Comparative Study On Set-up Errors,the Efficacy And The Acute Radiation Toxicity With IGRT In Head And Neck Tumor

Purpose To investigate the optimal alignment methods for the treatment of head and neck tumor in IGRT.The clinical efficacy and complications of IGRT and IMRT were compared to improve the accuracy of registration,to improve the local control rate of tumor radiotherapy,to reduce the incidence of side effects,and to improve the quality of life of patients.Material and Methods Siemens CTVision system was used to treat 22 patients with head and neck tumor respectively.CT-ON-RAIL images received before every treatment fraction.Compare the difference of bone alignment,grey alignment and manual alignment.Results 1.Total of 114 sets of CT-ON-RAIL images were analyzed for 22 head and neck tumor.The results of manual alignment,bone alignment and grey alignment showed that the mean±standard deviation in the X-axis was 0.06±0.16 cm,0.07±0.17 cm,0.06±0.18 cm,the mean±standard deviation in the Y-axis was 0.05±0.23 cm,0.06±0.24 cm,0.05±0.25 cm and the mean±standard deviation in the Z-axis was-0.03±0.17 cm,-0.03±0.14 cm,0.04±0.19 cm.It is suggested that set-up error in the X-axis was the largest,followed by Y-axis and Z-axis.But there was no significant difference in the three alignment methods(P>0.05).2.The efficiency was 93.75% in IGRT group and 87.5% in IMRT group.Theefficiency of the difference was not statistically significant(P>0.05).3.The acute bone marrow suppression was no significant difference comparing IGRT group with the IMRT group(P>0.05),skin toxicity,gastrointestinal reaction and other recent toxicity was significantly lower(P <0.05).Conclusions 1.CT-ON-RAIL system can reduce the set-up error in IGRT of head and neck tumor.It is recommended that manual adjustment after bone alignment should be applied.2.IGRT of head and neck tumor with CT-ON-RAIL system can improve the curative effect,has the less side effects and is worth promoting in clinic.