prostate-specific membrane antigen (PSMA) and C-11 acetate positron emission tomography (PET) into routine practice are unknown. A survey was distributed to 88 practicing North American GU experts who serve on decision-making committees of cooperative group research organizations. Questions pertained to knowledge about and personal opinions on the role of PSMA and C-11 PET in PCa management. Demographic questions and those designed to categorize practice patterns for PCa patients were submitted. Based on responses, participants were categorized as “supporters” or “opponents” of incorporation of novel imaging techniques into routine practice. Opinions regarding novel imaging were correlated with practice patterns using Fisher’s exact test. We received 48 responses and limited analysis to 42 radiation oncologist respondents. 17 participants (40%) have been in practice for > 20 years and 38 (90%) practice at an academic center. 19 participants (45%) see > 20 patients/month in consultation. 24 (57%) were supporters of PSMA PET and 29 (69%) were supporters of C-11 PET. Supporters were more likely to routinely treat pelvic nodes in patients with high risk PCa (88% vs. 56%, p < .01) and to treat patients with low/intermediate PCa with moderate (20-28 fractions) or extreme (5-15 fractions) hypofractionation (58% vs. 28%, p = .049). Supporters also trended to being more likely to offer to patients with high risk PCa brachytherapy boost (55% vs. 23%, p = .09), favor initial observation and early salvage over adjuvant radiation in patients with high risk features after prostatectomy (77% vs. 55%, p = .09), and to consider themselves expert brachytherapists (69% vs. 39%, p = .06). Nearly all (40, 95%) recommend active surveillance for patients with Gleason 6 PCa. A majority (27, 66%) feel there is not enough evidence to determine which modality, C-11 PET or PSMA PET, is superior. There is a stark polarization among prostate cancer radiation oncology experts regarding the use of novel imaging techniques in routine practice. Moreover, there appears to be a strong correlation between support of novel imaging and adoption of treatment approaches shown in randomized trials to be either clinically superior (such as brachytherapy boost), or less expensive (such as hypofractionation). Pre-existing biases regarding novel imaging among GU experts on national treatment-decision panels and leaders of cooperative group studies may affect the design of future clinical studies and influence the adoption of these technologies in clinical practice.