Search

Background: The aim of the present study was to evaluate the impact of intratumoral metabolic heterogeneity and quantitative 18 F-FDG PET/CT imaging parameters in predicting patient outcomes in thymic epithelial tumors (TETs)., Methods: This retrospective study included 100 patients diagnosed with TETs who underwent pretreatment 18 F-FDG PET/CT. The maximum and mean standardized uptake values (SUVmax and SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) on PET/CT were measured. Heterogeneity index-1 (HI-1; standard deviation [SD] divided by SUVmean) and heterogeneity index-2 (HI-2; linear regression slopes of the MTV according with different SUV thresholds), were evaluated as heterogeneity indices. Associations between these parameters and patient survival outcomes were analyzed., Results: The univariate analysis showed that Masaoka stage, TNM stage, WHO classification, SUVmax, SUVmean, TLG, and HI-1 were significant prognostic factors for progression-free survival (PFS), while MTV, HI-2, age, gender, presence of myasthenia gravis, and maximum tumor diameter were not. Subsequently, multivariate analyses showed that HI-1 (p < 0.001) and TNM stage (p = 0.002) were independent prognostic factors for PFS. For the overall survival analysis, TNM stage, WHO classification, SUVmax, and HI-1 were significant prognostic factors in the univariate analysis, while TNM stage remained an independent prognostic factor in multivariate analyses (p = 0.024). The Kaplan Meier survival analyses showed worse prognoses for patients with TNM stages III and IV and HI-1 ≥ 0.16 compared to those with stages I and II and HI-1 < 0.16 (log-rank p < 0.001)., Conclusion: HI-1 and TNM stage were independent prognostic factors for progression-free survival in TETs. HI-1 generated from baseline 18 F-FDG PET/CT might be promising to identify patients with poor prognosis., (© 2024 The Author(s). Thoracic Cancer published by John Wiley & Sons Australia, Ltd.)

Purpose: The aim of this study was to evaluate the potential role of [ 18 F]FDG positron emission tomography/computed tomography (PET/CT) in the characterization of thymic epithelial tumors (TETs). Materials and Methods: A total of 73 patients who underwent preoperative [ 18 F]FDG PET/CT were included in this study. Visual total score (VTS), maximum standard uptake values (SUV max ), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and heterogeneity index (HI) parameters were analyzed to investigate the prediction of histopathologic grade and advanced stage. Results: The cohort included 26 patients with low-grade thymoma (LGT), 36 patients with high-grade thymoma (HGT), and 11 patients with thymic carcinoma (TC). Ninety-one percent of TC had VTS >2, whereas 31% of LGT and 75% of HGT had VTS >2. SUV max , MTV, and TLG were statistically significantly higher in the TC group than in both thymoma and HGT. Using the cutoff value of 7.25 for SUV max , TC was differentiated from thymomas with 91% sensitivity and 74% specificity. TC had significantly lower HI values than thymomas. HI parameters showed good diagnostic ability to differentiate TC from thymoma and TC from HGT. SUV max , MTV, and TLG were significantly higher in advanced-stage disease than in early-stage disease. Conclusions: Visual and quantitative parameters can reliably predict both advanced disease and the grade of primary tumor in TETs. Therefore, as a promising metabolic imaging method, [ 18 F]FDG PET/CT makes important contributions to preoperative evaluation in routine clinical practice.

Objective: A high rate of unnecessary thymectomies has been reported. This study aimed to distinguish primary mediastinal lymphomas (PMLs) from thymic epithelial tumors (TETs) by evaluating volumetric and metabolic parameters with 18 F-FDG PET/CT. Methods: A total of 136 patients who were pathologically diagnosed with TETs or PMLs were enrolled, and 18 F-FDG PET/CT was performed before therapy. Volumetric parameters, including the mean SUV (SUVmean), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and SUVmax, were determined and compared between the 2 subtypes. The diagnostic performance of these parameters was evaluated with receiver operating characteristic (ROC) curve analysis. Results: All parameters significantly differed between patients with PMLs and TETs. Patients with lymphomas were younger and had higher SUVmean, SUVmax, TLG, and MTV values than patients with TETs. The MTV and TLG values had similar diagnostic performance. ROC analysis indicated that the areas under the curves of the SUVmean and SUVmax values performed similarly (approximately 0.76) in differentiating patients with PMLs from TETs, and both values were better than the MTV and TLG values. When age was included with the SUVmax in differentiating TETs from PMLs, the AUC was 0.91, and the sensitivity and specificity increased to 80% and 93%, respectively. Conclusions: The SUVmax and volumetric parameters of 18 F-FDG PET/CT can be used to distinguish patients with PMLs versus TETs, and thus may aid in preventing unnecessary thymectomies or other invasive operations., (Copyright: © 2020, Cancer Biology & Medicine.)

