An analysis of setup errors in helical tomotherapy for esophageal cancer patients

• DOI: 10.3760/cma.j.issn.1004-4221.2017.04.013
• Publication Date: 2017-04-15
• Authors: Zhen-Li Wang; Xiaodong Sun; Yaowen Zhang; Ruifang Liu; Qingshan Zhu; Hongling Du; Baichao Huang
• Keywords: Tomotherapy

Objective To analyze setup errors and guide the calculation of margins from clinical target volume (CTV) planning (PTV) in esophageal cancer patients treated with tomotherapy by MVCT image-guided system.

Methods Sixty-four our hospital 2016 were randomly selected. images acquired after patients’ positioning co-registered KVCT images. The x, y, z translations roll rotation analyzed t-test or one-way ANOVA. Meanwhile, PTV margin was calculated based on formula M= 2.5∑+ 0.7δ.

Results According to formula, CTV-PTV y directions are slightly different between cancers located cervical, upper thoracic, middle lower thoracic segments. In cancer, average error y-axis when head-neck-shoulder thermoplastic film fixation used than somatic (P=0.000); z-axis fifth sixth weeks less those first several (P=0.036); three image registration patterns similar (x-axis P=0.868, P=0.491, P=0.169, P=0.985).

Conclusions In treatment large, but TOMO HD system can greatly reduce errors, ensuring accuracy each treatment. It is further recommended that practice, should be for treatments Patients advised use fixation.

Key words: Esophageal neoplasms/helical tomotherapy; Setup error; Tomography, X-ray computed, megavoltage