WE‐A‐218‐01: NCICT a Computer Program for Organ and Effective Dose Calculation for Pediatric and Adult Patients Undergoing Computed Tomography

Abstract

Purpose: To develop a computer program for users to conveniently assess organ and effective doses for patients undergoing computed tomography (CT) examinations by using patient‐ and scan‐specific parameters. Methods: A comprehensive organ and effective dose database previously published by the authors was employed in this study. A series of pediatric and adult hybrid computational phantoms representing the International Commission on Radiological Protection (ICRP) reference data was coupled with a reference CT scanner model within Monte Carlo transport code to establish a set of five dimensional dose matrix, D (33 organs, 6 age groups, 2 genders, 3 tube potentials, scan positions with 1 cm z‐resolution). A graphical user interface (GUI) was designed using Visual Basic computer language to obtain user input (patient age and gender, scanner manufacturer and models, head/body filter, pitch, tube potential, tube current, a single rotation time, and scan start and end position). The GUI was then coupled with the dose matrix and a dose calculation routine was written. Organ doses were compared with the values obtained from previous CT dosimetry tools. Results: A computer program, named NCICT, was developed using pre‐ calculated dose matrix. As a result, a total of 33 organ doses and two effective doses based on ICRP Publication 60 and 103 are displayed. Major organ doses were calculated for head, chest, and abdomen‐pelvis scans and compared with the values from CT‐Expo and CTDosimetry. The comparison revealed that use of phantoms with realistic anatomy is crucial to improved accuracy in CT organ dosimetry. Conclusion: NCICT, a user‐ friendly computer program for CT dose calculation was developed and validated. The program provides more realistic patient anatomy, higher age resolution, advanced skeleton dosimetry, and several convenient features compared to the previous tools. The NCICT is under beta testing and will be available for research purpose in the near future.