Intraoperative doppler and b-mode sonography for the evaluation and management of renal tumors

PURPOSE:Main aim of our study is reexamining renal tumors-whose staging were evaluated byMRI which leaded to nephrectomy decisions-by using IOUS and inspecting effects of IOUSresults on partial or radical nephrectomy decisions made by surgical groups and comparingfindings of MRI and IOUS utilizing results of histopathologic examination as the goldstandart.MATERIALS AND METHODS:Study attempt was initiated with participation of patients whose renal masses weredetected in our instution or patients applied to our institution having similar results in otherinstutions during time period between July 2008 and September 2009, with a total of 49patients having 53 renal tumors. Some of the patients were excluded due to various reasons,as a result, 44 patients having 46 tumors were included in our study. MRI scans obtained inour instution or MRI scans acquired in other instutions satisfying criteria of our instution wereused in our research and IOUS scan were applied to all of the patients. MRI scans wereevaluated in a blind study by two radiologists having same level of experience and expertise.IOUS examinations were performed and annotated by a third radiologist specialized inultrasound. Pathologic specimens were examined and evaluated by a pathologist experiencedin his respected field of expertise. In the first part of our study, two radiologists who evaluatedpre-op MRI data, the third radiologist who applied IOUS scans and the pathologist scoredsurgical method they suggest while taking radical-partial nephrectomy criteria into account.Following scoring scheme was used: 1:"Radical nephrectomy decision" 2:"Partialnephrectomy may be given a chance" 3:"Only partial nephrectomy must be applied". In thesecond part of our study, 25 patients with assessable macroscopic specimen photographs wereevaluated retrospectively by two surgeons with similar level of experience and expertise andsuggested surgical method was scored using same scoring scheme mentioned above. In ourstudy, spectra of all variables were checked, Spearman Test was applied to evaluatecorrelation between inspection methods and "Chi-Square" test was utilized to inspectcorrelation between variables by using pathological data as the gold standart.RESULTS:In the first part of the study, IOUS and MRI findings were compared to pathologicalresults which were used as the gold standart. In a comparison between pathological findingsand IOUS findings, specificity, sensitivity, negative predictive value, pozitive predictivevalue, ratio of accuracy, were observed to be 100% in each category. Furthermore, in acomparision between the findings of two MRI reviewers and findings of pathologicalinspection, for the first expert sensitivity, specificity, negative predictive value, pozitivepredictive value, ratio of accuracy was respectively, 100%, 65.2%, 74.2%, 100%, 82.6%, andfor the second expert sensitivity, specificity, negative predictive value, pozitive predictivevalue, ratio of accuracy was respectively, 91.3%, 69.5%, 75%, 88.9%, 80.4%. In the secondpart of the study, it was found out that coherence between two surgical experts was observedto be 96% and both of the experts decided applying partial nephrectomy would be moreappropriate on 5 patients though they decided to apply radical nephrectomy on those patients.It was also revealed that diagnoses of IOUS methodology and pathologic inspection were incomplete coherence on these 5 patients.CONCLUSION :Rate of the correct diagnosis using MRI in cases of definite radical or partialnephrectomy indications was observed to be considerably high, however, in cases of renalsinus invasion was not clear and central localized lesions, diagnostic capabilities of MRI wasrevealed to decrease significantly but IOUS's diagnostic capabilites in cases of definiteradical or partial nephrectomy indications and incases of renal sinus invasion was not clearand central localized lesions, where MRI had difficulties in correct diagnose,observed to beclose to 100%. As a result, in selected cases having renal sinus invasion was not clear, centrallocalized and small lesions which cannot be clearly detected by MRI, IOUS is a usefulmethod in examination.Additionally, IOUS can also be used in evaluating existence of abberan vascularstructures and determining border properties of the lesion especially for the cases subject to apartial nephrectomy operation. Usage of IOUS can significantly lower complications duringoperation due to hemorrhage and rates of morbidity.