International Federation of Gynecology and Obstetrics Endometrial 2023 Is Better For Radiation Oncology Patients.

The International Federation of Gynecology and Obstetrics (FIGO) 2023 staging system for endometrial cancer has marked changes from the previous staging system instituted 14 years prior in 2009. The new staging system includes nonanatomic factors for the first time (lymphovascular space invasion and histology) and molecular classification, which impacts the stage in early-stage disease (IAmPOLEmut and IICmp53abn). The purpose of these changes was to provide (1) high accuracy in the predictive prognosis for patients and (2) identification of distinct treatment-relevant subgroups. Our understanding of the biology and natural history of endometrial cancer has undergone a radical transformation since the Cancer Genome Atlas results in 2013. The 2023 FIGO staging system harmonizes and integrates old and new knowledge on anatomic, histopathologic, and molecular features. Moreover, FIGO 2023 has distinct substages that improve adjuvant treatment decision making. Although the practicality of the new staging system has been debated, we postulate that FIGO 2023 is more useful for radiation oncologists aiming to provide personalized care recommendations. FIGO 2023 requires a change in our perception of a staging system, from a traditional anatomic borders-based system to a staging system integrating anatomy and tumor biology as pivotal prognostic factors for patients while providing important information for treatment decision making.

D-TERMINED, a phase 1 trial in newly diagnosed high-grade glioma with temozolomide, radiation, and minocycline followed by adjuvant minocycline/temozolomide.

Background: Standard treatment for newly diagnosed high-grade gliomas remains suboptimal. Preclinical data indicate that mesenchymal transition and radiation resistance in glioblastoma are driven by NF-κB and microglia activation, which can be inhibited by minocycline. We assessed the safety and efficacy of minocycline combined with standard radiation and temozolomide in newly diagnosed high-grade gliomas. Methods: Adults with newly diagnosed high-grade glioma were eligible. Minocycline was given with concurrent and adjuvant temozolomide. Minocycline doses were escalated using a 3 + 3 design and expanded to identify the maximum tolerated dose (MTD) and adverse event profile. Individual progression-free survival (PFS) was compared to predicted PFS based on RTOG RPA class using a binomial test. The relationships between mesenchymal and microglial biomarkers were analyzed with immunohistochemistry. Results: The MTD of minocycline was 150 mg twice per day (N = 20); 1 patient (5%) experienced CTCAE grade 3 + nausea and dizziness, and 2 patients (10%) demonstrated thrombocytopenia requiring temozolomide interruptions. Twelve patients exceeded their predicted PFS (60%), which did not meet the predefined efficacy endpoint of 70%. Symptoms increased during post-radiation treatment but remained mild. No significant correlation was seen between biomarkers and PFS. Expression levels of P-p65, a marker of NF-κB activation, were correlated with the microglia marker IBA-1. Conclusions: Minocycline at 150 mg twice per day is well tolerated with standard chemoradiation in patients with newly diagnosed high-grade gliomas. PFS was not significantly increased with the addition of minocycline when compared to historical controls. NF-κB activation correlates with microglia levels in high-grade glioma.

Clonal hematopoiesis in patients with HIV and cancer.

BACKGROUND: Cancer-related deaths for people living with HIV (PWH) are increasing due to longer life expectancies and disparately poor cancer-related outcomes. We hypothesize that advanced biological aging contributes to cancer-related morbidity and mortality for PWH and cancer. We sought to determine the impact of clonal hematopoiesis (CH) on cancer disparities in PWH. METHODS: We conducted a retrospective study to compare the prevalence and clinical outcomes of CH in PWH and people without HIV (PWoH) and cancer. Included in the study were PWH and similar PWoH based on tumor site, age, tumor sequence, and cancer treatment status. Biological aging was also measured using epigenetic methylation clocks. RESULTS: In 136 patients with cancer, PWH had twice the prevalence of CH compared to similar PWoH (23% vs 11%, p=0.07). After adjusting for patient characteristics, PWH were four-times more likely to have CH than PWoH (OR 4.1, 95% CI 1.3-13.9, p=0.02). The effect of CH on survival was most pronounced in PWH, who had a 5-year survival rate of 38% if they had CH (vs 59% if no CH), compared to PWoH who had a 5-year survival rate of 75% if they had CH (vs 83% if no CH). CONCLUSION: This study provides the first evidence that PWH may have a higher prevalence of CH than PWoH with the same cancers. CH may be an independent biological aging risk factor contributing to inferior survival for PWH and cancer.

