Patterns of utilization and clinical adoption of 0.35 Tesla MR-guided radiation therapy in the United States - Understanding the transition to adaptive, ultra-hypofractionated treatments.

Purpose/Objective: Magnetic resonance-guided radiation therapy (MRgRT) utilization is rapidly expanding worldwide, driven by advanced capabilities including continuous intrafraction visualization, automatic triggered beam delivery, and on-table adaptive replanning (oART). Our objective was to describe patterns of 0.35Tesla(T)-MRgRT (MRIdian) utilization in the United States (US) among early adopters of this novel technology. Materials/Methods: Anonymized administrative data from all US MRIdian treatment systems were extracted for patients completing treatment from 2014 to 2020. Detailed treatment information was available for all MRIdian linear accelerator (linac) systems and some cobalt systems. Results: Seventeen systems at 16 centers delivered 5736 courses and 36,389 fractions (fraction details unavailable for 1223 cobalt courses), of which 21.1% were adapted. Ultra-hypofractionation (UHfx) (1-5 fractions) was used in 70.3% of all courses. At least one adaptive fraction was used for 38.5% of courses (average 1.7 adapted fractions/course), with higher oART use in UHfx dose schedules (47.7% of courses, average 1.9 adapted fractions per course). The most commonly treated organ sites were pancreas (20.7%), liver (16.5%), prostate (12.5%), breast (11.5%), and lung (9.4%). Temporal trends show a compounded annual growth rate (CAGR) of 59.6% in treatment courses delivered, with a dramatic increase in use of UHfx to 84.9% of courses in 2020 and similar increase in use of oART to 51.0% of courses. Conclusions: This is the first comprehensive study reporting patterns of utilization among early adopters of MRIdian in the US. Intrafraction MR image-guidance, advanced motion management, and increasing adoption of adaptive radiation therapy has led to a substantial transition to ultra-hypofractionated regimens. 0.35 T-MRgRT has been predominantly used to treat abdominal and pelvic tumors with increasing use of on-table adaptive replanning, which represents a paradigm shift in radiation therapy.

Clinical adoption patterns of 0.35 Tesla MR-guided radiation therapy in Europe and Asia.

BACKGROUND: Magnetic resonance-guided radiotherapy (MRgRT) utilization is rapidly expanding, driven by advanced capabilities including better soft tissue imaging, continuous intrafraction target visualization, automatic triggered beam delivery, and the availability of on-table adaptive replanning. Our objective was to describe patterns of 0.35 Tesla (T)-MRgRT utilization in Europe and Asia among early adopters of this novel technology. METHODS: Anonymized administrative data from all 0.35T-MRgRT treatment systems in Europe and Asia were extracted for patients who completed treatment from 2015 to 2020. Detailed treatment information was analyzed for all MR-linear accelerators (linac) and -cobalt systems. RESULTS: From 2015 through the end of 2020, there were 5796 completed treatment courses delivered in 46,389 individual fractions. 23.5% of fractions were adapted. Ultra-hypofractionated (UHfx) dose schedules (1-5 fractions) were delivered for 63.5% of courses, with 57.8% of UHfx fractions adapted on-table. The most commonly treated tumor types were prostate (23.5%), liver (14.5%), lung (12.3%), pancreas (11.2%), and breast (8.0%), with increasing compound annual growth rates (CAGRs) in numbers of courses from 2015 through 2020 (pancreas: 157.1%; prostate: 120.9%; lung: 136.0%; liver: 134.2%). CONCLUSIONS: This is the first comprehensive study reporting patterns of utilization among early adopters of a 0.35T-MRgRT system in Europe and Asia. Intrafraction MR image-guidance, advanced motion management, and increasing adoption of on-table adaptive RT have accelerated a transition to UHfx regimens. MRgRT has been predominantly used to treat tumors in the upper abdomen, pelvis and lungs, and increasingly with adaptive replanning, which is a radical departure from legacy radiotherapy practices.

Time-Driven Activity-Based Costing of CT-Guided vs MR-Guided Prostate SBRT.

