Dosimetric impacts of cone-beam computed tomography (CBCT)-based anatomic changes in intensity-modulated radiotherapy for cervical cancer

• Published in: Annals of translational medicine 2022-12, Vol.10 (24), p.1381-1381
• Main Authors: Yang, Han, Zhao, Xiujuan, He, Yang, Tan, Xia, Peng, Haiyan, Zhong, Mingsong, Li, Qicheng, Liu, Xianfeng, He, Yanan, Luo, Huanli, Jin, Fu
• Format: Article
• Language: English
• Subjects: Original
• ISSN: 2305-5839; 2305-5839
• DOI: 10.21037/atm-22-6157

To evaluate the effects of dose to tumors and organs at risk (OARs) on inter-fractional anatomic changes. We evaluated nine patients with cervical cancer treated with intensity-modulated radiotherapy (IMRT) (45 Gy in 25 fractions) using kV cone-beam computed tomography (CBCT) image guidance once or twice a week before treatment. For each patient, the original plan on the computed tomography (CT) image was copied to merged images, and then the fractional doses were calculated. Subsequently, deformable accumulated doses were obtained by summing the fractional absolute doses into a single dose in MIM Maestro software. The volume changes in the target and OARs were compared between the original CT and merged CBCT images, and the differences in the fractional and accumulated doses were also evaluated. Sixty-nine merged CBCT images were obtained and analyzed in this study. For the target areas, the volume changes in the clinical target volume (CTV) and planning target volume (PTV) reached -18.05% and -24.11% at most, respectively. The fractional D of the CTV and PTV was generally higher than the original plans, and the accumulated deviations were 2.27%±0.82% (P