Effective dose evaluation for linac-integrated kV cone beam CT

VernacularTitle:加速器机载kV锥形束CT有效剂量的分析
Author: Na LU ; Linchun FENG ; Yunlai WANG ; Xiongfei LIAO ; Ruigang GE
Publication Type:Journal Article
Keywords: Cone beam CT; CT dose index; Dose length product; Effective dose
From: Chinese Journal of Radiological Medicine and Protection 2010;30(3):339-342
CountryChina
Language:Chinese
Abstract: Objective To evaluate the variations of effective doges with the preset scanning parameters from linac-integrated kV cone beam CT( CBCT). Methods Weighted CT dose index(CTDIW) were measured with PTW TM30009 CT ion chamber in head phantom and body phantom, respectively, for different combinations of tube voltage, mAs, collimator and gantry rotation range. Dose length products(DLP) were derived from CTDIW and effective doses(E) were calculated by the DLP and EDLP. Results CTDIW and effective dose had the quadratical relationship with tube voltage, depending linearly on product of tube current and exposure time. Effective dose had close relationship with the collimator and the gantry rotation range. Both the DLP and ED for CBCT were lower than the reference dose level recommended for conventional CT. Conclusions Effective dose from CBCT has a close relationship with the scanning parameters. Optimal imaging parameters should be chosen according to the patient's anatomy to reduce patient dose.