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PURPOSE/OBJECTIVE(S) Comparative effectiveness (CE) data for radiotherapy treatment options for African-American (AfA) men with unfavorable intermediate-risk prostate cancer (UIR-PCa) is limited as AfA are under-represented on clinical trials and few large-scale trials have been conducted in UIR-PCa, with most trials grouping these patients with favorable intermediate-risk or high-risk disease. CE data is needed as AfA men with UIR-PCa have survival outcomes close to those for high-risk disease. Using the National Cancer Database (NCDB), we examined whether 1) the addition of a brachytherapy boost (BT) to external beam radiotherapy (EBRT) ± androgen deprivation therapy (ADT) was associated with improved overall survival (OS) vs. EBRT ± ADT; 2) whether EBRT+BT without ADT was associated with better OS vs EBRT+ADT; and 3) whether the addition of ADT was associated with improved OS in patients treated with EBRT+BT. MATERIALS/METHODS 5,817 AfA men with UIR-PCa diagnosed between 2004 and 2015 that received EBRT ± ADT or EBRT+BT ± ADT were identified. EBRT was delivered with conventional fractionation (≥ 72 Gy in 1.8-2.0 Gy/fraction) or moderate hypofractionation (2.4-3.2 Gy/fraction with a biologically equivalent dose > 120 Gy). EBRT+BT consisted of EBRT to 40-50.4 Gy plus high-dose rate or low-dose rate BT. OS was evaluated using multivariable analysis (MVA). Covariables included in the analysis included age, CDCI score, insurance status, educational attainment, income, treatment at an academic center, PSA, Gleason score, clinical T stage, and year of diagnosis. Inverse probability of treatment weighting was used to balance measured confounders. Unweighted- and weighted- MVA using Cox regression was used to compare OS hazard ratios (HR). RESULTS AfA men were stratified into four treatment groups: (i) EBRT without ADT (n = 2505), (ii) EBRT + ADT (n = 2238), (iii) EBRT+BT without ADT (n = 631), and (iv) EBRT+BT + ADT (n = 443). Median age 66 (range 40-88). Median follow-up was 4.4 years (range, 0-14 years). Relative to EBRT without ADT, EBRT+ADT (HR: 0.92, [95% Confidence Interval: 0.80-1.05], P = .23) was not associated with improved OS but EBRT+BT without ADT (HR: 0.67 [0.52-0.86], P = 0.002) and EBRT+BT+ADT (HR: 0.63 [0.49-0.82], P = 0.0006) were associated with improved OS on MVA. EBRT+BT without ADT was associated with improved OS vs. EBRT+ADT on MVA (HR: 0.73 [0.57-0.94], P = 0.01). There was no difference between EBRT+BT without ADT vs. EBRT+BT+ADT (HR: 1.00 [0.71-1.42], P = 0.96). Weight-adjusted MVA demonstrated that brachytherapy boost (HR: 0.68 [0.57-0.82], P = 0.00006) correlated with improved OS, while ADT did not (HR: 0.94 [0.79-1.12], P = .48). CONCLUSION In an NCDB cohort of AfA men with UIR-PCa, brachytherapy boost was associated with improved OS. EBRT+BT without ADT was associated with improved OS vs. EBRT+ADT. The addition of ADT to EBRT+BT was not associated with improved OS. These findings are concordant with data that inform NCCN guidelines recommending EBRT+BT as an option for men with UIR-PCa.

