PROMISE Trial: Substudy to Assess for Effective Dose of Radiation

描述（由申请人提供）： 每年有数百万美国人出现提示冠状动脉疾病（CAD）的胸痛，并经常接受非侵入性诊断测试，如心肌灌注断层扫描（MPS）或最近的冠状动脉计算机断层扫描血管造影（CCTA）。这种测试占美国人口全部电离辐射负担的约10%。200个站点，10个，000例患者的“胸痛评价前瞻性多中心影像学研究（PROMISE）”试验正在检验以下假设：初始“解剖”（CCTA）测试策略在减少主要不良心血管事件方面上级初始“功能”负荷测试策略的常规治疗（使用医生选择的负荷成像（MPS或超声心动图）或负荷心电图））。然而，测试策略的全面比较不仅需要准确评估心血管事件，还需要对每种策略的成本和风险进行权衡。该辅助“评估有效辐射剂量的PROMISE子研究（PROMISE-SAFER）”的目的是比较初始解剖与功能测试策略的辐射负荷，以评价疑似CAD。其主要目的是确定与功能测试策略相比，解剖成像策略是否降低了有症状患者的累积辐射剂量。虽然PROMISE将记录初始CCTA和MPS检查的辐射负荷的基本测量值，但拟议的研究将开发一种更准确和全面的方法，以准确比较不同测试策略之间患者的累积辐射有效剂量。这将包括跟踪CAD评价的后续试验和评价偶然发现（如肺结节）的试验，以及每次随访试验的测量或插补患者特定剂量测定估计值，使用大剂量登记研究的数据进行插补。此外，准确估计CCTA中的辐射有效剂量将需要确定当代CT扫描仪的新转换因子，该转换因子将使用在物理拟人幻影中使用固态辐射探测器获得的测量值来执行。其他目的是比较使用美国国家科学院开发的放射流行病学模型确定的不同检测策略之间的癌症发病率的预计累积寿命归因风险，并描述心脏成像程序辐射剂量的变异性，确定预测高剂量和重复检测的患者、策略、部位和区域因素。

DESCRIPTION (provided by applicant): Millions of Americans develop chest pain suggestive of coronary artery disease (CAD) each year and often receive non-invasive diagnostic testing such as myocardial perfusion scintigraphy (MPS) or, more recently, coronary computed tomographic angiography (CCTA). Such testing accounts for ~10% of the entire ionizing radiation burden to the U.S. population. The 200-site, 10,000 patient "PROspective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE)" Trial is testing the hypothesis that an initial 'anatomic' (CCTA) testing strategy is superior in reducing major adverse cardiovascular events to usual care with an initial 'functional' stress testing strategy (using physician-selected stress imaging (MPS or echocardiography) or stress electrocardiography)) in low-intermediate CAD risk patients with chest pain. However, comprehensive comparison of testing strategies requires accurate assessment not just of cardiovascular events, but also weighting these against costs and risks for each strategy. The objective of this ancillary "PROMISE Substudy to Assess For Effective dose of Radiation (PROMISE-SAFER)" is to compare the radiation burden of initial anatomic vs. functional testing strategies for the evaluation of suspected CAD. Its primary aim is to determine whether cumulative radiation dose to symptomatic patients is decreased with an anatomic imaging strategy as compared to a functional testing strategy. While PROMISE will record basic measures of radiation burden from initial CCTA and MPS exams, the proposed study will develop a more accurate and comprehensive approach that is needed to accurately compare patients' cumulative radiation effective doses between testing strategies. This will include tracking subsequent tests for CAD evaluation and tests to evaluate incidental findings such as pulmonary nodules, and measured or imputed patient-specific dosimetry estimates from each follow-up test, with imputation performed using data from a large dose registry. Moreover, accurate estimation of radiation effective dose in CCTA will require determination of new conversion factors for contemporary CT scanners, to be performed using measurements obtained using solid-state radiation detectors in physical anthropomorphic phantoms. Additional aims are to compare projected cumulative lifetime attributable risk of cancer incidence, as determined using radioepidemiological models developed by the National Academies, between testing strategies, and to characterize the variability of radiation doses of cardiac imaging procedures, identifying patient, strategy, site, and regional factors predictive of high dose and repeated testing.