Objective: To investigate the value of 18F-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) in predicting the simplified WHO grade of malignancy in thymic epithelial tumors., Materials and Methods: We retrospectively reviewed 81 patients with pathologically proven thymic epithelial tumors who underwent F-FDG PET/CT before surgical resection. Maximum standardized uptake value (SUVmax) and SUVmax/tumor size were measured on the primary lesion. A receiver operating characteristics (ROC) curve were performed for assessing the ability of F-FDG PET/CT as a predictor of the simplified WHO classification., Results: There were 43 male patients (53.1%) and 38 female patients (46.9%), and the mean age was 55.6 ± 11.9 years. The mean tumor size was 53.2 ± 21.4 mm. There were 24 low-risk thymomas (29.6%) (A, AB, and B1), 29 high-risk thymomas (35.8%) (B2 and B3), and 28 thymic carcinomas (34.6%). The SUVmax and SUVmax/tumor size were found to be predictive factors that were useful to distinguish thymomas and thymic carcinomas, and area under the ROC curve were 0.820 and 0.691, respectively (P < 0.05), and the cutoff value for discriminating thymomas and thymic carcinomas was 5.34., Conclusion: In conclusion, a significant relationship was observed between SUVmax, SUVmax/tumor size and histological WHO classification of thymic epithelial tumors. F-FDG PET/CT may be useful for predicting the grade of malignancy in thymic epithelial.

Mixed epithelial and stromal tumor of the kidney (MESTK) is a rare tumor composed of epithelium and interstitium. In radiological imaging, the masses are cystic and solid, and it is difficult to distinguish MESTK from renal cystic lesions. A final diagnosis of MESTK depends on pathology. We report this rare case of MESTK that was diagnosed in a 21-year-old woman. 18F-labeled fluoro-2-deoxy glucose (18F-FDG) positron emission tomography (PET)/computerized tomography (CT) and contrast-enhanced computerized tomography features of MESTK are presented, and could potentially provide useful information for the differential diagnoses of cystic renal neoplasms and preoperative staging of the tumor.

Purpose: This study aimed to explore the clinical and prognostic significance of 18 F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) in epithelial ovarian cancer (EOC)., Methods: We retrospectively investigated 48 EOC patients who underwent preoperative 18 F-FDG PET/CT and primary cytoreductive surgery at our hospital between January 2010 and June 2015. None of these patients received neoadjuvant chemotherapy. PET/CT parameters including the maximum and average standardized uptake value (SUVmax, SUVavg), the metabolic tumor volume (MTV) were measured. Tumor proliferation marker Ki67 was evaluated using immunohistochemistry. The relationships between the PET/CT parameters and chemosensitivity, tumor proliferation, and overall survival (OS) were analyzed, respectively., Results: The median (range) SUVmax, SUVavg, and MTV values were 11.42 (3.14-20.20), 4.8 (2.55-9.47), and 150.11 (0.19-792.46), respectively. Overall, 93.8% (45/48) of patients had high-grade serous ovarian cancer. The SUVmax value had a positive correlation with the Ki67 index (P = 0.030, r = 0.314), and a higher SUVmax level was associated with chemosensitivity (P = 0.026). However, neither SUVavg nor MTV had associations with the patients' clinicopathological parameters. None of these three PET/CT parameters were found to be potential predictors of OS., Conclusions: Preoperative 18 F-FDG PET/CT had a predictive value on chemosensitivity and proliferation after primary debulking surgery in EOC patients noninvasively.

Mixed epithelial and stromal tumor of the kidney (MESTK) is a rare renal tumor composed of solid and cystic components. Mixed epithelial and stromal tumor of the kidney has no pathognomonic imaging feature. It is difficult to distinguish MESTK from other cystic renal neoplasms using current radiological methods. We report a rare case of MESTK that was diagnosed in a 46-year-old woman with breast cancer. F-FDG PET/CT and contrast-enhanced CT features of MESTK are presented, which could potentially provide useful information in the differential diagnoses of cystic renal neoplasms.

