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Traditionally, renal cell carcinoma (RCC) was considered a radioresistant tumor, thereby limiting definitive radiation therapy management options. However, several recent studies have demonstrated that stereotactic body radiation therapy (SBRT) can achieve high rates of local control for the treatment of primary RCC. In the setting of expanding use of SBRT for primary RCC, it is crucial to provide guidance on practical considerations such as patient selection, fractionation, target delineation, and response assessment. This is particularly important in challenging scenarios where a paucity of evidence exists, such as in patients with a solitary kidney, bulky tumors, or tumor thrombus. The Radiosurgery Society endorses this case-based guide to provide a practical framework for delivering SBRT to primary RCC, exemplified by 3 cases. This article explores topics of tumor size and dose fractionation, impact on renal function and treatment in the setting of a solitary kidney, and radiation's role in the management of inferior vena cava tumor thrombus. Additionally, we review existing evidence and expert opinion on target delineation, advanced techniques such as magnetic resonance imaging guided SBRT, and SBRT response assessment.
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BACKGROUND AND OBJECTIVE: Renal function preservation is particularly important following nonoperative treatment of localized renal cell carcinoma (RCC) since patients are often older with medical comorbidities. Our objective was to report long-term renal function outcomes after stereotactic ablative radiotherapy (SABR) including patients with a solitary kidney. METHODS: Patients with primary RCC treated with SABR with ≥2 yr of follow-up at 12 International Radiosurgery Consortium for Kidney institutions were included. Renal function was measured by estimated glomerular filtration rate (eGFR). KEY FINDINGS AND LIMITATIONS: In total, 190 patients (56 with a solitary kidney) underwent SABR and were followed for a median of 5.0 yr (interquartile range [IQR]: 3.4-6.8). In patients with a solitary kidney versus bilateral kidneys, pre-SABR eGFR (mean [standard deviation]) was 61.1 (23.2) versus 58.0 (22.3) ml/min (p = 0.32) and the median tumor size was 3.65 cm (IQR: 2.59-4.50 cm) versus 4.00 cm (IQR: 3.00-5.00 cm; p = 0.026). At 5 yr after SABR, eGFR decreased by -14.5 (7.6) and -13.3 (15.9) ml/min (p = 0.67), respectively, and there were similar rates of post-SABR dialysis (3.6% [n = 2/56] vs 3.7% [n = 5/134]). A multivariable analysis demonstrated that increasing tumor size (odds ratio [OR] per 1 cm: 1.57; 95% confidence interval [CI]: 1.14-2.16, p = 0.0055) and baseline eGFR (OR per 10 ml/min: 1.30; 95% CI: 1.02-1.66, p = 0.034) were associated with an eGFR decline of ≥15 ml/min at 1 yr. CONCLUSIONS AND CLINICAL IMPLICATIONS: With long-term follow-up after SABR, kidney function decline remains moderate, with no observed difference between patients with a solitary kidney and bilateral kidneys. Tumor size and baseline eGFR are dominant factors predictive of long-term renal function decline. PATIENT SUMMARY: With long-term follow-up, stereotactic ablative radiotherapy (SABR) yields moderate long-term renal function decline and low dialysis rates even in patients with a solitary kidney. SABR thus represents a promising noninvasive, nephron-sparing option for patients with localized renal cell carcinoma.
