Anesthetic Oxygen Use and Sex Are Critical Factors in the FLASH Sparing Effect

Purpose

Ultra High Dose-Rate (UHDR) radiation has been reported to spare normal tissue, compared with Conventional Dose-Rate (CDR) radiation. However, important work remains to be done to improve the reproducibility of the FLASH effect. A better understanding of the biologic factors that modulate the FLASH effect may shed light on the mechanism of FLASH sparing. Here, we evaluated whether sex and/or the use of 100% oxygen as a carrier gas during irradiation contribute to the variability of the FLASH effect.

Methods and Materials

C57BL/6 mice (24 male, 24 female) were anesthetized using isoflurane mixed with either room air or 100% oxygen. Subsequently, the mice received 27 Gy of either 9 MeV electron UHDR or CDR to a 1.6 cm2 diameter area of the right leg skin using the Mobetron linear accelerator. The primary postradiation endpoint was time to full thickness skin ulceration. In a separate cohort of mice (4 male, 4 female), skin oxygenation was measured using PdG4 Oxyphor under identical anesthesia conditions.

Results

Neither supplemental oxygen nor sex affected time to ulceration in CDR irradiated mice. In the UHDR group, skin damage occured earlier in male and female mice that received 100% oxygen compared room air and female mice ulcerated sooner than male mice. However, there was no significant difference in time to ulceration between male and female UHDR mice that received room air. Oxygen measurements showed that tissue oxygenation was significantly higher when using 100% oxygen as the anesthesia carrier gas than when using room air, and female mice showed higher levels of tissue oxygenation than male mice under 100% oxygen.

Conclusions

The skin FLASH sparing effect is significantly reduced when using oxygen during anesthesia rather than room air. FLASH sparing was also reduced in female mice compared to male mice. Both tissue oxygenation and sex are likely sources of variability in UHDR studies. These results suggest an oxygen-based mechanism for FLASH, as well as a key role for sex in the FLASH skin sparing effect.

Association of differential censoring with survival and suboptimal control arms among oncology clinical trials

Differential censoring (DC), referring to censoring imbalance between treatment arms, may bias the interpretation of survival outcomes in clinical trials. In 146 phase 3 oncology trials with statistically significant time-to-event surrogate primary endpoints (PEPs), we evaluated the association between DC in the surrogate PEP, control arm adequacy, and the subsequent statistical significance of OS results. Twenty-four (16%) trials exhibited DC favoring the control arm (ConDC), while 15 (10%) exhibited experimental arm DC (ExpDC). Positive OS was more common in ConDC trials (63%) than trials without DC (37%) or with ExpDC (47%; odds ratio [OR] 2.64, 95% CI 1.10-7.20; P=.04). ConDC trials more frequently used suboptimal control arms (46%) compared to 20% without DC and 13% with ExpDC (OR 3.60, 95% CI 1.29-10.0; P=.007). The presence of ConDC in trials with surrogate PEPs, especially in those with OS conversion, may indicate an inadequate control arm and should be examined and explained.

Disparities in outcomes and access to therapy options in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) disproportionately impacts racial and ethnic minorities and patients with lower socioeconomic status. These social determinants of health (SDH) lead to disparities in access to care and outcomes. We aim to understand the relationship between SDH and survival and locoregional treatment options in HCC.

METHODS

Using the National Cancer Database, we evaluated survival and access locoregional treatments including non-transplant surgery, liver transplant (LT), and liver-directed radiation therapy (LDRT) in patients with HCC diagnosed between 2004 and 2017. Variables including clinical stage, age, sex, race, income, rurality, year of diagnosis, facility type (FT), Charlson-Deyo score (CD), and insurance were evaluated. Cox proportional hazards multivariable regression and dominance analyses were used for analyses.

RESULTS

In total, 140 340 patients were included. Worse survival was seen with advanced stage, older age, Black race, rurality, public insurance, treatment at a nonacademic center, and lower income. The top predictors for survival included stage, age, and income. Completion of non-transplant surgery was best predicted by stage, FT, and insurance type, whereas LT was predicted by age, year of diagnosis, and CD score. LDRT utilization was most associated with year of diagnosis, FT, and CD score.

CONCLUSION

For patients with HCC, survival was predicted primarily by stage, age, and income. The primary sociodemographic factors associated with access to surgical treatments, in addition to FT, were insurance and income, highlighting the financial burdens of health care. Work is needed to address disparities in access to care, including improved insurance access, addressing financial inequities and financial toxicities of treatments, and equalizing care opportunities in community centers.

Can I Leave? Perspectives on Parental Leave and Parenthood in Medical Training Among Program Directors and Trainees in Oncologic Specialties

Purpose: Peak fertility commonly occurs during medical training, and delaying parenthood can complicate pregnancies. Trainee parental leave policies are varied and lack transparency. Research on the impacts of parenthood on trainee education is limited. Methods: A Qualtrics-based survey was distributed via e-mail/social media to program directors (PDs) within oncologic specialties with a request to forward a parallel survey to trainees. Questions assessed awareness of parental leave policies, supportiveness of parenthood, and impacts on trainee education. Statistical analyses included descriptive frequencies and bivariable comparisons by key groups. Results: A total of 195 PDs and 286 trainees responded. Twelve percent and 29% of PDs were unsure of maternity/paternity leave options, respectively. PDs felt they were more supportive of trainee parenthood than trainees perceived they were. Thirty-nine percent of nonparent trainees (NPTs) would have children already if not in medicine, and >80% of women trainees were concerned about declining fertility. Perceived impacts of parenthood on trainee overall education and academic productivity were more negative for women trainees when rated by PDs and NPTs; however, men/women parents self-reported equal impacts. Leave burden was perceived as higher for women trainees. Conclusions: A significant portion of PDs lack awareness of parental leave policies, highlighting needs for increased transparency. Trainees' perception of PD support for parenthood is less than PD self-reported support. Alongside significant rates of delayed parenthood and fertility concerns, this poses a problem for trainees seeking to start a family, particularly women who are perceived more negatively. Further work is needed to create a supportive culture for trainee parenthood.

Retrospective evidence for pediatric benefit of U.S. assault weapons ban as rationale for implementing an even more effective ban

BACKGROUND

With data available since 1981, firearm death rates in American children and adolescents can be evaluated for trends during the 13 years before, the decade of, and during 16 years since the United States (U.S.) 1994-2004 Federal Assault Weapons Ban (FAWB).

METHODS

National and regional firearm mortality trends in the U.S. during 1981-2020 were assessed with joinpoint regression applied to Centers for Disease Control and Prevention data.

RESULTS

After increasing exponentially before the FAWB, the national firearm death rate in 0-14 year-olds promptly reversed course and declined throughout the FAWB and then reversed again after the FAWB and resumed an exponential increase (all phases p<0.001). The reduction in firearm death rate occurred within 1-3 years of the start of the FAWB, in both sexes, in all four census regions of the U.S., and in all four major race/ethnicity subgroups, especially non-Hispanic blacks. No other form of violence in 0-14 year-olds had this temporal relationship with the FAWB. The firearm mortality reduction during the FAWB is strongly-highly correlated with the concomitant reduction in handgun manufacturing in 91 % of 24 sex, race/ethnicity and region subsets analyzed, These FAWB-related trends were also apparent in older adolescents and young adults and less so in older persons.

CONCLUSIONS

Firearm death rates in 0-14 year-olds before, during, and after the FAWB, and no other type of injury, implicate the FAWB as having had a beneficial effect. Legislation to mitigate firearm mortality and injury inclusive of a FAWB should be especially beneficial to children and young adolescents, and regardless of sex, race/ethnicity or region in the U.S.

Anesthetic oxygen use and sex are critical factors in the FLASH sparing effect

Introduction

Ultra-high dose-rate (UHDR) radiation has been reported to spare normal tissue compared to conventional dose-rate (CDR) radiation. However, reproducibility of the FLASH effect remains challenging due to varying dose ranges, radiation beam structure, and in-vivo endpoints. A better understanding of these inconsistencies may shed light on the mechanism of FLASH sparing. Here, we evaluate whether sex and/or use of 100% oxygen as carrier gas during irradiation contribute to the variability of the FLASH effect.