Cancer Treatment Disparities in People With HIV in the United States, 2001-2019.

PURPOSE: People with HIV (PWH) have worse cancer outcomes, partially because of inequities in cancer treatment. We evaluated cancer treatment disparities among PWH, including an assessment of changes in disparities over time. METHODS: We used data from the HIV/AIDS Cancer Match Study, a population-based HIV and cancer registry linkage to examine diffuse large B-cell lymphoma (DLBCL), Hodgkin lymphoma (HL), and cancers of the cervix, lung, anus, prostate, colon, and female breast. Outcomes included receipt of (1) any cancer treatment and (2) standard therapy among patients with local-stage cancer. We assessed associations between HIV and each outcome by estimating adjusted prevalence odds ratios (aORs) with 95% CI and trends over time. We identified predictors of nonreceipt of cancer treatment in PWH. RESULTS: From 2001 to 2019, compared with people with cancer without HIV (n = 2,880,955), PWH (n = 16,334) were more likely to not receive cancer treatment for cervical cancer (aOR, 2.03 [95% CI, 1.52 to 2.70]), DLBCL (aOR, 1.53 [95% CI, 1.38 to 1.70]), HL (aOR, 1.39 [95% CI, 1.19 to 1.63]), lung cancer (aOR, 1.79 [95% CI, 1.65 to 1.93]), prostate cancer (aOR, 1.32 [95% CI, 1.21 to 1.44]), colon cancer (aOR, 1.73 [95% CI, 1.43 to 2.08]), and breast cancer (aOR, 1.38 [95% CI, 1.07 to 1.77]). Similar associations were observed in PWH with local-stage cancers although no difference was observed for anal cancers. The association between HIV and nonreceipt of cancer treatment significantly decreased over time for breast, colon, and prostate cancers (all P trend <.0001), but PWH remained less likely to receive treatment in 2014-2019 for DLBCL, cervix, and lung cancers. Among PWH, Black individuals, people who inject drugs, and those 65 years and older were less likely to receive cancer treatment. CONCLUSION: Disparities in receipt of cancer treatment persist for PWH in the United States in contemporary time periods. Solutions to address inequitable receipt of cancer treatment among PWH are urgently needed.

Differentiation of survival outcomes by anatomic involvement and histology with the revised 2023 International Federation of Gynecology and Obstetrics staging system for endometrial cancer.

OBJECTIVES: The International Federation of Gynecology and Obstetrics (FIGO) staging system for endometrial cancer underwent revision in 2023, incorporating histology, lymphovascular space invasion, and molecular classification. Herein, we compare overall survival (OS) outcomes by anatomic and histologic involvement for patients staged by the 2009 system versus 2023 system. METHODS: The National Cancer Database (NCDB) was queried for patients with newly-diagnosed uterine adenocarcinoma from 2004 to 2015, with follow-up data extending through 2020. Stage was determined by both the 2009 and 2023 FIGO staging systems. Kaplan-Meier estimators and Cox proportional hazards models were used for survival analysis. RESULTS: A total of 134,677 patients were analyzed. Per 2023 classification, patients with stage I disease decreased from 96,161 to 70,101 (-27.1%, p < 0.01), while stage II disease increased from 9295 to 36,294 (+390.5%, p < 0.01). Greatest OS change was observed for 2023 stage IA3 patients (low-risk, synchronous endometrial and ovarian tumors with a clonal relationship), whose 10-year OS was 73.4%, compared to 52.6% for 2009 stage IIIA disease. Ten-year OS for 2023 stage IIIB2 (pelvic peritoneal involvement), previously 2009 stage IVB, was 49.4%, compared to 18.7% for 2009 stage IVB patients. Akaike information criterion, Bayesian information criterion, and Harrel's concordance index were used to evaluate OS prognostication of each staging system across all stages, with likelihood ratio favoring the 2023 system (p = 0.020). CONCLUSIONS: With FIGO's 2023 endometrial cancer anatomic and histologic staging system, stage migration is greatest in early-stage disease. New staging groups may offer more precise prognostication. These changes may affect future management.

Reducing the Environmental Impact of Health Care Conferences: A Study of Emissions and Practical Solutions.

