ABSTRACT
BACKGROUND: It is recommended for each set of radiation data and algorithm that subtle deliberation is done regarding dose calculation accuracy. Knowing the errors in dose calculation for each treatment plan will result in an accurate estimate of the actual dose achieved by the tumor. OBJECTIVE: This study aims to evaluate the equivalent path length (EPL) and equivalent tissue air ratio (ETAR) algorithms in radiation dose calculation. MATERIAL AND METHODS: In this experimental study, the TEC-DOC 1583 guideline was used. Measurements and calculations were obtained for each algorithm at specific points in thorax CIRS phantom for 6 and 18 MVs and results were compared. RESULTS: In the EPL, calculations were in agreement with measurements for 27 points and differences between them ranged from 0.1% to 10.4% at 6 MV. The calculations were in agreement with measurements for 21 points and differences between them ranged from 0.4% to 13% at 18 MV. In ETAR, calculations were also in consistent with measurements for 21 points, and differences between them ranged from 0.1% to 9% at 6 MV. Moreover, for 18 MV, the calculations were in agreement with measurements for 17 points and differences between them ranged from 0% to 11%. CONCLUSION: For the EPL algorithm, more dose points were in consistent with acceptance criteria. The errors in the ETAR were 1% to 2% less than the EPL. The greatest calculation error occurs in low-density lung tissue with inhomogeneities or in high-density bone. Errors were larger in shallow depths. The error in higher energy was more than low energy beam.
ABSTRACT
INTRODUCTION: Operating rooms in hospitals are facilitated with different types of electronic systems, which produce electromagnetic waves. High intensities of magnetic waves may have harmful effects on biological environments. This study aims to evaluate the electromagnetic field intensity at different parts of operating rooms at the first stage and estimate the occupational exposure to operating room personnel at the next phase. MATERIALS AND METHODS: At this cross-sectional study, the magnetic field intensity was evaluated using teslameter at several parts of operating rooms, during operating procedures, while electrical instruments were working. Background electromagnetic field intensity was measured when all the electrical systems were idle. Statistical analysis was performed using SPSS software. The results were compared with ICNIRP standards. RESULTS: The maximum intensity of magnetic field was measured around high-voltage systems at the distance of 50 cm in the personnel's standing area at DCR and PCNL operating procedures were 5.9 and 5.6, respectively. The number of on-mode electrical systems was inconsistent with the intensity of electromagnetic fields at the standing area of operating room personnel's. The intensity of magnetic fields around high-voltage systems, which was about 46.75 mG at the distance of 10 cm, was the highest among measured electromagnetic fields. CONCLUSIONS: The highest magnetic field intensity measured in this study was related to high-voltage systems and is lower than advised intensity by ICNIRP for occupational exposure. Based on this study, it can be concluded that there are no considerable risks of electromagnetic exposure for operating room personnels.