Methods

C57BL/6 mice (24 male, 24 female) were anesthetized using isoflurane mixed with either room air or 100% oxygen. Subsequently, the mice received 27 Gy of either 9 MeV electron UHDR or CDR to a 1.6 cm2 diameter area of the right leg skin using the Mobetron linear accelerator. The primary post-radiation endpoint was time to full thickness skin ulceration. In a separate cohort of mice (4 male, 4 female) skin oxygenation was measured using PdG4 Oxyphor under identical anesthesia conditions.

Results

In the UHDR group, time to ulceration was significantly shorter in mice that received 100% oxygen compared to room air, and amongst them female mice ulcerated sooner compared to males. However, no significant difference was observed between male and female UHDR mice that received room air. Oxygen measurements showed significantly higher tissue oxygenation using 100% oxygen as the anesthesia carrier gas compared to room air, and female mice showed higher levels of tissue oxygenation compared to males under 100% oxygen.

Conclusion

The FLASH sparing effect is significantly reduced using oxygen during anesthesia compared to room air. The FLASH sparing was significantly lower in female mice compared to males. Both tissue oxygenation and sex are likely sources of variability in UHDR studies. These results suggest an oxygen-based mechanism for FLASH, as well as a key role for sex in the FLASH skin sparing effect.

Selection and Prejudice: Addressing Clinical Trial Disparities With a Review of Current Shortcomings and Future Directions

Growing evidence has demonstrated significant, persistent, and widespread disparities in cancer clinical trial enrollment across myriad disease sites and target populations. Although mechanisms underlying such disparities are complex and multifactorial, clinical trial eligibility criteria may serve as a key structural barrier to equitable and diverse trial enrollment. In this review, we provide an overview of the data describing historical and current disparities in cancer clinical trial enrollment and subsequently describe several patient-, institution-, and trial-related factors which appear to be key drivers of enrollment inequity, with specific discussion regarding the impact of eligibility criteria. We further describe the landscape of ongoing professional efforts aimed at eliminating clinical trial disparities through various medical, professional, and advocacy groups. The review concludes with a practical discussion of how modernization of eligibility criteria in clinical trials may decrease or eliminate trial disparities, including specific actionable recommendations aimed at improving the quality of future eligibility criteria.

Consensus Quality Measures and Dose Constraints for Lung Cancer From the Veterans Affairs Radiation Oncology Quality Surveillance Program and ASTRO Expert Panel

PURPOSE

For patients with lung cancer, it is critical to provide evidence-based radiation therapy to ensure high-quality care. The US Department of Veterans Affairs (VA) National Radiation Oncology Program partnered with the American Society for Radiation Oncology (ASTRO) as part of the VA Radiation Oncology Quality Surveillance to develop lung cancer quality metrics and assess quality of care as a pilot program in 2016. This article presents recently updated consensus quality measures and dose-volume histogram (DVH) constraints.

METHODS AND MATERIALS

A series of measures and performance standards were reviewed and developed by a Blue-Ribbon Panel of lung cancer experts in conjunction with ASTRO in 2022. As part of this initiative, quality, surveillance, and aspirational metrics were developed for (1) initial consultation and workup; (2) simulation, treatment planning, and treatment delivery; and (3) follow-up. The DVH metrics for target and organ-at-risk treatment planning dose constraints were also reviewed and defined.

RESULTS

Altogether, a total of 19 lung cancer quality metrics were developed. There were 121 DVH constraints developed for various fractionation regimens, including ultrahypofractionated (1, 3, 4, or 5 fractions), hypofractionated (10 and 15 fractionations), and conventional fractionation (30-35 fractions).

CONCLUSIONS

The devised measures will be implemented for quality surveillance for veterans both inside and outside of the VA system and will provide a resource for lung cancer-specific quality metrics. The recommended DVH constraints serve as a unique, comprehensive resource for evidence- and expert consensus-based constraints across multiple fractionation schemas.

Effects of UHDR and Conventional Irradiation on Behavioral and Cognitive Performance and the Percentage of Ly6G+ CD45+ Cells in the Hippocampus

We assessed the effects of conventional and ultra-high dose rate (UHDR) electron irradiation on behavioral and cognitive performance one month following exposure and assessed whether these effects were associated with alterations in the number of immune cells in the hippocampus using flow cytometry. Two-month-old female and male C57BL/6J mice received whole-brain conventional or UHDR irradiation. UHDR mice were irradiated with 9 MeV electrons, delivered by the Linac-based/modified beam control. The mice were irradiated or sham-irradiated at Dartmouth, the following week shipped to OHSU, and behaviorally and cognitively tested between 27 and 41 days after exposure. Conventional- and UHDR-irradiated mice showed impaired novel object recognition. During fear learning, conventional- and UHDR-irradiated mice moved less during the inter-stimulus interval (ISI) and UHDR-irradiated mice also moved less during the baseline period (prior to the first tone). In irradiated mice, reduced activity levels were also seen in the home cage: conventional- and UHDR-irradiated mice moved less during the light period and UHDR-irradiated mice moved less during the dark period. Following behavioral and cognitive testing, infiltrating immune cells in the hippocampus were analyzed by flow cytometry. The percentage of Ly6G+ CD45+ cells in the hippocampus was lower in conventional- and UHDR-irradiated than sham-irradiated mice, suggesting that neutrophils might be particularly sensitive to radiation. The percentage of Ly6G+ CD45+ cells in the hippocampus was positively correlated with the time spent exploring the novel object in the object recognition test. Under the experimental conditions used, cognitive injury was comparable in conventional and UHDR mice. However, the percentage of CD45+ CD11b+ Ly6+ and CD45+ CD11b+ Ly6G- cells in the hippocampus cells in the hippocampus was altered in conventional- but not UHDR-irradiated mice and the reduced percentage of Ly6G+ CD45+ cells in the hippocampus might mediate some of the detrimental radiation-induced cognitive effects.

Phase 2 study of preoperative chemotherapy with nab-paclitaxel and gemcitabine followed by chemoradiation for borderline resectable or node-positive pancreatic ductal adenocarcinoma

BACKGROUND

Neoadjuvant treatment with nab-paclitaxel and gemcitabine for potentially operable pancreatic adenocarcinoma has not been well studied in a prospective interventional trial and could down-stage tumors to achieve negative surgical margins.

METHODS

A single-arm, open-label phase 2 trial (NCT02427841) enrolled patients with pancreatic adenocarcinoma deemed to be borderline resectable or clinically node-positive from March 17, 2016 to October 5, 2019. Patients received preoperative gemcitabine 1000 mg/m² and nab-paclitaxel 125 mg/m² on Days 1, 8, 15, every 28 days for two cycles followed by chemoradiation with 50.4 Gy intensity-modulated radiation over 28 fractions with concurrent fluoropyrimidine chemotherapy. After definitive resection, patients received four additional cycles of gemcitabine and nab-paclitaxel. The primary endpoint was R0 resection rate. Other endpoints included treatment completion rate, resection rate, radiographic response rate, survival, and adverse events.

RESULTS

Nineteen patients were enrolled, with the majority having head of pancreas primary tumors, both arterial and venous vasculature involvement, and clinically positive nodes on imaging. Among them, 11 (58%) underwent definitive resection and eight of 19 (42%) achieved R0 resection. Disease progression and functional decline were primary reasons for deferring surgical resection after neoadjuvant treatment. Pathologic near-complete response was observed in two of 11 (18%) resection specimens. Among the 19 patients, the 12-month progression-free survival was 58%, and 12-month overall survival was 79%. Common adverse events were alopecia, nausea, vomiting, fatigue, myalgia, peripheral neuropathy, rash, and neutropenia.

CONCLUSION

Gemcitabine and nab-paclitaxel followed by long-course chemoradiation represents a feasible neoadjuvant treatment strategy for borderline resectable or node-positive pancreatic cancer.