Objective: Standardised uptake value (SUV) and volumetric parameters such as metabolic tumour volume (MTV) and total lesion glycolysis (TLG) from 18 F-FDG PET/CT are useful criteria for disease prognosis in pre-operative and post-treatment epithelial ovarian cancer (EOC). Ki67 is another prognostic biomarker in EOC, associated with tumour aggressiveness. The aim of this study is to evaluate the association between 18 F-FDG PET/CT measurements and Ki67 in pre-treatment EOC to determine if PET/CT parameters could non-invasively predict tumour aggressiveness., Material and Methods: A pre-treatment PET/CT was performed on 18 patients with suspected or newly diagnosed EOC. Maximum SUV (SUVmax), mean SUV (SUVmean), whole-body MTV (wbMTV), and whole-body TLG (wbTLG) with a threshold of 30% and 40% of the SUVmax were obtained. Furthermore, Ki67 index (mean and hotspot) was estimated in tumour tissue specimens. Immunohistochemical findings were correlated with PET parameters., Results: The mean age was 57.0 years old (standard deviation 13.6 years). A moderate correlation was observed between mean Ki67 index and SUVmax (r=0.392), SUVmean 30% (r=0.437), and SUVmean 40% (r=0.443), and also between hotspot Ki67 index and SUVmax (r=0.360), SUVmean 30% (r=0.362) and SUVmean 40% (r=0.319). There was a weaker correlation, which was inversely negative, between mean and hotspot Ki67 and volumetric PET parameters. However, no statistical significant differences were found for any correlations., Conclusions: SUVmax and SUVmean were moderately correlated with Ki67 index, whereas volumetric PET parameters overall, showed a weaker correlation. Thus, SUVmax and SUVmean could be used to assess tumour aggressiveness in pre-treatment EOC., (Copyright © 2017 Elsevier España, S.L.U. y SEMNIM. All rights reserved.)

Objective: To retrospectively investigate the standardized uptake value (SUV)-related and heterogeneous texture parameters individually and in combination for differentiating between low- and high-risk 18 Fluorone-fludeoxyglucose ( 18 F-FDG)-avid thymic epithelial tumours (TETs) with positron emission tomography (PET)/CT., Methods: SUV-related and 6 texture parameters (entropy, homogeneity, dissimilarity, intensity variability, size-zone variability and zone percentage) were compared between 11 low-risk and 23 high-risk TETs (metabolic tumour volume >10.0 cm 3 and SUV ≥2.5). Diagnostic performance was evaluated by receiver operating characteristic analysis. The diagnostic value of combining SUV and texture parameters was examined by a scoring system., Results: High-risk TETs were significantly higher in SUVmax (p = 0.022), entropy (p = 0.038), intensity variability (p = 0.041) and size-zone variability (p = 0.045) than low-risk TETs. Diagnostic accuracies of these 4 parameters, dissimilarity and zone percentage which also showed significance in receiver operating characteristic analysis ranged between 64.7 and 73.5% without significant differences in AUC (range; 0.71 to 0.75) (p ≥ 0.05 each). Each parameter was scored as 0 (negative for high-risk) or 1 (positive for high-risk) according to each threshold criterion, then scores were summed [0 or 1 for low-risk TETs (median; 1); ≥2 for high-risk TETs (median; 4)]. The sensitivity, specificity and accuracy of detecting high-risk TETs were 100, 81.8 and 94.1%, respectively, with an AUC of 0.99., Conclusion: The diagnostic performances of individual SUVmax and texture parameters were relatively low. However, combining these parameters can significantly increase diagnostic performance when differentiating between relatively large low- and high-risk 18 F-FDG-avid TETs. Advances in knowledge: Combined use of SUVmax and texture parameters can significantly increase the diagnostic performance when differentiating between low- and high-risk TETs.

