Implementation of PSMA PET/CT and alignment of ordering to SNMMI appropriate use criteria in a large network system.

INTRODUCTION: The Society of Nuclear Medicine and Molecular Imaging (SNMMI) provides appropriate use criteria (AUC) for prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) which include guidance on imaging in newly diagnosed prostate cancer and in patients with biochemically recurrent (BCR) disease. This study aims to examine trends in PSMA implementation and the prevalence and outcomes of scans ordered in scenarios deemed rarely appropriate or not meeting SNMMI AUC. METHODS: We retrospectively identified patients who were diagnosed with presumptive National Comprehensive Cancer Network unfavorable intermediate, high, or very high risk prostate cancer, patients who underwent staging for BCR, and all patients staged with PSMA between July 2021 and March 2023. Positivity was validated by adherence to a predetermined reference standard. RESULTS: The frequency of PSMA use increased in initial staging from 24% to 80% and work-up of BCR from 91% to 99% over our study period. In addition, 5% (17/340) of PSMA scans ordered for initial staging did not meet AUC and 3% (15/557) of posttreatment scans were deemed rarely appropriate. Initial staging orders not meeting SNMMI AUC resulted in no positivity (0/17), while rarely appropriate posttreatment scans were falsely positive in 75% (3/4) of cases. Urologists (53%, 17/32) comprised the largest ordering specialty in rarely appropriate use. CONCLUSION: The frequency of PSMA use rose across the study period. A significant minority of patients received PSMA PET/CT in rarely appropriate scenarios yielding no positivity in initial staging and significant false positivity post-therapy. Further education of providers and electronic medical record-based interventions could help limit the rarely appropriate use of PET imaging.

Utilization of genetic testing in men with advanced prostate cancer.

BACKGROUND: Genetic evaluation of men with advanced prostate cancer is recognized as imperative both to guide treatment decisions and to trigger cascade genetic testing of family members. Here we investigate utilization patterns of genetic testing among a contemporary cohort of men with advanced prostate cancer at our institution. METHODS: We queried the Northwestern Electronic Data Warehouse from January 2021 to present for all men diagnosed with National Comprehensive Cancer Network high-risk/very high-risk, regional, or metastatic prostate cancer. Patients were excluded from analyses if treated at an outside institution and/or presented for a second opinion evaluation. Statistics were performed using t-test, Chi-squared test, and univariable and multivariable logistic regression with significance defined as p < 0.05. RESULTS: Atotal of 320 men (52.5%) had local/regional disease and 290 (47.5%) had metastatic disease, 53 (18.3%) of whom had castrate resistant prostate cancer. Rates of germline genetic testing rate were low in patients with localized disease (9.4%) and metastatic disease (34.1%). Only 19 (35.8%) men diagnosed with metastatic castrate resistant prostate cancer underwent germline genetic evaluation. Germline testing was most frequently discussed or ordered by medical oncologists (52%) followed by urologists (20%). Men who underwent germline testing were younger (p < 0.001), more likely to have Medicaid or private insurance (p = 0.002), and more likely to have metastatic disease (p < 0.001). There were no statistically significant differences in baseline PSA, ethnicity, race, or castration sensitivity status. Age (odds ratio [OR]: 0.94, 95% confidence interval [CI]: 0.91-0.97, p < 0.001) and metastatic disease (OR: 5.71, 95% CI: 3.63-9.22, p < 0.001) were significant independent predictors of genetic testing on multivariable logistic regression. CONCLUSIONS: Here we report that utilization of genetic testing is associated with metastatic disease and inversely associated with age. Overall, utilization rates of genetic testing remain low in all patient groups, including in the metastatic castrate resistant setting, where genetic testing can identify patients with homologous recombination repair deficiency who may benefit from use of targeted therapeutics such as PARP inhibitors. Genetic testing in men with aggressive prostate cancer is critical and barriers to routine implementation of testing require further study to develop strategies to improve utilization rates.