Incidence of Primary End Point Changes Among Active Cancer Phase 3 Randomized Clinical Trials

Importance

Primary end point (PEP) changes to an active clinical trial raise questions regarding trial quality and the risk of outcome reporting bias. It is unknown how the frequency and transparency of the reported changes depend on reporting method and whether the PEP changes are associated with trial positivity (ie, the trial met the prespecified statistical threshold for PEP positivity).

Objectives

To assess the frequency of reported PEP changes in oncology randomized clinical trials (RCTs) and whether these changes are associated with trial positivity.

Design, Setting, and Participants

This cross-sectional study used publicly available data for complete oncology phase 3 RCTs registered in ClinicalTrials.gov from inception through February 2020.

Main Outcomes and Measures

The main outcome was change between the initial PEP and the final reported PEP, assessed using 3 methods: (1) history of tracked changes on ClinicalTrials.gov, (2) self-reported changes noted in the article, and (3) changes reported within the protocol, including all available protocol documents. Logistic regression analyses were performed to evaluate whether PEP changes were associated with US Food and Drug Administration approval or trial positivity.

Results

Of 755 included trials, 145 (19.2%) had PEP changes found by at least 1 of the 3 detection methods. Of the 145 trials with PEP changes, 102 (70.3%) did not have PEP changes disclosed within the manuscript. There was significant variability in rates of PEP detection by each method (χ2 = 72.1; P < .001). Across all methods, PEP changes were detected at higher rates when multiple versions of the protocol (47 of 148 [31.8%]) were available compared with 1 version (22 of 134 [16.4%]) or no protocol (76 of 473 [16.1%]) (χ2 = 18.7; P < .001). Multivariable analysis demonstrated that PEP changes were associated with trial positivity (odds ratio, 1.86; 95% CI, 1.25-2.82; P = .003).

Conclusions and Relevance

This cross-sectional study revealed substantial rates of PEP changes among active RCTs; PEP changes were markedly underreported in published articles and mostly occurred after reported study completion dates. Significant discrepancies in the rate of detected PEP changes call into question the role of increased protocol transparency and completeness in identifying key changes occurring in active trials.

Impact of a Virtual Introduction to Radiation Oncology Presentation on Stimulating Interest in the Specialty Among Diverse Medical Students at Multiple Institutions

PURPOSE

Many US medical students lack access to radiation oncology (RO). The authors' hypothesis was that a virtual, cross-institutional presentation introducing students to a career in RO would be valuable in exposing students to RO who are less likely to access it otherwise and would increase students' interest in a career in RO regardless of their gender, race, or ethnicity.

METHODS

A 1-hour, live, virtual, extracurricular presentation was offered to deans of US medical schools lacking affiliated RO departments and/or having high enrollments of students underrepresented in medicine (UIM) and also student groups composed primarily of UIM students. Presentations were given individually to each school by a single radiation oncologist. An electronic survey captured data from participating students.

RESULTS

One hundred ninety-seven students from 13 institutions attended presentations; 114 students responded to the survey (response rate, 58%). Ninety-two students (81%) were aware of the specialty of RO before the presentation; however, UIM students were significantly less likely to be aware of RO than all others (69% versus 87%, P = .05). Only 19 students (17%) reported previously hearing presentations from radiation oncologist (29% among second- to fourth-year students versus 9% among first-year students, P = .01). Ninety-eight students (86%) expressed more interest in pursuing a career in RO after the presentation. There was no significant difference in interest in RO for any demographic subgroups.

CONCLUSIONS

Virtual RO exposure was feasible to deliver to students less likely to be exposed otherwise and successfully stimulated interest in the specialty regardless of students' gender, race, or ethnicity.

Phase 1b study to assess the safety of neoadjuvant trifluridine/tipiracil with concurrent radiation in resectable stage II/III rectal cancer

TPS274

Background: Treatment of locally advanced rectal cancer currently involves tri-modal therapy with pre-operative chemo-radiation (CRT), surgery, and combination chemotherapy. Total neoadjuvant therapy (TNT) is emerging as an important treatment pathway that can increase rates of complete response (CR) leading to better overall outcomes. Novel radio-sensitizing agents may improve rates of CR. Trifluridine/tipiracil (TFD/TPI) is a novel fluoropyrimidine that has demonstrated clinical efficacy in patients with treatment-refractory metastatic colorectal cancer. Importantly, TFD/TPI has superior radio-sensitization in vitro compared to 5-fluorouracil, and we hypothesize that this can improve the tumor response of patients. This phase 1 study assesses the safety and preliminary efficacy of using TFD/TPI for long-course CRT for rectal cancer followed by FOLFOX chemotherapy in the TNT setting. Methods: NCT04104139 is a prospective, dose-finding phase I study using Bayesian Optimal Interval (BOIN) design to determine the maximum tolerated dose (MTD) of TFD/TPI with concurrent standard dose/fractionation radiation for resectable rectal cancer. Adults with previously untreated rectal adenocarcinoma, with clinical stage II (T3-4aN0) and stage III (T1-4aN1+) by MRI and endoscopy are eligible. Patients must first receive CRT with standard radiation (45-50 Gy over 25-28 fractions) followed by up to 8 cycles of standard FOLFOX, or alternatively 5 cycles of CAPOX chemotherapy. During CRT, the first dose level of TFD/TPI is PO 25mg/m2 twice a day from Mon to Fri (5 weekdays) alternating on weeks 1, 3, and 5 concurrent with 5-6 weeks of radiation. The second dose level is 30mg/m2, and third dose level is 35mg/m2. The MTD of TFD/TPI in combination with radiation is the dose corresponding to a dose limiting toxicity (DLT) probability of 30% using the BOIN design with escalation/de-escalation of each dose level occurring in cohorts of 3 participants until a maximum total of 18 participants, sub-total of 12 patients within one dose level, or another stopping rule based on serious toxicities. The primary endpoint is proportion of DLTs for TFD/TPI at MTD. Secondary endpoints include overall tolerability profile, delayed toxicities during FOLFOX, rates of clinical CR, rates of pathologic CR, and correlative biomarkers. The study was activated December 2019 and has accrued 8 of intended 18 patients. Clinical trial information: NCT04104139 .

Pilot Study Exploring the Feasibility of Incorporating Radiation Oncology Into Pre-existing Early Pathway Programs for Diverse Premedical Students

PURPOSE

Many medical schools in the United States have affiliated pathway, preparatory, and/or prematriculation programs that enroll a high percentage of students historically underrepresented in medicine (URiM). The purpose of this pilot study was to better characterize exposures to radiation oncology (RO) among students in these programs and determine the feasibility of incorporating a radiation oncologist within their pre-existing format if nonexistent.

METHODS AND MATERIALS

During the summers of 2021 and 2022, a radiation oncologist gave a presentation about basic principles of cancer care to 18 unique student groups in 12 premedical programs affiliated with 8 medical schools. Participating students were asked to complete an anonymous postpresentation questionnaire. Descriptive statistics are reported.

RESULTS

A total of 467 students attended the presentations, and 241 completed the questionnaire (response rate 52.0%). The majority of participants reported being female (63.5%), URiM (66.4%), and low income (57.3%). Students were less likely to report previous teaching from a radiation oncologist (11.2%) than a surgical (17.0%) or medical oncologist (18.3%). Prior clinical shadowing with a radiation oncologist (2.9%) was also less likely than shadowing a surgical oncologist (5.0%), medical oncologist (6.6%), or any other physician (53.1%). Students were also less likely to previously believe that radiation could cure cancer (65.8%) compared with surgery (74.9%) or chemotherapy (89.3%). After the presentation, 168 students (69.7%) were more interested in a career in RO, and 211 students (87.6%) responded that the presentation was either quite or extremely valuable (median Likert-type score, 5; interquartile range, 4-5).

CONCLUSIONS

Many of the students in premedical programs lack prior exposure to RO or knowledge of multidisciplinary cancer care, which was ameliorated by a simple yet effective presentation across a variety of different types of programs in this study. Longitudinal assessment of different types of educational initiatives and students' ultimate career trajectory will help optimize future RO initiatives among premedical URiM students.