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BACKGROUND AND OBJECTIVE: The extent of prostate cancer found on biopsy, as well as prostate cancer grade and genomic tests, can affect clinical decision-making. The impact of these factors on the initial management approach and subsequent patient outcomes for men with favorable-grade prostate cancer has not yet been determined on a population level. Our objective was to explore the association of Decipher 22-gene genomic classifier (GC) biopsy testing on the initial use of conservative management versus radical prostatectomy (RP) and to determine the independent effect of GC scores on RP pathologic outcomes. METHODS: A total of 87 140 patients diagnosed with grade group 1 and 2 prostate cancer between 2016 and 2018 from the Surveillance, Epidemiology, and End Results registry data were linked to GC testing results (2576 tested and 84 564 untested with a GC). The primary endpoints of interest were receipt of conservative management or RP, pathologic upgrading (pathologic grade group 3-5), upstaging (pathologic ≥T3b), and adverse pathologic features (pathologic upgrading, upstaging, or lymph node invasion). Multivariable logistic regressions quantified the association of variables with outcomes of interest. KEY FINDINGS AND LIMITATIONS: GC tested patients were more likely to have grade group 2 on biopsy (51% vs 46%, p < 0.001) and lower prostate-specific antigen (6.1 vs 6.3, p = 0.016). Conservative management increased from 37% to 39% and from 22% to 24% during 2016-2018 for the GC tested and untested populations, respectively. GC testing was significantly associated with increased odds of conservative management (odds ratio [OR] 2.1, 95% confidence interval [CI] 1.9-2.4, p < 0.001). The distribution of biopsy GC risk was as follows: 45% low risk, 30% intermediate risk, and 25% high risk. In adjusted analyses, higher GC (per 0.1 increment) scores (OR 1.24, 95% CI 1.17-1.31, p < 0.001) and percent positive cores (1.07, 95% CI 1.02-1.12, p = 0.009) were significantly associated with the receipt of RP. A higher GC score was significantly associated with all adverse outcomes (pathologic upgrading [OR 1.29, 95% CI 1.12-1.49, p < 0.001], upstaging [OR 1.31, 95% CI 1.05-1.62, p = 0.020], and adverse pathology [OR 1.27, 95% CI 1.12-1.45, p < 0.001]). Limitations include observational biases associated with the retrospective study design. CONCLUSIONS AND CLINICAL IMPLICATIONS: Men who underwent GC testing were more likely to undergo conservative management. GC testing at biopsy is prognostic of adverse pathologic outcomes in a large population-based registry. PATIENT SUMMARY: In this population analysis of men with favorable-risk prostate cancer, those who underwent genomic testing at biopsy were more likely to undergo conservative management. Of men who initially underwent radical prostatectomy, higher genomic risk but not tumor volume was associated with adverse pathologic outcomes. The use of genomic testing at prostate biopsy improves risk stratification and may better inform treatment decisions than the use of tumor volume alone.
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Recognizing sexual orientation and gender identity (SOGI) is paramount in the management of genitourinary cancers, as sexual and gender minority (SGM) individuals encounter unique healthcare challenges leading to disparities. SGM patients often confront systemic barriers, provider biases, and scarcity of tailored resources, resulting in diminished satisfaction and adverse health outcomes. The evaluation and treatment of genitourinary cancers in SGM patients demand a nuanced, multidisciplinary approach that focuses on the unique health determinants often overlooked by the healthcare system. This review highlights recommendations for the inclusivity of SGM patients within the clinic, from inclusive signage to gender inclusive language. For the evaluation and treatment of SGM patients with genitourinary cancers, it is recommended to employ organ-based language, to utilize validated questionnaires encompassing mental health, sexual behavior, and patient-reported outcomes, and to provide timely referrals to social work and onco-fertility when appropriate. Ultimately, approaching inclusivity through education targeted at both SGM patients and healthcare providers is pivotal for centering care around the patient, improving the quality of life and outcomes for SGM patients facing genitourinary cancers.
