| Part 1: Therapeutic response and prognostic value of the SUVmax change calculated by dual-time-point 18F-FDG PET imaging in patients with non-surgical stage Ⅲ non-small cell lung cancerBackground: The dual-time-point（DTP）positron emission tomography / computed tomography（PET/CT）has been widely used to identify the benign and malignant tumor of lung and lymph nodes due to its high predictive accuracy.Studies have shown that DTP PET/CT can predict the survival of resectable non-small cell lung cancer（NSCLC）.However,no research has been used to analyze therapeutic response and prognosis of non-surgical stage Ⅲ NSCLC.The purpose of this study was to investigate therapeutic response and prognostic value of the standardized uptake value maximum（SUVmax）change calculated by DTP 18F-Fluorodeoxyglucose(18F-FDG)PET/CT imaging in patients with non-surgical stage Ⅲ NSCLC.Patients and Methods: We conducted a retrospective review of 65 patients with non-surgical stage Ⅲ NSCLC who underwent pretreatment DTP 18F-FDG PET/CT acquired at 1 h and 2 h after injection.Clinical data,PET imaging parameters and survival data were recorded.The SUVmax from early images（SUVmax1）and delayed images（SUVmax2）were recorded and used to calculate the respectively SUVmax changes,including the SUVmax increment（?SUVmax）and percent change of the SUVmax（%?SUVmax）.All patients were treated with platinum-based chemotherapy and chest radiotherapy.The efficacy was evaluatedaccording to the Response Evaluation Criteria in Solid Tumors（RECIST）criteria after 4-8 weeks of treatment completion.The patients with complete response（CR）or partial response（PR）were classified into response group.The patients with stable disease（SD）or progressive disease（PD）were included in the non-response group.Statistical difference between response and non-response groups was calculated by receiver operating characteristic curve（ROC curve）.Progression-free survival（PFS）and overall survival（OS）were determined by the Kaplan–Meier method and were compared with the studied PET parameters,and the clinico-pathological prognostic factors in univariate analyses and multivariate analyses were constructed using Cox proportional hazards regression.Results: Sixty-five consecutive patients were reviewed,and the median follow-up time was 29.5 months.The estimated median PFS and OS were 11.8 months and 25.6 months,respectively.Thirty-four patients were classified into response group and 31 patients were included in the non-response group.According to ROC curve analysis,the cutoffs of SUVmax1,SUVmax2,?SUVmax,and %?SUVmax are 8.7,11,4,and 35%,respectively,and the areas under the curve for SUVmax1,SUVmax,?SUVmax,and %?SUVmax are 0.607,0.658,0.775,and 0.75,respectively.The sensitivity of SUVmax ≤ 4 to predict tumor response was 87%,and the specificity was 75%.The sensitivity of % SUVmax ≤ 35% to predict tumor response was 83% and the specificity was 74%.Two groups were significantly different in PFS and OS by Kaplan-Meier method.In univariate analysis,ECOG scores（p < 0.001）,clinical stage（p = 0.007）,radiotherapy technology（p = 0.007）,?SUVmax（p = 0.003）,and %?SUVmax（p < 0.001）were significant prognostic factors for PFS.ECOG scores（p < 0.001）and clinical stage（p = 0.014）were significantly correlated with OS.In multivariate analysis,ECOG scores（p < 0.001）,?SUVmax（p = 0.023）,and %?SUVmax（p < 0.001）were significant factors for PFS.On the other hand,ECOG scores（p = 0.043）and clinical stage（p = 0.016）were identified as independent predictors of OS.Conclusion: Our results demonstrated SUVmax changes in pre-treatment 18F-FDG PET images could predict therapeutic response in patients with non-surgical stage Ⅲ NSCLC who had undergone radical concurrent chemoradiation.This predictor was proved to be powerful for PFS in the Cox regression model but could not predict OS.A larger prospective study is still needed to confirm these results.Part 2: Prognostic value of volume-based parameters of metastatic lymph node on 18F-FDG PET/CT in patients with limited-stage small cell lung cancer with lymph nodes involvementObjectives: Thoracic lymph nodes are common metastatic sites for small cell lung cancer（SCLC）.In patients with limited-stage SCLC（LS-SCLC）with lymph node involvement,even after radical radiotherapy and preventive brain irradiation for chest lesions,their prognosis is still very different,which may be related to tumor heterogeneity.There are many methods to evaluate the prognosis,but there is no unified standard in clinical practice.Previous studies have suggested that lymph node metastasis is an unfavorable factor in the prognosis of patients with SCLC,but lack of evaluation of its metabolic function.We assessed the prognostic value of metabolic parameters of different lesions,including primary tumors（PTs）and metastatic lymph nodes（LNs）,measured by 18F-Fluorodeoxyglucose(18F-FDG)positron emission tomography/computed tomography（PET/CT）in patients with limited-stage small cell lung cancer（LS-SCLC）with LN metastasis.Materials and Methods: This retrospective study was conducted from 349 patients who underwent PET/CT examination prior to treatment from January 2011 to December 2014,and finally included 46 patients with LS-SCLC with LN metastasis.All patients underwent complete first-line therapy（concurrent chemoradiation therapy and prophylactic cranial irradiation）.The subjects of this study included PET related parameters of LS-SCLC PT,metastatic LNs,the sum of lesions,and progression-free survival time（PFS）and overall survival（OS）.PET parameters including maximal standardized uptake value（SUVmax）,mean standardized uptake value（SUVmean）,metabolic tumor volume（MTV）,and total lesion glycolysis（TLG）values of the PTs and metastatic LNs were measured on PET.Using SUV = 2.5 as a threshold,the volume of interest（VOI）of tumor PT and metastasis LN was automatically delineated,respectively.Specific metabolic parameters,such as PT SUVmax（Pt SUVmax）,PT SUVmean（Pt SUVmean）,PT MTV（Pt MTV）,PT TLG（Pt TLG）,LNSUVmax（Ln SUVmax）,LN SUVmean（Ln SUVmean）,LN MTV（Ln MTV）,LN TLG（Ln TLG）,the sum of the MTV（Sum MTV）and TLG（Sum TLG）,and their bounds were obtained by analysis of receiver operating characteristic curve（ROC curve）.Kaplan-Meier survival curves were used for evaluation of PFS and OS.The univariate and multivariate Cox proportional hazards models were used to analyze the prognostic factors.Results: The median OS and PFS were 25.9 months（range,8.2–63.5 months）and 21 months（range,6.4–55.3 months）,respectively.The parameters of PT and metastatic LN were compared and there was no statistical difference.From the ROC curve analysis,the cutoffs for Pt SUVmax,Pt SUVmean,Pt MTV,Pt TLG,Ln SUVmax,Ln SUVmean,Ln MTV,Ln TLG,Sum MTV,and Sum TLG were 16,10,58,559,9,5,39,137,68,and 628,respectively.The univariate analysis demonstrated that Eastern Cooperative Oncology Group performance scores（ECOG PS）,N1 station involvement,subcarinal node metastasis,Ln MTV,Ln TLG,Sum MTV,and Sum TLG were significant predictive factors（p < 0.05）.ECOG PS,subcarinal node metastasis,Ln MTV,and Ln TLG were independent predictive factors of PFS and OS in the multivariate analysis.Conclusion: The volume-based parameters of metastatic LNs,other than lung lesions,are independent prognostic factors in patients with LS-SCLC with LN metastasis.These parameters could further stratify the prognosis of these patients,and these findings might provide functional imaging evidence for future study of the mechanisms of metastasis. |
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