Variation in content discussed by specialty in consultations for clinically localized prostate cancer.

INTRODUCTION: Multidisciplinary consultations improve decisional conflict and guideline-concordant treatment for men with prostate cancer (PC), but differences in the content discussed by specialty during consultations are unknown. METHODS: We audiorecorded and transcribed 50 treatment consultations for localized PC across a multidisciplinary sample of urologists, radiation oncologists, and medical oncologists. Conversation was coded for narrative content using an open coding approach, grouping similar topics into major content areas. The number of words devoted to each content area per consult was used as a proxy for time spent. Multivariable Poisson regression calculated incidence rate ratios (IRR) for content-specific word count across specialties after adjustment for tumor risk and patient demographics. RESULTS: Coders identified 8 narrative content areas: overview of PC; medical history; baseline risk; cancer prognosis; competing risks; treatment options; physician recommendations; and shared decision making (SDM). In multivariable models, specialties significantly differed in proportion of time spent on treatment options, SDM, competing risks, and cancer prognosis. Urologists spent 1.8-fold more time discussing cancer prognosis than medical oncologists (IRR1.80, 95%CI:1.14-2.83) and radiation oncologists (IRR1.84, 95%CI:1.10-3.07). Urologists (IRR11.38, 95%CI:6.62-19.56) and medical oncologists (IRR10.60, 95%CI:6.01-18.72) spent over 10-fold more time discussing competing risks than radiation oncologists. Medical oncologists (IRR2.60, 95%CI:1.65-4.10) and radiation oncologists (IRR1.77, 95%CI:1.06-2.95) spent 2.6- and 1.8-fold more time on SDM than urologists, respectively. CONCLUSIONS: Specialists focus on different content in PC consultations. Our results suggest that urologists should spend more time on SDM and radiation oncologists on competing risks. Our results also highlight the importance of medical oncologists in facilitating SDM.

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.

A practical guide for assessing and managing cardiovascular risk during androgen-deprivation therapy in patients with prostate cancer.

Prostate cancer is the most common malignancy among men worldwide, and androgen-deprivation therapy (ADT) is a mainstay of treatment. There are observational data demonstrating an increased risk of cardiovascular events in patients who receive ADT, particularly those who have an elevated baseline cardiovascular risk. Because, for most patients with prostate cancer, death is predominantly from noncancer-related causes, cardiovascular disease and its risk factors should be optimized during cancer treatment. This review provides an overview of the landscape of ADT treatment and serves as a guide for appropriate cardiovascular screening and risk-mitigation strategies. The authors emphasize the importance of shared communication between the multidisciplinary cancer team and primary care to improve baseline cardiovascular screening and treatment of modifiable risk factors within this higher risk population.

Real-World Utilization of Radiation Therapy in Multiple Myeloma: An Analysis of the Connect MM Registry.

PURPOSE: Radiation therapy (RT) is an important treatment modality for patients with multiple myeloma (MM). Although patients are living longer with MM, they are more likely to have comorbidities related to treatment, such as bone pain; however, RT can provide symptom relief. To date, the characterization of patients who have received RT in the real-world setting has been limited. METHODS AND MATERIALS: The Connect® MM Registry is a large, US multicenter, prospective observational cohort study of adult patients with newly diagnosed MM from mostly community sites. RT utilization and outcomes were analyzed quarterly throughout treatment. Factors associated with RT use were identified via multivariable analysis. RESULTS: A total of 3011 patients were enrolled in the Connect MM Registry with 903 patients (30%) having received RT at any time. There was a significant difference (P < .05) in overall RT use among patients with an Eastern Cooperative Oncology Group performance status of 0 to 1 versus ≥2, International Staging System disease stage I/II versus III, a history of plasmacytoma or a novel agent in their first regimen, and any number of bone lesions or severe osteoporosis/fracture. RT use was associated with having bone lesions or severe osteoporosis (vs not having bone lesions). Additionally, RT use was associated with ethnicity (Hispanic vs not) and Connect MM Registry cohort (cohort 1 [enrolled 2009-2011] vs 2 [enrolled 2012-2016]). In the 6 months before death, increased RT use was associated with increasing number of treatment lines (P < .0001) and high- versus standard-risk disease (per International Myeloma Working Group criteria; P = .0028). CONCLUSIONS: Real-world results from the Connect MM Registry show RT is frequently used and is associated with clinical factors, including performance status and disease stage. Earlier in MM diagnosis, RT may be used as an adjunct to palliate symptoms or delay systemic therapy. Toward the end of life, RT is more frequently used for palliation when treatment options are often limited.