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The purpose of this European Society for Radiotherapy and Oncology (ESTRO) project, endorsed by the European Association of Urology, is to explore expert opinion on the management of patients with oligometastatic and oligoprogressive renal cell carcinoma by means of stereotactic ablative radiotherapy (SABR) on extracranial metastases, with the aim of developing consensus recommendations for patient selection, treatment doses, and concurrent systemic therapy. A questionnaire on SABR in oligometastatic renal cell carcinoma was prepared by a core group and reviewed by a panel of ten prominent experts in the field. The Delphi consensus methodology was applied, sending three rounds of questionnaires to clinicians identified as key opinion leaders in the field. At the end of the third round, participants were able to find consensus on eight of the 37 questions. Specifically, panellists agreed to apply no restrictions regarding age (25 [100%) of 25) and primary renal cell carcinoma histology (23 [92%] of 25) for SABR candidates, on the upper threshold of three lesions to offer ablative treatment in patients with oligoprogression, and on the concomitant administration of immune checkpoint inhibitor. SABR was indicated as the treatment modality of choice for renal cell carcinoma bone oligometatasis (20 [80%] of 25) and for adrenal oligometastases 22 (88%). No consensus or major agreement was reached regarding the appropriate schedule, but the majority of the poll (54%-58%) retained the every-other-day schedule as the optimal choice for all the investigated sites. The current ESTRO Delphi consensus might provide useful direction for the application of SABR in oligometastatic renal cell carcinoma and highlight the key areas of ongoing debate, perhaps directing future research efforts to close knowledge gaps.
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Carcinoma, Renal Cell , Consensus , Delphi Technique , Kidney Neoplasms , Radiosurgery , Humans , Male , Carcinoma, Renal Cell/radiotherapy , Carcinoma, Renal Cell/secondary , Carcinoma, Renal Cell/pathology , Disease Progression , Europe , Kidney Neoplasms/pathology , Kidney Neoplasms/radiotherapy , Neoplasm Metastasis , Radiosurgery/standards , Urology/standardsABSTRACT
Knowledge related to how oncology treatment trial design influences enrollment of racial and ethnic minorities is limited. Rigorous identification of clinical trial design parameters that associate favorably with minority accrual provides educational opportunities for individuals interested in designing more representative treatment trials. We identified oncology trials with a minimum of 10 patients at an NCI-Designated Comprehensive Cancer Center from 2010 to 2021. We defined a study endpoint of racial and ethnic minority accrual greater than zero. Multivariable logistic regression was used to determine whether co-variables predicted our study endpoint. P-values of less than 0.05 were considered significant. A total of 352 cancer trials met eligibility criteria. These studies enrolled a total of 7981 patients with a total of 926 racial and ethnic minorities leading to a median enrollment of 10%. Trials open in community sites (yes versus no) were more likely to have a minority patient (OR, 2.21; 95% CI, 1.02-4.96) as well as pilot/phase I studies compared to phase II/III (OR, 3.19; 95% CI, 1.34-8.26). Trials incorporating immunotherapy (yes versus no) were less likely to have a minority patient (OR, 0.47; 95% CI, 0.23-0.94). Trials open in community sites as well as early phase treatment studies were more likely to accrue minority patients. However, studies including immunotherapy were less likely to accrue racial and ethnic minorities. Knowledge gained from our analysis may help individuals design oncology treatment trials that are representative of more diverse populations.
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BACKGROUND: In this study, we provide the largest analysis to date of a US-based cancer cohort to characterize death from COVID-19. METHODS: A total of 4â020â669 patients across 15 subtypes living with cancer in 2020 and included in the National Cancer Institute's Surveillance, Epidemiology, and End Results database were abstracted. We investigated prognostic factors for death due to COVID-19 using a Cox proportional hazards model and calculated hazard ratios (HRs). Standardized mortality ratios were calculated using observed mortality counts from Surveillance, Epidemiology, and End Results and expected mortality based on US mortality rates. RESULTS: A total of 291â323 patients died, with 14â821 (5.1%) deaths attributed to COVID-19 infection. The COVID-19 disease-specific mortality rate was 11.81/10â000-persons years, and the standardized mortality ratio of COVID-19 was 2.30 (95% confidence interval [CI] = 2.26 to 2.34; P < .0001). COVID-19 ranked as the second leading cause of death following ischemic heart disease (5.2%) among 26 noncancer causes of death. Patients who are older (80 years and older vs 49 years and younger: HR = 21.47, 95% CI = 19.34 to 23.83), male (vs female: HR = 1.46, 95% CI = 1.40 to 1.51), unmarried (vs married: HR = 1.47, 95% CI = 1.42 to 1.53), and Hispanic or non-Hispanic African American (vs non-Hispanic White: HR = 2.04, 95% CI = 1.94 to 2.14 and HR = 2.03, 95% CI = 1.94 to 2.14, respectively) were at greatest risk of COVID-19 mortality. CONCLUSIONS: We observed that people living with cancer are at 2 times greater risk of dying from COVID-19 compared with the general US population. This work may be used by physicians and public health officials in the creation of survivorship programs that mitigate the risk of COVID-19 mortality.