Background and Objectives: The decision to perform secondary cytoreductive surgery for recurrent ovarian cancer is generally determined by clinical criteria. The aim of this study was to assess the predictive capability of FDG-PET/CT in identifying patients for whom secondary optimal debulking can be obtained., Methods: We reviewed the records of all women with suspected recurrent ovarian cancer (CA-125 levels >35 U/ml and/or clinical symptoms), at two medical centers, between January 2004 and December 2013. Patients in whom CT scans were negative, indeterminate or indicative of localized disease, were referred for preoperative FDG-PET/CT study. We analyzed the outcomes of those who subsequently underwent cytoreductive surgery., Results: Of 282 women with suspected recurrent ovarian cancer, 48 underwent FDG-PET/CT. The 24 for whom localized disease was detected on PET/CT, subsequently underwent secondary debulking surgery. Patients with PET/CT evidence of multifocal recurrent sites were referred for chemotherapy. Tumor debulking was optimal in 20 patients, and suboptimal in 4. The positive predictive value of PET/CT for optimal debulking was 83.3%., Conclusions: The findings extend prior reports on the role of FDG-PET/CT in the management of recurrent ovarian cancer, to the prediction of secondary optimal debulking. Future studies should aim to investigate the impact on survival., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objectives: To evaluate the prognostic value of metabolic activity of metastatic lesions measured by 18 F-flurodeoxyglucose ( 18 F-FDG) uptake on preoperative positron emission tomography/computed tomography (PET/CT) in patients with advanced serous epithelial ovarian cancer (EOC)., Methods: Clinico-pathological variables and PET/CT parameters such as the maximum standardised uptake value of the ovarian cancer (SUV ovary ), metastatic lesions (SUV meta ), and the metastatic lesion-to-ovarian cancer standardised uptake value ratio (SUV meta /SUV ovary ) were assessed in International Federation of Gynaecology and Obstetrics (FIGO) stage III, IV patients., Results: Clinico-pathological data were retrospectively reviewed for 94 eligible patients. The median progression-free survival (PFS) was 18.5 months (range, 6-90 months), and 57 (60.6%) patients experienced recurrence. Older age [P = 0.017, hazard ratio (HR) 1.036, 95% CI 1.006-1.066], residual disease after surgery (P = 0.024, HR 1.907, 95% CI 1.087-3.346), and high SUV meta /SUV ovary (P = 0.019, HR 2.321, 95% CI 1.148-4.692) were independent risk factors of recurrence. Patients with high SUV meta /SUV ovary showed a significantly worse PFS than those with low SUV meta /SUV ovary (P = 0.007, log-rank test)., Conclusions: Preoperative SUV meta /SUV ovary was significantly associated with recurrence and has an incremental prognostic value for PFS in patients with advanced serous EOC., Key Points: • The prognostic value of the metabolic activity of metastatic lesions was investigated. • SUV meta /SUV ovary was significantly associated with recurrence of serous EOC. • Preoperative SUV meta /SUV ovary can be a predicator of serous EOC recurrence.

Background: We investigated the role of 18 F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) in predicting the effect of induction therapy in patients with thymic epithelial tumors., Methods: Fourteen patients with thymic epithelial tumors who underwent PET-CT before and after induction therapy were retrospectively analyzed. The relationship between the change in the maximum standardized uptake value (SUV max ) in PET-CT, the response evaluation criteria in solid tumors and the pathologic response (Ef0, no necrosis of tumor cells; Ef1, some necrosis of tumor cells with more than one-third of viable tumor cells; Ef2, less than one-third of tumor cells were viable; and Ef3, no tumor cells were viable) was analyzed., Results: The study cohort consisted of 5 males and 9 females. Nine of the patients had thymoma, and 5 had thymic carcinoma. The induction therapy included chemotherapy in 9 cases, chemoradiation therapy in 4 cases and radiation therapy in 1 case. Among the 8 patients with a pathologic response of Ef0/1, 5 were clinically evaluated as having stable disease (SD), while 3 were found to have had a partial response (PR). The SUV max was elevated in 2 cases, unchanged in 1 and decreased in 5. On the other hand, 3 of the 6 patients with a pathologic response of Ef2, 3 were classified as having SD, while the other 3 had a PR. The SUV max decreased in all of the patients., Conclusions: In comparison with CT, PET-CT seems to be useful for predicting the pathologic response to induction therapy in patients with thymic epithelial tumors.