PURPOSE: We aimed to examine the impact of different conference formats (in-person, virtual, and hybrid) of the ASCO conference on greenhouse gas (GHG) emissions and to recommend sustainable options for future conferences. MATERIALS AND METHODS: This study used data on the number of attendees, their departure locations, and the type of attendance (in-person v virtual) provided by ASCO between 2019 and 2022. The GHG emissions resulting from air and ground travel, remote connectivity, conference space utilization, hotel stays, distributed conference materials, and electricity use were estimated for each year. Emissions were stratified by attendee country of origin, type of attendance, and year. Simulations were conducted to evaluate how changes in conference size, location, and format impact emissions, as well as estimate the resulting mitigations from adopting the proposed changes. RESULTS: The highest estimated GHG emissions, calculated in carbon dioxide equivalents (CO2e), were associated with the 2019 in-person conference (37,251 metric tons of CO2e). Although international attendees had the largest contribution to emissions in all years (>50%), location optimization models, which selected conference locations that most minimized GHG emissions, yielded only minimal reductions (approximately 3%). Simulations examining changes to the conference format, location, and attendance percentage suggested that hub-and-spoke, where multiple conference locations are selected by global region, or hybrid models, with both in-person and virtual components, are likely to cause the largest drops in emissions (up to 86%). CONCLUSION: Using historical conference data, this study identifies key aspects that can be modified to reduce emissions and consequently promote more sustainable and equitable conference attendance. Hybrid conferences may be the best solution to maintain the networking opportunities provided by conferences while balancing out their environmental footprint.

The impact of a positive COVID-19 test on timeliness of radiation in patients receiving brachytherapy.

BACKGROUND: Delays in initiating and completing brachytherapy may have adverse oncologic outcomes for patients with cervical, uterine, and prostate cancer. The impact of the COVID-19 pandemic on brachytherapy in the United States has not been well-characterized. OBJECTIVES: We aim to evaluate how a positive COVID-19 test affected timeliness of treatment for patients undergoing brachytherapy for cervical, uterine, and prostate cancer. METHODS: We queried the National Cancer Database to identify patients diagnosed with cervical, uterine, and prostate cancer in 2019 and 2020 who received brachytherapy in their treatment. Patients who tested positive for COVID-19 between cancer diagnosis and start of radiation were compared to those who did not test positive for COVID-19. Time in days from cancer diagnosis to initiation of radiation was compared using two-sample t-tests with p < 0.05 signifying significant differences. RESULTS: We identified 38,341 patients with cervical (n = 6,925), uterine (n = 18,587), and prostate cancer (n = 12,829). Rates of COVID-19 positivity were cervical cancer (n = 135; 2%), uterine cancer (n = 236; 1.3%), and prostate cancer (n = 141; 1%). Of those, 35% of cervical, 49% of uterine, and 43% of prostate cancer patients tested positive between their cancer diagnosis and initiation of radiation. Median days to radiation was significantly longer in these patients: 78 versus 51 for cervical cancer (p < 0.01), 150 versus 104 for uterine cancer (p < 0.01), and 154 versus 124 for prostate cancer (p < 0.01). CONCLUSIONS: For patients with cervical, uterine, and prostate cancer diagnosed between 2019-2020, testing positive for COVID-19 after their cancer diagnosis was associated with a delay to initiation of radiation by 4-7 weeks.

Image-guided preplanning workflow for high-dose-rate interstitial brachytherapy for gynecological malignancies.

PURPOSE: To demonstrate image-guided preplan workflows for high-dose-rate (HDR) brachytherapy for advanced gynecological malignancies. METHODS AND MATERIALS: Two different preplanning scenarios are presented: (1) CT- or MRI-based preplan with partial applicator in place; (2) Preplans generated from prior fractions. The first scenario can be applied to Syed-Neblett template-based implants or hybrid brachytherapy applicators, while the second scenario applies to hybrid applicators. Both scenarios use MRI or CT images acquired with the applicator in place to demonstrate tumor and applicator relative locations and therefore, provide the ability to show optimized suggested needle positions including the implant depths before the actual insertion. RESULTS: The preplanning techniques have demonstrated feasibility and shown five areas of potential improvement: (1) shorter procedure time, (2) decreased number of total needles inserted, (3) shorter physician tumor contour time, (4) shorter planning time, and (5) evaluation of appropriateness for brachytherapy. CONCLUSIONS: The use of image-guided brachytherapy preplanning improves clinical efficiency and is recommended for consideration for adaptation into clinical workflows for HDR interstitial and hybrid brachytherapy.

