| Part One Predictive value of 18F-FDG PET/CT related parameters for KRAS mutation in colorectal cancerPurpose The aim of this study was to explore the predictive value of 18F-FDG PET/CT related parameters for KRAS mutation in colorectal cancer(CRC)patients.Methods Retrospective analysis was conducted in 150 patients(105males,45fe-males,median age 63 years)with CRC who underwent 18F-FDG PET/CT examinati-on in Changhai Hospital between November 2011 and August 2017.Inclusion criteri-a:(1)All patients were newly diagnosed with CRC,and none of the patients rec-eived prior chemotherapy or radiation therapy before PET/CT examination;(2)T-he primary tumor were removed by surgery and received genetic testing in one mo-nth after PET scans;Pathology was adenocarcinoma or adenocarcinoma with partial-mucous adenocarcinoma.Exclusion criteria:(1)Multiple primary carcinomas;(2)Other pathological types(such as neuroendocrine tumor an-d squamous cell carcino-ma);(3)Patients with incomplete data.18F-FDG PET/CT related parameters were measured,including SUVmax,MTV2.5,MTV20%,MTV30%,MTV40%,MTV50%,TLG2.5,TLG20%,TLG30%,TLG40%,TLG50%.The relationship between the clinicopathological features and the KRAS mutation was detected by ?2 test,when p-values<0.05 was considered statistically significant.The relationship between the 18F-FDG PET/CT re-lated parameters and the KRAS mutation was determined by nonparametric test(M-ann-Whitney U test),and when p-values<0.05 was considered statistically significant.We then carried out a stepwise multivariate logistic regression analysis including o-nly parameters with univariate p-values<0.2,and when p-values<0.05 was considered statistically significant.For meaningful 18F-FDG PET/CT parameters,the cut-off val-ue are obtained through the ROC curve and the area under the corresponding curv-e was calculated.Results(1)The number of patients for KRAS-mutated and wild-type were 78 and 72,respectively.There ware no significant correlations between KRAS mutation and age,sex,tumor location,CEA,CA19-9,lymph node metastasis,T stage,M stage and Histological type in 150 patients.(2)The 18F-FDG PET/CT related parameters of SUVmax(P<0.001).MTV2.5(P=0.001)?TLG2.5(P<0.001)?TLG2o%(P=0.001)?TLG30%(P=.001)?TLG40%(P=0.001)and TLG50%(P=0.001))were higher in KRAS mutation patients than those in wild type patients.Multivariate logistic regression analysis showed that SUVmax(OR,1.122;95%CI,1.058-1.190,P<0.001)?lymph node metastasis(OR,2.429;95%Cl,1.183-4.989,P = 0.016).Histological type(OR,2.778;95%CI,1.099.7.025;P = 0.031)were predictors of KRAS mutation,with SUVmax=15.5 as the cut-off value,the corresponding accuracy of SUVmax was 67.33%(sensitivity:58.97%,specificity 76.39%,positive predictive value of 73.02%,negative predictive value of 63.22%);The accuracy corresponding of SUVmax for predicting KRAS mutation was higher in rectal or sigmoid-colon cancers,70.79%with SUVmax = 15.5 as the cut-off value.Conclusion SUVmax can predict KRAS mutation in CRC,the higher the para-meter value,the greater the probability of KRAS mutation.;The accuracy correspon-ding of SUVmax for predicting KRAS mutation was higher in rectal or sigmoidcolo-n cancers;PET/CT related parameters MTV and TLG can't predict KRAS mutation.Part Two The value of 18F-FDG PET/CT related parameters to predict postoperative prognosis of colorectal cancerPurpose To explore the clinical value of 18F-FDG PET/CT related parameters for the prediction of tumor disease-free survival time(DFS)and overall survival time(OS)after radical resection of CRC.Methods Retrospective analysis was conducted in 132 patients(93 males,39 f-emales,median age 63 years)with CRC who underwent 18F-FDG PET/CT examinat ion in Changhai Hospital between November 2011 and October 2016.The primary tumors were removed by surgery in one month after PET scans.None of the patie-nts received prior chemotherapy or radiation therapy before PET/CT