Background Ultrahypofractionation using stereotactic body radiotherapy (SBRT) is an increasingly utilized technique for men with prostate cancer (PC). The comparative efficacy of SBRT plus androgen deprivation therapy (ADT) compared to fractionated radiotherapy (EBRT) plus ADT in higher-risk prostate cancer is unknown. Methods Men > 40 years old with localized PC treated with external beam radiation and concomitant ADT for curative intent between 2004 and 2016 were analyzed from the National Cancer Database. Patients who lacked ADT or risk stratification data were excluded. 558 men treated with SBRT versus 40,797 men treated with conventional or moderately hypofractionated EBRT were included. Patients were stratified by unfavorable intermediate (UIR) and high (HR) risk using NCCN criteria. Kaplan Meier and Cox proportional hazards were used to compare overall survival (OS) between RT modality, adjusting for age, race, and comorbidity index. Results With a median follow up of 74 months, there was no difference in estimated 6-year OS between men treated with SBRT versus EBRT regardless of risk group. On multivariable analysis, there was no difference in risk of death for men treated with SBRT compared to EBRT (UIR: adjusted HR 1.09, 95% CI 0.68–1.74, p = .72; HR: adjusted HR 0.93, 95% CI 0.76–1.14, p = .51). On sensitivity analyses, when confining the cohort to men treated with NCCN-preferred dose fractionations, with no comorbidities, or Conclusion Within study limitations, we found no difference in survival between SBRT+ADT and standard of care EBRT+ADT for UIR or HR PC. These results support recent NCCN guideline updates, which include SBRT as a non-preferred option for higher risk men. Prospective validation would further strengthen the evidence basis behind these recommendations.

PURPOSE/OBJECTIVE(S) The addition of a brachytherapy boost to external beam radiation therapy (EBRT) reduces prostate cancer (PCa) recurrence compared with dose-escalated EBRT alone. However, combination therapy is associated with worse genitourinary (GU) toxicity compared with EBRT monotherapy. Whether brachytherapy boost technique, specifically low-dose-rate (LDR-BT) versus high-dose-rate (HDR-BT), impacts treatment-related toxicity is unclear and the subject of this analysis. MATERIALS/METHODS This single institutional cohort study included 104 adult men with intermediate/high risk PCa treated with combination EBRT plus brachytherapy boost, with either LDR-BT or HDR-BT, between 2012 and 2018. Patient-reported outcomes (PRO) were assessed by the International Prostate Symptom Score (IPSS) and Expanded Prostate Cancer Index Composite for Clinical Practice (EPIC-CP) surveys at 3-6-month intervals for up to three years following treatment, with higher scores indicating more severe toxicity. Provider-reported GU and gastrointestinal (GI) toxicities were assessed and graded per CTCAE V5.0 at each follow-up. Linear mixed models comparing PROs between LDR-BT versus HDR-BT were fitted. Stepwise multivariable analysis (MVA) was performed to account for age, gland size, androgen deprivation therapy (ADT) use, and alpha-blocker medication use. Incidence rates of grade 2+ GU/GI toxicity was compared using Chi-square test or Fisher's exact test. RESULTS The median complete follow up time for LDR-BT and HDR-BT cohorts was 17 and 18.4 months, respectively. There was no difference in alpha-blocker use at baseline between groups (P = 0.16). Median prostate gland size was larger in the HDR-BT cohort compared with the LDR-BT cohort (39.99cc vs 26.58cc for HDR-BT vs LDR-BT, respectively; P < 0.001). The use of LDR-BT was associated with a greater change in IPSS (P = 0.003) and EPIC-CP urinary irritative score (P = 0.002) compared with HDR-BT, but effect size diminished over time (LDR-BT versus HDR-BT: baseline to 6-/24-month mean IPSS change, +6.4/+1.4 versus +2.7/-3.0, respectively; mean EPIC-CP irritative/obstructive change, +2.5/+0.1 versus +0.9/+0.1, respectively). These results remained significant on MVA. Incidence of post-treatment grade 2+ GU toxicity was significantly higher in the LDR-BT group (77.5% versus 42.9% for LDR-BT and HDR-BT, respectively; P < 0.001). There were no significant differences between LDR-BT and HDR-BT in EPIC-CP (total, urinary incontinence, bowel function, sexual, vitality) or provider-reported grade 2+ GI toxicity. CONCLUSION In this single institution cohort, HDR-BT was associated with lower patient- and provider-reported GU toxicity compared with LDR-BT. However, differences in patient-reported toxicity diminished by 24 months post-treatment.

