ABSTRACT
Objective To compare and observe the effect and side effect of two different kinds of simulation mode for nasopharyngeal carcinoma conventional radiotherapy. Methods 147 cases were randomly divided into the study group (74 cases, CT simulation) and the control group (73 cases, X-ray radiography simulation). In the study group three-dimensional treatment planning system (IPS) was used to draw target volume and organ at risk, and then beam eye view (BEV) function was utilized to design treatment plan and subsequent plan modulation. In the control group X-ray simulation radiography was used. Two groups of plan design and subsequent plan modulation mode were exactly the same, and the radiotherapy were performed on the same accelerator. Results For these two groups, there were 5-59 months follow-up. The recent therapeutic effect of nasopharyngeal carcinoma primary site and cervical lymph node metastasis was regular,and no statistical significance (P >0.05). For the study group 3-year local recurrence rate was 5.4 % (4/74) while the control group was 16.4 %(12/73), and there was obvious statistical significance between two groups. About one year and three year accumulated survival rate, the study group was 98.5 %, 77.4 %, and for the control group was 92.9 %, 64.7 %. Two groups survival curves were examined by Log-rank test: the survival curves showed statistical significance between two groups(P <0.05). In control group, stage II and III radiotheray reaction of oralis mucosa was significantly increased compared with that of the study group (P < 0.05). There were two cases radioactivity cerebral palsy and one case optic nerve damage in the control group, but no serious dermatosis, soft tissue fibrosis and radioactivity posterior cranial nerve damage. Conclusion The CT simulation which is applied to nasopharyngeal carcinoma conventional radiotheraphy could improve therapeutic effect and reduce cancer recurrence and radiation side effect.