Choonsik Lee1, Michael J Flynn2, Phillip F Judy3, Dianna D Cody4, Wesley E Bolch5, Randell L Kruger6. 1. 1 Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr, Rm 7E448, MSC 9778, Rockville, MD 20850. 2. 2 Department of Radiology, Henry Ford Health System, Detroit, MI. 3. 3 Department of Radiology, Brigham and Women's Hospital, Boston, MA. 4. 4 Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, TX. 5. 5 J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL. 6. 6 System Radiology, Marshfield Clinic Health System, Marshfield, WI.
Abstract
OBJECTIVE: We calculated body size-specific organ and effective doses for 23,734 participants in the National Lung Screening Trial (NLST) using a CT dose calculator. MATERIALS AND METHODS: We collected participant-specific technical parameters of 23,734 participants who underwent CT in the clinical trial. For each participant, we calculated two sets of organ doses using two methods. First, we computed body size-specific organ and effective doses using the National Cancer Institute CT (NCICT) dosimetry program, which is based on dose coefficients derived from a library of body size-dependent adult male and female computational phantoms. We then recalculated organ and effective doses using dose coefficients from reference size phantoms for all examinations to investigate potential errors caused by the lack of body size consideration in the dose calculations. RESULTS: The underweight participants (body mass index [BMI; weight in kilograms divided by the square of height in meters] < 18.5) received 1.3-fold greater lung dose (median, 4.93 mGy) than the obese participants (BMI > 30) (3.90 mGy). Thyroid doses were approximately 1.3- to 1.6-fold greater than the lung doses (6.3-6.5 mGy). The reference phantom-based dose calculation underestimates the body size-specific lung dose by up to 50% for the underweight participants and overestimates that value by up to 200% for the overweight participants. The median effective dose ranges from 2.01 mSv in obese participants to 2.80 mSv in underweight participants. CONCLUSION: Body size-specific organ and effective doses were computed for 23,734 NLST participants who underwent low-dose CT screening. The use of reference size phantoms can lead to significant errors in organ dose estimates when body size is not considered in the dose assessment.
RCT Entities:
OBJECTIVE: We calculated body size-specific organ and effective doses for 23,734 participants in the National Lung Screening Trial (NLST) using a CT dose calculator. MATERIALS AND METHODS: We collected participant-specific technical parameters of 23,734 participants who underwent CT in the clinical trial. For each participant, we calculated two sets of organ doses using two methods. First, we computed body size-specific organ and effective doses using the National Cancer Institute CT (NCICT) dosimetry program, which is based on dose coefficients derived from a library of body size-dependent adult male and female computational phantoms. We then recalculated organ and effective doses using dose coefficients from reference size phantoms for all examinations to investigate potential errors caused by the lack of body size consideration in the dose calculations. RESULTS: The underweight participants (body mass index [BMI; weight in kilograms divided by the square of height in meters] < 18.5) received 1.3-fold greater lung dose (median, 4.93 mGy) than the obeseparticipants (BMI > 30) (3.90 mGy). Thyroid doses were approximately 1.3- to 1.6-fold greater than the lung doses (6.3-6.5 mGy). The reference phantom-based dose calculation underestimates the body size-specific lung dose by up to 50% for the underweight participants and overestimates that value by up to 200% for the overweight participants. The median effective dose ranges from 2.01 mSv in obeseparticipants to 2.80 mSv in underweight participants. CONCLUSION: Body size-specific organ and effective doses were computed for 23,734 NLST participants who underwent low-dose CT screening. The use of reference size phantoms can lead to significant errors in organ dose estimates when body size is not considered in the dose assessment.
Entities:
Keywords:
National Lung Screening Trial; body size; effective dose; low-dose CT; organ dose
Authors: Sebastian Tschauner; Robert Marterer; Eszter Nagy; Georg Apfaltrer; Michael Riccabona; Georg Singer; Georg Stücklschweiger; Helmuth Guss; Erich Sorantin Journal: PLoS One Date: 2017-06-01 Impact factor: 3.240
Authors: Sebastian Tschauner; Robert Marterer; Eszter Nagy; Georg Singer; Michael Riccabona; Erich Sorantin Journal: Skeletal Radiol Date: 2020-06-14 Impact factor: 2.199