State of the science and future directions for research on HIV and cancer: Summary of a joint workshop sponsored by IARC and NCI.

An estimated 38 million people live with human immunodeficiency virus (HIV) worldwide and are at excess risk for multiple cancer types. Elevated cancer risks in people living with HIV (PLWH) are driven primarily by increased exposure to carcinogens, most notably oncogenic viruses acquired through shared transmission routes, plus acceleration of viral carcinogenesis by HIV-related immunosuppression. In the era of widespread antiretroviral therapy (ART), life expectancy of PLWH has increased, with cancer now a leading cause of co-morbidity and death. Furthermore, the types of cancers occurring among PLWH are shifting over time and vary in their relative burden in different parts of the world. In this context, the International Agency for Research on Cancer (IARC) and the US National Cancer Institute (NCI) convened a meeting in September 2022 of multinational and multidisciplinary experts to focus on cancer in PLWH. This report summarizes the proceedings, including a review of the state of the science of cancer descriptive epidemiology, etiology, molecular tumor characterization, primary and secondary prevention, treatment disparities and survival in PLWH around the world. A consensus of key research priorities and recommendations in these domains is also presented.

Culturally-informed adaptation and psychometric properties of the Cataldo Cancer Stigma Scale in Northern Tanzania.

BACKGROUND: Cancer-related stigma impacts patients' emotional health, care engagement, and cancer outcomes, but few measures of cancer stigma exist. We culturally adapted and assessed psychometric properties of the Cataldo Cancer Stigma Scale (CCSS) in Tanzania. METHODS: We administered the CCSS short version (21 items), plus 12 locally-derived items, to 146 adult cancer patients. We conducted exploratory factor analysis, examined internal consistency/reliability, and assessed convergent validity with relevant measures. RESULTS: We identified a 17-item cancer stigma scale with strong psychometric properties and four subscales: enacted stigma, shame and blame, internalized stigma, and disclosure concerns. Stigma was rare except for disclosure concerns. Stigma was positively associated with depression and anxiety and negatively associated with social support, quality of life, and illness acceptance. CONCLUSIONS: The scale provides valid, culturally-informed measurement of cancer stigma in Tanzania. Future studies should assess associations with care engagement, which will inform interventions to reduce stigma and improve outcomes.

Cancer Treatment Decision-Making for People Living With HIV: Physician-Reported Barriers, Facilitators, and Recommendations.

BACKGROUND: Compared with the general cancer population, people living with HIV (PLWH) and cancer are less likely to receive treatment and have significantly elevated cancer-specific mortality for many common cancer types. Physician recommendations drive the cancer therapy that patients receive, yet there is limited information assessing how cancer treatment decisions are made for people living with HIV and cancer. We sought to understand oncologist decision-making in PLWH and cancer by eliciting barriers, facilitators, and recommendations for enhancing care delivery. SETTING: Participants were recruited between May 2019 and May 2021 from one academic medical center in the western United States (n = 13), another in the southeastern United States (n = 7), and community practices nationwide (n = 5). METHODS: Using an inductive qualitative approach, we conducted in-depth interviews with 25 oncologists from two academic medical centers and community practices. RESULTS: Facilitators of cancer care delivery included readily available information regarding HIV status and stage, interdepartmental communication, and antiviral therapy adherence. Barriers included a lack of formal education on HIV malignancies, perceptions of decreased life expectancy, fear of inadvertent disclosure, and drug-drug interactions. Recommendations included improved provider communication, patient social and mental health resources, and continuing education opportunities. CONCLUSION: The study revealed drivers of cancer treatment decision-making, highlighting physician-reported barriers and facilitators, and recommendations to support treatment decision-making. This is the first known study examining oncologists' perceptions of caring for PLWH. Given that cancer is a leading cause of death among PLWH, there is an urgent need to improve care and outcomes.

Multi-Institutional Analysis of Cancer Patient Exposure, Perceptions, and Trust in Information Sources Regarding Complementary and Alternative Medicine.

