PROMISE Trial: Substudy to Assess for Effective Dose of Radiation

描述(由申请人提供)： 每年，数以百万计的美国人出现提示冠心病(CAD)的胸痛，并经常接受非侵入性诊断测试，如心肌灌注闪烁成像(MPS)或最近的冠状动脉计算机断层血管成像(CCTA)。这种测试约占美国人口全部电离辐射负担的10%。这项有200个地点、10,000名患者参加的“用于评估胸痛的前瞻性多中心成像研究(PROMISE)”试验正在检验这样一种假设，即初始‘解剖学’(CCTA)测试策略在将主要不良心血管事件减少到常规护理的初期‘功能’压力测试策略(使用医生选择的负荷成像(MPS或超声心动图)或负荷心电图)中对有胸痛的中低危冠心病患者具有优势。然而，测试策略的全面比较不仅需要准确评估心血管事件，还需要将这些与每种策略的成本和风险进行权衡。这项辅助的“评估有效辐射剂量的Promise亚研究(Promise-SAFER)”的目的是比较初始解剖测试策略和功能测试策略在评估可疑冠心病方面的辐射负担。它的主要目的是确定与功能测试策略相比，解剖成像策略是否减少了对有症状患者的累积辐射剂量。虽然Promise将记录最初的CCTA和MPS检查的辐射负担的基本测量，但拟议的研究将开发一种更准确和更全面的方法，这是准确比较患者在不同检测策略下的累积辐射有效剂量所需的方法。这将包括跟踪后续的CAD评估测试和评估偶然发现(如肺结节)的测试，以及从每次后续测试中测量或推算患者特定剂量的估计，并使用大剂量登记的数据进行推算。此外，准确估计CCTA中的辐射有效剂量将需要确定当代CT扫描仪的新换算系数，这将使用物理拟人模型中的固态辐射探测器获得的测量结果来执行。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癌症发病率的预计累积寿命归因风险与测试策略，并表征心脏成像程序的辐射剂量的变异性，确定预测高剂量和重复测试的患者、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.