EAU guideline of prostate cancer recommends a bone scan for newly diagnosed patients with International Society of Urological Pathology (ISUP) grade group 3 disease, which implicated patients of unfavorable intermediate-, high and very high-risk prostate cancer according to American Urological Association and National Comprehensive Cancer Network. The current AUA guidelines recommend that clinicians should not routinely perform imaging in asymptomatic patients with low- or intermediate-risk prostate cancer, and those imaging types should be reserved for patients with high-risk disease. We aimed to validate the necessity of bone scan in low- and very low risk newly diagnosed prostate cancer.

This single center retrospective study included patient with treatment naïve low- and very low risk from 2011 to 2019 at National Taiwan University Hospital. All of the patients presented with Gleason score 3+3, with mean age 66.7 years old and mean prostate specific antigen (PSA) 6.17 ng/ml,. We traced back the images performed upon diagnosis, with latest within 3 months upon pathological confirmation. Findings among urology field and other fields were reviewed individually. Bone scan is mainly studied while other images discussed concomitantly.

The data included 250 patients with low- and very-low risk. Amongst the results, imaging utilization included pelvic MRI (96.4%, 241 patients), bone scan (88.4%, 221 patients) and CT (6.0%, 15 patients). Bone scan was performed in 88.4% of patients, 5(2.3%) of which was noted with PCa-significant findings of bone, however all of them were not considered metastases after repeated discussion of multiple radiologist and oncologist experts.

We noticed that there is a trait of over- imaging in low- and very low risk with most bone scans yielding minimal Pca-significant results and may need further extra imaging(e.g. PSMA PET) to reconfirm the authenticity. However, under the clinical practice of National Health Insurance coverage, this may be acceptable and works as a routine for urologists in Taiwan.