Objective:To explore and compare the value of radiomic features based on 18F-fluorodeoxyglucose (FDG) PET and CT in distinguishing epidermal growth factor receptor (EGFR) mutation status in patients with lung adenocarcinoma. Methods:Pretreatment 18F-FDG PET/CT images and EGFR gene status of 114 patients (64 males and 50 females, aged range: 35-84 (average age: 61) years) with primary lung adenocarcinoma between January 2017 and December 2017 were retrospectively collected. The volume of interest was drawn manually slice by slice, then the features were extracted by the LIFEx software. The parameters were screened by least absolute shrinkage and selection operator (LASSO) method for 200 times, and ten-fold cross-validation was used to select the best tuning parameter λ. Three models, namely M PET, M CT, M PET+ CT, were constructed by binary logistic stepwise regression. The receiver operating characteristic (ROC) curve was generated and the corresponding area under the curve (AUC), sensitivity, specificity and accuracy were calculated. The AUCs of three models were compared by Delong test. Results:Totally, 53.51%(61/114) patients were with wild type EGFR and 46.49%(53/114) patients had EGFR mutation. There were 3, 3, 7 parameters selected to form M PET, M CT, M PET+ CT, respectively. The AUCs for M PET, M CT, M PET+ CT were 0.730, 0.752 and 0.866 respectively. When the cut-off values were 0.427, 0.522, 0.378 for M PET, M CT and M PET+ CT, the Youden index were up to the maximum as 0.420, 0.405, 0.630, with sensitivities of 83.0%(44/53), 58.5%(31/53), 92.5%(49/53), specificities of 59.0%(36/61), 82.0%(50/61), 70.5%(43/61) and accuracies of 70.2%(80/114), 71.1%(81/114), 80.7%(92/114), respectively. There was no significant difference between AUC of M PET and M CT ( z=-0.320, P>0.05). The differences of AUCs between M PET+ CT and M PET, M PET+ CT and M CT were statistically significant ( z values: 2.963, 2.523, both P<0.05). Conclusions:PET, CT and PET+ CT radiomic features are all associated with EGFR gene expression in lung adenocarcinoma. M PET+ CT has the highest predictive efficiency.

Objective To investigate the clinical value of radiomics nomogram,which is established by 18F-fluorodeoxyglucose (FDG) PET/CT radiomics signature combined with clinical-pathologic risk factors,in predicting the prognosis of patients with postoperative gastric carcinoma.Methods 18F-FDG PET/CT data of 207 patients (143 males,64 females,age range:20-85 years) with postoperative gastric carcinoma from January 2008 to August 2015 was reviewed retrospectively.Patients were divided into training group (n=104) and validation group (n =103),and the clinicopathologic information and disease-free survival (DFS) data were acquired.Significant textural features were selected from PET/CT images,and radiomics score (RS) for individual patient was calculated based on the radiomics signatures.The relationship between RS and DFS was analyzed.Cox regression analysis was performed to determine the risk factors ofDFS.The radiomics nomo-gram,obtained from combination of RS with clinicopathologic risk factors,was established and further evaluated in predictive value for recurrence or metastasis of postoperative gastric carcinoma,and the concordance index (C-index) was calculated.Results Cox regression analysis demonstrated that RS,tumor location,depth of invasion,lymph node metastasis,and distant metastasis were the significant risk factors for DFS (hazard ratios:2.148-2.828,all P＜0.05).The radiomics nomogram combined with RS and 4 clinicopathologic risk factors had a better prediction for the estimated DFS,comparing to RS alone.C-index of radiomics nomogram and RS were 0.830 and 0.700 in training group,and 0.776 and 0.681 in validation group,respectively.Conclusion Radiomics nomogram which is established by radiomics signatures and clinicopathologic risk factors may be better for predicting DFS of patients with postoperative gastric carcinoma.

