Technical parameters and interpretive issues in screening computed tomography scans for lung cancer

Lung Cancer Screening, Version 3.2018, NCCN Clinical Practice Guidelines in Oncology

Lung cancer is the leading cause of cancer-related mortality in the United States and worldwide. Early detection of lung cancer is an important opportunity for decreasing mortality. Data support using low-dose computed tomography (LDCT) of the chest to screen select patients who are at high risk for lung cancer. Lung screening is covered under the Affordable Care Act for individuals with high-risk factors. The Centers for Medicare & Medicaid Services (CMS) covers annual screening LDCT for appropriate Medicare beneficiaries at high risk for lung cancer if they also receive counseling and participate in shared decision-making before screening. The complete version of the NCCN Guidelines for Lung Cancer Screening provides recommendations for initial and subsequent LDCT screening and provides more detail about LDCT screening. This manuscript focuses on identifying patients at high risk for lung cancer who are candidates for LDCT of the chest and on evaluating initial screening findings.

The 10 Pillars of Lung Cancer Screening: Rationale and Logistics of a Lung Cancer Screening Program

On the basis of the National Lung Screening Trial data released in 2011, the U.S. Preventive Services Task Force made lung cancer screening (LCS) with low-dose computed tomography (CT) a public health recommendation in 2013. The Centers for Medicare and Medicaid Services (CMS) currently reimburse LCS for asymptomatic individuals aged 55-77 years who have a tobacco smoking history of at least 30 pack-years and who are either currently smoking or had quit less than 15 years earlier. Commercial insurers reimburse the cost of LCS for individuals aged 55-80 years with the same smoking history. Effective care for the millions of Americans who qualify for LCS requires an organized step-wise approach. The 10-pillar model reflects the elements required to support a successful LCS program: eligibility, education, examination ordering, image acquisition, image review, communication, referral network, quality improvement, reimbursement, and research frontiers. Examination ordering can be coupled with decision support to ensure that only eligible individuals undergo LCS. Communication of results revolves around the Lung Imaging Reporting and Data System (Lung-RADS) from the American College of Radiology. Lung-RADS is a structured decision-oriented reporting system designed to minimize the rate of false-positive screening examination results. With nodule size and morphology as discriminators, Lung-RADS links nodule management pathways to the variety of nodules present on LCS CT studies. Tracking of patient outcomes is facilitated by a CMS-approved national registry maintained by the American College of Radiology. Online supplemental material is available for this article.

Radiation risks in lung cancer screening programs: a comparison with nuclear industry workers and atomic bomb survivors

The National Lung Cancer Screening Trial (NLST) demonstrated that screening with low-dose CT (LDCT) scan reduced lung cancer and overall mortality by 20% and 7%, respectively. The LDCT scanning involves an approximate 2-mSv dose, whereas full-chest CT scanning, the major diagnostic study used to follow up nodules, may involve a dose of 8 mSv. Radiation associated with CT scanning and other diagnostic studies to follow up nodules may present an independent risk of lung cancer. On the basis of the NLST, we estimated the incidence and prevalence of nodules detected in screening programs. We followed the Fleischner guidelines for follow-up of nodules to assess cumulative radiation exposure over 20- and 30-year periods. We then evaluated nuclear worker cohort studies and atomic bomb survivor studies to assess the risk of lung cancer from radiation associated with long-term lung cancer screening programs. The findings indicate that a 55-year-old lung screening participant may experience a cumulative radiation exposure of up to 280 mSv over a 20-year period and 420 mSv over 30 years. These exposures exceed those of nuclear workers and atomic bomb survivors. This assessment suggests that long-term (20-30 years) LDCT screening programs are associated with nontrivial cumulative radiation doses. Current lung cancer screening protocols, if conducted over 20- to 30-year periods, can independently increase the risk of lung cancer beyond cigarette smoking as a result of cumulative radiation exposure. Radiation exposures from LDCT screening and follow-up diagnostic procedures exceed lifetime radiation exposures among nuclear power workers and atomic bomb survivors.

Lung cancer screening: state of the art

Results from the National Lung Screening Trial have confirmed that lung cancer mortality is reduced using low-dose CT screening. Opening a lung cancer screening program requires a multidisciplinary approach. While the fundamental aspects of a screening program are similar, such as scheduling, performing, and managing follow-up, there are aspects of a lung cancer screening program that are unique. This article will discuss factors important in establishing a state of the art lung cancer screening program.