BACKGROUND AND PURPOSE: Stereotactic body radiation therapy (SBRT) has become a standard-of-care option for localized prostate cancer. While prostate SBRT has traditionally been delivered using computed-tomography-guided radiation therapy (CTgRT), MR-imaging-guided radiation therapy (MRgRT) is now available. MRgRT offers real-time soft-tissue visualization and ease of adaptive planning, obviating the need for fiducial markers, and potentially allowing for smaller planning target volume (PTV) margins. Although prior studies have focused on evaluating the cost-effectiveness of MRgRT vs CTgRT from a payor perspective, the difference in provider costs to deliver such treatments remains unknown. This study thus used time-driven activity-based costing (TDABC) to determine the difference in provider resources consumed by delivering prostate SBRT via MRgRT vs CTgRT. METHODS: Data was collected from a single academic institution where prostate SBRT is routinely performed using both CTgRT and MRgRT. Five-fraction SBRT (40 Gy total dose) was assumed to be delivered through volumetric-modulated arc therapy for CTgRT patients, and through step-and-shoot, fixed-gantry intensity-modulated radiation therapy for MRgRT patients. Process maps were constructed for each portion of the radiation delivery process via interviews/surveys with departmental personnel and by measuring CTgRT and MRgRT treatment times. Prior to simulation, only CTgRT patients underwent placement of three gold fiducial markers. Personnel capacity cost rates were calculated by dividing total personnel costs by the annual minutes worked by a given personnel. Equipment costs included both an annualized purchase price and annual maintenance costs. Ultimately, the total costs of care encompassing personnel, space/equipment, and materials were aggregated across the entire chain of care for both CTgRT and MRgRT patients in a base case. RESULTS: Direct costs associated with delivering a 5-fraction course of prostate SBRT were $1,497 higher with MRgRT than with CTgRT - comprised of personnel costs ($210 higher with MRgRT), space/equipment ($1,542 higher with MRgRT), and materials ($255 higher with CTgRT). Only CTgRT patients underwent fiducial placement, which accounted for $591. MRgRT patients were assumed to undergo both CT simulation (for electron density calculation) and MRI simulation, with the former accounting for $168. Mean time spent by patients in the treatment vault per fraction was 20 minutes (range 15-26 minutes) for CTgRT, and 31 minutes (range 30-34 minutes) for MRgRT. Patient time spent during fiducial placement (CTgRT only) was 60 minutes. Modifying the number of fractions treated would result in the cost difference of $1,497 (5 fractions) changing to $441 (1 fraction) or to $2,025 (7 fractions). CONCLUSION: This study provides an approximate comparison of the direct resources required for a radiation oncology provider to deliver prostate SBRT with CTgRT vs MRgRT. We await findings from the currently accruing phase III MIRAGE trial, which is comparing these modalities, and will subsequently measure acute and late genitourinary/gastrointestinal (GU/GI) toxicities, temporal change in quality-of-life outcomes, and 5-year biochemical, recurrence-free survival. Results from studies comparing the efficacy and safety of MRgRT vs CTgRT will ultimately allow us to put this cost difference into context.

Mortality and Costs Associated with Wearable Cardioverter-defibrillators after Acute Myocardial Infarction: A Retrospective Cohort Analysis of Medicare Claims Data.

Ventricular arrhythmias are common in the early period after myocardial infarction (MI), with the highest risk occurring in the immediate postinfarct window. The wearable cardioverter-defibrillator (WCD) has been proven to have efficacy in treating sudden cardiac arrest in patients soon after MI. However, data concerning clinical and health economic outcomes of WCD usage among Medicare patients have not been evaluated. The aim of this study was therefore to investigate the clinical and health economic impacts of WCD use among Medicare patients hospitalized for MI. A 5% sample of Medicare's Standard Analytical Files (2010-2012) was used to identify patients. Beneficiaries with an acute inpatient admission for acute MI were stratified by WCD presence and absence, respectively. Baseline clinical history, all-cause mortality, and the total cost of health-care expenditures over one year were collected. In total, 16,935 patients were included in the final analysis; of these, 89 were placed in the WCD group and 16,846 were placed in the non-WCD group. Overall, WCD patients were younger (70 versus 74 years of age; p < 0.001), more likely to be male (74.2% versus 57.4%; p = 0.002), and more likely to have congestive heart failure and/or ventricular arrhythmias prior to the indexed acute MI. At 30 days, the mortality rate in the WCD group (not reported due to volume < 11 Medicare beneficiaries) was lower in comparison with the non-WCD group (10.4%; p = 0.18). At one year, the adjusted mortality rates were 11.5% for the WCD group and 19.8% for the non-WCD group (hazard ratio: 0.46; p = 0.017). For the WCD group, the one-year incremental cost-effectiveness ratio was $12,373 per life-year gained. Among Medicare beneficiaries, WCD use after an acute MI was associated with better 30-day and one-year survival. Thus, our findings indicate that WCD use was cost-effective in the present sample of Medicare patients.