Radical cystectomy versus trimodality therapy for muscle-invasive bladder cancer: a multi-institutional propensity score matched and weighted analysis.

BACKGROUND: Previous randomised controlled trials comparing bladder preservation with radical cystectomy for muscle-invasive bladder cancer closed due to insufficient accrual. Given that no further trials are foreseen, we aimed to use propensity scores to compare trimodality therapy (maximal transurethral resection of bladder tumour followed by concurrent chemoradiation) with radical cystectomy. METHODS: This retrospective analysis included 722 patients with clinical stage T2-T4N0M0 muscle-invasive urothelial carcinoma of the bladder (440 underwent radical cystectomy, 282 received trimodality therapy) who would have been eligible for both approaches, treated at three university centres in the USA and Canada between Jan 1, 2005, and Dec 31, 2017. All patients had solitary tumours less than 7 cm, no or unilateral hydronephrosis, and no extensive or multifocal carcinoma in situ. The 440 cases of radical cystectomy represent 29% of all radical cystectomies performed during the study period at the contributing institutions. The primary endpoint was metastasis-free survival. Secondary endpoints included overall survival, cancer-specific survival, and disease-free survival. Differences in survival outcomes by treatment were analysed using propensity scores incorporated in propensity score matching (PSM) using logistic regression and 3:1 matching with replacement and inverse probability treatment weighting (IPTW). FINDINGS: In the PSM analysis, the 3:1 matched cohort comprised 1119 patients (837 radical cystectomy, 282 trimodality therapy). After matching, age (71·4 years [IQR 66·0-77·1] for radical cystectomy vs 71·6 years [64·0-78·9] for trimodality therapy), sex (213 [25%] vs 68 [24%] female; 624 [75%] vs 214 [76%] male), cT2 stage (755 [90%] vs 255 [90%]), presence of hydronephrosis (97 [12%] vs 27 [10%]), and receipt of neoadjuvant or adjuvant chemotherapy (492 [59%] vs 159 [56%]) were similar between groups. Median follow-up was 4·38 years (IQR 1·6-6·7) versus 4·88 years (2·8-7·7), respectively. 5-year metastasis-free survival was 74% (95% CI 70-78) for radical cystectomy and 75% (70-80) for trimodality therapy with IPTW and 74% (70-77) and 74% (68-79) with PSM. There was no difference in metastasis-free survival either with IPTW (subdistribution hazard ratio [SHR] 0·89 [95% CI 0·67-1·20]; p=0·40) or PSM (SHR 0·93 [0·71-1·24]; p=0·64). 5-year cancer-specific survival for radical cystectomy versus trimodality therapy was 81% (95% CI 77-85) versus 84% (79-89) with IPTW and 83% (80-86) versus 85% (80-89) with PSM. 5-year disease-free survival was 73% (95% CI 69-77) versus 74% (69-79) with IPTW and 76% (72-80) versus 76% (71-81) with PSM. There were no differences in cancer-specific survival (IPTW: SHR 0·72 [95% CI 0·50-1·04]; p=0·071; PSM: SHR 0·73 [0·52-1·02]; p=0·057) and disease-free survival (IPTW: SHR 0·87 [0·65-1·16]; p=0·35; PSM: SHR 0·88 [0·67-1·16]; p=0·37) between radical cystectomy and trimodality therapy. Overall survival favoured trimodality therapy (IPTW: 66% [95% CI 61-71] vs 73% [68-78]; hazard ratio [HR] 0·70 [95% CI 0·53-0·92]; p=0·010; PSM: 72% [69-75] vs 77% [72-81]; HR 0·75 [0·58-0·97]; p=0·0078). Outcomes for radical cystectomy and trimodality therapy were not statistically different among centres for cancer-specific survival and metastasis-free survival (p=0·22-0·90). Salvage cystectomy was done in 38 (13%) trimodality therapy patients. Pathological stage in the 440 radical cystectomy patients was pT2 in 124 (28%), pT3-4 in 194 (44%), and 114 (26%) node positive. The median number of nodes removed was 39, the soft tissue positive margin rate was 1% (n=5), and the perioperative mortality rate was 2·5% (n=11). INTERPRETATION: This multi-institutional study provides the best evidence to date showing similar oncological outcomes between radical cystectomy and trimodality therapy for select patients with muscle-invasive bladder cancer. These results support that trimodality therapy, in the setting of multidisciplinary shared decision making, should be offered to all suitable candidates with muscle-invasive bladder cancer and not only to patients with significant comorbidities for whom surgery is not an option. FUNDING: Sinai Health Foundation, Princess Margaret Cancer Foundation, Massachusetts General Hospital.