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COVID-19 , Neoplasms , SARS-CoV-2 , SEER Program , Humans , COVID-19/mortality , COVID-19/epidemiology , Male , Female , Neoplasms/mortality , United States/epidemiology , Middle Aged , Aged , Aged, 80 and over , Adult , Risk Factors , Cause of Death , Proportional Hazards ModelsABSTRACT
Exercise oncology clinical trials contribute to the advancement of our scientific knowledge and to the safety and care of patients diagnosed with cancer. Nevertheless, regulatory reviewers and committees may not be familiar with the well-documented long-term health benefits and safety of the regular practice of physical activity. Moreover, they may not see how the benefits outweigh the risks in the context where patients diagnosed with cancer are typically seen as vulnerable. Therefore, we would like to provide a purpose-built overview of exercise oncology clinical trials for members involved in institutional review committees, including the Scientific Review Committee (SRC), the Institutional Review Board (IRB), and the Data Safety Monitoring Committee (DSMC) to facilitate a greater understanding of the safety and benefits of physical activity during cancer treatments. Communication is key to improve the success of exercise oncology clinical trials, which are vital for patients diagnosed with cancer.
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Ethics Committees, Research , Neoplasms , Humans , Medical Oncology , Neoplasms/therapy , Research Subjects , Clinical Trials as TopicABSTRACT
OBJECTIVE: To determine the prevalence and severity of SpaceOAR-related adverse events using the Manufacturer and User Facility Device Experience (MAUDE) database. METHODS: We analyzed SpaceOAR-related adverse event reports in the Manufacturer and User Facility Device Experience (MAUDE) database from January 2015 to May 2023. For each report, the event type, associated device and patient problems, event description, event timing, and event severity stratified by the Common Terminology Criteria for Adverse Events version 5.0 (CTCAE) grading system were recorded. RESULTS: From 2015 to 2022, 206,619 SpaceOAR devices were sold. From January 2015 to May 2023, we identified 981 reports describing 990 SpaceOAR-related adverse events. Malfunctions were the most common event type (N = 626), followed by patient injuries (N = 350) with few reported deaths (N = 5). Device positioning problems were the most frequent device issue (N = 686). Pain was the most reported patient problem (N = 216). Abscesses and fistulas related to the device were each reported in 91 events. A noteworthy portion of relevant adverse events occurred before the initiation of radiation (N = 35, 22.4%), suggesting the device, rather than the radiation, was responsible. In total, 470 (50.2%) and 344 (36.7%) of the adverse events were CTCAE grade 1 and 2, respectively. There were 123 (13.1%) events that were CTCAE grade ≥3. CONCLUSION: We identified multiple reports of SpaceOAR-related adverse events, many of which are more serious than have been reported in clinical trials. While SpaceOAR use is common, suggesting these events are rare, these data highlight the need for continued postmarket surveillance.