Clinical and economic outcomes after surgical aortic valve replacement in Medicare patients.

BACKGROUND: Aortic valve replacement (AVR) is the standard of care for patients with severe, symptomatic aortic stenosis who are suitable surgical candidates, benefiting both non-high-risk and high-risk patients. The purpose of this study was to report long-term medical resource use and costs for patients following AVR and validate our assumption that high-risk patients have worse outcomes and are more costly than non-high-risk patients in this population. METHODS: Patients with aortic stenosis who underwent AVR were identified in the 2003 Medicare 5% Standard Analytic Files and tracked over 5 years to measure clinical outcomes, medical resource use, and costs. An approximation to the logistic EuroSCORE (European System for Cardiac Operative Risk Evaluation) based on administrative data was used to assess surgical risk, with a computed logistic EuroSCORE > 20% considered high-risk. RESULTS: We identified 1474 patients with aortic stenosis who underwent AVR, of whom 1222 (82.9%) were non-high-risk and 252 (17.1%) were high-risk. Among those who were non-high-risk, the mean age was 73.3 years, 464 (38.2%) were women, and the mean logistic EuroSCORE was 7%, whereas in those who were high-risk, the mean age was 77.6 years, 134 (52.8%) were women, and the mean logistic EuroSCORE was 37%. All-cause mortality was 33.2% for non-high-risk and 66.7% for high-risk patients at 5 years. Over this time period, non-high-risk patients experienced an average of 3.9 inpatient hospitalizations and total costs of $106,277 per patient versus 4.7 hospitalizations and total costs of $144,183 for high-risk patients. CONCLUSION: Among elderly patients undergoing AVR, long-term mortality and costs are substantially greater for high-risk than for non-high-risk individuals. These findings indicate that further research is needed to understand whether newer approaches to aortic valve replacement such as transcatheter AVR may be a lower cost, clinically valuable alternative.

Five-year clinical and economic outcomes among patients with medically managed severe aortic stenosis: results from a Medicare claims analysis.

BACKGROUND: Patients with severe, symptomatic aortic stenosis, who do not undergo valve replacement surgery have a poor long-term prognosis. Limited data exist on the medical resource utilization and costs during the final stages of the disease. METHODS AND RESULTS: We used data from the 2003 Medicare 5% standard analytic files to identify patients with aortic stenosis and a recent hospitalization for heart failure, who did not undergo valve replacement surgery within the ensuing 2 calendar quarters. These patients (n=2150) were considered to have medically managed severe aortic stenosis and were tracked over 5 years to measure clinical outcomes, medical resource use, and costs (from the perspective of the Medicare Program). The mean age of the cohort was 82 years, 64% were female, and the estimated logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) (a measure of predicted mortality with cardiac surgery) was 17%. During 5 years of follow-up, overall mortality was 88.4% with a mean survival duration of 1.8 years. During this time period, patients experienced an average of 4.4 hospital admissions, 52% were admitted to skilled nursing care, and 28% were admitted to hospice care. The total 5-year costs were $63 844 per patient, whereas mean annual follow-up costs (excluding the index quarter) per year alive were $29 278. CONCLUSIONS: Elderly patients with severe aortic stenosis undergoing medical management have limited long-term survival and incur substantial costs to the Medicare Program. These results have important implications for policy makers interested in better understanding the cost-effectiveness of emerging treatment options such as transcatheter aortic valve replacement.

