The Study Of ¹⁸F-FDG PET-CT In The Staging Of Non-Small Cell Lung Cancer

Partâ… ¹⁸F-FDG PET-CT in the Presurgical T Staging of Non-Small Cell Lung CancerObjective To evaluate the diagnostic value of integrated positron emission tomography and computed tomography(PET-CT) with fluorine 18 fluorodeoxy-glucose (¹⁸F-FDG) in preoperative primary tumor stage(T stage) of non-small lung cancer(NSCLC).Materials and Methods Ninety NSCLC patients underwent curative surgical ressection after integrated ¹⁸F-FDG PET-CT examination and then breathhold CT examination from Oct 2006 to Mar 2009.Two blinded experienced radiologist staging all primary tumors in consensus by CT and PET-CT images.Surgical and histopathologic results served as the "golden standard" for determing the staging value of CT and PET-CT.T stage was assigned on the basis of image analysis by using American Joint Committee on Cancer staging systems.Results According to pathological result,there are 22 patients in T1 stage,42 in T2, 14 in T3,12 in T4.CT and integrated PET-CT classified T stage accurately in 76.7% (69 of 90 patients) and 83.3%(75 of 90 patients),respectively(P =0.063).CT and PET-CT classified accurately 3 and 6 patients respectively in 8 patients of central cancer with atelectasis,diagnosed accurately 2 and 4 metastases respectively in 5 patients at the ipsilateral lung,3 and 4 pleural metastases respectively in 6 patients.Conclusions Describing the size,modality,and infiltrative region of primary tumor in NSCLC distinctly,CT is the main imaging method for T stage.¹⁸F-FDG PET-CT has unique value in differentiating center cancer with atelectasis,and diagnosing pulmonary or pleural metastasis. Partâ…¡¹⁸F-FDG PET-CT in the Preoperative N Staging of Non-Small Cell Lung CancerPurpose To evaluate the diagnostic value of integrated positron emission tomography and computed tomography(PET-CT) with fluorine 18 fluorodeoxyglucose(FDG) in preoperative regional lymph nodal stage(N stage) of NSCLC,especially the additional value of CT attenuation and the dual-time-point imaging in determining the status of lymph nodes in China where tubercular granulomatous disease is epidemic.Materials and Methods Eighty NSCLC patients underwent curative surgical resection after integrated ¹⁸F-FDG PET-CT examination from Oct 2006 to Mar 2009. The CT and PET-CT images were analyzed by two blinded radiologist.For CT scan, the status of lymph nodes was diagnosed by their size.For PET-CT scan,the initial scan images were analysed by two methods.In method 1,nodal status was determined by glucose uptake only.Lymph nodes with high uptake were considered malignant, otherwise considered benign.In method 2,nodal status was determined by uptake associated with CT attenuation.If the glucose uptake was high,lymph nodes with calcification or higher attenuation than aorta on CT images were interpreted as benign, otherwise as malignant.Nodal uptake was interpreted visually and semi-quantitatively. The uptake of lymph node higher than the mediastinum background or its maximum standardized uptake value(SUV_max)=2.5 was defined as high uptake.For dual-time-point imaging,the retention index(RI)＞10%were regarded increasing trend.Histopathologic results served as the reference standard.N stage was assigned on the basis of image analysis by using American Joint Committee on Cancer staging systems.The data results were analyzed statistically.Results A total of 265 nodal groups were sampled,of which 51 nodal groups were malignant according to pathological result.On per-nodal-station(group) basis,the diagnostic sensitivity,specificity,accuracy,positive predictive value(PPV),and negative predictive value(NPV) were 45.1%,92.5%,83.4%,58.9%and 87.6% respectively by CT;66.7%,89.7%,85.3%,60.7%and 91.9%respectively by method 1 of PET-CT;64.7%,96.7%,90.6%,82.5%and 92.0%respectively by method 2 of PET-CT.The sensitivity beween CT and method 1 had statistically significant difference(P＜0.01).The specificity and accuracy between method 1 and 2 had statistically significant difference(P＜0.01).Thirty-nine nodal groups with high uptake in the initial scan underwent dual-time-point imaging and the difference ofΔSUV_max and RI between benign and malignant groups both had no statistical significance (P＞0.05).On per-patient basis,the accuracy was 67.5%by CT,70.0%with PET-CT by method 1,and 76.2%by method 2.The accuracy for N2 staging between CT and PET-CT(method 2) had statistically significant difference.Conclusions ¹⁸F-FDG PET-CT has high diagnostic value in preoperative N staging of NSCLC patients,and combining uptake with CT attenuation of lymph nodes can improve the specificity and accuracy.For the lymph nodes with high uptake in the initial scan,dual-time-point imaging has limited value for diagnositic differentiaion. Partâ…¢Relationship between ¹⁸F-FDG uptake of primary tumor at PET-CT and pathological stage,along with regional lymph nodal metastases in NSCLCObjective To investigate the relationship between ¹⁸F-FDG uptake of primary tumor and pathological stage(T and N stage) of NSCLC.Furthermore,we analyzed the possible risk factors for regional lymph nodal metastases and determine whether the degree of ¹⁸F-FDG uptake of the primary tumor is an independent predictor of nodal metastases in patients with NSCLC.Materials and Methods Eighty NSCLC patients underwent curative surgical resection after integrated ¹⁸F-FDG PET-CT examination were enrolled,with their disease thoroughly pathological staged.The primary tumor ¹⁸F-FDG uptake were compared with T and N staging groups respectively.When significant differences were found,further correlation was performed between ¹⁸F-FDG uptake and stage. The risk factors of regional lymph nodal metastases was performed by univariate and multivariate analysis.¹⁸F-FDG uptake was quantitated by maximum standardized uptake value(SUV_max).Results A positive correlation was found between SUV_max and size of primary tumor (r=0.591,P=0.000).The difference in SUV_max of primary tumor among different T staging groups and the correlation between SUV_max and T stage both had statistical significant(F=5.701,P=0.005;r=0.378,P=0.001).Similarly,the SUV_max of primary tumor was significantly associated with N stage(F=4.124,P=0.023;r=0.438, P=0.000).In the study of the risk factors which may affecting the nodal metastases, tumor size,histological grade,blood tumor marker level and SUV_max of primary tumor were factors significantly associated with lymph node involvement in univariate analysis.Logistic multivariate analysis showed that SUV_max of primary tumor and blood tumor maker level was both significant predictive factors for lymph nodal metastases in NSCLC patients.Conclusion There are significantly relationships between the SUV_max of the primary tumor and pathological stage(T and N stage) of NSCLC.¹⁸F-FDG uptake by the primary tumor may be an independent predictor of regional lymph node metastases in patients with NSCLC.