PURPOSE/OBJECTIVE(S) Current recommendations regarding radiotherapy treatment for unfavorable intermediate-risk prostate cancer (UIR-PCa) include external beam radiotherapy (EBRT) ± brachytherapy boost (BT) ± androgen deprivation therapy (ADT). Dose-escalated EBRT ± ADT is associated with excellent long-term outcomes, but ERBT+BT ± ADT can achieve higher dose escalation beyond what can be achieved with EBRT alone. Prior studies have shown improved biochemical control and reduced distant metastasis with EBRT+BT vs. EBRT in men with intermediate-risk disease, but it is unclear if this translates into a survival benefit. MATERIALS/METHODS Men with UIR-PCa diagnosed between 2004 and 2015 and treated with EBRT ± ADT or EBRT+BT ± ADT were identified in the National Cancer Database (NCDB). EBRT was delivered with conventional fractionation (≥ 72 Gy in 1.8-2.0 Gy per fraction), while EBRT+BT was defined as patients receiving EBRT to a total dose of 40-50.4 Gy plus high-dose rate or low-dose rate brachytherapy. Patients with a Charlson-Deyo comorbidity index (CDCI) score > 1, who received systemic therapy other than ADT, or missing key information were excluded. Propensity-weighted multivariable analysis (MVA) using Cox regression modeling was used to compare overall survival (OS) hazard ratios. Covariables included age, race, ethnicity, year of diagnosis, CDCI score, insurance status, educational and socioeconomic metrics, treatment at an academic center, PSA at diagnosis, Gleason score, clinical T-stage, and receipt of ADT. RESULTS The study cohort included 32,246 unfavorable intermediate-risk prostate cancer patients treated with: (i) EBRT (n = 13,265), (ii) EBRT+ADT (n = 13,123), (iii) EBRT+BT (n = 3,440), or (iv) EBRT+BT+ADT (n = 2,418). Cumulative doses of EBRT ± ADT are summarized in Table 1. The average time to follow-up was 62 months (standard deviation ± 39 months). Propensity-weighted MVA showed that EBRT+BT ± ADT was associated with improved OS relative to increasing doses of EBRT ± ADT. However, the OS benefit associated with EBRT+BT ± ADT diminished as the cumulative dose of radiation in the EBRT ± ADT cohort increased (Table 1). CONCLUSION The addition of brachytherapy to EBRT correlated with reduced mortality in men with UIR prostate cancer, including patients treated with EBRT ± ADT to ≥80 Gy. The relative OS benefit associated with EBRT+BT declined as the radiation dose increased in the EBRT ± ADT cohort.