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Hydrogels , Prostatic Neoplasms , Humans , Prostatic Neoplasms/radiotherapy , Male , Hydrogels/adverse effects , Equipment Failure/statistics & numerical dataABSTRACT
Studying survivorship and causes of death in patients with advanced or metastatic cancer remains an important task. We characterize the causes of death among patients with metastatic cancer, across 13 cancer types and 25 non-cancer causes and predict the risk of death after diagnosis from the diagnosed cancer versus other causes (e.g., stroke, heart disease, etc.). Among 1,030,937 US (1992-2019) metastatic cancer survivors, 82.6% of patients (n = 688,529) died due to the diagnosed cancer, while 17.4% (n = 145,006) died of competing causes. Patients with lung, pancreas, esophagus, and stomach tumors are the most likely to die of their metastatic cancer, while those with prostate and breast cancer have the lowest likelihood. The median survival time among patients living with metastases is 10 months; our Fine and Gray competing risk model predicts 1 year survival with area under the receiver operating characteristic curve of 0.754 (95% CI [0.754, 0.754]). Leading non-cancer deaths are heart disease (32.4%), chronic obstructive and pulmonary disease (7.9%), cerebrovascular disease (6.1%), and infection (4.1%).
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Breast Neoplasms , Heart Diseases , Male , Humans , Cause of Death , Risk Factors , CausalityABSTRACT
BACKGROUND: Brain metastases (BM) affect clinical management and prognosis but limited resources exist to estimate BM risk in newly diagnosed cancer patients. Additionally, guidelines for brain MRI screening are limited. We aimed to develop and validate models to predict risk of BM at diagnosis for the most common cancer types that spread to the brain. METHODS: Breast cancer, melanoma, kidney cancer, colorectal cancer (CRC), small cell lung cancer (SCLC), and non-small cell lung cancer (NSCLC) data were extracted from the National Cancer Database to evaluate for the variables associated with the presence of BM at diagnosis. Multivariable logistic regression (LR) models were developed and performance was evaluated with Area Under the Receiver Operating Characteristic Curve (AUC) and random-split training and testing datasets. Nomograms and a Webtool were created for each cancer type. RESULTS: We identify 4,828,305 patients from 2010-2018 (2,095,339 breast cancer, 472,611 melanoma, 407,627 kidney cancer, 627,090 CRC, 164,864 SCLC, and 1,060,774 NSCLC). The proportion of patients with BM at diagnosis is 0.3%, 1.5%, 1.3%, 0.3%, 16.0%, and 10.3% for breast cancer, melanoma, kidney cancer, CRC, SCLC, and NSCLC, respectively. The average AUC over 100 random splitting for the LR models is 0.9534 for breast cancer, 0.9420 for melanoma, 0.8785 for CRC, 0.9054 for kidney cancer, 0.7759 for NSCLC, and 0.6180 for SCLC. CONCLUSIONS: We develop accurate models that predict the BM risk at diagnosis for multiple cancer types. The nomograms and Webtool may aid clinicians in considering brain MRI at the time of initial cancer diagnosis.
When patients are diagnosed with cancer, it is unknown which patients have a significant risk of cancer spread to the brain. Cancer spread to the brain is important to diagnose since it changes how patients are treated and affects their prognosis. This study used a large national database of patients diagnosed with cancer and studied the characteristics that were associated with cancer spread to the brain. The results can be used by doctors to assess the risk of cancer spread to the brain and determine which patients with cancer may benefit most from brain imaging.
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What are the factors that physicians could consider in an academic radiation oncology practice job offer? In this minireview, we discuss how prospective academic faculty could evaluate the "big 3" domains: (1) the compensation, including the direct and indirect payments; (2) the daily job, including aspects of the clinic, research, and education; and (3) the location, including geography, atmosphere, environment, and culture. If a prospective academic radiation oncologist believes that the academic practice is "great" in at least 2 of the 3 and "good" in the remaining 1, then they should likely sign the contract.
