Introduction
The project rationale describes a potential improvement opportunity for lung cancer screening (LCS) programs related to radiation exposure as documented in peer-reviewed literature and national guideline documents (see References below). This information is presented to provide facility personnel with an overview of the Lung Cancer Screening Registry (LCSR) measures and the impact on patient care.
The radiation exposure measures can help facilities determine the extent to which higher radiation dose affects their LCS program so that performance improvement activities can be initiated as needed.
This information is a first step in completing a performance improvement project using the PDSA model and is intended to provide a step-wise understanding of radiation exposure to patients in your practice used during low-dose CT lung cancer screening examinations. The project is based on your data entered in the LCSR, including comparison to national data, and tailored to practices like yours.
Radiation Dose Measures
The table below itemizes the measures to consider for evaluating performance relative to achieving appropriate radiation dose for patients.
Measurement | Description |
Radiation exposure, Mean CTDIvol – overall mGy | Mean Volumetrics CT Dose Index (CTDIvol) across all screening exams performed |
| Mean Volumetrics CT Dose Index (CTDIvol) across all screening exams performed on underweight patients (BMI less than 18.5) |
| Mean Volumetrics CT Dose Index (CTDIvol) across all screening exams performed on healthy weight patients (BMI of 18.5 to 24.9) |
| Mean Volumetrics CT Dose Index (CTDIvol) across all screening exams performed on overweight patients (BMI 25 to 29.9) |
| Mean Volumetrics CT Dose Index (CTDIvol) across all screening exams performed on all obese patients |
| Mean Volumetrics CT Dose Index (CTDIvol) across all screening exams performed on all obese class 1 patients (BMI 30 to 34.9) |
| Mean Volumetrics CT Dose Index (CTDIvol) across all screening exams performed on all obese class 2 patients (BMI 35 to 39.9) |
| Mean Volumetrics CT Dose Index (CTDIvol) across all screening exams performed on all obese class 3 patients (BMI 40 and above) |
| Mean Volumetrics CT Dose Index (CTDIvol) across all low-dose screening exams performed |
| Mean Volumetrics CT Dose Index (CTDIvol) across all routine screening exams performed |
Project Rationale: Why is the Measure Important in Clinical Practice?
LCS CT examinations are performed with low-dose technique. This is important, as patients undergoing screening starting as young as age 50 are eligible to be screened through 80 years of age annually according to the latest USPSTF guidelines. They may additionally undergo low-dose nodule CTs for the evaluation of positive screen-detected abnormalities between annual screens. One of the concerns raised with the rollout of lung cancer screening nationally is the ability of radiology imaging facilities to perform appropriate low-dose chest CT, which means both low-dose, and low-dose appropriate to a patient’s size. In other words, As Low As Reasonably Achievable (ALARA principle) for the detection task at hand.
References
Peng R, Mardakhaev E, Shmukler A, et al. Meeting ACR dose guidelines for CT lung cancer screening in an overweight and obese population. Acad Radiol. 2021;28(3):381-386. doi: 10.1016/j.acra.2020.02.009
Kazerooni EA, Austin JHM, Black WC, et al. ACR–STR practice parameter for the performance and reporting of lung cancer screening thoracic computed tomography (CT). Available at: https://www.acr.org/-/media/ACR/Files/Practice-Parameters/CT-LungCaScr.pdf. American College of Radiology. Updated 2019. Accessed October 25, 2022.
USPSTF Lung cancer screening recommendation statement. Available at: https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/lung-cancer-screening.
US Preventative Services Task Force. Updated March 2021. Accessed October 25, 2022.
Lung CT Screening Reporting & Data System (Lung-RADS) version 1.1. Available at: https://www.acr.org/Clinical-Resources/Reporting-and-Data-Systems/Lung-Rads. American College of Radiology. Updated 2019. Accessed October 25, 2022.