Objective To explore the differences in the prognosis of patients with different immunophenotypes gastrointestinal diffuse large B-cell lymphoma (GI-DLBCL) who received different treatment strategies.Methods From March 2006 to January 2016,at Nanfang Hospital,Southern Medical University in Guangzhou,the clinical data of 99 patients with pathologically confirmed GI-DLBCL were retrospectively analyzed.According to treatment strategies,patients were divided into chemotherapy alone group and combination of surgery and chemotherapy group.According to immunophenotypes,patients were divided into germinal center B-cell-like (GCB) type and non-GCB type.The two-year progression-free survival (PFS) rate and overall survival (OS) rate were evaluated.Kaplan-Meier analysis,log-rank test and Cox regression were performed for statistical analysis.Results Among the 99 patients with GI-DLBCL,51 patients were treated with chemotherapy alone,and 48 patients were treated with combination of surgery and chemotherapy.Forty-one cases were GCB phenotype and 40 cases were non-GCB phenotype.The median follow-up time was 25 months.The two-year PFS and OS rates were 70.9％ and 89.5％,respectively.The two-year PFS and OS rates of chemotherapy alone group were 63.6％ and 85.0％,respectively;both were lower than those of combination of surgery and chemotherapy group (79.4％ and 94.7％),and the differences were statistically significant (x2 =4.232,P =0.040 and x2 =4.260,P =0.039).The two-year PFS and OS rates of GCB group were 68.8％ and 93.9％,respectively.And the two-year PFS and OS rates of non-GCB group were 73.2％ and 85.6％,respectively.There were no statistically significant differences between these two groups (both P ＞ 0.05).Among 41 patients with GCB type,25 were treated with combination of surgery and chemotherapy and 16 were treated with chemotherapy alone.The two-year PFS rate of patients treated with combination of surgery and chemotherapy (83.1％) was higher than that of patients treated with chemotherapy alone (49.2％),and the difference was statistically significant (x2 =5.627,P =0.018).The results of multivariate analysis indicated that treatment strategy was not an independent prognostic factor for all the enrolled patients and in patients with GCB type (all P ＞ 0.05).Conclusions Immunophenotypes may lack evaluation value of prognosis in patients with GI-DLBCL.Although among all the enrolled patients and patients with GCB type,the prognosis of patients treated with combination of surgery and chemotherapy is better than that of patients treated with chemotherapy alone,treatment strategy is not an independent prognostic factor.Multi-factors should be evaluated before selection of treatment strategy.

Objective To analyze the causes of Crohn's disease (CD) misdiagnosed as intestinal malignancy by 18F-fluorodeoxyglucose (FDG) PET/CT.Methods The clinical and 18F-FDG PET/CT data of 70 CD patients (48 males,22 females;average age:(32.1± 16.7) years) confirmed pathologically from June 2010 to June 2016 in PET Center of Nanfang Hospital were retrospectively reviewed.Patients misdiagnosed as malignancy were selected.The locations,morphologic and metabolic features were retrospectively analyzed.Results Six of seventy CD cases were misdiagnosed as intestinal malignancy (maximum standardized uptake value (SUVmax):7.8-29.8).Among them,4 patients were misdiagnosed as colonic carcinoma and 2 patients were misdiagnosed as intestinal lymphoma.All the intestinal lesions in 6 patients were FDG-avid,4 patients that were misdiagnosed as colonic carcinoma presented as localized irregular mass with extra luminal wall air bubble sign on CT.Two cases that were misdiagnosed as intestinal lymphoma presented as segmental diffusive intestinal wall thickening companied with bowel stiffness,intestinal loops enlargement and finger-pressing pattern along the surface of the intestinal mucosa on CT.Conclusions FDG-avid CD presenting as single localized irregular mass or segmental diffusive intestinal thickening can mimic intestinal malignancy.CT features are useful for differential diagnosis and reducing diagnostic errors.

