Impacts of ring applicator reconstruction uncertainties on radiation dose in patients with cervical cancer
Author(s): WANG Xianliang, YUAN Zuo, KANG Shengwei, LI Jie, XIAO Mingyong, LI Xiaolan, FENG Zuo, WANG Pei
Pages: 316-319
Year: 2017 Issue: 3
Journal: Chinese Journal of Radiation Oncology
Keyword: Applicator reconstruction; Cervical neoplasms/brachytherapy; Dosimetry;
Abstract: Objective To investigate the impacts of ring applicator ( Nucletron#090617 ) reconstruction uncertainties on the radiation dose of computed tomography?guided three?dimensional ( 3D) brachytherapy for cervical cancer. Methods Twenty patients with cervical cancer who completed radical treatment were enrolled as subjects. In a treatment planning system, dose distribution was simulated with reconstruction uncertainties of tandem applicator, ring applicator, and both tandem and ring applicators, respectively. Two directions of reconstruction uncertainties were towards the tip (+) and the connector end (-) of the applicator. Reconstruction uncertainties of ± 1 mm, ± 2 mm, and ± 3 mm were simulated. The D100 , D90 , and D50 for clinical target volume ( CTV) and D0.1cc , D1cc , and D2cc for the bladder, rectum, and small intestine were evaluated. The effects of applicator reconstruction uncertainties on radiation dose of 3D brachytherapy were analyzed. Results The tandem applicator had greater impacts on radiation dose than the ring applicator. The dose deviation due to applicator reconstruction uncertainties increased with the increase in volume for CTV parameters but decreased with the increase in volume for parameters of organs at risk. The impacts of applicator reconstruction uncertainties were greatest on the dose to the small intestine. The deviation due to 3 mm reconstruction uncertainty of tandem applicator, ring applicator, and both tandem and ring applicators was 090%, 162%, and 174% for D90 of CTV, 133%, 153%, and 178% for D2cc of the bladder, 089%, 185%, and 197% for D2cc of the rectum, and 086%, 304%, and 350% for D2cc of the small intestine, respectively. Conclusions Applicator reconstruction uncertainties have certain impacts on the radiation dose of 3D brachytherapy. In order to improve the accuracy of brachytherapy, comprehensive quality control is recommended for applicator reconstruction.
Pages: 316-319
Year: 2017 Issue: 3
Journal: Chinese Journal of Radiation Oncology
Keyword: Applicator reconstruction; Cervical neoplasms/brachytherapy; Dosimetry;
Abstract: Objective To investigate the impacts of ring applicator ( Nucletron#090617 ) reconstruction uncertainties on the radiation dose of computed tomography?guided three?dimensional ( 3D) brachytherapy for cervical cancer. Methods Twenty patients with cervical cancer who completed radical treatment were enrolled as subjects. In a treatment planning system, dose distribution was simulated with reconstruction uncertainties of tandem applicator, ring applicator, and both tandem and ring applicators, respectively. Two directions of reconstruction uncertainties were towards the tip (+) and the connector end (-) of the applicator. Reconstruction uncertainties of ± 1 mm, ± 2 mm, and ± 3 mm were simulated. The D100 , D90 , and D50 for clinical target volume ( CTV) and D0.1cc , D1cc , and D2cc for the bladder, rectum, and small intestine were evaluated. The effects of applicator reconstruction uncertainties on radiation dose of 3D brachytherapy were analyzed. Results The tandem applicator had greater impacts on radiation dose than the ring applicator. The dose deviation due to applicator reconstruction uncertainties increased with the increase in volume for CTV parameters but decreased with the increase in volume for parameters of organs at risk. The impacts of applicator reconstruction uncertainties were greatest on the dose to the small intestine. The deviation due to 3 mm reconstruction uncertainty of tandem applicator, ring applicator, and both tandem and ring applicators was 090%, 162%, and 174% for D90 of CTV, 133%, 153%, and 178% for D2cc of the bladder, 089%, 185%, and 197% for D2cc of the rectum, and 086%, 304%, and 350% for D2cc of the small intestine, respectively. Conclusions Applicator reconstruction uncertainties have certain impacts on the radiation dose of 3D brachytherapy. In order to improve the accuracy of brachytherapy, comprehensive quality control is recommended for applicator reconstruction.
Related Articles