A Prospective Study On The Consistency Of CT And Pathology In Lung Adenocarcinoma Lymph Node Metastasis

Objective:Explore the consistency of CT and pathology in lung adenocarcinoma lymph nodemetastasis, offer the basis for delineating target area.Methods:Selected20lung adenocarcinoma patients who received complete resection withsystemic lymph node dissection in thoracic surgeon department of The SecondAffiliated Hospital of Dalian Medical University from sep1,2012to mar31,2013.9males and11females. Age:47-74years old, the median age is59years old.Video-assisted thoracoscopic radical resection for10patients,and radical operation for10patients. A total of20patients received spiral CT scan before operation, andrecorded the number and the size of lymph node on CT according to the staging systemdeveloped by Mountain and Dresler. Then recorded the number and the size of lymphnode during the operation on the basis of staging system,and recorded the number andthe size of lymph node after operation(be fixed in4%formalin) and pathology（bedehydrated） respectively once again.Analyzed these records compared with CT;definethe lymph node metastasis by pathological examination. Compare the size of lymphnode in CT、during operation、after operation and pathology.Analyse the relationshipbetween the size of lymph node and metastasis.Observed true positive, true negative,false positive, false negative, sensitivity, specificity, positive predictive value, negativepredictive value, accuracy.Results:1.Twenty patients are all adenocarcinoma.A total of318lymph nodes were foundin81areas.The average group of lymph node dissected was4.05and the averagenumber of lymph node dissected was15.9for each case.A total of57positive lymphnodes were found in17lymph node groups, and they were20.9%（17/81）of totalgroup and17.9%(57/318) of total number respectively.There are211lymph nodes on CT corresponding to dissected,and107lymph nodes can not find or distinguish.A totalof44positive lymph nodes were found in211lymph nodes.2.Compare the size of lymph node on CT、during operation、after operation andpathology:There are211lymph nodes on CT correspond to dissected,and107lymphnodes dissected are invisible or can not be distinguished;the the average number oflymph node long diameter on CT is10.682±4.862mm,the average number of shortdiameter is7.526±3.809mm;the long diameter and short diameter on CT are smallerthan the measurement during operation;the measurement on CT and during operationare smaller than after operation; the measurement on CT、during operation and afteroperation are bigger than pathology.3.The relationship between lymph node size and metastasis rate: The metastasisrate is9.2%when short diameter is＜10mm on CT, the metastasis rate is57.1%whenshort diameter is10-19mm on CT, the metastasis rate is83.3%when length is≥20mmon CT. Length≥15mm is lymph node metastasis. Define metastasis standard is shortdiameter≥10mm,then the metastasis rate of short diameter＜10mm is9.2%(15/163);The metastasis rate of short diameter≥10mm is60.4%(29/48),and false positive is39.6%(19/48).4.Metastasis standard is short diameter≥10mm on CT:Sensitiity65.9%（29/44）,Specificity88.6%（148/167）, Positive predictive value60.4%（29/48）, Negativepredictive value90.8%（148/163）, Accuracy83.9%（177/211）.Conclusion:1. The size of lymph node on CT is basically the same to true size,but there is acertain degree change of the size in CT、during operation、after operation and pathology;2.Lymph node short diameter on CT is more reasonable than long diameter asmetastasis standard.3.It can provide useful diagnostic information when the standard of lymph nodemetastasis on CT is set to the short diameter≥1cm.