Objective To explore whether the prognostic efficiency of international prognostic index (IPI) can be further improved by interim 18F-fluorodeoxyglucose (FDG) PET/CT.Methods A total of 185 patients (116 males,69 females;average age 49 years) with pathologically confirmed diffuse large Bcell lymphoma (DLBCL) from January 2004 to January 2014 were enrolled in this retrospective study.The risk was classified by IPI (0-2 was considered as low risk,3-5 was considered as high risk) and all patients underwent 18F-FDG PET/CT scan before and after 4 cycles of immunochemotherapy.Based on interim 18 F-FDG PET/CT imaging,5-point Deauville score was used to reclassify DLBCL patient into negative group and positive group,and the interpretations were evaluated for 2-year progression-free survival (PFS) and overall survival (OS) rates.Kaplan-Meier analysis,log-rank test and Cox regression were used for data analysis.Results With a median follow-up of 27 (2-146) months,the 2-year PFS and OS rates were 60％(111/185) and 81％(150/185),respectively.A total of 114 patients were included in the low-risk group and 71 patients were in the high-risk group.Both 2-year PFS rates and OS rates between the 2 groups were statistically different:72％(82/114) vs 37％(26/71),x2=20.86,P＜0.01;90％(103/114) vs 63％(45/71),x2=13.39,P＜0.01.The interim PET/CT showed 113 patients with negative results and 72 patients with positive results,whose 2-year PFS rates and OS rates were also statistically different:82％ (93/113) vs 24％(17/72),x2 =66.66,P＜0.01;90％(102/113) vs 51％(37/72),x2 =33.11,P＜0.01.In the low-risk group,85 patients were PET-negative and 29 patients were PET-positive.The 2-year PFS rates were 88％ (75/85) and 31％(9/29),respectively (x2 =35.52,P＜0.01).The 2-year OS rates were 96％ (82/85) and 66％(19/29),respectively (x2 =11.88,P＜0.01).In the high-risk group,28 patients were PET-negative and 43 patients were PET-positive.The 2-year PFS and OS rates were 64％(18/28) vs 19％(8/43;x2 =17.33,P＜0.01) and 86％(24/28) vs 49％(21/43;x2=9.95,P＜0.01),respectively.Conclusions Both IPI and interim 18F-FDG PET/CT have the prognostic value for patients with DLBCL.Interim 18F-FDG PET/CT can improve the prognostic efficiency of IPI.

Objective To evaluated the value of PET conventional parameters and texture parameters in prediction of the Kirsten rat sarcoma viral oncogene (KRAS) gene expression status in colorectal cancer (CRC) by analyzing the relationship between those parameters and KRAS gene status. Methods From December 2012 to January 2017, 18 F-fluorodeoxyglucose (FDG) PET/ CT data and KRAS gene status of 58 CRC patients (40 males, 18 females, average age 56.31 years) before anti-tumor therapies were collected. The relation-ship between PET parameters and KRAS gene expression was analyzed. Receiver operating characteristic (ROC) curve analysis was used to evaluate the values of PET conventional parameters and texture parame-ters for predicting the KRAS gene status. Spearman rank correlation and Mann-Whitney u test were used to analyze the data. Results Of 58 CRC patients, 19(32.8％) had KRAS mutation, while 39(67.2％) were with wild type KRAS. Among the 46 PET image parameters extracted by Chang-Gung image texture analysis (CGITA), 14 PET image parameters were selected by Spearman rank correlation (all ︳rs︳>0.8), inclu-ding 12 texture parameters and 2 conventional parameters (maximum standardized uptake value (SUVmax ) and total lesion glycolysis (TLG)). Six PET image parameters (4 texture parameters and 2 conventional pa-rameters) were found to be different between KRAS gene mutant group and wild group (u values: from -4.481 to -2.046, all P < 0. 05). Among the 4 texture parameters, standardized uptake value ( SUV) kurtosis (SUVkur ) had the best prediction value, while SUVmax was the better one for prediction in the 2 conventional parameters. When 4.27 was selected as the cut-off value for SUVkur , the Youden index was up to the maxi-mum as 0. 35 and it yielded 0.667 on the area under curve (AUC) (95％ CI: 0.517-0.816, P = 0.041) with the sensitivity of 15/ 19 and specificity of 56.4％(22/ 39), respectively. When 16.6 was selected as the cut-off value of for SUVmax , the Youden index was up to the maximum as 0.64 and the AUC on predicting the KRAS mutant was 0.865 (95％ CI: 0.770-0.960, P<0.001) with the sensitivity of 17/ 19 and specifici-ty of 74.4％(29/ 39), respectively. The efficacy of SUVmax for predicting KRAS mutation was significantly better than that of SUVkur(z= 3.258, P= 0.001). Conclusion PET texture parameters and conventional pa-rameters can be used to predict the KRAS gene status in CRC patients, and SUVmax may be the best parameter.

