A Nationwide Persistent Underutilization of Adjuvant Radiotherapy in North American Prostate Cancer Patients

Intra-fractional geometric and dose/volume metric variations of magnetic resonance imaging-guided stereotactic radiotherapy of prostate bed after radical prostatectomy

Background and purpose

Magnetic Resonance Imaging (MRI)-guided Stereotactic body radiotherapy (SBRT) treatment to prostate bed after radical prostatectomy has garnered growing interests. The aim of this study is to evaluate intra-fractional anatomic and dose/volume metric variations for patients receiving this treatment.

Materials and methods

Nineteen patients who received 30-34 Gy in 5 fractions on a 0.35T MR-Linac were included. Pre- and post-treatment MRIs were acquired for each fraction (total of 75 fractions). The Clinical Target Volume (CTV), bladder, rectum, and rectal wall were contoured on all images. Volumetric changes, Hausdorff distance, Mean Distance to Agreement (MDA), and Dice similarity coefficient (DSC) for each structure were calculated. Median value and Interquartile range (IQR) were recorded. Changes in target coverage and Organ at Risk (OAR) constraints were compared and evaluated using Wilcoxon rank sum tests at a significant level of 0.05.

Results

Bladder had the largest volumetric changes, with a median volume increase of 48.9 % (IQR 28.9-76.8 %) and a median MDA of 5.1 mm (IQR 3.4-7.1 mm). Intra-fractional CTV volume remained stable with a median volume change of 1.2 % (0.0-4.8 %). DSC was 0.97 (IQR 0.94-0.99). For the dose/volume metrics, there were no statistically significant changes observed except for an increase in bladder hotspot and a decrease of bladder V32.5 Gy and mean dose. The CTV V95% changed from 99.9 % (IQR 98.8-100 %) to 99.6 % (IQR 93.9-100 %).

Conclusion

Despite intra-fractional variations of OARs, CTV coverage remained stable during MRI-guided SBRT treatments for the prostate bed.

Impact of Medicaid expansion on the multimodal treatment of biliary tract cancer

INTRODUCTION

The impact of Medicaid expansion (ME) on the treatment of patients with cancer remains controversial, especially individuals requiring complex multidisciplinary care. We sought to evaluate the impact of Medicaid expansion (ME) on receipt of multimodal care, including surgical resection, for Stage I-III biliary tract cancer (BTC).

METHODS

Patients diagnosed with BTC between 40 and 65 years of age were identified from the National Cancer Database and divided into pre- (2008-2012) and post- (2015-2018) ME cohorts. Difference-in-difference (DID) analysis was used to determine the impact of ME on the utilization of surgery and multimodal chemotherapy and/or radiotherapy treatment for BTC.

RESULTS

Among 12,415 patients with BTC (extrahepatic, n = 5622, 45.3%; intrahepatic, n = 4352, 35.1%; gallbladder, n = 1944, 15.7%; overlapping, n = 497, 4.0%), 5835 (47.0%) and 6580 (53.0%) patients were diagnosed before versus after ME, respectively. Overall utilization of surgery (OR 1.13, 95% CI 1.02-1.26) and multimodality therapy (OR 1.13, 95% CI 1.01-1.27) increased in states that adopted ME. Utilization of surgery among uninsured/Medicaid patients in ME states increased relative to patients living in non-ME states (∆+10.1%, p = 0.01). Similarly, the use of multimodal treatment increased among uninsured/Medicaid patients living in ME versus non-ME states (∆+6.4%, p = 0.04); in contrast, there were no difference among patients with other insurance statuses (overall: ∆+1.5%, private: ∆-2.0%, other: ∆+3.9%, all p > 0.5). Uninsured/Medicaid patients with BTC who lived in a ME state had a lower risk of long-term death in the post-ME era (HR 0.81, 95% CI 0.67-0.98; p = 0.03).

CONCLUSIONS

Implementation of ME positively impacted survival among patients who underwent surgical and multimodal treatment for Stage I-III BTC.

Quality-of-Life Outcomes and Toxicity Profile Among Patients With Localized Prostate Cancer After Radical Prostatectomy Treated With Stereotactic Body Radiation: The SCIMITAR Multicenter Phase 2 Trial

PURPOSE

Postoperative radiation therapy (RT) is an underused standard-of-care intervention for patients with prostate cancer and recurrence/adverse pathologic features after radical prostatectomy. Although stereotactic body RT (SBRT) is a well-studied and convenient option for definitive treatment, data on the postprostatectomy setting are extremely limited. The purpose of this study was to evaluate short-term physician-scored genitourinary (GU) and gastrointestinal (GI) toxicities and patient-reported outcomes after postprostatectomy SBRT.

METHODS AND MATERIALS

The SCIMITAR trial was a phase 2, dual-center, open-label, single-arm trial that enrolled patients with postoperative prostate-specific antigen >0.03 ng/mL or adverse pathologic features. Coprimary endpoints were 4-year biochemical recurrence-free survival, physician-scored acute and late GU and GI toxicities by the Common Terminology Criteria for Adverse Events (version 4.03) scale, and patient-reported quality-of-life (QOL) outcomes, as represented by the Expanded Prostate Cancer Index-26 and the International Prostate Symptom Score. Patients received SBRT 30 to 34 Gy/5 fractions to the prostate bed ± bed boost ± pelvic nodes with computed tomography (CTgRT) or magnetic resonance imaging guidance (MRgRT) in a nonrandomized fashion. Physician-scored toxicities and patient-reported QOL outcomes were collected at baseline and at 1, 3, and 6 months of follow-up. Univariable and multivariable analyses were performed to evaluate predictors of toxicities and QOL outcomes.

