CAJ | 학술논문

目的研究EBT剂量胶片在临床电子线百分深度剂量(PDD)中的测量方法.方法采用14.7 cm×5.1 cm的矩形射野,在同一张EBT胶片上进行5阶梯度的剂量刻度.应用上述刻度方法,针对4、6、8、10、12和15 MeV电子线,在小水箱中采用竖直和倾斜5°两种方式测量PDD,并与半导体探头的三维水箱扫描结果以及平行板电离室在小水箱中测量结果进行比较和分析°结果当剂量胶片上端与水面平齐时,EBT测量的PDD曲线与两种探头测量的结果具有较好一致性,并且倾斜和竖直测量两种方式无明显差异.当剂量胶片上端伸出水面时,在竖自测量方式下剂量建成区内测量结果明显低于其他测量结果,而倾斜测量方式下则无明显影响.结论新的剂量刻度方式快捷可靠,可显著减少剂量胶片用量.在测量电子线PDD时建议将胶片倾斜一定角度进行,以便减小胶片上端与水面不平齐所引起的测量误差.
목적 연구EBT제량효편재림상전자선백분심도제량(PDD)중적측량방법.방법 채용14.7 cm×5.1 cm적구형사야,재동일장EBT효편상진행5계제도적제량각도.응용상술각도방법,침대4、6、8、10、12화15 MeV전자선,재소수상중채용수직화경사5°량충방식측량PDD,병여반도체탐두적삼유수상소묘결과이급평행판전리실재소수상중측량결과진행비교화분석°결과당제량효편상단여수면평제시,EBT측량적PDD곡선여량충탐두측량적결과구유교호일치성,병차경사화수직측량량충방식무명현차이.당제량효편상단신출수면시,재수자측량방식하제량건성구내측량결과명현저우기타측량결과,이경사측량방식하칙무명현영향.결론 신적제량각도방식쾌첩가고,가현저감소제량효편용량.재측량전자선PDD시건의장효편경사일정각도진행,이편감소효편상단여수면불평제소인기적측량오차.
Objective To evaluate the dosimetry of high-energy electron beams by using GafChromic EBT film. Methods The percent depth doses of electron beams of 4 MeV,6 MeV,8 MeV,10MeV, 12 MeV and 15 MeV were measured with EBT. The results were then compared with the measurements with diode detector in RFA and parallel plate chamber in water tank. Results The percent depth dose curves using EBT film had a good agreement with those using the other two detectors. Furthermore, no differences were found between up-right and tilt setup methods. When film upper edge is higher than water surface, a sharp drop of measurement results using EBT film was observed in comparison with those from diode detector in build-up region. Conclusions EBT film can be applied to measure percent depth doses of high-energy electron beams. During the EBT film measurements, the film should be tilted at the angle of 5degrees to the central axis of the field. When choosing up-right setup method, the edge of the film should be parallel to the water surface.