Objective: To investigate the relationship between maximum standardised uptake value (SUVmax) of ovarian lesions and histopathology subtypes, and their involvement in the response and prognosis of patients with epithelial ovarian carcinoma (EOC)., Material and Methods: A retrospective analysis of 31 patients with EOC and 18 F-FDG-PET/CT before treatment, including an assessment of the SUVmax of ovarian lesion. Histopathological diagnosis and follow-up was performed. A study was made on the relationship between the SUVmax and histological type (type I and II) and tumour stage, as well as the role of various parameters (SUVmax, histology, stage) on the patient outcomes (complete response [CR], overall survival [OS], disease-free survival [DFS], and disease-free [DF] status, at 12 and 24 months)., Results: The medium SUVmax in type I lesions was lower than in type II (6.3 and 9.3, respectively; P=.03). A 7.1 cut-off was set for SUVmax in order to identify type II EOC (sensitivity: 77.8%, specificity: 69.2%; AUC=0.748; P=.02). No significant relationship was found between tumour stage and SUVmax. CR was more common in early stages; relative risk (RR) of 1.64; P=.003, as well as in type I tumours and a lower SUVmax. Tumour stage was decisive in DFS (P=.04), LE24m (0.07) and OS (P=.08). Longer DFS and a higher percentage of DF 24m were observed in type I tumours (RR: 1.32; P=.26)., Conclusions: SUVmax was related to EOC histology, so could predict the response and prognosis of these patients. No association was found between glycolytic activity of the primary tumor with the response and prognosis., (Copyright © 2017 Elsevier España, S.L.U. y SEMNIM. All rights reserved.)

We retrospectively assessed the dual-time-point (DTP) F-18 FDG PET/CT findings of thymic epithelial neoplasms (TENs) and investigated the diagnostic capacity of PET/CT compared to that of CT for predicting carcinoma. We calculated the ratio of the standardized uptake value of the tumor and that of the aortic arch (T/M ratio) for both the 90-min early scan and the 2-h delayed scan in 56 TEN patients. We used a multivariate logistic regression (MLR) analysis to estimate the CT features of carcinoma. We compared the diagnostic capacities of PET/CT and chest CT using receiver operating characteristic (ROC) analyses. The ROC curve revealed that the appropriate cut-off T/M ratio value for the highest accuracy was 2.39 with 75.0% accuracy. The area under the curve (AUC) was 0.855. The statistical analyses for DTP scans of 35 TEN patients demonstrated 74.3% accuracy and 0.838 AUC for the early scan versus 82.9% and 0.825 for the delayed scan. The MLR analysis indicated that mediastinal fat infiltration was a predictor of carcinoma. The ROC curve obtained for the model yielded an AUC of 0.853. Delayed scanning could improve the diagnostic capacity for carcinoma. The T/M ratio and mediastinal fat infiltration are predictive of carcinoma with moderate diagnostic accuracy., Competing Interests: No potential conflict of interest relevant to this article was reported.

Background: Patients with advanced or recurrent thymic epithelial tumors (TETs) often need several consecutive lines of chemotherapy. The aim of this retrospective monocentric study was to test whether 18 F-Fluorodeoxyglucose positron emission tomography-computed tomography ( 18 F-FDG PET-CT) is able to monitor standard chemotherapy efficacy in those patients and whether metabolic response correlates with morphovolumetric response as assessed by Response Evaluation Criteria in Solid Tumor (RECIST)., Methods: We evaluated 27 consecutive patients with advanced (16 patients) or recurrent (11 patients) TETs. All patients underwent 18 F-FDG PET-CT before and after at least 3 cycles of chemotherapy. Maximum standardized uptake value (SUV max ) of all detected lesions was recorded and the most 18 F-FDG avid lesion in each patient was selected for determination of percentage change of SUV max (ΔSUV max ) in pre- and post-treatment scans. Tumor response was assessed by contrast-enhanced computed tomography (CE-CT) using RECIST criteria. Receiver operating characteristic (ROC) curve analysis was performed to define the optimal threshold of ΔSUV max discriminating responders from non-responders., Results: Metabolic response expressed as ΔSUV max was significantly correlated with morphovolumetric response (Spearman's rank correlation, r = 0.64, p = 0.001). ROC curve analysis showed that a ΔSUV max value of -25% could discriminate responders from non-responders with a sensitivity of 88% and a specificity of 80%. Conversely, basal SUV max values were not predictive of morphovolumetric tumor response., Conclusions: Our findings indicate that metabolic response assessed by 18 F-FDG PET-CT, through evaluation of ΔSUV max , may allow identification of responders and non-responders thus guiding adaptation of therapy in patients with advanced or recurrent TETs.