Application of a genetic signature of late GU toxicity in SCIMITAR, a Post-op SBRT trial.

Predictors of genitourinary toxicity after post-prostatectomy radiotherapy remain elusive. A previously defined germline DNA signature (PROSTOX) has shown predictive ability for late grade ≥ 2 GU toxicity after intact prostate stereotactic body radiotherapy. We explore whether PROSTOX would predict toxicity among patients receiving post-prostatectomy SBRT on a phase II clinical trial.

The role of adaptive planning in margin-reduced, MRI-guided stereotactic body radiotherapy to the prostate bed following radical prostatectomy: Post-hoc analysis of a phase II clinical trial.

BACKGROUND AND PURPOSE: We examined the interfractional variations of clinical target volumes (CTVs), planning target volumes (PTVs), and organs-at-risk (OARs) in patients receiving MRI-guided stereotactic body radiotherapy (SBRT) to the prostate bed and evaluated the potential role of adaptive planning. MATERIALS AND METHODS: 31 patients received 30-34 Gy in five fractions to the prostate bed on a phase II clinical trial. OARs, CTVs, and PTVs were retrospectively contoured on daily pretreatment MRIs (n = 155). Geometric comparisons were made between initial planning contours and daily pretreatment contours. Predicted treatment plans for each fraction were evaluated using the following constraints: CTV V95%>93%, PTV V95%>90%, bladder Dmax < 36.7 Gy, bladder V32.5 Gy < 35%, rectum Dmax < 36.7 Gy, rectum V27.5 Gy < 45%, rectum 32.5 Gy < 30%, and rectal wall V24Gy < 50%. Adaptive planning was simulated for all fractions that failed to meet these criteria. Plans were then re-evaluated. RESULTS: Median change in volume was 0.48% for CTV, -24.5% for bladder, and 6.95% for rectum. Median DSC was 0.89 for CTV, 0.79 for bladder, and 0.76 for rectum. 145/155 fractions (93.5%) met CTV V95%>93%. 75/155 fractions (48.4%) failed at least one OAR dose constraint. Overall, 83/155 fractions (53.5%) met criteria for adapting planning. This affected 24/31 patients (77.4%). Following adaptive planning, all fractions met CTV V95%>93% and PTV V95%>90% and 120/155 fractions (77.4%) met all OAR constraints. CONCLUSION: Due to significant interfractional variations in anatomy, a majority of fractions failed to meet both target volume and OAR constraints. However, adaptive planning was effective in overcoming these anatomic changes. Adaptive planning should be routinely considered in prostate bed SBRT.

Knowledge and Understanding of Radiation Therapy Among Patients With Breast Cancer From Culturally Diverse Backgrounds at a Safety-Net Hospital.