RESULTS

One hundred participants were enrolled (CTgRT, n = 69; MRgRT, n = 31). The median follow-up was 29.5 months (CTgRT: 33.3 months, MRgRT: 22.6 months). The median (range) prostate bed dose was 32 (30-34) Gy. Acute and late grade 2 GU toxicities were both 9% while acute and late grade 2 GI toxicities were 5% and 0%, respectively. Three patients had grade 3 toxicity (n = 1 GU, n = 2 GI). No patient receiving MRgRT had grade 3 GU or grade ≥2 GI toxicity. Compared with CTgRT, MRgRT was associated with a 30.5% (95% confidence interval, 11.6%-49.5%) reduction in any-grade acute GI toxicity (P = .006). MRgRT was independently associated with improved any-grade GI toxicity and improved bowel QOL.

CONCLUSIONS

Postprostatectomy SBRT was well tolerated at short-term follow-up. MRgRT may decrease GI toxicity. Longer toxicity and/or efficacy follow-up and randomized studies are needed.

Narrative Review of the Post-Operative Management of Prostate Cancer Patients: Is It Really the End of Adjuvant Radiotherapy?

Simple Summary

Among patients with prostate cancer who have been operated on, a subset harboring high-risk features will present with a biochemical recurrence (BCR). Adjuvant radiotherapy (aRT) was proven to significantly reduce the risk of BCR when compared to salvage radiotherapy (SRT) but suffered from several limitations: a lack of patient selection criteria, a higher treatment-related morbidity and an uncertain benefit for long-term clinical endpoints. In the same clinical setting, early SRT (eSRT) appears as non-inferior to aRT with a lower morbidity, replacing aRT as the preferred option. In this review, we insist on the need for multidisciplinary discussions to fully comprehend the individual characteristics of each patient and propose the best treatment strategy for every patient.

Abstract

Despite three randomized trials indicating a significant reduction in biochemical recurrence (BCR) in high-risk patients, adjuvant radiotherapy (aRT) was rarely performed, even in patients harboring high-risk features. aRT is associated with a higher risk of urinary incontinence and is often criticized for the lack of patient selection criteria. With a BCR rate reaching 30–70% in high-risk patients, a consensus between urologists and radiation oncologists was needed, leading to three different randomized trials challenging aRT with early salvage radiotherapy (eSRT). In these three different randomized trials with event-free survival as the primary outcome and a planned meta-analysis, eSRT appeared as non-inferior to aRT, answering, for some, this never-ending question. For many, however, the debate persists; these results raised several questions among urologists and radiation oncologists. BCR is thought to be a surrogate for clinically meaningful endpoints such as overall survival and cancer-specific survival but may be poorly efficient in comparison with metastasis-free survival. Imaging of rising prostate-specific antigen (PSA), post-operative persistent PSA and BCR was revolutionized by the broader use of MRI and nuclear imaging such as PET-PSMA; these imaging modalities were not analyzed in the previous randomized trials. A sub-group of very high-risk patients could possibly benefit from an adjuvant radiotherapy; but their usual risk factors such as high Gleason score or invaded surgical margins mean they are unable to be selected. More precise biomarkers of early BCR or even metastatic-relapse were developed in this setting and could be useful for the patients’ stratification. In this review, we insist on the need for multidisciplinary discussions to fully comprehend the individual characteristics of each patient and propose the best treatment strategy for every patient.

Non-cancer mortality in elderly prostate cancer patients treated with combination of radical prostatectomy and external beam radiation therapy

BACKGROUND

To test for rates of other cause mortality (OCM) and cancer-specific mortality (CSM) in elderly prostate cancer (PCa) patients treated with the combination of radical prostatectomy (RP) and external beam radiation therapy (EBRT) versus RP alone, since elderly PCa patients may be over-treated.

METHODS

Within the Surveillance, Epidemiology and End Results database (2004-2016), cumulative incidence plots, after propensity score matching for cT-stage, cN-stage, prostate specific antigen, age and biopsy Gleason score, and multivariable competing risks regression models (socioeconomic status, pathological Gleason score) addressed OCM and CSM in patients (70-79, 70-74, and 75-79 years) treated with RP and EBRT versus RP alone.

RESULTS

Of 18,126 eligible patients aged 70-79 years, 2520 (13.9%) underwent RP and EBRT versus 15,606 (86.1%) RP alone. After propensity score matching, 10-year OCM rates were respectively 27.9 versus 20.3% for RP and EBRT versus RP alone (p < .001), which resulted in a multivariable HR of 1.4 (p < .001). Moreover, 10-year CSM rates were respectively 13.4 versus 5.5% for RP and EBRT versus RP alone. In subgroup analyses separately addressing 70-74 year old and 75-79 years old PCa patients, 10-year OCM rates were 22.8 versus 16.2% and 39.5 versus 24.0% for respectively RP and EBRT versus RP alone patients (all p < .001).

CONCLUSION

Elderly patients treated with RP and EBRT exhibited worrisome rates of OCM. These higher than expected OCM rates question the need for combination therapy (RP and EBRT) in elderly PCa patients and indicate the need for better patient selection, when combination therapy is contemplated.