Shielding evaluator actual treatment leaf: A program for automatic shielding assessment using patient data

Abstract

Purpose: In this paper, we propose shielding evaluator actual treatment leaf (SEATTLE), a program that evaluates radiation shielding and calculates the maximum number of treatable patients, using the Digital Imaging and Communications in Medicine Radiation Therapy (DICOM RT) plan files of the actual treated patients. Methods: MATLAB App Designer was used for GUI-based program development and DICOM RT plan file analysis. The intensity-modulated radiation therapy (IMRT) factor was calculated based on the monitor unit (MU) value obtained from the DICOM RT plan file; the use factor considering the MU for each gantry angle was obtained. For shielding calculation, the workload and dose were calculated using the formula based on the National Council on Radiation Protection and Measurements (NCRP)-151 report; the maximum number of treatable patients was calculated. For evaluation and validation of the program, an shielding evaluation was performed using anonymized patient data from seven treatment rooms at four institutions for one week of treatment. Results: The average IMRT factor calculated from patient data for the pilot institution was 3.0 +/- 0.9, confirming a difference of up to 58.8% compared to the currently used IMRT factor of 5; moreover, the use factor had a difference of up to 33.8% compared to the NCRP-151 value. The measurement data and shielding evaluation result of the transmitted dose at each point in the treatment rooms with SEATTLE showed an error of up to 0.01145 mSv/week. The program was designed with simple operation for user convenience; it was possible to evaluate shielding for the treatment room and the number of patients available for treatment. Conclusions: The program developed in this study performs shielding evaluation considering the clinical environment, and it will be possible to build a real-time shielding management system using actual patient data.