The multidisciplinary management of cholangiocarcinoma

Cholangiocarcinoma is a lethal malignancy of the biliary epithelium that can arise anywhere along the biliary tract. Surgical resection confers the greatest likelihood of long-term survivability. However, its insidious onset, difficult diagnostics, and resultant advanced presentation render the majority of patients unresectable, highlighting the importance of early detection with novel biomarkers. Developing liver-directed therapies and emerging targeted therapeutics may offer improved survivability for patients with unresectable or advanced disease. In this article, the authors review the current multidisciplinary standards of care in resectable and unresectable cholangiocarcinoma, with an emphasis on novel biomarkers for early detection and nonsurgical locoregional therapy options.

Angiotensin receptor blockade and stereotactic body radiation therapy for early stage lung cancer ARB & SBRT for early stage lung cancer

Stereotactic body radiotherapy (SBRT) demonstrates excellent local control in early stage lung cancer, however a quarter of patients develop recurrence or distant metastasis. Transforming growth factor-beta (TGF-β) supports metastasis and treatment resistance, and angiotensin receptor blockade (ARB) indirectly suppresses TGF-β signaling. This study investigates whether patients taking ARBs while undergoing SBRT for early stage lung cancer exhibited improved overall survival (OS) or recurrence free survival (RFS) compared to patients not taking ARBs. This was a single institution retrospective analysis of 272 patients treated with SBRT for early stage lung cancer between 2009 and 2018. Patient health data was abstracted from the electronic medical record. OS and RFS were assessed using Kaplan-Meier method. Log-rank test was used to compare unadjusted survival between groups. Univariable and multivariable Cox proportional hazard regression models were used to estimate hazard ratios (HRs). Of 247 patients analyzed, 24 (10%) patients took ARBs for the duration of radiotherapy. There was no difference in mean age, median tumor diameter, or median biologic effective dose between patients taking ARBs or not. Patients taking ARBs exhibited increased OS (ARB = 96.7 mo.; no ARB = 43.3 mo.; HR = 0.25 [95% CI: 0.10 to 0.62, P = .003]) and increased RFS (median RFS, ARB = 64.3 mo.; No ARB = 35.1 mo.; HR = 0.26 [95% CI: 0.10 to 0.63, P = .003]). These effects were not seen in patients taking angiotensin converting enzyme inhibitors (ACEIs) or statins. ARB use while undergoing SBRT for early stage lung cancer may increase OS and RFS, but ACEI use does not show the same effect.

Association of fall rate and functional status by APOE genotype in cancer survivors after exercise intervention

PURPOSE/OBJECTIVES

Cancer treatment survivors often report impaired functioning and increased falls. Not all survivors experience the same symptom burden, suggesting individual susceptibilities. APOE genotype is a potential genetic risk factor for cancer treatment related side effects. Lifestyle factors such as physical activity can mitigate the effect of APOE genotype on measures of clinical interest in individuals without a history of cancer. We tested the hypothesis that APOE genotype influences cancer treatment related side effects and symptoms as well as response to exercise intervention.

MATERIALS AND METHODS

Data from a subsample of a study of fall prevention exercise in post-treatment female cancer survivors aged 50-75 years old (https://clinicaltrials.gov NCT01635413) were used to conduct a secondary data analysis. ApoE genotype was determined by serum sampling. Physical functioning, frequency of falls, and symptom burden were assessed using survey instruments.

RESULTS

Data from 126 female cancer survivors a median of 49 months out from cancer diagnosis were analyzed. ApoE4 carriers trended toward a higher fall rate at baseline (p = 0.059), but after exercise intervention had a fall rate lower than E4 non-carriers both immediately after structured intervention (p = 0.013) and after 6 months of follow up (p = 0.002). E2 carriers did not show improved measures of depressive symptoms and self-report disability after exercise intervention. E3 homozygotes showed increased self report physical activity after the 6 month exercise intervention, but E4 and E2 carriers did not.

CONCLUSIONS

APOE genotype may modulate cancer treatment related side effects and symptoms and response to exercise intervention.

Oncologic emergencies and urgencies: A comprehensive review

Patients with advanced cancer generate 4 million visits annually to emergency departments (EDs) and other dedicated, high-acuity oncology urgent care centers. Because of both the increasing complexity of systemic treatments overall and the higher rates of active therapy in the geriatric population, many patients experiencing acute decompensations are frail and acutely ill. This article comprehensively reviews the spectrum of oncologic emergencies and urgencies typically encountered in acute care settings. Presentation, underlying etiology, and up-to-date clinical pathways are discussed. Criteria for either a safe discharge to home or a transition of care to the inpatient oncology hospitalist team are emphasized. This review extends beyond familiar conditions such as febrile neutropenia, hypercalcemia, tumor lysis syndrome, malignant spinal cord compression, mechanical bowel obstruction, and breakthrough pain crises to include a broader spectrum of topics encompassing the syndrome of inappropriate antidiuretic hormone secretion, venous thromboembolism and malignant effusions, as well as chemotherapy-induced mucositis, cardiomyopathy, nausea, vomiting, and diarrhea. Emergent and urgent complications associated with targeted therapeutics, including small molecules, naked and drug-conjugated monoclonal antibodies, as well as immune checkpoint inhibitors and chimeric antigen receptor T-cells, are summarized. Finally, strategies for facilitating same-day direct admission to hospice from the ED are discussed. This article not only can serve as a point-of-care reference for the ED physician but also can assist outpatient oncologists as well as inpatient hospitalists in coordinating care around the ED visit.

Radiotherapy reimagined: Integrating nanomedicines into radiotherapy clinical trials

Radioenhancing nanoparticles (NPs) are being evaluated in ongoing clinical trials for various cancers including head and neck, lung, esophagus, pancreas, prostate, and soft tissue sarcoma. Supported by decades of preclinical investigation and recent randomized trial data establishing clinical activity, these agents are poised to influence future multimodality treatment paradigms involving radiotherapy. Although the physical interactions between NPs and ionizing radiation are well characterized, less is known about how these agents modify the tumor microenvironment, particularly regarding tumor immunogenicity. In this review, we describe the key multidisciplinary considerations related to radiation, surgery, immunology, and pathology for designing radioenhancing NP clinical trials. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Patterns of Care and Barriers to Utilization of Definitive Concurrent Chemoradiation Therapy for Stage III Non-Small Cell Lung Cancer in Russia

BACKGROUND

Definitive concurrent chemoradiation (cCRT) is offered to only 3% of Russian patients with stage III NSCLC. To determine the patterns of care and barriers to cCRT utilization in Russia, we conducted a survey of practicing radiation oncologists (ROs).

METHODS

Electronic IRB-approved survey containing 15 questions was distributed to Russian ROs. Fisher's exact test or Cochran-Armitage test of trend was used to assess the associations between clinical experience, practice type, and patterns of care.

RESULTS

We analyzed 58 questionnaires completed by ROs-16 respondents from tertiary referral hospitals, and 42 from community or private centers. A total of 88% of respondents formulate treatment recommendations in multi-disciplinary tumor boards. For unresectable stage III NSCLC, the most common recommendation is sequential CRT (50%), followed by concurrent CRT (40%), with an observed higher utilization of cCRT in tertiary centers (9/16, 56% vs 14/42, 33%). Of the respondents, 31% do not offer cCRT to their pts. Among reasons for avoiding cCRT are (1) poor performance of pts (76%); (2) high toxicity of therapy (55%); (3) lack of consensus among tumor board members (33%); and (4) preference for sequential CRT (31%). Only 3% do not irradiate elective LNs. Eighty-six percent of respondents counsel their NSCLC pts regarding smoking cessation.

CONCLUSIONS

Despite level 1 evidence, cCRT is rarely used in Russia for pts with locally advanced NSCLC, and preference for sequential therapy and concerns over high toxicity are the most common barriers. Education of Russian ROs may increase cCRT utilization, leading to improved survival, notably in the era of maintenance immunotherapy.