Rechargeable spinal cord stimulation versus non-rechargeable system for patients with failed back surgery syndrome: a cost-consequences analysis.

OBJECTIVES: Spinal cord stimulation (SCS) has been used for almost 40 years to treat refractory neuropathic pain after failed back surgery. Fully implantable non-rechargeable pulse generators have a battery life of between 2 and 5 years. A new SCS system with a rechargeable power source may last 10 to 25 years, or longer. The potential economic implications of longer battery life with a new SCS system has yet to be assessed. The study objective is to estimate the average difference in lifetime costs between rechargeable and non-rechargeable pulse generators used in treatment with SCS for failed back surgery syndrome. METHODS: A generalized state-transition probability framework was used to model costs. Input parameters for the base case analysis were obtained from several data sources including published literature, Medicare fee schedules, Medicare claims data, and expert opinion. RESULTS: A rechargeable SCS system is projected to require from 2.6 to 4.2 fewer battery generator replacements for battery depletion than a non-rechargeable SCS system. The total lifetime savings of a rechargeable system range from $104,000 to $168,833. In all of the one-way sensitivity analyses conducted, a rechargeable system saves money. Among all of the assumptions underlying the analysis, the annual cost after device removal contributes the most uncertainty. CONCLUSIONS: A rechargeable SCS system is projected to save up to $100,000 over a patient's lifetime. Fewer pulse generator replacements will also decrease patient discomfort and morbidity from procedural complications.

Cost effectiveness of paclitaxel-eluting stents for patients undergoing percutaneous coronary revascularization: results from the TAXUS-IV Trial.

OBJECTIVES: This study sought to compare aggregate medical care costs for patients undergoing percutaneous coronary intervention with paclitaxel-eluting stents (PES) and bare-metal stents (BMS) and to formally evaluate the incremental cost effectiveness of PES for patients undergoing single-vessel percutaneous coronary intervention. BACKGROUND: Although the cost effectiveness of SES has been studied in both clinical trials and decision-analytic models, few data exist on the cost effectiveness of alternative drug-eluting stent (DES) designs. In addition, no clinical trials have specifically examined the cost effectiveness of DES among patients managed without mandatory angiographic follow-up. METHODS: We performed a prospective economic evaluation among 1,314 patients undergoing percutaneous coronary revascularization randomized to either PES (N = 662) or BMS (N = 652) in the TAXUS-IV trial. Clinical outcomes, resource use, and costs (from a societal perspective) were assessed prospectively for all patients over a 1-year follow-up period. Cost effectiveness was defined as the incremental cost per target vessel revascularization (TVR) event avoided and was analyzed separately among cohorts assigned to mandatory angiographic follow-up (n = 732) or clinical follow-up alone (n = 582). RESULTS: The PES reduced TVR by 12.2 events per 100 patients treated, resulting in a 1-year cost difference of 572 dollars per patient with incremental cost-effectiveness ratios of 4,678 dollars per TVR avoided and 47,798 dollars/quality-adjusted life year (QALY) gained. Among patients assigned to clinical follow-up alone, the net 1-year cost difference was 97 dollars per patient with cost-effectiveness ratios of 760 dollars per TVR event avoided and $5,105/QALY gained. CONCLUSIONS: In the TAXUS-IV trial, treatment with PES led to substantial reductions in the need for repeat revascularization while increasing 1-year costs only modestly. The cost-effectiveness ratio for PES in the study population compares reasonably with that for other treatments that reduce coronary restenosis, including alternative drug-eluting stent platforms.

Clinical and economic effects of coronary restenosis after percutaneous coronary intervention in a managed care population.