PURPOSE: Complementary and alternative medicine (CAM) use during cancer treatment is controversial. We aim to evaluate contemporary CAM use, patient perceptions and attitudes, and trust in various sources of information regarding CAM. METHODS: A multi-institutional questionnaire was distributed to patients receiving cancer treatment. Collected information included respondents' clinical and demographic characteristics, rates of CAM exposure/use, information sources regarding CAM, and trust in each information source. Comparisons between CAM users and nonusers were performed with chi-squared tests and one-way analysis of variance. Multivariable logistic regression models for trust in physician and nonphysician sources of information regarding CAM were evaluated. RESULTS: Among 749 respondents, the most common goals of CAM use were management of symptoms (42.2%) and treatment of cancer (30.4%). Most CAM users learned of CAM from nonphysician sources. Of CAM users, 27% reported not discussing CAM with their treating oncologists. Overall trust in physicians was high in both CAM users and nonusers. The only predictor of trust in physician sources of information was income >$100,000 in US dollars per year. Likelihood of trust in nonphysician sources of information was higher in females and lower in those with graduate degrees. CONCLUSION: A large proportion of patients with cancer are using CAM, some with the goal of treating their cancer. Although patients are primarily exposed to CAM through nonphysician sources of information, trust in physicians remains high. More research is needed to improve patient-clinician communication regarding CAM use.

Cancer treatment delays among cancer patients living with HIV during the COVID-19 pandemic in the United States.

BACKGROUND: The COVID-19 pandemic led to care disruptions across the cancer continuum. It is unknown if immunosuppressed patients with cancer, who may be at higher risk for complications of SARS-CoV-2 infection, are disproportionately impacted. Thus, we aimed to compare delays in cancer treatment initiation between people living with HIV (PLWH) and cancer, the general cancer population (GCP), and patients with cancer and a history of solid organ transplant (SOT). Comparisons were made across the period 2 years preceding the pandemic versus the first year of the pandemic. METHODS: We used data from a real-world electronic health record-derived de-identified database (2018-2021) comprised of US patients with cancer from 800 sites of care across the country. We included patients with 19 different cancer types. We calculated time to cancer treatment initiation (TTI) as the difference between the date of cancer diagnosis and the earliest date that cancer treatment was recorded. RESULTS: The sample included 181 PLWH, 65,073 GCP patients, and 195 patients with a SOT. Difference-in-difference regression models adjusted for age, sex, and presence of metastatic disease at cancer diagnosis revealed a significant increase in delayed TTI among PLWH compared to the GCP during COVID-19 versus prior to COVID-19, with delays increasing by approximately 1 month during the pandemic (DID: 32.6 days [8.9-56.3]; p = 0.007). The increase in TTI for PLWH was observed across treatment modalities, including surgery (DID: 55.1 [28.8-81.3], p < 0.001) and systemic therapy (DID: 30.4 [4.6-56.3], p = 0.021). CONCLUSIONS/RELEVANCE: PLWH experienced significant delays in cancer treatment initiation after diagnosis during the first year of COVID-19, delays that may negatively impact cancer outcomes. These data warrant patient and provider attention as the pandemic continues to impact the US healthcare system.

Differences in epigenetic age by HIV status among patients with a non-AIDS defining cancer.

OBJECTIVE: People with HIV (PWH) are living longer and experiencing higher numbers of non-AIDS-defining cancers (NADC). Epigenetic aging biomarkers have been linked to cancer risk, and cancer is now a leading cause of death in PWH, but these biomarkers have not been investigated in PWH and cancer. DESIGN: In order to compare epigenetic age by HIV status, HIV-uninfected participants were matched to PWH by reported age, tumor site, tumor sequence number, and cancer treatment status. METHODS: DNA from blood was assayed using Illumina MethylationEPIC BeadChip, and we estimated immune cell composition and aging from three epigenetic clocks: Horvath, GrimAge, and epiTOC2. Age acceleration by clock was computed as the residual from the expected value, calculated using linear regression, for each study participant. Comparisons across HIV status used the Wilcoxon rank sum test. Hazard ratios and 95% confidence intervals for the association between age acceleration and survival in PWH were estimated with Cox regression. RESULTS: Among 65 NADC participants with HIV and 64 without, biological age from epiTOC2 ( P  < 0.0001) and GrimAge ( P  = 0.017) was significantly higher in PWH. Biological age acceleration was significantly higher in PWH using epiTOC2 ( P  < 0.01) and GrimAge ( P  < 0.0001), with the difference in GrimAge remaining statistically significant after adjustment for immune cell composition. Among PWH, GrimAge acceleration was significantly associated with increased risk of death (hazard ratio 1.11; 95% confidence interval (CI) 1.04-1.18). CONCLUSION: We observed a higher epigenetic age in PWH with a NADC diagnosis compared with their HIV-uninfected counterparts, as well as a significant association between this accelerated biological aging and survival for patients diagnosed with a NADC.

