Meeting ACR Dose Guidelines for CT Lung Cancer Screening in an Overweight and Obese Population.
Academic Article
Overview
abstract
RATIONALE AND OBJECTIVES: Lung cancer screening adoption coincides with a growing obesity epidemic. Maintaining high-quality imaging at low radiation dose is challenging in obesity. We investigate the feasibility of meeting American College of Radiology (ACR) dose guidelines for lung cancer screening in a predominantly overweight and obese population. MATERIALS AND METHODS: Radiation dose (Volumetric CT dose index [CTDIvol], dose-length product), and body mass index (BMI) were collected for baseline screening CTs December, 2012-December, 2017. Dose metrics were analyzed according to BMI classification (normal <25, overweight 25-29, obese ≥30 kg/m2), using k = 0.014 mSv/mGy*cm. Results were compared to ACR dose guidelines and mean national 2017 Lung Cancer Screening Registry dose metrics. Analysis used Kruskal-Wallis (SPSS, version 24.0.0, IBM corp, Armonk, NY). RESULTS: Study population comprised 1478 patients (49.2% [727] women: mean BMI 28.1 ± 6.5 kg/m2, 26.9% [397] normal weight, 35.9% [530] overweight, 37.2% [551] obese). ACR dose requirements were met for both genders in all BMI classifications. Dose metrics were higher in men than in women; median effective dose and CTDIvol were 1.39 (0.8-1.58) mSv and 2.78 (1.41-2.80) mGy in men versus 1.16 (0.71-1.43) mSv and 2.70 (1.4-2.78) mGy in women. There were significant differences in dose metrics between men and women in the same BMI classification and between BMI classifications (p < 0.001). Mean dose metrics in our program were considerably lower than 2017 national average- mean CTDIvol and effective dose 2.45 ± 1.14 mGy and 1.26 ± 0.59 mSv versus 3.24 mGy and 1.35 mSv, respectively for our program and nationally. Mean dose metrics were also lower in our obese patients versus obese patients nationally. CONCLUSION: ACR dose metrics for lung cancer screening were met and can be appropriately tailored in a predominantly overweight and obese population clinical program.