PURPOSE: The epidemiology of coronary restenosis after percutaneous coronary intervention (PCI) has been documented extensively in clinical trials, but no data exist on the clinical and economic burden of restenosis in a managed care population. DESIGN: Retrospective cohort with a nationally representative managed care claims database (IHCIS, Waltham, Mass.) representing 2.8 million members. METHODOLOGY: Patients undergoing initial PCI between 1/1/00 and 12/31/00 (N=3,258) were identified and followed to 1 year. Clinical events, resource use, and costs between 1 month and 1 year after the initial PCI were identified. The clinical restenosis rate was estimated by multiplying the observed repeat revascularization rate by 0.85, based on previously published studies. All costs are reported from a managed care perspective in Year 2000 dollars. PRINCIPAL FINDINGS: Overall, 14.7 percent of patients required 1 or more repeat revascularization procedures between 1 month and 1 year after initial PCI, which implies an estimated clinical restenosis rate of 12.5 percent. Mean 1-year costs were nearly 6-fold higher among patients with and without repeat revascularization (dollars 31,954 +/- dollars 31,857 vs. dollars 5,474 +/- dollars 12,006, P<.001). After adjusting for baseline imbalances, the independent incremental cost for each patient with repeat revascularization was dollars 24,955 (95 percent confidence interval, dollars 23,401-dollars 26,510). Annual follow-up costs attributable to restenosis were dollars 3,118 per initial PCI recipient (i.e., dollars 24,955 x 12.5 percent). CONCLUSION: Clinical restenosis occurred in approximately 12.5 percent of real-world managed care PCI patients and increased health care costs by an average of dollars 3,118 per patient. These findings have important implications for the cost-effectiveness of new treatments that substantially reduce restenosis.

Changing treatment patterns for coronary artery revascularization in Canada: the projected impact of drug eluting stents.

BACKGROUND: To evaluate current treatment patterns for coronary artery revascularization in Canada and explore the potential impact of drug eluting stents (DES) on these treatment patterns. METHODS: Eleven cardiologists at multiple Canadian academic centers completed a questionnaire on coronary artery revascularization rates and treatment patterns. RESULTS: Participating physicians indicated slightly higher rates of PTCA, CABG, and stent implantation than reported in CCN publications. Participants estimated that 24% of all patients currently receiving bare metal stents (BMS) would receive DES in the first year following DES approval in Canada, although there was a large range of estimates around this value (5% to 65%). By the fifth year following DES approval, it was estimated that 85% of BMS patients would instead receive DES. Among diabetic patients, estimates ranged from 43% in the first year following approval to 91% in the fifth year. For all patients currently receiving CABG, mean use of DES instead was estimated at 12% in the first year to 42% at five years; rates among diabetic patients currently undergoing CABG were 17% in the first year to 49% in the fifth year. CONCLUSIONS: These results suggest a continued increase in revascularization procedures in Canada. Based on the panel's responses, it is likely that a trend away from CABG towards PTCA will continue in Canada, and will be augmented by the availability of DES as a treatment option. The availability of DES as a treatment option in Canada may change the threshold at which revascularization procedures are considered.

Clinical and economic outcomes of percutaneous coronary interventions in the elderly: an analysis of medicare claims data.

BACKGROUND: Outcomes after percutaneous coronary intervention (PCI) have been documented extensively in clinical trials and single-center series, but few data exist on the clinical and economic outcomes after PCI in an unselected population. METHODS AND RESULTS: We used the Medicare Standard Analytic File to identify all initial PCI procedures performed in 1998 among a random sample of 5% of all Medicare beneficiaries > or =65 years of age. These patients (n=9868) were followed up for 1 year after PCI to identify clinical outcomes, medical resource use, and costs. Between 1 month and 1 year after PCI, 16.9% of patients required > or =1 repeat revascularization procedures. Mean 1-year medical care costs increased 5-fold among patients with repeat revascularization compared with those without (26,186 dollars versus 5344 dollars; P<0.001). After adjustment for baseline differences, the independent cost of repeat revascularization was 19,074 dollars (95% CI, 18,440 to 19,707). Assuming from previous studies that 85% of repeat revascularization procedures over the first year of follow-up are attributable to restenosis, the estimated clinical restenosis rate was 14.4%, and the 1-year economic burden of restenosis to the healthcare system was 2747 dollars per initial PCI procedure. CONCLUSIONS: Among unselected elderly patients undergoing PCI, repeat revascularization occurs in approximately 14% and increases 1-year healthcare costs by >19,000 dollars per occurrence. These findings have important implications for the cost-effectiveness of new treatments that substantially reduce restenosis.

