| ObjectiveAs a newly boomed surgical technique , Radioguided surgery ( RGS ) enables the surgeon to corroborate tumur existence, delineate its margin and find occult metastases. It will result in more accurate TNM staging and play a important role in the project of surgical management. With the sucessfully results of the applications of this technique on colorectal cancer, breast cancer and malignant melenoma, more and more surgeons try to apply it to the diagnosis and management of tumors.To find certain tumor -specific tracer, such as monoclonal antibody and to research the mechanism of tumor uptaking radiopharma-ceuticals or the related affecting factors, therefore resulting in in-proved T/NT, at all times are the research hotspot for nuclear medicine staff and related research personnel.In our study , We choose methoxy - isobutylisonitrile ( MIBI) as tracer and carry out the primary application of RGS on lung neopalasm . We aim at assessing the sensitivity, specificity and accuracy of intr-operative detecting of RGS on lung neoplasm. And , immunohisto-chemistry stain and Microscope Image Analyzer were used to investigate the correlation of the expression of Pgp and Ki - 67 antigen with T/NT ratio in patients with lung cancer underwent radioguided surger-Materials1. Object From July 2001 to June 2002 thirty - two cases with operable lung tumor underwent RGS. Of which, 27 cases were with lung cancer ; All were confirmed by pathological results.2. Principal reagent (1) 99mTc - MIBI (2) Mouse monoclonal antibody of Ki - 67 (MAB-0129) , Pgp (MA-0237) and (3) SP test kit3. Principal instrument ( 1) Hand - held gamma detecting probe was NAVIGATOR GPS Positioning System. ( 2) Microscope Microscope Image Analyzer) was MetaMorph/DP10/BX51.Methods1. Patients were intravenously injected 740MBq 99mTc - MIBI as tracer one hour before operation , During thoracotomy, the surgeon explores the thorax systematically without destroying the tumors' or lymph nodes blood supply. One hour after injection , GDP scanning of the whole lung field , neoplasm and lymph nodes was carried out. Prior to resection , radioactivity at adjacent nonpathological tissues was assessed and the tumor, lymph nodes were inspected in traditional manner and counted for radioactivity. 3 to 5 times of counts per 10 seconds was acquired in vivo . All the specimens were counted ex vivo by GDP . Specimens were also detected the radioactivity on GC - 1200-r radio - immunity counter to confirm the accuracy of GDP detection .2. Immunohistochemistry( Streptomycin - biotin - Peroxide ,S -P methodd) was used to measure the expression of Pgp and Ki - 67 antigen in lung cancer.3. Using Microscope Image Analyzer , each slice was quantifiedthe extent of Pgp and Ki - 67 expression in tumors, and evaluated as labeling index (LI) in three randomly selected high -power fields.4. Data was analysed and processed by Microsoft Excel 2000 and SASv6. 12 statistical package. The statistical differences between the means of two samples were determined with t test. Spearsman non -parametric correlation analy - sis was used to evaluate the relationship of Pgp LI or Ki - 67 LI with T/NT .Results1. No obvious side effect occurs after patients were intravenously injected 740MBq 99mTc - MIBI as tracer.2. Counts on tumor especially on malignant tumor remarkablely higher than nomal tissue. The maximum of T/NT is 5. 8 ,the minimum is 1.4. Using this tichnique, the surgeon can corroborated tumor existence introperatively. Occult metastasis with maximum diameter less than 1 cm was detected in two cases with lung adenocarcinoma.3. We considered a tumor to be malignant with a T/NT equal or higher than 2/1. Regarding the nature of lung tumor,the sensitivity, specificity and accuracy of GDP detection were 92. 6% ,80. 0% ,90. 6% , respectively.4. 27 cases with lung cancer underwent lymph node detecting by GDP. 177 lymph nodes were detected. Positive lymph nodes were 63 and negative ones were 114 according to pathological... |
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