Prognostic Value Of Whole-body Metabolic Tumor Volume On ¹⁸F-FDG PET/CT Imaging In Patients With Non-small Cell Lung Cancer

ObjectiveWhole-body metabolic tumor volume（MTVwb）to evaluate the prognosis value of measured by ¹⁸F-FDG PET/CT-based imaging in patients with non-small cell lung cancer（NSCLC）.MethodsUsing retrospective analysis,all patients with NSCLC who had undergone pre-treatment examination at the PET/CT center of People’s Hospital of Gansu Province from July 2011 to March2016 were identified and confirmed by pathology or late follow-up.Finally,130 patients meeting the inclusion and exclusion criteria were enrolled to obtain images and some clinical data of ¹⁸F-FDG PET/CT imaging.Metabolic tumor volume（MTV）measurement threshold set to 42%maximum normalized uptake（SUVmax）.MTVwb was measured by semi-automatic method,and it is the sum of the MTV value of the primary tumor,the MTV value of the metabolic lymph node,and the MTV value of distant metastasis.The relationship between gender,age,clinical TNM staging,MTVwb,median of MTVwb,quartile of MTVwb and overall survival（OS）can be analyzed by Log-rank test,Kaplan-Meier survival analysis method and Cox proportional hazards regression model.Simultaneously,using C-statistic values to compare the value of each of the above prognostic factors on the prognosis.ResultsUsing 4.16 cm³as the median of MTVwb,the half survival time of patients with MTVwb below the median（<4.16 cm³）about 13.13（95%CI:8.5²1.5）months,and the half survival time of patients with a median of MTVwb above（≥4.16 cm³）was approximately 4.67（95%CI:3.97⁸.6）months.The median OS in all patients was 5.82 months（range,0.1 to 55.6 months）.Univariate analysis was performed using the Cox proportional hazards regression model,the results showed IV stage of clinical TNM stage（P=0.001,HR=3.012）,MTVwb（P=0.000,HR=1.604）,and median of MTVwb（P=0.002,HR=1.925）was the main factor affecting the prognosis of patients with NSCLC.Multivariate analysis of clinical TNM stage and MTVwb showed that only MTVwb（P=0.003,HR=1.466）was an independent factor influencing the prognosis of patients with NSCLC.and the C-value for MTVwb（0.634）>C-value for clinical TNM stage（0.609）>C-value for the median of MTVwb（0.580）.ConclusionMTVwb in ¹⁸F-FDG PET/CT imaging has a higher clinical value in the evaluation of prognosis of NSCLC patients,and has better prognostic value compared with clinical TNM stage,age and gender.Therefore,the whole-body metabolic tumor volume（MTVwb）can better evaluate the prognosis of patients with NSCLC than the clinical TNM stage system,may more reasonably predict the overall survival of NSCLC patients,and as an independent predictor of overall survival of NSCLC patients.