A 59-year-old woman with back pain underwent an F-NaF PET/CT bone scan. Unexpectedly, multiple foci of increased tracer uptake were present in the abdomen and pelvis, which corresponded to the calcified soft tissue masses. The subsequent F-FDG PET/CT not only confirmed increased FDG activity in these partially calcified mass but also revealed abnormal activity in noncalcified lesions. The pathological examination demonstrated that the patient had ovarian cancer.

Purpose: To evaluate the clinical usefulness of the results obtained with (18)F-FDG PET/CT in relation to CT in the preoperative staging of patients with peritoneal carcinomatosis secondary to primary or recurrent ovarian cancer candidates to cytoreductive surgery and hyperthermic intraoperative intraperitoneal chemotherapy (HIPEC)., Material and Methods: A retrospective study comparing the results obtained with CT and (18)F-FDG PET/CT in the preoperative evaluation of a series of 59 patients was performed. In all patients the peritoneal carcinomatosis index (PCI) was determined by preoperative radiological CT and 18F-FDG PET/CT and compared with surgical PCI, which was considered as reference., Results: Of the 59 patients studied, in 55 peritoneal carcinomatosis presences were confirmed (4 patients had complete responses to neoadjuvant chemotherapy). The mean surgical, CT and 18F-FDG PET/CT PCI was 9.46±7.70, 3.69±3.96 and 2.25±1.02, respectively. In the global disease detection, CT showed a higher positive likelihood ratio (LR+) than (18)F-FDG PET/CT (15.3, 95% CI 8.35-28.04 vs. 3.47, 95% CI 3.36-5.11) and a lower negative likelihood ratio (LR-) than 18F-FDG PET/CT (0.67, 95% CI 0.61-0.73 vs. 0.82, 95% CI 0.76-0.88). In every region of the abdomen the CT showed a greater LR+ than 18F-FDG PET/CT and a lower LR- than 18F-FDG PET/CT., Conclusions: CT showed the best diagnostic results compared to (18)F-FDG PET/CT to confirme the presence of peritoneal disease. The lower performance of the (18)F-FDG PET/CT suggests that the main utility of (18)F-FDG PET/CT is to evaluate a possible metastatic extraperitoneal spread of the disease., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Objective: We aimed to explore the ability of textural heterogeneity indices determined by (18)F-FDG PET/CT for grading the malignancy of thymic epithelial tumors (TETs)., Methods: We retrospectively enrolled 47 patients with pathologically proven TETs who underwent pre-treatment (18)F-FDG PET/CT. TETs were classified by pathological results into three subgroups with increasing grades of malignancy: low-risk thymoma (LRT; WHO classification A, AB and B1), high-risk thymoma (B2 and B3), and thymic carcinoma (TC). Using (18)F-FDG PET/CT, we obtained conventional imaging indices including SUVmax and 20 intratumoral heterogeneity indices: i.e., four local-scale indices derived from the neighborhood gray-tone difference matrix (NGTDM), eight regional-scale indices from the gray-level run-length matrix (GLRLM), and eight regional-scale indices from the gray-level size zone matrix (GLSZM). Area under the receiver operating characteristic curve (AUC) was used to demonstrate the abilities of the imaging indices for differentiating subgroups. Multivariable logistic regression analysis was performed to show the independent significance of the textural indices. Combined criteria using optimal cutoff values of the SUVmax and a best-performing heterogeneity index were applied to investigate whether they improved differentiation between the subgroups., Results: Most of the GLRLM and GLSZM indices and the SUVmax showed good or fair discrimination (AUC >0.7) with best performance for some of the GLRLM indices and the SUVmax, whereas the NGTDM indices showed relatively inferior performance. The discriminative ability of some of the GLSZM indices was independent from that of SUVmax in multivariate analysis. Combined use of the SUVmax and a GLSZM index improved positive predictive values for LRT and TC., Conclusions: Texture analysis of (18)F-FDG PET/CT scans has the potential to differentiate between TET tumor grades; regional-scale indices from GLRLM and GLSZM perform better than local-scale indices from the NGTDM. The SUVmax and heterogeneity indices may have complementary value in differentiating TET subgroups.