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Radiation Oncology , Radiation Oncology/education , Humans , Radiation Oncologists , Faculty, MedicalABSTRACT
PURPOSE: Pelvic radiation therapy may lead to decreased bone mineral density (BMD) and increased risk of fracture that could be of particular concern in patients with prostate cancer who also receive androgen deprivation therapy (ADT). We performed an exploratory analysis of a randomized, double-masked, placebo-controlled trial to determine whether exposure to prior pelvic external beam radiation therapy (XRT) affects BMD and risk of fracture in patients with prostate cancer treated with ADT. METHODS AND MATERIALS: Patients with nonmetastatic prostate cancer aged ≥70 years or <70 years with low BMD (T-score < -1) or osteoporotic fracture who had been receiving ADT for ≥12 months were randomly assigned to receive densoumab or placebo every 6 months for 3 years. BMD was measured at baseline and at months 1, 3, 6, 12, 24, and 36. We applied multivariable linear mixed-effects models with an interaction term between the treatment arm and exposure to prior pelvic XRT to evaluate differential XRT effect on percent BMD change between the 2 treatment arms. RESULTS: Among 1407 eligible patients, 31% (n = 447) received prior pelvic XRT. There was no significant difference in any clinical fractures among patients with (5.8%, 26 of 447) or without (5.2%, 50 of 960) prior pelvic XRT (P = .42). Prior pelvic XRT was associated with a significant (0.54%) improvement in BMD (95% CI, 0.05-1.02) in the placebo group and a nonsignificant (0.04%) decline in BMD (95% CI, -0.47 to -0.35) in the denosumab group (interaction P = .007). There was no significant difference in pelvic XRT effect on percent BMD change in the lumbar spine (P = .65) or total hip (P = .39) between the 2 treatment groups. CONCLUSIONS: We did not find sufficient evidence to suggest any detrimental effect of pelvic XRT on the treatment effect from denosumab on percent BMD change, with only an approximately 5% incidence of clinical fractures.
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Bone Density Conservation Agents , Fractures, Bone , Prostatic Neoplasms , Male , Humans , Bone Density , Bone Density Conservation Agents/therapeutic use , Denosumab/pharmacology , Denosumab/therapeutic use , Androgen Antagonists/therapeutic use , Prostatic Neoplasms/pathology , Lumbar VertebraeABSTRACT
PURPOSE: Partial breast irradiation (PBI) and intraoperative radiation (IORT) represent alternatives to whole breast irradiation (WBI) following breast conserving surgery. However, data is mixed regarding outcomes. We therefore performed a pooled analysis of Kaplan-Meier-derived patient data from randomized trials to evaluate the hypothesis that PBI and IORT have comparable long-term rates of ipsilateral breast tumor recurrence as WBI. METHODS: In February, 2023, PubMed, EMBASE and Cochrane Central were systematically searched for randomized phase 3 trials of early-stage breast cancer patients undergoing breast-conserving surgery with PBI or IORT as compared to WBI. Time-to-event outcomes of interest included ipsilateral breast tumor recurrence (IBTR), overall survival (OS) and distant disease-free survival (DDFS). Statistical analysis was performed with R Statistical Software. RESULTS: Eleven randomized trials comprising 15,460 patients were included; 7,675 (49.6%) patients were treated with standard or moderately hypofractionated WBI, 5,413 (35%) with PBI and 2,372 (15.3%) with IORT. Median follow-up was 9 years. PBI demonstrated comparable IBTR risk compared with WBI (HR 1.20; 95% CI 0.95-1.52; p = 0.12) with no differences in OS (HR 1.02; 95% CI 0.90-1.16; p = 0.70) or DDFS (HR 1.15; 95% CI 0.81-1.64; p = 0.43). In contrast, patients treated with IORT had a higher IBTR risk (HR 1.46; 95% CI 1.23-1.72; p < 0.01) compared with WBI with no difference in OS (HR 0.98; 95% CI 0.84-1.14; p = 0.81) or DDFS (HR 0.91; 95% CI 0.76-1.09; p = 0.31). CONCLUSION: For patients with early-stage breast cancer following breast-conserving surgery, PBI demonstrated no difference in IBTR as compared to WBI while IORT was inferior to WBI with respect to IBTR.