Patient-clinician communication and patient-centered outcomes among patients with suspected stage I non-small cell lung cancer: a prospective cohort study

Among patients with suspected early-stage non-small cell lung cancer (NSCLC), we sought to evaluate the association of patient-clinician communication (PCC) with patient-centered outcomes (PCOs). We conducted a multicenter, prospective cohort study examining PCOs at five time points, up to 12-months post-treatment. We used generalized estimating equation (GEE) models adjusted for sociodemographic and clinical variables to examine the relationship between PCC (dichotomized as high- or low-quality) and decisional conflict, treatment self-efficacy, and anxiety. The cohort included 165 patients who were 62% male with a mean age of 70.7 ± SD 8.1 years. Adjusted GEE analysis including 810 observations revealed high-quality PCC was associated with no decisional conflict (adjusted odds ratio [aOR] = 0.14, 95% CI = 0.07 to 0.27) and higher self-efficacy (β = -0.26, 95% CI = -0.37 to -0.14). High-quality PCC was not associated with moderately severe anxiety (aOR = 0.68, 95% CI = 0.41 to 1.09), though was associated with decreased anxiety scores (β = -3.91, 95% CI = -6.48 to -1.35). Among individuals with suspected early-stage NSCLC, high-quality PCC is associated with less decisional conflict and higher self-efficacy; the relationship with anxiety is unclear. Clinicians should prioritize enhanced treatment-related communication at critical and vulnerable periods in the cancer care trajectory to improve PCOs.

Characterization of older adults with cancer seeking acute emergency department care: A prospective observational study

INTRODUCTION

Disparities in care of older adults in cancer treatment trials and emergency department (ED) use exist. This report provides a baseline description of older adults ≥65 years old who present to the ED with active cancer.

MATERIALS AND METHODS

Planned secondary analysis of the Comprehensive Oncologic Emergencies Research Network observational ED cohort study sponsored by the National Cancer Institute. Of 1564 eligible adults with active cancer, 1075 patients were prospectively enrolled, of which 505 were ≥ 65 years old. We recruited this convenience sample from eighteen participating sites across the United States between February 1, 2016 and January 30, 2017.

RESULTS

Compared to cancer patients younger than 65 years of age, older adults were more likely to be transported to the ED by emergency medical services, have a higher Charlson Comorbidity Index score, and be admitted despite no significant difference in acuity as measured by the Emergency Severity Index. Despite the higher admission rate, no significant difference was noted in hospitalization length of stay, 30-day mortality, ED revisit or hospital admission within 30 days after the index visit. Three of the top five ED diagnoses for older adults were symptom-related (fever of other and unknown origin, abdominal and pelvic pain, and pain in throat and chest). Despite this, older adults were less likely to report symptoms and less likely to receive symptomatic treatment for pain and nausea than the younger comparison group. Both younger and older adults reported a higher symptom burden on the patient reported Condensed Memorial Symptom Assessment Scale than to ED providers. When treating suspected infection, no differences were noted in regard to administration of antibiotics in the ED, admissions, or length of stay ≤2 days for those receiving ED antibiotics.

DISCUSSION

We identified several differences between older (≥65 years old) and younger adults with active cancer seeking emergency care. Older adults frequently presented for symptom-related diagnoses but received fewer symptomatic interventions in the ED suggesting that important opportunities to improve the care of older adults with cancer in the ED exist.

Linguistic Biases in Letters of Recommendation for Radiation Oncology Residency Applicants from 2015 to 2019

We aimed to investigate whether implicit linguistic biases exist in letters of recommendation (LORs) for applicants to radiation oncology (RO) residency. LORs (n = 487) written for applicants (n = 125) invited to interview at a single RO residency program from the 2015 to 2019 application cycles were included for analysis. Linguistic Inquiry and Word Count (LIWC) software was used to evaluate LORs for length and a dictionary of predetermined themes. Language was evaluated for gender bias using a publicly available gender bias calculator. Non-parametric tests were used to compare linguistic domain scores. The median number of the LORs per applicant was 4 (range 3-5). No significant differences by applicant gender were detected in LIWC score domains or gender bias calculator (P > 0.05). However, LORs for applicants from racial/ethnic backgrounds underrepresented in medicine were less likely to include standout descriptors (P = 0.008). Male writers were less likely to describe applicant characteristics related to patient care (P < 0.0001) and agentic personality (P = 0.006). LORs written by RO were shorter (P < 0.0001) and included fewer standout descriptors (P = 0.014) but were also more likely to include statements regarding applicant desirability (P = 0.045) and research (P = 0.008). While language was globally male-biased, assistant professors were less likely than associate professors (P = 0.0064) and full professors (P = 0.023) to use male-biased language. Significant linguistic differences were observed in RO residency LORs, suggesting that implicit biases related to both applicants and letter writers may exist. Recognition, and ideally eradication, of such biases are crucial for fair and equitable evaluation of a diverse applicant pool of RO residency candidates.

Palliative Care Needs and Clinical Outcomes of Patients with Advanced Cancer in the Emergency Department

Background: Older adults with cancer use the emergency department (ED) for acute concerns. Objectives: Characterize the palliative care needs and clinical outcomes of advanced cancer patients in the ED. Design: A planned secondary data analysis of the Comprehensive Oncologic Emergencies Research Network (CONCERN) data. Settings/Subjects: Cancer patients who presented to the 18 CONCERN affiliated EDs in the United States. Measurements: Survey included demographics, cancer type, functional status, symptom burden, palliative and hospice care enrollment, and advance directive code status. Results: Of the total (674/1075, 62.3%) patients had advanced cancer and most were White (78.6%) and female (50.3%); median age was 64 (interquartile range 54-71) years. A small proportion of them were receiving palliative (6.5% [95% confidence interval; CI 3.0-7.6]; p = 0.005) and hospice (1.3% [95% CI 1.0-3.2]; p = 0.52) care and had a higher 30-day mortality rate (8.3%, [95% CI 6.2-10.4]). Conclusions: Patients with advanced cancer continue to present to the ED despite recommendations for early delivery of palliative care.

Electron flash-RT program in clinical setting for human translation

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Background: A FLASH-RT program was established at Dartmouth-Hitchcock Medical Center in minimally-modified clinical setting by joint efforts of biomedical engineering, radiation oncology, radiation biology and medical physics teams. Various projects on dosimetry, chemical sensing, molecular profiling, software/hardware development, and translational studies have been conducted. The aim is to share logistical considerations and experience on running a FLASH-RT program to support institution-wide academic activities with an ultimate goal of treating human patients with FLASH-RT in 2022. Methods: A linac was converted in the clinical setting by qualified engineers to deliver an ultra-high dose rate (UHDR) electron beam. Routine safety and dosimetry checks were done by physicists for every reversible conversion. Long-term record-keeping and retrospective surveys were carried out to demonstrate the feasibility, safety, stability and accuracy of this dual-purpose (FLASH and conventional RT) approach. Comprehensive failure mode and effects analysis (FMEA) has been completed to systematically evaluate safety related considerations. A treatment planning system (TPS) has been developed in Varian Eclipse to facilitated comparative studies. The FLASH-capable linac has been utilized as shared resource to support institution-wide academic activities as well as normal clinical treatments. Results: With its safety (no accident or FLASH-related malfunction), flexibility (> 100 conversions in 2 years), reliability (̃6000 hours in flash mode and ̃5x105 Gy accumulative dose delivered at isocenter) and accuracy (̃5% conversion-to-conversion variations) demonstrated by commissioning, long-term user experience and comprehensive FMEA analysis, the FLASH-RT platform has been actively utilized for researches in six major categories 1) FLASH beam dosimetry; 2) real-time beam delivery monitoring and control; 3) oximetry and chemical sensing; 4) preclinical/translational small/large animal treatment with tumor control and normal tissue complication endpoints, 5) treatment plan and delivery optimization; 6) the design of phase I/II trials. Key findings in each category will be reported. Conclusions: A FLASH-RT program in clinical setting is established at Dartmouth with joint efforts, promoting collaborative projects to advance FLASH-RT to clinical treatment. The system has been reliably utilized for over two years for mechanistic as well as translational studies and support a phase I/II trial treating cutaneous lymphoma with eFLASH-RT.