The early dynamic 18 F?FDG PET/CT can reflect perfusion, bio?distribution, uptake and excretion of 18 F?FDG in certain organs ( or lesions) in the early phase post injection. This imaging technique could be used to evaluate the organ ( or lesion) perfusion and to serve as a supplement for conventional 18 F?FDG PET/CT in the evaluation of glucose metabolism. This review summarizes the basic principle, imaging methods and clinical application of early dynamic 18 F?FDG PET/CT.

Objective To investigate the imaging presentation of T-and NK/T-cell lymphomas with different pathology subtypes on 18F-FDG PET/CT.Methods A total of 95 patients (66 males, 29 females, average age 38.42 years) with T-and NK/T-cell lymphoma proved by pathology from June 2006 to February 2016 were retrospectively analyzed.18F-FDG uptake (SUVmax), nodal invasion, nodal distribution, extra-nodal involvement and staging were compared among 7 pathological subtypes of T-and NK/T-cell lymphomas.One-way analysis of variance, Fisher exact test and Kruskal-Wallis H test were used for data analysis.Results There were significant differences in terms of 18F-FDG uptake, nodal invasion, nodal distribution, extra-nodal involvement and staging among different pathological subtypes of T-and NK/T-cell lymphomas (F=2.937, P<0.05;Fisher exact test,all P<0.01;H=19.883, P<0.01).NK/T-cell lymphoma was found to be prone to invade the nasal cavity and nasopharynx, enteropathic type T-cell lymphoma was specific to the intestine, and subcutaneous panniculitis-like T-cell lymphoma presented with subcutaneous infiltration.All those 3 subtypes were quite specific in their extra-nodal involvement.Most patients with angioimmunoblastic T-cell lymphoma (ATCL), peripheral unspecified T-cell lymphoma (PUTCL) and T immunoblastic lymphoma (TIBL) presented as stage Ⅳ disease.Widespread lymph node disease associated with splenic, parotid and serous membrane involvement were often seen in ATCL patients (most commonly to involve the parotid glands and serous membrane among the 7 subtypes).Nodal involvement was found in PUTCL patients, but extranodal involvement was rather non-specific.TIBL had a non-specific pattern of nodal involvement with low 18F-FDG uptake, lower than ATCL and the other 5 subtypes.Anaplastic large cell lymphoma subtypes had the highest 18F-FDG uptake when compared with the other 6 subtypes, but were less often to manifest as stage Ⅳ disease despite their preponderance for marrow and nodal infiltration.Conclusion Different pathological subtypes of T-and NK/T-cell lymphoma manifest different imaging presentations on 18F-FDG PET/CT, which are useful for understanding their biological characteristics.