Trends in use of radiation therapy, chemotherapy, and combination chemoradiotherapy in advanced uterine cancer before, during, and after GOG 258.

OBJECTIVE: To explore the use of Gynecologic Oncology Group 258 (GOG 258) study regimens before, during, and after the study. METHODS: Patients aged 18 years or older with endometrial cancer between 2004-2019 were identified in the National Cancer Database. Inclusion criteria were stage III or IVA of any histology and stage I-IVA clear cell or serous histologies with positive washings that received adjuvant therapy. Adjuvant therapy use was examined in the pre-GOG 258 era (before 2009), during GOG 258 enrollment and maturation (2010-2017), and after results presentation in 2017 (2018-2019). Two-sided Cochran-Armitage tests, Wilcoxen rank sum tests, and χ2 tests were used for continuous and categorical variables. Multi-variable logistic regression assessed factors associated with the receipt of chemoradiotherapy compared with chemotherapy only or radiation therapy only. RESULTS: From 2004 to 2019, 41 408 high-risk endometrial cancer patients received adjuvant therapy (12% radiation therapy, 38% chemotherapy, 50% chemoradiotherapy). Chemoradiotherapy increased over the GOG 258 study period (40% before study opening, 54% during enrollment, and 59% after results). Serous (OR 0.6, 95% CI 0.6 to 0.7) and clear cell histology (0.7, 0.6 to 0.8), higher grade (0.8, 0.7 to 0.9), and lymph node positivity (0.8, 0.7 to 0.9) were negatively associated with receipt of chemoradiotherapy compared with single-modality treatment. Non-Hispanic Black ethnicity (0.8, 0.8 to 0.9) and residing ≥50 miles from the treatment facility (0.8, 0.7 to 0.9) were also negatively associated with chemoradiotherapy. Private insurance (1.2, 1.0 to 1.4) and treatment at community hospitals (1.2, 1.2 to 1.3) were positively associated with chemoradiotherapy. CONCLUSION: Despite the lack of benefit in the GOG 258 experimental arm, chemoradiotherapy use increased during study enrollment and after results publication.

Dosimetric Evaluation of Organs at Risk From SAVE Protocol.

PURPOSE: The objective of this work was to evaluate dosimetric characteristics to organs at risk (OARs) from short-course adjuvant vaginal cuff brachytherapy (VCB) in early endometrial cancer compared with standard of care (SOC) in a multi-institutional prospective randomized trial. METHODS AND MATERIALS: SAVE (Short Course Adjuvant Vaginal Brachytherapy in Early Endometrial Cancer Compared to Standard of Care) is a prospective, phase 3, multisite randomized trial in which 108 patients requiring VCB were randomized to an experimental short-course arm (11 Gy × 2 fractions [fx] to surface) and SOC arm. Those randomized to the SOC arm were subdivided into treatment groups based on treating physician discretion as follows: 7 Gy × 3 fx to 5 mm, 5 to 5.5 Gy × 4 fx to 5 mm, and 6 Gy × 5 fx to surface. To evaluate doses to OARs of each SAVE cohort, the rectum, bladder, sigmoid, small bowel, and urethra were contoured on planning computed tomography, and doses to OARs were compared by treatment arm. Absolute doses for each OAR and from each fractionation scheme were converted to 2 Gy equivalent dose (EQD23). Each SOC arm was compared with the experimental arm separately using 1-way analysis of variance, followed by pairwise comparisons using Tukey's honestly significant difference test. RESULTS: The experimental arm had significantly lower doses for rectum, bladder, sigmoid, and urethra compared with the 7 Gy × 3 and 5 to 5.5 Gy × 4 fractionation schemes; however, the experimental arm did not differ from the 6 Gy × 5 fractionation scheme. For small bowel doses, none of the SOC fractionation schemes were statistically different than the experimental. The highest EQD23 doses to the examined OARs were observed to come from the most common dose fractionation scheme of 7 Gy × 3 fx. With a short median follow-up of 1 year, there have been no isolated vaginal recurrences. CONCLUSIONS: Experimental short-course VCB of 11 Gy × 2 fx to the surface provides a comparable biologically effective dose to SOC courses. Experimental short-course VCB was found to reduce or be comparable to D2cc and D0.1cc EQD23 doses to rectum, bladder, sigmoid, small bowel, and urethra critical structures. This may translate into a comparable or lower rate of acute and late adverse effects.