Purpose/objective(s) The role of the advanced practice provider (APP) in radiation oncology (RO) is not well defined but it has been shown that the APP can provide safe and efficient patient care. Most APPs are certified for primary care without specific concentration in oncology or RO during formal training. There are very limited fellowships available to train APPs before providing care in a specialty setting such as RO and even fewer resources for disease-site specific training. The purpose of this work is to describe our workflow and integration of a Nurse Practitioner (NP) into the RO clinic with a specific emphasis on independent management of a central nervous system (CNS) follow-up and survivorship clinic. Materials/methods MDs and NPs provide services for our NCI Designated Comprehensive Cancer Center which includes 10 hospitals/clinics with services/technology including external beam radiation therapy, brachytherapy, Gamma Knife radiosurgery (GK) and proton beam therapy. The hospital which is designated for GK includes 7 radiation oncologists (3 subspecializing in CNS diseases), 2 neurosurgeons who perform GK, and 2 NPs. Within this hospital, a NP assumed leadership of our CNS follow up clinic. We herein reviewed the clinical workflow for implementing this service and evaluated metrics associated with this clinic. Results In 2019, a NP assumed leadership for our CNS follow up clinic. Upon development of this workflow, our CNS radiation oncologists and neurosurgeons developed standardized imaging and follow up schedules for the various CNS diseases treated. The MDs provided education to the NP on management of CNS radiation side effects and imaging review. For 3-6 months prior to implementation of our clinic, the NP saw follow ups in conjunction with the radiation oncologist and neurosurgeon. This provided confidence to the NP and MDs to ensure the images were reviewed properly and the patients were satisfied with their quality of care. Given the complexity of imaging review, the NP introduced a weekly CNS imaging review meeting during which the imaging of all follow ups are reviewed. The NP also became the organizer of a bimonthly CNS tumor conference. In 2020 the NP provided independent management of the clinic and saw 360 CNS specific follow ups (out of 1,040 of their total follow ups) accounting for 35% of their practice. This correlated with an approximate increase of 10% in the number of consultations RO providers saw during this time period. In 2020, the NP's overall patient satisfaction score was 94.9% compared to an average of 90% for all RO providers. Conclusion A CNS follow up clinic led by a NP was successfully implemented at our NCI Designated Cancer Center. This service was associated with excellent patient care and satisfaction and provided additional time and effort for our RO providers and neurosurgeons to see new consults and perform procedures. With specialty training from the radiation oncologist and neurosurgeon, an APP can be a critical asset to the RO team specifically in the CNS setting.

Purpose/Objective(s) Like other specialties, radiation oncology (RO) has seen declines in Medicare reimbursement (MCR). There are no recent studies analyzing how changes in MCR for specific billing codes contribute to changes over time in overall reimbursement for RO. We compared total MCR for specific Healthcare Common Procedure Coding System (HCPCS) codes in 2019 to MCR for those codes in 2010 & 2015, corrected for inflation, to see how the same basket of RO services in 2019 would have been reimbursed in 2010 & 2015 (projected MCR). We hypothesized that the decline in MCR from 2010-2019 would be driven disproportionately by decreased reimbursement for IMRT codes. Materials/Methods The CMS Physician/Supplier Procedure Summary database was used for MCR data for 2010, 2015 & 2019. All charges were classified by HCPCS codes, mapping old codes to their current equivalents. Actual MCR for 2010, 2015 & 2019 was calculated as the inflation-adjusted sum of allowed charges. For each code, the total allowed charge was divided by the number of submitted claims to calculate the average MCR per claim in 2010, 2015 & 2019. The 2019 billing frequency for each code was then multiplied by the inflation-adjusted average MCR for those codes in 2010 & 2015 to determine what the MCR would have been in 2010 & 2015 using 2019 dollars and utilization rates. These results were compared to actual 2019 MCR to calculate the projected difference. Results Actual MCR for all RO services in 2019 was $2,006 million (M), which was a $353M (15%) & $76M (4%) cut vs MCR in 2010 & 2015 expressed in 2019 dollars. For the codes examined in this analysis, 2019 MCR was $1,822M, which was a $687M (27%) & $183M (9%) cut vs inflation and utilization corrected MCR in 2010 & 2015 for these same codes. Table 1 shows the difference in MCR by treatment codes. IMRT delivery & IMRT planning account for 50% (-$341M) & 53% (-$97M) of the total projected difference from 2010-2019 & 2015-2019. Conclusion MCR in 2019 declined compared to actual inflation corrected 2010 & 2015 MCR & declined even more precipitously when compared to MCR for 2010 & 2015 corrected for both inflation and utilization, which holds constant factors that could potentially increase MCR over time (e.g., population growth; increased use of IMRT) or decrease MCR (hypofractionation). Decline in IMRT reimbursement was the primary driver of the decline in MCR. Policymakers should consider the significant cuts to reimbursement that have already occurred when considering further cuts and the impact such cuts could have on quality and access to care.