Drug-eluting stent task force: final report and recommendations of the working committees on cost-effectiveness/economics, access to care, and medicolegal issues.

Coronary artery disease remains a major health problem worldwide. Since introduction of percutaneous transluminal coronary angioplasty and stents, much progress has been made. Percutaneous coronary intervention, however, has been limited by restenosis (repeat obstruction of arteries that have been previously treated. Introduction of drug-eluting stents (DESs) in April 2003 was a major breakthrough in preventing restenosis. In March 2003, The Society for Cardiovascular Angiography and Interventions (SCAI) published a position statement on the clinical implications of DESs, recommending an evidence-based adoption strategy. Subsequently, in May 2003, SCAI formed a multidisciplinary Drug Eluting Stent (DES) Task Force to address the significant nonclinical ramifications posed by DESs: medicolegal, financial, and access to care. The Task Force included representatives from physician societies, industry, academia, the reimbursement community, and health policy organizations. The resultant report presents analyses, options, and recommendations regarding those nonclinical issues based on the collective experience and knowledge of the Task Force members. The Task Force trusts that this report will be of value to the diverse constituencies involved with introduction of this important new technology.

Mortality rates after subarachnoid hemorrhage: variations according to hospital case volume in 18 states.

OBJECT: The goal of this study was to determine whether a hospital's volume of subarachnoid hemorrhage (SAH) cases affects mortality rates in patients with SAH. For certain serious illnesses and surgical procedures, outcome has been associated with hospital case volume. Subarachnoid hemorrhage, usually resulting from a ruptured cerebral aneurysm, yields a high mortality rate. There has been no multistate study of a diverse set of hospitals to determine whether in-hospital mortality rates are influenced by hospital volume of SAH cases. METHODS: The authors conducted an analysis of a retrospective, administrative database of 16,399 hospitalizations for SAH (9290 admitted through emergency departments). These hospitalizations were from acute-care hospitals in 18 states representing 58% of the US population. Both univariate and multivariate analyses were used to assess the case volume-mortality rate relationship. The authors used patient age, sex, Medicaid status, hospital region, data source year, hospital case volume quartile, and a comorbidity index in multivariate generalized estimating equations to model the relationship between hospital volume and mortality rates after SAH. Patients with SAH who were treated in hospitals in which low volumes of patients with SAH are admitted through the emergency department had 1.4 times the odds of dying in the hospital (95% confidence interval 1.2-1.6) as patients admitted to high-volume hospitals after controlling for patient age, sex, Medicaid status, hospital region, database year, and comorbid conditions. CONCLUSIONS: Patients with a diagnosis of SAH on their discharge records who initially presented through the emergency department of a hospital with a high volume of SAH cases had significantly lower mortality rates. Concentrating care for this disease in high-volume SAH treatment centers may improve overall survival.

A checklist for retrospective database studies--report of the ISPOR Task Force on Retrospective Databases.

INTRODUCTION: Health-related retrospective databases, in particular claims databases, continue to be an important data source for outcomes research. However, retrospective databases pose a series of methodological challenges, some of which are unique to this data source. METHODS: In an effort to assist decision makers in evaluating the quality of published studies that use health-related retrospective databases, a checklist was developed that focuses on issues that are unique to database studies or are particularly problematic in database research. This checklist was developed primarily for the commonly used medical claims or encounter-based databases but could potentially be used to assess retrospective studies that employ other types of databases, such as disease registries and national survey data. RESULTS: Written in the form of 27 questions, the checklist can be used to guide decision makers as they consider the database, the study methodology, and the study conclusions. Checklist questions cover a wide range of issues, including relevance, reliability and validity, data linkages, eligibility determination, research design, treatment effects, sample selection, censoring, variable definitions, resource valuation, statistical analysis, generalizability, and data interpretation. CONCLUSIONS: For many of the questions, key references are provided as a resource for those who want to further examine a particular issue.