examination.Adjuvant chemotherapy was performed after surgery according to the the patients'condition.Observation indicators:(1)Measurement of 18F-FDG PET/CT related par-ameters including SUVmax?MTV2.5?MTV20%?MTV30%?MTV40%?MTV50%?TLG2.5?TLG20%?TLG30%?TLG40%and TLG50%;(2)Treatment.Follow-up:Patients were followed up by outpatient examination and telephone interview.DFS was def-ined from the first days after the operation to first discovery of tumor recurrence?progression?death or end of follow-up;OS was first day after the operation to the patient's death or follow-up.The deadline of follow-up for this study was October 2017.The relationship between the clinicopathological features and 18F-FDG PET/CT related parameters were determined by nonparametric test(Mann-Whitney U test),when p-values<0.05 was considered statistically significant.The recurrence of the to-mor was a positive event,18F-FDG PET/CT related parameters were used to predic-t the best cut-off value of DFS by ROC curve and calculate the area under the R-OC curve.the median was the cut-off value if there was smaller AUC.According to cut-off value,the patients were divided into two groups.Survival analysis was p-erformed by Kaplan-Meier method.Univariate analysis was performed by Log-rank test.Multivariate analysis was conducted by COX proportional hazards model.Wh-en p-values<0.05 was considered statistically significant.Results(1)The relationship between the clinicopathological features and 18F-FDG PET/CT related parameters There was Statistical correlation between MTV2.5 and CEA;while MTV20%,MTV30%and MTV40%were Statistical correlation to the primary tumor location and histological type;MTV50%was Statistical correlat-ion to the primary tumor location and clinical stage;TLG2.5 and TLG20%were Stat-istical correlation to CEA and lymph node metastasis;TLG30%?TLG40%and TLG50%were Statistical correlation to CEA?lymph node metastasis and clinical stage.(2)The survival analysis of DFS The AUC of 18F-FDG PET/CT related parameters ob-tained by ROC curve,the ROC curve predicted DFS cut-off value,SUVmax=19.36(sensitivity:66.67%,specificity:73.96%)?MTV2.5= 22.64 cm3(sensitivity:48.61%,specificity:76.67%)?TLG2.5=117.78g(sensitivity:49.32%,specificity:77.97%)?TLG 20%=129.74 g(sensitivity:47.06%specificity:73.44%)?TLG30%=107.O5g(sensitivity:48.48%,specificity:74.24%)?TLG40%=73.22 g(sensitivity:47.30%,specificity:75.86%)?TLG50%=56.13 g(sensitivity:48.48%,specificity:75.00%).Because the AUC of MTV20%?MTV30%?MTV40%and MTV50%were smaller(AUC<0.5),the median of MTV20%(21.00cm3)?MTV30%(14.28cm3)?MTV40%(10.15cm3)were the cut-off value.Univariate analysis showed that CEA,CA19-9,lymph node metastasis,clinical stage,chemotherapy,SUVmax,MTV2.5,TLG2.5,TLG20%,TLG30%,TLG40%and TLG50%were the factors influencing postoperative DFS(P<0.05).Multivariate analysis showed that SUVmax(P<0.001,OR=3.308,95%CI:1.882-5.815).clinic-al stage(P=0.008,OR=2.164,95%CI:1.226-3.819).CA19-9(P=0.011,OR=2.098,95%CI:1.182-3.724)were independent risk factors for postoperative DFS(P<0.05).(3)The survival analysis of OS Univariate analysis showed that CEA,CA19-9,Histological type,SUVmax,MTV2.5,TLG2.5,TLG20%,TLG30%,TLG40%and TLG50%were the factors influencing postoperative OS(P<0.05).Multivariate anal ysis showed that SUVmax(P=0.026,OR=2.735,95%CI:1.129-6.624)?TLG50%(P=0.006,OR=5.699,95%CI:1.640-19.801)?CA19-9(P=0.001,OR=4.550,95%CI:1.868-11.084)were the independent risk factors for postoperative OS(P<0.05).Conclusion 18F-FDG PET/CT related parameter SUVmax was an independent p rognostic factor influencing the DFS and OS of CRC patients after radical resection,TLG50%was an independent prognostic factor influencing OS of CRC patients afte-r radical resection.18F-FDG PET/CT related parameter SUVmax and TLG50%can predict the prognosis of patients with CRC,the higher the parameter value,the wor-se prognosis. |
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