The Therapeutic Effect Of Three-dimensional Conformal Radiation Therapy Combined With Conventional Radiotherapy For Nasopharyngeal Carcinoma

Objective:To observe the therapeutic effect of three-dimensional conformal radiation therapy (3DCRT) for nasopharyngeal carcinoma (NPC).Method:For78patients with untreated NPC, treated by radiation schedule in two phases. In the first phases, nasopharyngeal lesions and metastases of all patients were treated by three-dimensional conformal radiation therapy (3DCRT) with a fraction of2-5Gy daily,5day per weeks, total dose30Gy. The second phase T1N0or parts of T2N0patients were done by Conventional radiotherapy with total dose55Gy on two small lateral opposing fields+with total dose50Gy on neck on tangential field, adding a3cm block.Patients with lymph node metastasis were given55Gy on the dacio-neck field(After40Gy, two small lateral opposing fields were used to boost the primary tumor while the spinal cord shielded)+with total dose55Gy on lower neck on tangential field.The upper bound of designed therapeutic field was set to connect with lower bound of main therapeutic field.Results:Three months after treatment,the rate of CR、PR、SD、PD were38.5%、55.1%、5.1%、1.3%, Total effective rate (CR+PR) were93.6%. The1-year、2-year、3-year and5-year local-regional control rates were92.3%、88.5%、78.2%、70.5%. The1-year、2-year、3-year and5-year overall survival rate were96.2%、89.7%、83.3%、71.8%. Appearing early radiation response is well tolerated and not observed obviously mouth difficulties and cranial nerve damage.Conclusions:1. Clinical result of early-course three-dimensional conformal radiation therapy(3DCRT) for nasopharyngeal carcinoma (NPC) is good.2. In this study, early radiation response is mainly around1and2grade response, appearing early radiation response is well tolerated and not observed obviously mouth difficulties and cranial nerve damage. Three-dimensional conformal radiation therapy (3DCRT) for nasopharyngeal carcinoma (NPC) is safe.3.variate logistic regression analysis showed that gender,age, clinical stage, T stage, N stage, skull base invasion, cranial nerve invasion, nasal cavity invasion, cervical node metastasis, unilateral/bilaterat neck node metastasis, cervical node metastasis position, external beam diotherapy method and chemotherapy were ignificantly associated with the control rate of nasopharynx, tumor-free survival,and overall survival(P=0.000或<0.05).4.Multivariate logistic regression analysis showed that gender,age, clinical stage, T stage, unilateral/bilaterat neck node metastasis were independent influential factors of control rate of nasopharynx, tumor-free survival,and overall survival.5. Sugest that in clinic, if the conditions were allowable, should get clinicopathologic analysis to make more effective treatment.6. The problems of whether that patients with neck negative NPC should be trealed with whole neck or upper neck is in dispute in the academic field, needs to be intensively studied.