Incidence and impact of proportional hazards violations in phase 3 cancer clinical trials

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Background: Hazard ratio (HR)-based analyses used in oncology trials rely on the assumption of proportional hazards, i.e. a HR that is constant over time. Proportional hazards violations (PHVs) may lead to misinterpretation of trial results. Restricted mean survival time (RMST) is valid with non-proportional hazards and has received recent attention specifically for immunotherapy (IO) trials but has not been routinely adopted in oncology trial design as a whole. We aimed to comprehensively characterize the incidence and factors associated with PHVs among phase 3 oncology trials and assess RMST as an alternate measure of treatment effect in survival analysis. Methods: We used Clinicaltrials.gov to identify all superiority-design, 2-arm phase 3 cancer trials with time-dependent endpoints with published results through February 2020. We manually reconstructed patient-level data from published Kaplan-Meier (KM) curves, assessed PHVs with the Schoenfeld residual test (p <.05) and analyzed the RMST. To assess reconstruction accuracy, reported and reconstructed HRs were compared. Univariable logistic regression was used to assess the likelihood of PHVs by trial characteristic, with statistically significant factors (p <.05) included in a multivariable analysis. Concordance of RMST-based and HR-based analysis was established when both tests agreed as to the statistical significance of the comparison. Results: Of 342 KM comparisons eligible for reconstruction, 318 comparisons across 315 trials, enrolling 347,538 patients from 1989-2017, were accurately reconstructed and analyzed. PHVs were identified in 76/318 (23.9%) trials. There was no difference in likelihood of PHVs among IO vs non-IO trials (LR 2.31, 95% CI 0.30 – 17.85, P =.37), nor by disease site, year of trial initiation, or sample size. Few trials with PHVs (16/76) pre-specified a plan to account for non-proportional hazards in statistical design. Trials with an overall survival (OS) primary endpoint (PEP) were less likely to have PHVs than trials with a non-OS PEP (LR: 0.50, 95% CI 0.28 - 0.90, P =.02). Trials whose PEP was non-significant were more likely to have PHVs (LR 1.73, 95% CI 1.01 - 2.97, P =.047). No factor remained significantly associated with PHV in multivariable analysis. Overall, 291/318 (91.5%) KM comparisons were concordant. Among trials with PHVs, 5/76 were significant by RMST but not HR, and 5/76 were significant by HR but not RMST. Of these, 1 led to FDA drug approval, and 2 others are cited in NCCN guidelines. Conclusions: PHVs are common across all phase 3 cancer clinical trials. Attempts to account for PHVs in trial design are lacking despite the potential for trial misinterpretation in the event of non-proportional hazards. RMST-based analysis is broadly concordant with HR-based analysis and may aid in interpretation of trials with PHVs. Hence, we recommend that prospective trials include a priori a statistical plan to account for PHVs.

Geriatric patient outcomes in a multidisciplinary central nervous system community hospital clinic for radiation oncology and neurosurgery (RADIANS)

INTRODUCTION

Management of older adult patients with central nervous system (CNS) cancers requires a patient-centric, multidisciplinary approach. Assessment of neurosurgical and radiation treatment outcomes can assist in establishing guidelines for this patient population. We previously reported on the RADIANS clinic, a novel community hospital-based multidisciplinary clinic (MDC) for CNS cancer care, providing simultaneous radiation oncology and neurosurgery evaluation in a same-day, single-setting clinic. We now provide a focused analysis of our older adult patient population and recommendations for triage and standardization of care.

METHODS

Consecutive older adult patients (age ≥ 65) evaluated at the RADIANS clinic for CNS disease were identified and retrospectively reviewed. Observed 30-day neurosurgical outcomes were compared to predicted outcomes determined by the American College of Physicians NSQIP Surgical Risk Calculator. One-sample binomial exact tests were used to evaluate binary outcome measures. A two-sample t-test was used to evaluate the length of hospital stay. Brier Scores were calculated to assess the deviation between predicted probabilities and observed outcomes for binary outcome measures. Overall survival at 90 days was reported.

RESULTS

Fifty-six older adult patients with malignant (42/56) and benign (14/56) CNS disease were evaluated. Mean distance traveled for multidisciplinary evaluation at the RADIANS clinic was 43.4 miles. There was no incidence of radiation-induced toxicity. Mean length of hospital stay for RADIANS patients was significantly shorter by about 1.5 to 3.5 days (95% CI). There was no statistically significant difference for other outcome measures, however, Brier Scores demonstrated that NSQIP was not a good predictive tool for any or serious complications, UTI, venous thromboembolism, return to OR, readmission, or death in our cohort. Local tumor control rate and progression-free survival at 90 days were 97.4% and 76.9%, respectively.

CONCLUSIONS

This is the first report of CNS disease outcomes in older adult patients evaluated by radiation oncology and neurosurgery at a community hospital-based MDC. We observed minimal adverse radiation outcomes and high tumor control in our cohort. Findings show significantly shorter postoperative hospital stay for patients evaluated and managed at the RADIANS clinic.

Racial and Gender Differences in Patient Satisfaction Scores Among Oncologists

BACKGROUND

Patient satisfaction scores (PSS) have been adopted in health care reimbursement and faculty promotion metrics. Oncology patients face a challenging prognosis, where PSS may be perceived differently. We hypothesized that PSS differed based on gender and racial demographics of oncologists.

MATERIALS AND METHODS

This was an institutional review board exempt cross-sectional study utilizing PSS data for outpatient oncologists within a large comprehensive cancer center. Patient demographics included age, gender, race/ethnicity, geographical residence, and disease site. Characteristics of oncologists included gender and race/ethnicity. We used PSS ≥95 to make comparisons. The association between patient and physician characteristics were evaluated using the t test and χ2 test.

RESULTS

A total of 15,849 oncology patients were identified between 2011 and 2020. Survey respondents were predominantly female (53.2%), white (93.4%), between 50 and 70 years of age (55.3%), and living in an urban setting (63.6%). There were 303 oncologists with the majority being male (64.4%) and white (58.1%). Compared with white oncologists, Asian and Hispanic oncologists received lower PSS (P=0.001 and 0.0085, respectively). On subset analysis, these differences were significant among patients older than 50 years, living in rural counties, and reporting white or non-Hispanic race/ethnicity, or among patients of either gender (all P<0.05). Patients with genitourinary malignancies provided lower PSS for female oncologists (P=0.005).

CONCLUSIONS

Asian and Hispanic oncologists were more likely to receive lower PSS. In addition, female oncologists treating genitourinary malignancies received lower PSS. Appropriate statistical adjustments are needed for PSS among oncologists to account for race, gender, and physician subspecialization to allow for equitable professional opportunities across demographics.

Association between Prior Malignancy Exclusion Criteria and Age Disparities in Cancer Clinical Trials

Simple Summary

Recent studies have shown that the incidence of age disparities in cancer clinical trials may be increasing over time. Excluding patients with prior malignancies is one such eligibility criterion through which elderly may inadvertently be excluded from clinical trial participation. While strict enrollment criteria may improve internal validity of studies, they can also negatively impact generalizability of results. As such, we sought to characterize the incidence of prior malignancy exclusion criteria in phase III cancer clinical trials and assess if this eligibility criterion may directly contribute to age disparities. These data support efforts to modernize eligibility criteria and inform best practices regarding acceptable versus unacceptable exclusionary timeframes for prior malignancy exclusion criteria.

