The Value Of The Diagnosis And The Preoperative Assessment Of Multi-slice Spiral CT In Primary Retroperitoneal Tumoms

Primary retroperitoneal tumors is the neoplasm originated from the tissuein the retroperitoneal space，but retroperitoneal substance organs are excluded，such as kidney，pancreas，adrenal gland，etc.It is common in malignant，andpathological type is various As retroperitoneal space has large capacity,earlysymptoms of the onset is occult.when symptoms appear,tumor size usually hasbeen quite great and invaded adjacent organs and vascular,Then completeresection is not easy,surgery is very complex and difficult.At present,surgicalresection remains the most effective method of treatment of PRT.In addition tothe retroperitoneal lymphoma and germ cell tumors,complete resection of thetumor will determine the success or failure of cancer treatment andpostoperative recurrence.So it is particularly important to assess of preoperativeof Primary retroperitoneal tumoms. There is some limitation in traditionalImaging examination on PRT diagnosis and its preoperation evaluation.MSCTcan collect data continuously certain volume of data,and then3D reconstructedand processing,Which is useful for tumor location and whether there isinvaded to organs surrounding,vessels and uretero.However,for now, nativeresearches are mainly about medical imaging diognosis of PRT.There is littlecomprehensive on PRT preoperative assessment research.Objectiv：To evaluate the accuracy multi-slice spiral CT(MSCT)for thediagnosis and preoperative evaluation of Primary retroperitoneal tumor(PRT)，in order to provide important information for clinical doctors in assessing of thedifficulty of the surgery, making rational operation plan and taking specifictreatment measures during the operation.Methods：50patients with PRT were confirmed by surgery and histopathology who came from our hospital inpatients from June，2010toDecember，2011，there are26are male，and24female，the average age of thesepatients is47.6. And all tumors are completely excised，together with adjacentviscera or cutted partly by surgery. there are31cases with malignanttumors，the others19with benign ones by surgery and histopathology.Theclinical manifestations and signs are mainly abdominal discomfort anddistension， lumbago，abdominal mass，and partly associated with intestinalobstruction. All of these patients were performed plain scanning beforeenhanced scanning with3or2phases in MSCT. The Concrete necessarycondition is Fasting for4to6hour before examination， drinking water500mlto600ml until5or15minutes before examination， lying for scanning， spanof scanning is from Diaphragmatic muscle top to Sciatic nodules. layerdistance5.0mm，slice thickness5.0mm,pitch1.0mm Contrastmedium iohexol（100ml），velocity of ejection3ml／s，delay time:arterial-phase(AP)20-25s，venous-phase(VP)60s， portal-phase (PP)120s. Thin axial images of1.0mmwere reconstructed with the raw data,then MPR,MIP，CPR images werereconstructed on Semens Definition workstation．Combine the axial imagineswith3D imagines to assess evaluation indexes of PRT before operation:tumorlocation and its relationship with surrounding organs and vessels; invasion ofneighboring organs,vessels and ureter, the value of diagnosis of CT in PRTwere compared with Preoperative and postoperative histopathologyrespectively．Data of these patients were analyzed by SPSS17.0software．Byusing Kappa to test the diagnostic concordance of MSCT and Preoperative andpostoperative histopathology. P<0.05suggests matching was in agreementbetween them；the diagnostic concordance is worse（Kappa=0.2—0.4）,thediagnostic concordance is bad（Kappa=0.4—0.6）, the diagnostic concordanceis good （Kappa=0.6—0.8）, the diagnostic concordance is better（Kappa=0.4—1.0）.Result：MSCT for thepositioning accuracy of the Primary retroperitonealtumoms reached98%，one cases of primitive neuroectodermal tumors is large，and closely reached with the jejunum initial segment,CT misdiagnose for smallintestinal stromal tumor.；MSCT for the qualitative diagnosis of Primaryretroperitoneal tumoms have certain limits；MSCT shows adjacent organs，major vascular nearby and ureter with or without violation with intraoperativeor pathological results in good agreement（p<0.05）,and highly or extremelystrong consistency（kappa value=0.77-0.91）.Conclusion： Athough MSCT for primary retroperitoneal tumorsqualitative diagnosis have certain limit, but to the tumor location, especially theMPR, MIP reconstruction technique applied to the location very accurate.MSCT in the diagnosis of primary retroperitoneal tumors with or without bloodvessels and surrounding organs, ureter violations of reliable diagnostic value inPreoperative.for shortening operating time, increased surgical precision andprovide detail and important information for clinical doctors in assessing of thedifficulty of the surgery, making rational operation plan and taking specifictreatment measures during the operation.