INTRODUCTION: Comprehensive understanding of oncologic treatment is essential for shared decision-making. However, comprehension of information in radiation oncology consults is poorly understood, particularly among Spanish-speaking patients at safetynet hospitals. The purpose of this pilot study was to examine post-consultation radiation oncology knowledge and health literacy among breast cancer patients from culturally diverse backgrounds. METHODS: After consultation for curative post-operative breast radiotherapy (cT1-4N1-3M0), the Radiation Oncology Knowledge Assessment Survey (ROKAS) was administered to Spanish- and English-speaking patients ≥ 18 years old, from January 2021 to January 2022 at a safety-net hospital. Radiation knowledge was assessed using the ROKAS which included eight radiation-specific multiple-choice questions and two separate questions regarding short- and long-term side effects. Additional independent variables included validated questionnaires related to health literacy, health numeracy, acculturation, primary language, and sociodemographic factors. Bivariate Pearson correlations and T-test analyses were conducted to examine the relationship between the independent variables and post-consultation radiation knowledge. RESULTS: Fifty ROKAS were obtained from 25 English- and 25 Spanish-speaking breast cancer patients (median age 57 [IQR 49.75-62.25]). When compared to Englishspeaking patients, Spanish-speaking patients had lower health literacy, health numeracy, and acculturation. There was no difference in the multiple-choice ROKAS score between English- and Spanish-speakers, or correlation with the other independent factors. Higher health numeracy correlated with a higher accuracy for identifying short-term side effects. Lower accuracy of identifying long-term side effects was seen in patients with lower education levels, health literacy, health numeracy, and acculturation, with the most missed long-term side effects being arm swelling, skin toxicity, and heart toxicity. CONCLUSIONS: Patients with low health literacy, health numeracy, acculturation, and education levels as well as Spanish-speaking patients were associated with poor understanding of radiotherapy long-term side effects. Determining barriers to radiation knowledge is crucial to improve shared decision-making between patients and providers in a culturally diverse population.

Consensus Quality Measures and Dose Constraints for Prostate Cancer From the Veterans Affairs Radiation Oncology Quality Surveillance Program and American Society for Radiation Oncology Expert Panel.

PURPOSE: There are no agreed upon measures to comprehensively determine the quality of radiation oncology (RO) care delivered for prostate cancer. Consequently, it is difficult to assess the implementation of scientific advances and adherence to best practices in routine clinical practice. To address this need, the US Department of Veterans Affairs (VA) National Radiation Oncology Program established the VA Radiation Oncology Quality Surveillance (VA ROQS) Program to develop clinical quality measures to assess the quality of RO care delivered to Veterans with cancer. This article reports the prostate cancer consensus measures. METHODS AND MATERIALS: The VA ROQS Program contracted with the American Society for Radiation Oncology to commission a Blue Ribbon Panel of prostate cancer experts to develop a set of evidence-based measures and performance expectations. From February to June 2021, the panel developed quality, aspirational, and surveillance measures for (1) initial consultation and workup, (2) simulation, treatment planning, and delivery, and (3) follow-up. Dose-volume histogram (DVH) constraints to be used as quality measures for definitive and post-prostatectomy radiation therapy were selected. The panel also identified the optimal Common Terminology Criteria for Adverse Events, version 5.0 (CTCAE V5.0), toxicity terms to assess in follow-up. RESULTS: Eighteen prostate-specific measures were developed (13 quality, 2 aspirational, and 3 surveillance). DVH metrics tailored to conventional, moderately hypofractionated, and ultrahypofractionated regimens were identified. Decision trees to determine performance for each measure were developed. Eighteen CTCAE V5.0 terms were selected in the sexual, urinary, and gastrointestinal domains as highest priority for assessment during follow-up. CONCLUSIONS: This set of measures and DVH constraints serves as a tool for assessing the comprehensive quality of RO care for prostate cancer. These measures will be used for ongoing quality surveillance and improvement among veterans receiving care across VA and community sites. These measures can also be applied to clinical settings outside of those serving veterans.

Targeting barriers to wider use of trimodality therapy in localized muscle invasive bladder cancer.

