Introduction:

The American Urological Association (AUA) and National Comprehensive Cancer Network (NCCN) provide highly recognized guidelines on staging imaging for prostate cancer (PCa).  However, recommendations are vague as to type (CT vs MRI) and extent (abdomen vs pelvis) of axial imaging, raising concern for redundant imaging.  To investigate if guidelines can become more specific, we explored the utilization and findings of staging imaging in IR and HR PCa patients. 

Methods:

493 PCa patients diagnosed between 2011-2017 were stratified according to AUA and NCCN IR and HR groups. Staging imaging was captured and frequency of redundant (CT + MRI) and abdominal imaging determined.  Significance of radiologist findings, for both redundant and abdominal imaging, were classified as non-urologic, non-significant urologic, and PCa significant.

Results:

Among AUA and NCCN risk groups, 82 (35.7%) and 95 (37.3%) patients, respectively, experienced redundant imaging, of which only 7 patients in AUA and 9 patients in NCCN risk groups had an abnormal CT with normal MRI (Table 1).  However, only 3 of these CTs had PCa significant findings, of which 2 identified bone mets, likely detectable on bone scan.  In regards to the extent of imaging, a total of 157 (68.2%) AUA and 178 (69.8%) NCCN IR and HR patients received abdominal scans, of which only 35 and 38 were abnormal among AUA and NCCN risk groups, respectively (Table 2).  Among these abnormal abdominal scans, only 8 showed PCa significant findings of which half were bone mets and again likely identifiable on bone scan. 

Conclusion:

Due to non-specific staging guidelines in IR and HR PCa regarding type and extent of axial imaging, patients are frequently receiving redundant imaging.  Based on low occurrences of unique PCa significant findings in CT and abdominal imaging, our exploratory analysis suggests that narrowing initial recommendations to pelvic MRI and bone scan may reduce redundancy while maintaining sufficient staging. 

Funding: N/A