West Michigan Cancer Center, Inc.

Prospective trials have reported isotoxicity and improved oncologic outcomes with external beam radiation therapy (EBRT) microboost to a dominant intraprostatic lesion. There is often variability in the rate of adoption of new treatments, and current microboost practice patterns are unknown. We leveraged prospectively collected data from the multicenter Michigan Radiation Oncology Quality Consortium to understand the current state of microboost usage for localized prostate cancer.

Men with intermediate- and high-risk prostate adenocarcinoma treated with curative-intent radiation between October, 26, 2020, and June, 26, 2023, were included across 26 centers. Demographic-, tumor-, and treatment-related data along with DICOM files were prospectively collected. Microboost intent was prospectively documented and DICOM-confirmed. Multivariable analyses were used to evaluate associations with microboost receipt, and mixed-effects modeling evaluated facility-level variation.

Most patients received EBRT without brachytherapy (71%, n = 524/741). Of those, a minority received an EBRT microboost (10%, n = 53/524) at a subset of sites (27%, n = 7/26), without a change in rate over the study period (P = .62). Grade group 4/5 (odds ration [OR] = 2.35; 95% confidence interval [CI]: 1.02-5.28), magnetic resonance imaging planning (OR = 6.34; 95%CI: 2.16-27.12), and fiducial marker/rectal spacer placement (OR = 2.59; 95% CI: 1.14-6.70) were associated with microboost use. Significant facility-level variability was present (minimum 0%; 95% CI: 0.0-10.7 to maximum 71%; 95% CI: 55.5-83.2, unadjusted, P < .0001). Median boost volume was 20.7cc, and median boost D98% was 94.4 EQD2Gy. Compared with non-microboost cases, intermediate doses to rectum in the microboost cohort were increased (eg, V20Gy [EQD2] of 53.8% vs 36.5%, P = .03). However, the proportion exceeding NRG/RTOG bladder/rectal constraints was low and not significantly different between cohorts.

Despite prospective data demonstrating its benefit, EBRT microboost was used within a diverse statewide quality consortium in only 10% of cases at 27% of sites with significant facility-level heterogeneity. Concerted efforts are required to understand current barriers to microboost utilization, and results from trials such as PIVOTALboost (ISRCTN80146950) are eagerly awaited.

To identify predictors of referral and completion of germline genetic testing among newly diagnosed ovarian cancer patients, with a focus on geographic social deprivation, oncologist-level practices, and time between diagnosis and completion of testing.

Clinical and sociodemographic data were abstracted from medical records of patients newly diagnosed with ovarian cancer between 2014 and 2019 in the University of North Carolina Health System. Factors associated with referral for genetic counseling, completion of germline testing, and time between diagnosis and test results were identified using multivariable regression.

307/459 (67%) patients were referred for genetic counseling and 285/459 (62%) completed testing. The predicted probability of test completion was 0.83 (95% CI: 0.77-0.88) for patients with a referral compared to 0.27 (95% CI: 0.18-0.35) for patients without a referral. The predicted probability of referral was 0.75 (95% CI: 0.69-0.82) for patients at the 25th percentile of ZIP code-level Social Deprivation Index (SDI) and 0.67 (0.60-0.74) for patients at the 75th percentile of SDI. Referral varied by oncologist, with predicted probabilities ranging from 0.47 (95% CI: 0.32-0.62) to 0.93 (95% CI: 0.85-1.00) across oncologists. The median time between diagnosis and test results was 137 days (IQR: 55-248 days). This interval decreased by a predicted 24.46 days per year (95% CI: 37.75-11.16).

We report relatively high germline testing and a promising trend in time from diagnosis to results, with variation by oncologist and patient factors. Automated referral, remote genetic counseling and sample collection, reduced out-of-pocket costs, and educational interventions should be explored.