Abstract

Prior malignancy exclusion criteria (PMEC) are often utilized in cancer clinical trials; however, the incidence of PMEC and the association of PMEC with trial participant age disparities remain poorly understood. This study aimed to identify age disparities in oncologic randomized clinical trials as a result of PMEC. Using a comprehensive collection of modern phase III cancer clinical trials obtained via ClinicalTrials.gov, we assessed the incidence and covariates associated with trials excluding patients with prior cancers within 5+ years from registration (PMEC-5). Using the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) database, we further sought to determine the correlation between PMEC-5 and age disparities. PMEC-5 were used in 41% of all trials, with higher PMEC-5 utilization among industry-supported trials as well as trials evaluating a targeted therapy. Comparing trial patient median ages with population-matched median ages by disease site and time-period, we assessed the association between PMEC-5 and age disparities among trial participants. PMEC-5 were independently associated with heightened age disparities, which further worsened with longer exclusionary timeframes. Together, PMEC likely contribute to age disparities, suggesting that eligibility criteria modernization through narrower PMEC timeframes may work toward reducing such disparities in cancer clinical trial enrollment.

Initial observation of contrast profiles for 3D and 2D MRI sequences in MR-guided radiation therapy for locally advanced pancreatic cancer

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Background: MR-guided stereotactic body radiation therapy (MR-SBRT) is a novel method of treating mobile tumors with soft-tissue gating and on-table adaptive planning. In our experience using the ViewRay MRIdian system (VR) for treating locally advanced pancreatic cancer (PA) with MR-SBRT, the true-fast imaging with steady-state free precession (TRUFI) sequences on the VR impart differing intensities for relevant structures seen on the pre-treatment high resolution 3D MRI (3D MRI) versus the real-time 2D cine MRI (2D cine) used for target tracking. Since these variations can confound target tracking selection, we propose that an understanding of the differing contrast profiles could improve selection of tracking structures and optimize treatment delivery. Methods: We retrospectively reviewed both 3D MRI and 2D cine images for patients (pts) with PA (n =20) treated on the VR. At simulation, an appropriate tracking target was identified and contoured on a single 3mm sagittal slice of the 3D MRI. This sagittal slice was directly compared to the registered 7mm 2D cine to identify structures with notable discrepancies in signal intensity. The 3D MRI was then explored in additional planes to confirm structure identities. For quantitative verification of the clinically observed differences, the pixel intensity distributions of 3D MRI and 2D cine DICOM image datasets were statistically compared. Results: In all pts reviewed, arteries (aorta, celiac, SMA) appeared with similar contrast profiles on both images. However, veins (portal vein, SMV) appeared hypointense on 3D MRI but hyperintense on 2D cine. Biliary structures appeared hyperintense on 3D MRI but only mildly hyperintense on 2D cine. The pixel intensity distributions extracted from 3D MRI and 2D cine images were confirmed to differ significantly (two sample Kolmogorov-Smirnov test; test statistic =0.40; p < 0.001). Conclusions: There are significant variations in image intensity between the initial treatment planning 3D MRI and the immediate pre-treatment 2D cine obtained with the VR. Understanding these discrepancies can guide radiation oncologists in choosing optimal tracking targets. Future work will focus on identifying the particular causes and frequencies of target tracking failures and exploring alternative tracking algorithms using artificial intelligence which could ultimately allow for VMAT on the ViewRay system.

Observation unit use among patients with cancer following emergency department visits: Results of a multicenter prospective cohort from CONCERN

PURPOSE

Emergency department (ED) visits by patients with cancer frequently end in hospitalization. As concerns about ED and hospital crowding increase, observation unit care may be an important strategy to deliver safe and efficient treatment for eligible patients. In this investigation, we compared the prevalence and clinical characteristics of cancer patients who received observation unit care with those who were admitted to the hospital from the ED.

METHODS

We performed a multicenter prospective cohort study of patients with cancer presenting to an ED affiliated with one of 18 hospitals of the Comprehensive Oncologic Emergency Research Network (CONCERN) between March 1, 2016 and January 30, 2017. We compared patient characteristics with the prevalence of observation unit care usage, hospital admission, and length of stay.

RESULTS

Of 1051 enrolled patients, 596 (56.7%) were admitted as inpatients, and 72 (6.9%) were placed in an observation unit. For patients admitted as inpatients, 23.7% had a length of stay ≤2 days. The conversion rate from observation to inpatient was 17.1% (95% CI 14.6-19.4) among those receiving care in an observation unit. The average observation unit length of stay was 14.7 h. Patient factors associated ED disposition to observation unit care were female gender and low Charlson Comorbidity Index.

CONCLUSION

In this multicenter prospective cohort study, the discrepancy between observation unit care use and short inpatient hospitalization may represent underutilization of this resource and a target for process change.

Preclinical data on co-delivery of temozolomide and talazoparib by fucodain-coated nanoscale metal organic frameworks for colorectal cancer chemoradiation

Nanoparticle characterization and in vitro data on the effects of combined PARP inhibition and DNA damage by chemoradiation are shown. This data accompanies the research article “Fucoidan-coated nanoparticles target radiation-induced P-selectin to enhance chemoradiotherapy in murine colorectal cancer” (DuRoss et al., 2021) Additional characterization of the physiochemical properties of nanoscale metal organic frameworks (nMOFs) comprised of hafnium and 1,4-dicarboxybenzene (Hf-BDC) loaded with temozolomide (TMZ) and talazoparib (Tal) are presented. Toxicity data of the drug-loaded nMOF coated with fucoidan (TT@Hf-BDC-Fuco) in colorectal cancer cells, CT-26, from alamarBlue-based chemoradiation experiments are shown. Experimental methods for the nanoparticle characterization and cell-based assays of the nMOF formulation are presented.

Management of Muscle Invasive Bladder Cancer with Bladder Preservation in Russia: a Survey-Based Analysis of Current Practice and the Impact of an Educational Workshop on Clinical Expertise

Trimodality bladder preservation (BP) is an accepted alternative to radical cystectomy for patients with muscle invasive bladder cancer (MIBC). The global utilization of BP is variable, and practice patterns have not been previously studied in Russia. We sought to elucidate the contemporary BP practice patterns in Russia and determine the impact of the BP workshop on attitudes of Russian radiation oncologists (ROs) towards BP. The workshop was focused on patient workup, selection for BP, chemotherapy choices, radiation therapy (RT) contouring and planning, patient counseling. A total of 77 pre- and 32 matched post-workshop IRB-approved surveys, based on the workshop content, were analyzed using descriptive statistics to determine baseline clinical experience and patterns of care. The impact was judged by changes in participants' responses. A total of 56% of respondents had experience with delivering bladder-directed RT, and 60% of those treated both operable and inoperable MIBC patients. Only 10% felt uncomfortable offering an operable patient BP modality. Prior to the workshop, almost half of respondents estimated universal poor bladder (44%) and erectile functions (47%) after BP. The workshop resulted in dramatic change in participants' attitudes towards long-term urinary (Stuart-Maxwell test, p < 0.01) and sexual (exact McNemar test, p < 0.01) side effects. Prior to the workshop, only 47% of respondents routinely discussed smoking cessation (SC) with their patients, whereas after workshop, 88% agreed that SC discussion is mandatory (exact McNemar test, p = 0.04). BP for MIBC is commonly used in Russia. Our workshop resulted in dramatically improved understanding of long-term BP toxicities and inspired Russian ROs to incorporate SC counseling into routine clinical management.

Geographic Disparities in Referral Rates and Oncologic Outcomes of Intrahepatic Cholangiocarcinoma: A Population-Based Study

BACKGROUND

Intrahepatic cholangiocarcinoma (ICC) is a rare cancer. Patients in rural areas may face reduced access to advanced treatments often only available at referral centers. We evaluated the association of referral center treatment with treatment patterns, outcomes, and geography in patients with ICC.

METHODS

We queried the Oregon State Cancer Registry for ICC between 1997 and 2016, collecting clinicopathologic, demographic, and oncologic data. Patients were classified by treatment at a referral center or non-referral center. 'Crowfly' distance to the nearest referral center (DRC) was calculated. Outcomes were evaluated using Kaplan-Meier, Cox proportional hazards modeling, and logistic regression.