Radical cystectomy with bilateral pelvic lymphadenectomy and trimodality bladder-sparing therapy or TMT, are both curative options for patients with nonmetastatic muscle invasive bladder cancer. Patients should be afforded the opportunity for a multidisciplinary evaluation with equipoise in discussing these options for eligible patients. We discuss the barriers to broader acceptance and utilization of TMT and encourage support of clinical trials of TMT.

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.

Oligometastatic Prostate Cancer: Current Status and Future Challenges.

In accordance with the spectrum theory of metastatic disease, an oligometastatic clinical state has been proposed as an intermediary step along the natural history of cancer with few (typically 1-3) metastatic lesions identifiable on imaging that may be amenable to metastasis-directed therapy. Effective therapy of oligometastatic disease is anticipated to impact cancer evolution by delaying progression and improving patient outcome at a minimal or acceptable cost of toxicity. There has been increasing recognition of oligometastatic disease in prostate cancer with the advent of new-generation imaging agents, most notably the recently approved PET radiotracers based on targeting prostate-specific membrane antigen. Early clinical trials with metastasis-directed therapy of oligometastases have provided evidence for delaying the employment of systematic therapy and improving outcome in selected patients. Despite these encouraging results, much needs to be investigated and learned about the underlying biology of the oligometastatic state along the evolutionary clinical course of prostate cancer, the identification of relevant imaging and nonimaging predictive and prognostic biomarkers, and the development of treatment strategies to optimize short-term and long-term patient outcome. We provide a review of the current status and the lingering challenges of this rapidly evolving clinical space in prostate cancer.

Racial/ethnic disparities in patient experiences with care and Gleason score at diagnosis of prostate cancer: a SEER-CAHPS study.

PURPOSE: To determine whether racial/ethnic differences in patient experiences with care, potentially leading to underutilization of necessary care, are associated with disparities in Gleason score at diagnosis. METHODS: We used the SEER-CAHPS linked dataset to identify Medicare beneficiaries who completed a Consumer Assessment of Healthcare Providers and Systems (CAHPS) survey prior to diagnosis of prostate cancer. Independent variables included aspects of patient experiences with care captured by CAHPS surveys. We conducted survey weighted multivariable multinomial logistic regression analyses, stratified by patient race/ethnicity, to estimate associations of CAHPS measures with Gleason score at diagnosis. RESULTS: Of the 4,245 patients with prostate cancer, most were non-Hispanic white (NHW) (77.6%), followed by non-Hispanic black (NHB) (8.4%), Hispanic (8.4%), and Asian (5.6%). Excellent experience with getting needed prescription drugs was associated with lower odds of Gleason scores of 7 and 8-10 in NHBs (7: OR = 0.19, 95% CI = 0.05-0.67; 8-10: OR = 0.04, 95% CI = 0.01-0.2) and lower odds of 8-10 in NHWs (OR = 0.61, 95% CI = 0.40-0.93). For NHBs, excellent primary physician ratings were associated with greater odds of a Gleason score of 8-10 (OR = 13.28, 95% CI = 1.53-115.21). CONCLUSION: Patient experiences with access to care and physician relationships may influence Gleason score in different ways for patients of different racial/ethnic groups. More research, including large observational studies with greater proportions of racial/ethnic minority patients, is necessary to understand these relationships and target interventions to overcome disparities and improve patient outcomes.

Geographic Access to Radiation Therapy Facilities in the United States.