Objective To establish rat models of extrahepatic biliary atresia,and to observe the characteristics of 99Tcm-MIBI hepatobiliary scintigraphy and evaluate its association with the expression Pglycoprotein (P-gp) in intestinal tissues.Methods A total of 12 SD rats were randomly divided into the normal control group (3 rats) and the group of common bile duct ligation (CBDL;9 rats).CBDL was used to establish the rat model of extrahepatic biliary atresia.99Tcm-MIBI hepatobiliary scintigraphy was performed at 2,3 and 4 weeks after ligation in the CBDL group and normal control group with continuous dynamic acquisition (3 min/frame) for 30 min and then delaying imaging at 30 min,1,2 and 3 h.After that,all rats were sacrificed,and the blood samples were taken out for the determination of serum ALT,AST,TBIL,DBIL,IBIL,ALP,γ-GT and TBA,and the tissues of duodenum,jejunum,ileum,colon and cecum were taken out for analyzing the expression level of P-gp by immunohistochemistry.Two-sample t test and one-way analysis of variance were used.Results Compared with the normal control group,the serum levels of ALT,AST,TBIL,DBIL,IBIL,ALP,γ-GT and TBA were significantly increasing at 2,3,4 weeks after ligation in CBDL group (t:-3.04 to-44.54,all P＜0.05).99Tcm-MIBI hepatobiliary imaging showed that there was radioactive accumulation in colon or cecum area,excluding the duodenum,jejunum and ileum area,at 3 h after intravenous injection of 99Tcm-MIBI in CBDL group.The results of immunohistochemistry showed that with the obstruction time prolonged,the expression levels of P-gp in duodenum,jejunum and ileum segments were gradually decreased (F=5.17,9.07,23.52;all P＜0.05),while the expression levels in the colon and cecum segments were not changed obviously (F=2.00,3.17;both P＞0.05).Conclusion 99Tcm-MIBI can be excreted through intestinal mucosa,and this process may be associated with P-gp expression.

Objective To explore the diagnostic value of 18F-FDG PET/CT in the inflammatory bowel diseases (IBD).Methods The clinicopathological data of 75 patients(46 males,29 females;average age 38 years) with IBD confirmed by colonoscopy from March 2010 to March 2014 were reviewed retrospectively.Among the 75 patients,30 were with ulcerative colitis(UC) and 45 were with Crohn's disease (CD).All underwent whole-body 18F-FDG PET/CT imaging.Enteroscope and CRP examination were performed within 1 week before or after PET/CT imaging.The results of 18F-FDG PET/CT were compared with those of located CT and enteroscope (x2,t tests).Linear correlation analysis was used to analyze the relationship between CRP and the SUVmax of lesions presented in IBD.Results (1) 18 F-FDG PET/CT accurately detected 65 patients with IBD,while located CT diagnosed 55 patients with IBD.The diagnostic sensitivities were significantly different:86.7％ (65/75) vs 73.3％ (55/75),x2 =4.167,P＜0.05.(2) Among 65 patients with positive results in 18F-FDG PET/CT,lesions were consistent with those detected by endoscopy in 33 (33/75,44.0％)patients.Results of the 2 methods in 24 patients (24/75,32.0％)were not completely same,those in 8 patients (8/75,10.7％)were totally different.18F-FDG PET/CT detected 145 lesions,while enteroscope only detected 119 lesions.Diffuse high FDG uptake was shown in intestinal wall in 40 of 65 patients,and mild mucosa injury was showed by enteroscope in 18 patients (45.0％,18/40).(3)Fortyeight of 65 patients detected by PET/CT were proven clinically to be in active stage,and the rest were in stable stage.The SUVmax of active stage group (8.31±4.21) was significantly higher than that of the chronic stage group (6.36±3.15;t =2.033,P＜0.05).There was a linear correlation between CRP and SUVmax of patients in active stage(r=0.453,P＜0.01).Conclusions 18F-FDG PET/CT is helpful to assess the activity of IBD and may serve as a supplementary diagnosing tool to detect the lesions under the epithelium of bowel,which are often false-negative by enteroscope.