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Brachytherapy , Breast Neoplasms , Mammary Neoplasms, Animal , Humans , Animals , Female , Breast Neoplasms/radiotherapy , Breast Neoplasms/surgery , Brachytherapy/methods , Neoplasm Recurrence, Local/pathology , Breast/pathology , Disease-Free Survival , Mastectomy, Segmental , Mammary Neoplasms, Animal/surgeryABSTRACT
Artificial intelligence (AI) applications have enabled remarkable advancements in healthcare delivery. These AI tools are often aimed to improve accuracy and efficiency of histopathology assessment and diagnostic imaging interpretation, risk stratification (i.e., prognostication), and prediction of therapeutic benefit for personalized treatment recommendations. To date, multiple AI algorithms have been explored for prostate cancer to address automation of clinical workflow, integration of data from multiple domains in the decision-making process, and the generation of diagnostic, prognostic, and predictive biomarkers. While many studies remain within the pre-clinical space or lack validation, the last few years have witnessed the emergence of robust AI-based biomarkers validated on thousands of patients, and the prospective deployment of clinically-integrated workflows for automated radiation therapy design. To advance the field forward, multi-institutional and multi-disciplinary collaborations are needed in order to prospectively implement interoperable and accountable AI technology routinely in clinic.
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Artificial Intelligence , Prostatic Neoplasms , Male , Humans , Prostatic Neoplasms/diagnosis , Prostatic Neoplasms/therapy , Prospective Studies , Algorithms , BiomarkersABSTRACT
Importance: Randomized clinical trials have demonstrated the noninferiority of shorter radiotherapy (RT) courses (termed hypofractionation) compared with longer RT courses in patients with localized prostate cancer. Although shorter courses are associated with cost-effectiveness, convenience, and expanded RT access, their adoption remains variable. Objective: To identify the current practice patterns of external beam RT for prostate cancer in the US. Design, Setting, and Participants: This cohort study obtained data from the National Cancer Database, which collects hospital registry data from more than 1500 accredited US facilities on approximately 72% of US patients with cancer. Patients were included in the sample if they had localized prostate adenocarcinoma that was diagnosed between 2004 and 2020 and underwent external beam RT with curative intent. Analyses were conducted between February and March 2023. Exposures: Radiotherapy schedules, which were categorized as ultrahypofractionation (≤7 fractions), moderate hypofractionation (20-30 fractions), and conventional fractionation (31-50 fractions). Main Outcomes and Measures: Longitudinal pattern in RT fractionation schedule was the primary outcome. Multivariable logistic regression was performed to evaluate the variables associated with shorter RT courses. Covariables included age, National Comprehensive Cancer Network risk group, rurality, race, facility location, facility type, median income, insurance type or status, and Charlson-Deyo Comorbidity Index. Results: A total of 313 062 patients with localized prostate cancer (mean [SD] age, 68.8 [7.7] years) were included in the analysis. There was a temporal pattern of decline in the proportion of patients who received conventional fractionation, from 76.0% in 2004 to 36.6% in 2020 (P for trend <.001). From 2004 to 2020, use of moderate hypofractionation increased from 22.0% to 45.0% (P for trend <.001), and use of ultrahypofractionation increased from 2.0% to 18.3% (P for trend <.001). By 2020, the most common RT schedule was ultrahypofractionation for patients in the low-risk group and moderate hypofractionation for patients in the intermediate-risk group. On multivariable analysis, treatment at a community cancer program (compared with academic or research program; odds ratio [OR], 0.54 [95% CI, 0.52-0.56]; P < .001), Medicaid insurance (compared with Medicare; OR, 1.49 [95% CI, 1.41-1.57]; P < .001), Black race (compared with White race; OR, 0.90 [95% CI, 0.87-0.92]; P < .001), and higher median income (compared with lower median income; OR, 1.28 [95% CI, 1.25-1.31]; P < .001) were associated with receipt of shorter courses of RT. Conclusions and Relevance: Results of this cohort study showed an increase in the use of shorter courses of RT for prostate cancer from 2004 to 2020; a number of social determinants of health appeared to be associated with reduced adoption of shorter treatment courses. Realignment of reimbursement models may be necessary to enable broader adoption of ultrahypofractionation to support technology acquisition costs.