RESULTS

Over 20 years, 740 patients with ICC had a median age of 66 years. Slightly more than half (n = 424, 57%) were non-referral center treated and 316 (43%) were referral center treated. Referral center treatment increased over time (odds ratio [OR] 1.03/year, p < 0.05). Referral center-treated patients had improved overall survival in all patients (median 9 vs. 4 months, p < 0.001), in the non-metastatic group (median 13 vs. 6 months, p < 0.001), and in patients not receiving liver resection (median 6 vs. 3 months, p < 0.05). On multivariable analysis, referral center-treated patients more often underwent chemotherapy, resection, or radiation (all p < 0.05). Increasing DRC (OR 0.98/20 km, p < 0.05) was independently associated with non-referral center treatment.

CONCLUSION

Patients with ICC who are evaluated at a referral center are more likely to receive treatments associated with better oncologic outcomes, including patients who are not managed with hepatic resection. Increasing the DRC is associated with treatment at a non-referral center; interventions to facilitate referral, such as telemedicine, may lead to improved outcomes for patients with ICC in rural states.

Financial relationships between industry and principal investigators of US cooperative group randomized cancer clinical trials

Financial conflicts of interest (FCOIs) could bias the potentially practice-changing oncologic randomized clinical trials (RCTs) of tomorrow. This investigation characterized the FCOIs of the principal investigators (PIs) of all currently accruing trials of the four (adult) cooperative groups of the National Clinical Trials Network. For our study, the PI list was first compiled, and each name was then searched in the CMS Open Payments database. For each transaction (general payments (GPs) or research funding (RF)), the amount/number/source of payments was recorded. Results showed that from 2014 to 2019, the 91 PIs collectively accepted nearly one-third of a billion dollars ($10 477 023 GPs and $320 096 233 RF). The mean and median GP was $6505 and $945, respectively, and $301 693 and $49 824 RF, respectively. Multivariable Gamma regression analysis revealed that higher GP sums were associated with RCTs involving any type of systemic therapy, and higher RF sums with medical oncologist PIs, trials with phase III components, and RCTs involving radiotherapy (P < .05 for all). Both higher-volume GPs and RF were predicted by PIs having accepted payment(s) from the manufacturer of the drug utilized in their RCT (P < .001 GP, P = .008 RF). Taken together, the main message of this investigation is that FCOIs may be particularly high in PIs of phase III systemic therapy trials, especially if the PI accepted payments from the manufacturer of the drug utilized in their trial. Such RCTs should be thoroughly scrutinized by medical journals, the FDA, and insurance companies for potential "industry bias" that could influence the integrity of their conclusions.

Contemporary radiotherapy: present and future

Oncology care is increasingly a multidisciplinary endeavour, and radiation therapy continues to have a key role across the disease spectrum in nearly every cancer. However, the field of radiation oncology is still one of the most poorly understood of the cancer disciplines. In this Review, we attempt to summarise and contextualise developments within the field of radiation oncology for the non-radiation oncologist. We discuss advancements in treatment technologies and imaging, followed by an overview of the interplay with advancements in systemic therapy and surgical techniques. Finally, we review new frontiers in radiation oncology, including advances within the metastatic disease continuum, reirradiation, and emerging types of radiation therapy.

Mitigating Implicit Bias in Radiation Oncology

Implicit bias is one of the most insidious and least recognizable mechanisms that can cause inequity and disparities. There is increasing evidence that both implicit and explicit biases have a negative effect on patient outcomes and patient-physician relationships. Given the impact of Implicit bias, a joint session between ASTROs Committee on Health Equity, Diversity, and Inclusion and the National Cancer Institute (the ASTRO-National Cancer Institute Diversity Symposium) was held during the American Society of Radiation Oncology (ASTRO) 2020 Annual Meeting, to address the effect of implicit bias in radiation oncology through real life and synthesized hypothetical scenario discussions. Given the value of this session to the radiation oncology community, the scenarios and discussion are summarized in this manuscript. Our goal is to heighten awareness of the multiple settings in which implicit bias can occur as well as discuss resources to address bias.

Factors Associated With Age Disparities Among Cancer Clinical Trial Participants

Importance

Seminal investigation 2 decades ago alerted the oncology community to age disparities in participation in cooperative group trials; less is known about whether these disparities persist in industry-funded research.

Objective

To characterize the age disparities among trial enrollees on randomized clinical trials (RCTs) of common cancers in clinical oncology and identify factors associated with wider age imbalances.

Data Sources

Phase 3 clinical oncology RCTs were identified through ClinicalTrials.gov.

Study Selection

Multiarm RCTs assessing a therapeutic intervention for patients with breast, prostate, colorectal, or lung cancer (the 4 most common cancer disease sites) were included.

Data Extraction and Synthesis

Trial data were extracted from ClinicalTrials.gov. Trial screening and parameter identification were independently performed by 2 individuals. Data were analyzed in 2018.

Main Outcomes and Measures

The difference in median age (DMA) between the trial participant median age and the population-based disease-site-specific median age was determined for each trial.

Results

Three hundred two trials met inclusion criteria. The trials collectively enrolled 262 354 participants; 249 trials (82.5%) were industry-funded. For all trials, the trial median age of trial participants was a mean of 6.49 years younger than the population median age (95% CI, -7.17 to -5.81 years; P < .001). Age disparities were heightened among industry-funded trials compared with non-industry-funded trials (mean DMA, -6.84 vs -4.72 years; P = .002). Enrollment criteria restrictions based on performance status or age cutoffs were associated with age disparities; however, industry-funded trials were not more likely to use these enrollment restrictions than non-industry-funded trials. Age disparities were also larger among trials that evaluated a targeted systemic therapy and among lung cancer trials. Linear regression modeling revealed a widening gap between trial and population median ages over time at a rate of -0.19 years annually (95% CI, -0.37 to -0.01 years; P = .04).

Conclusions and Relevance

Age disparities between trial participants and the incident disease population are pervasive across trials and appear to be increasing over time. Industry sponsorship of trials is associated with heightened age imbalances among trial participants. With an increasing role of industry funding among cancer trials, efforts to understand and address age disparities are necessary to ensure generalizability of trial results as well as equity in trial access.

Mentorship Initiatives in Radiation Oncology: A Scoping Review of the Literature

PURPOSE

Although mentorship is described extensively in academic medical literature, there are few descriptions of mentorship specific to radiation oncology. The goal of the current study was to investigate the state of mentorship in radiation oncology through a scoping review of the literature.

METHODS AND MATERIALS

A search protocol was defined according to Preferred Reporting Items for Systematic Reviews and Meta Analyses extension for scoping reviews (PRISMA-ScR) guidelines. Predefined search terms and medical subject headings were used to search PubMed for English language articles published after January 1, 1990, on mentorship in radiation oncology. Additionally, in-press articles from major radiation oncology and medical education journals were searched. Three reviewers determined article eligibility. Included articles were classified based on predefined evaluation criteria.

RESULTS

Fourteen publications from 2008 to 2019 met inclusion criteria. The most commonly described form of mentorship was the dyad (64.3%), followed by team (14.3%) and peer (7.1%); 2 articles did not specify mentorship type (14.3%). The most commonly mentored participants were residents (35.7%), followed by medical students (35.7%) and attendings (21.4%); 1 study included participants of all levels (7.1%). Thirteen studies (92.9%) identified an experimental study design, most of which were cross-sectional (42.9%), followed by cohort studies (28.6%) and before/after (21.4%). Median sample size, reported in 12 of 13 experimental studies, was 132 (coefficient of variation, 1.06). Although outcomes varied widely, the majority described successful implementation of mentorship initiatives with high levels of participant satisfaction.

CONCLUSIONS

Although few initiatives are currently reported, the present study suggests that these initiatives are successful in promoting career development and increasing professional satisfaction. The interventions overwhelmingly described mentorship dyads; other forms of mentorship are either less common or understudied. Limitations included interventions not being evaluated in a controlled setting, and many were assessed using surveys with low response rates. This review highlights rich opportunities for future scholarship to develop, evaluate, and disseminate radiation oncology mentorship initiatives.