Effects of different postures on three dimensional conformal therapy for head and neck tumors

Abstract

Objective To investigate the effect of different postures in three dimensional conformal therapy for head and neck tumors. Methods 40 patients with head and neck cancer were selected as the research subjects.All patients were randomly divided into observation group and control group, 20 cases in each group.The observation group for neck shoulder film fixed position, the control group was the first film fixed position each patient, radiotherapy 10 times.The display error condition of different position fixing of the two groups was compared. Results There was no significant difference in the error of the two groups in the X direction (P>0.05). The Y direction error, Z direction error of observation group were (0.12±0.12)mm, (0.10±0.11)mm, which were significantly lower than those of the control group[(0.23±0.19)mm, (0.19±0.15)mm] (t=2.189, 2.163, all P<0.05). Set-up repeatability errors in the Y axis, error more than 2mm in the observation group was 14 times, the error rate was 7%, which in the control group was 40 times, the error rate was 20%, the observation group was significantly smaller than the control group, the differences were statistically significant(χ2=29.286, 7.236, all P<0.05). Set-up repeatability error in the Z axis, error more than 2mm in the observation group was 12 times, the error rate was 6%, which in the control group was 34 times, the error rate was 17%, the observation group was significantly smaller than the control group, the differences were statistically significant(χ2=29.286, 5.944, all P<0.05). Conclusion For the patients with head and neck cancer who received three-dimensional conformal radiotherapy, the positioning accuracy and repeatability of the head and neck shoulder film position is better, has higher clinical value, it is worth to be popularized. Key words: Head and neck neoplasms; Radoitherapy, conformal; Position