The Correlation Of Primary Tumor Volume Of NPC With The Metastasis Of Cervical Lymph Nodes

[Objectives] To investigate the correlation beween primary tumor volume of NPC and the rate,size,distribution of metastatic cervical lymph nodes of NPC.[Methods] One hundred and twenty-eight patients received CT enhanced scanning, applying 3-dimensional Treatment Planning System(TPS)to calculate the volume of primary tumor of NPC and the diameter of metastatic cervical lymph nodes.[Results] 89 patients had lymph nodes metastasis in 128 patients with NPC. The rate of lymph nodes metastasis was 69.5%. When the primary tumor volume were≤20㎝~3,21～40㎝ ,41～60 3㎝ 3 ,>60㎝ 3 , the rate of lymph nodes metastasis were 47.4%,78.3%,84.0% and 73.3% (P=0.004). when the diameter of cervical lymph nodes was >2㎝the rate of cervical lymph nodes metastasis were 18.4%,63.0%,68.0% and 47.4%in different volume(P=0.000). Along with primary tumor volume increasing, levelⅢwas the more frequently involved area. Nodal distributional rate were 0 in levelⅠA,0% in leveⅥ.The rest levels(Ⅱ,Ⅳ,Ⅴ,retropharyngeal)were not positive correlation.[Conclusions] There was relative between the primary tumor volume of NPC and cervical Lymph nodes matastasiss. There was significant difference especially between PTV≤20㎝~3and PTV>20㎝~3.At present,this study has not been reported, hence, it will provide a new clue for the study of NPC metastasis and prognosis in future, moreover it has practical value of clinic appliance.