PURPOSE: The current distribution of radiation therapy (RT) facilities in the United States is not well established. A comprehensive inventory of U.S. RT facilities was last assessed in 2005, based on data from state regulatory agencies and dosimetric quality assurance bodies. We updated this database to characterize population-level measures of geographic access to RT and analyze changes over the past 15 years. METHODS AND MATERIALS: We compiled data from regulatory and accrediting organizations to identify U.S. facilities with linear accelerators used to treat humans in 2018 to 2020. Addresses were geocoded and analyzed with Geographic Information Services software. Geographic access was characterized by assessing the Euclidian distance between ZIP code tabulation areas/county centroids and RT facilities. Populations were assigned to each county to estimate the effect of facility changes at the population level. Logistic regressions were performed to identify features associated with increased distance to RT and associated with regions that gained an RT facility between the 2 time points studied. RESULTS: In 2020, a total of 2313 U.S. RT facilities were reported, compared with 1987 in 2005, representing a 16.4% growth in facilities over nearly 15 years. Based on population attribution to the centroids of ZIP Code Tabulation Areas, 77.9% of the U.S. population lives within 12.5 miles of an RT facility, and 1.8% of the U.S. population lives more than 50 miles from an RT facility. We found that increased distance to RT was associated with nonmetro status, less insurance, older median age, and less populated regions. Between 2005 and 2020, the population living within 12.5 miles from an RT facility increased by 2.1 percentage points, whereas the population living furthest from RT facilities decreased 0.6 percentage points. Regions with improved geographic RT access are more likely to be higher income and better insured. CONCLUSIONS: The percentage of the U.S. population with limited geographic access to RT is 1.8%. We found that people benefiting from improved access to RT facilities are more economically advantaged, suggesting disparities in geographic access may not improve without intervention.

Interfractional Geometric Variations and Dosimetric Benefits of Stereotactic MRI Guided Online Adaptive Radiotherapy (SMART) of Prostate Bed after Radical Prostatectomy: Post-Hoc Analysis of a Phase II Trial.

PURPOSE: To evaluate geometric variations of patients receiving stereotactic body radiotherapy (SBRT) after radical prostatectomy and the dosimetric benefits of stereotactic MRI guided adaptive radiotherapy (SMART) to compensate for these variations. MATERIALS/METHODS: The CTV and OAR were contoured on 55 MRI setup scans of 11 patients treated with an MR-LINAC and enrolled in a phase II trial of post-prostatectomy SBRT. All patients followed institutional bladder and rectum preparation protocols and received five fractions of 6-6.8 Gy to the prostate bed. Interfractional changes in volume were calculated and shape deformation was quantified by the Dice similar coefficient (DSC). Changes in CTV-V95%, bladder and rectum maximum dose, V32.5Gy and V27.5Gy were predicted by recalculating the initial plan on daily MRI. SMART was retrospectively simulated if the predicted dose exceeded pre-set criteria. RESULTS: The CTV volume and shape remained stable with a median volumetric change of 3.0% (IQR -3.0% to 11.5%) and DSC of 0.83 (IQR 0.79 to 0.88). Relatively large volumetric changes in bladder (median -24.5%, IQR -34.6% to 14.5%) and rectum (median 5.4%, IQR - 9.7% to 20.7%) were observed while shape changes were moderate (median DSC of 0.79 and 0.73, respectively). The median CTV-V95% was 98.4% (IQR 94.9% to 99.6%) for the predicted doses. However, SMART would have been deemed beneficial for 78.2% of the 55 fractions based on target undercoverage (16.4%), exceeding OAR constraints (50.9%), or both (10.9%). Simulated SMART improved the dosimetry and met dosimetric criteria in all fractions. Moderate correlations were observed between the CTV-V95% and target DSC (R2 = 0.73) and bladder mean dose versus volumetric changes (R2 = 0.61). CONCLUSIONS: Interfractional dosimetric variations resulting from anatomic deformation are commonly encountered with post-prostatectomy RT and can be mitigated with SMART.

Racial disparities in the use of palliative radiotherapy for black patients with multiple myeloma in the United States.

Multiple myeloma (MM) is characterized by painful lesions that are amenable to palliative radiotherapy (PRT) but racial disparities may exist. In the current study, the National Cancer Database was queried for patients diagnosed with MM from 2004 to 2016 who received PRT. The percentages of patients receiving PRT within 12 months of diagnosis by race/ethnicity were: 15.5% non-Hispanic white (NHW), 14.3% African American (AA), 15.8% Hispanic, and 14.4% other. On multivariable logistic regression, the odds of receiving RT were 13% less for AAs compared to NHWs (OR = 0.87, 95% CI = 0.83-0.90, p < .0001) and the odds of dying within 30 days of PRT were 18% less for AAs compared to NHWs (OR = 0.82, 95% CI = 0.67-1.00, p = .046). This study highlights a health disparity affecting AA patients who despite having a higher incidence and mortality from MM are also less likely to receive PRT within 1 year of diagnosis and near the end of life.