Purpose/Objective(s) Polyethylene glycol (PEG) hydrogel perirectal spacers can reduce prostate cancer (PCa) radiotherapy (RT)-related gastrointestinal (GI) toxicity. Accurate hydrogel contouring requires T2 MRI simulation (sim), as hydrogels have Hounsfield units (HU) comparable to soft tissue on computerized tomography (CT). A PEG hydrogel containing covalently bound iodine was recently developed and approved for clinical use. However, its characteristics in routine clinical practice have yet to be reported. Here we evaluated iodinated hydrogel volume, perirectal spacing, and HU from treatment images for PCa patients receiving RT at our institution. Materials/Methods Patients with biopsy-proven, clinically localized PCa (cT1c-cT2N0M0) who had same-day CT/MRI sim after fiducial markers and iodinated hydrogel placement were identified. Hydrogel was contoured on CT sim, MRI, and cone beam CT (CBCT) at treatment start (CBCT#1) and completion (CBCT#2). Prostate and hydrogel volumes and anterior-posterior mid-gland perirectal spacing at midline were measured on CT/MRI and CBCTs, and HU was measured on CT sim and CBCTs using treatment planning software. Patient differences were evaluated using paired, two-tailed Student's t-tests, with significance at P Results Twenty-three patients were identified (mean age 71.1 ± 7.8 years; mean prostate volume 61.9 ± 29.2 cm3; mean initial PSA 7.36 ± 1.9), treated with IMRT: 79.2 Gy/44 fx (n = 3), 70 Gy/28 fx (n = 15), or 36.25 Gy/5 fx (n = 5). Hydrogel was identified on all sim scans and was larger on T2 MRI vs CT (MRI mean volume 9.9 ± 1.7 cm3 vs CT 9.3 ± 1.6 cm3 vs; P = 0.03), and comparable mean perirectal distance at mid-gland/midline (MRI 1.02 ± 0.55 cm vs CT 1.03 ± 0.53 cm; P = 0.65). Perirectal spacing was maintained between CT sim and CBCT#1 (1.03 ± 0.51 cm; P = 0.97) done an average of 16.7 ± 7.1 days post sim and CT sim and CBCT#2 (1.03 ± 0.53 cm vs 1.02 ± 0.54; P = 0.74) done an average of 53.8 ± 19 days post sim. No significant change in hydrogel volume between CBCT#1 and CBCT#2 for 44 fx (10.9 ± 1.7 cm vs 10.4 ± 1.3 cm; P = 0.17), 28 fx (10.2 ± 1.4 vs 9.83 ± 1.7 cm; P = 0.11), or 5 fx (9.9 ± 2.1 vs 9.54 ± 1.9; P = 0.45) patients was observed. Hydrogel mean HU on CT sim was not significantly changed at CBCT#1 (CT sim 152.1 ± 30.5 vs CBCT#1 129.1 ± 51.6; P = 0.08), but mean HU at CBCT#2 (109.3 ± 47.9 cm) was lower vs CT sim (P = 0.001). For 44 fx treatments hydrogel HU significantly decreased between CBCT#1 and CBCT#2 (140.7 ± 10.0 vs 94.2 ± 80.4; P = 0.01), but not for 28 fx (123.5 ± 54.4 vs 103.4 ± 44.0; P = 0.13) or 5 fx (138.4 ± 38.5 vs 136 ± 37.2; P = 0.60) regimens. Conclusion PEG-based iodinated hydrogel can be delineated on CT sim comparable to MRI sim, and maintains visibility and perirectal spacing through 5, 28, and 44 fx RT courses as assessed by CBCT. Hydrogel HU decreased over 44 fx relative to CT sim, with no significant difference in HU seen for 28 fx and 5 fx courses. Use of perirectal hydrogel containing covalently bound iodine may obviate reliance on T2 MRI for accurate hydrogel contouring during RT treatment planning.