Role of Ki-67, MRE11, and PD-L1 as Predictive Biomarkers for Recurrence Pattern in Muscle-invasive Bladder Cancer.

BACKGROUND/AIM: Muscle invasive bladder cancer (MIBC) is an aggressive disease with high rates of local recurrence following radical cystectomy (RC). Currently, there are no clinically validated biomarkers to predict local only recurrence (LOR) and guide adjuvant treatment decisions. This pilot study evaluated the role of Ki-67, MRE11 and PD-L1 as predictive biomarkers for recurrence patterns in patients undergoing RC for MIBC. PATIENTS AND METHODS: Our institutional cystectomy database containing cases from 1992-2014 was queried for patients with local only recurrence (LOR), and case-matched to patients with distant recurrence (DR) and no recurrence (NR). Clinicopathological data were collected and a tissue microarray was analyzed for presence of Ki-67, MRE11, and PD-L1 using immunofluorescence and immunohistochemistry. RESULTS: Pathologic specimens from 42 patients (18 NR, 16 LOR, and 8 DR) were reviewed. Compared to normal bladder tissue, tumors had increased expression of Ki-67 (p<0.01) and PD-L1 (p<0.05). High Ki-67 was associated with recurrence pattern (local vs. distant) on univariate analysis (p<0.05). Ki-67 cell density varied by recurrence type: LOR (1354 cells/mm2), DR (557 cells/mm2) and NR (1111 cells/mm2) (p=0.034). CONCLUSION: Our selected biomarkers could distinguish MIBC from normal bladder tissue but could not classify samples by recurrence pattern.

Primary CNS Extranodal Marginal Zone B-Cell Lymphoma: A Case Series of 2 Patients Treated with External Beam Radiation Therapy.

Primary CNS extranodal marginal zone B-cell lymphoma (MZBL) is a rare low-grade non-Hodgkin lymphoma characterized predominantly by small B cells, plasma cells, monocytoid cells, and scattered large immunoblasts. As a slow-growing tumor that remains localized, primary CNS MZBL carries an excellent clinical prognosis. Here, we report two cases of primary CNS MZBL successfully treated using external beam radiation therapy along with a literature review.

Disparities in male versus female oncologic outcomes following bladder preservation: A population-based cohort study.

INTRODUCTION: In surgical series of muscle-invasive bladder cancer (MIBC), women have higher recurrence rates, disease progression, and mortality following radical cystectomy than men. Similar reports of oncologic differences between men and women following trimodality therapy (TMT) are rare. Our hypothesis was that there would be no difference in overall survival (OS) between sexes receiving TMT. METHODS: We queried the National Cancer Database (NCDB) for patients diagnosed with clinical stage T2-T4aN0 M0 MIBC between 2004-2016. We considered patients to have received TMT if they received 55 Gy in 20 fractions or 59.4-70.2 Gy of radiotherapy with concurrent chemotherapy following a transurethral resection of bladder tumor (TURBT). We used multivariable Cox proportional hazard models to determine whether sex was associated with risk of mortality. In addition to OS, we calculated relative survival (RS) to adjust for the fact that females generally survive longer than males. RESULTS: Of the patients, 1960 underwent TMT and had survival data. Less than one quarter were female. In the first year following treatment, women had worse OS and RS than men (p = 0.093 and p = 0.030, respectively). However, overall and relative survival differences between sexes were not statistically significantly different in Years 2 and later. Unlike with OS, the RS between sexes remained significant at 9 years; in multivariable analysis based on RS, women were 43% more likely to die than men (p < 0.001). CONCLUSIONS: Women had a higher initial risk of death than men in the first year following TMT. However, long-term survival between sexes was similar. TMT is an important treatment option in both men and women seeking bladder preservation.