Clinical value of fluorine-18-fluorodeoxyglucose PET/MRI for liver metastasis in colorectal cancer: a prospective study.

PURPOSE: To evaluate the diagnostic performance of liver 18F-FDG PET/MRI in addition to whole-body PET/CT and to compare it with MRI in the detection and clinical management of liver metastasis in patients with colorectal cancer (CRC). MATERIAL AND METHODS: Seventy-eight patients with CRC who underwent whole-body 18F-FDG PET/CT followed by liver PET/MRI were prospectively included. Histopathological confirmation and/or at least 3 months of clinical follow-up after PET/MRI were accepted as gold standard. Lesion and patient-based analyses were performed to evaluate the diagnostics performances of PET/CT, PET/MRI and MRI. In addition, changes of clinical management were evaluated. RESULTS: On lesion-based analysis, for PET/CT, PET/MRI and MRI; sensitivity (Se): 55.6%, 97.2% and 100%; specificity (Sp): 98.5%, 100% and 80.5%; and accuracy (Acc): 70.7%, 98.2% and 93.1% were calculated, respectively. Se and Acc of PET/MRI and MRI were significantly superior than PET/CT (P < 0.001). Se and Acc of PET/MRI and MRI were comparable; however, Sp of PET/MRI was significantly better than MRI (P < 0.001). On patient-based analysis, Se: 75.6%, 100% and 100%; Sp: 97.3%, 100% and 86.5%; and Acc: 85.9%, 100% and 93.5% were calculated, respectively. Se and Acc of PET/MRI were significantly superior than PET/CT (P < 0.001). Also, Se of MRI was significantly superior than PET/CT (P < 0.001). Se of PET/MRI and MRI were comparable, but Sp and Acc of PET/MRI were significantly better than MRI. The additional information obtained from liver PET/MRI changed treatment strategy in 14/78 (18%) patients compared to PET/CT or alone liver MRI. CONCLUSION: Diagnostic performances of PET/MRI and MRI for detection of CRC liver metastasis is superior to PET/CT. PET/MRI especially helps in the accurate detection of liver metastases that are suspicious on MRI and has the potential to change the clinical management of especially oligometastatic patients by identifying uncertain liver lesions.

Can Radiomics Analyses in 18F-FDG PET/CT Images of Primary Breast Carcinoma Predict Hormone Receptor Status?

OBJECTIVES: This study aimed to investigate the role of preoperative 18fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) radiomics features and metabolic parameters of primary breast tumors in predicting hormone receptor (HR) positivity. METHODS: A total of 153 patients with breast carcinoma who underwent preoperative 18F-FDG PET/CT were included. All PET/CT images were retrospectively reevaluated. Radiomics features of primary breast lesions reflecting tumor heterogeneity as well as standardized uptake value (SUV) metrics (SUVmin, SUVmean, SUVmax, and SUVpeak) and volumetric parameters such as metabolic tumor volume and total lesion glycolysis (TLG) were extracted by commercial texture analysis software package (LIFEx; https://www.lifexsoft.org/ index.php). WEKA and SPSS were used for statistical analysis. Binary logistic regression analysis was used to determine texture features predicting HR positivity. Accuracy, F-measure, precision, recall, and precision-recall curve area were used as data-mining performance criteria of texture features to predict HR positivity. RESULTS: None of the radiomics parameters were significant in predicting HR status. Only SUV metrics and TLG were statistically important. Mean ± standard deviations for SUVmean, SUVmax, and SUVpeak for the HR-negative group were significantly higher than those in the HR-positive group (6.73±4.36 vs. 5.20±3.32, p=0.027; 11.55±7.42 vs. 8.63±5.23, p=0.006; and 8.37±6.81 vs. 5.72±4.86; p=0.012). Cut-off values of SUVmean, SUVmax, and SUVpeak for the prediction of HR positivity were 4.93, 8.35, and 6.02, respectively. Among data-mining methods, logistic regression showed the best performance with accuracy of 0.762. CONCLUSION: In addition to the relatively limited number of patients in this study, radiomics parameters cannot predict the HR status of primary breast cancer. SUV levels of the HR-negative group were significantly higher than those of the HR-positive group. To clarify the role of metabolic and radiomics parameters in predicting HR status in breast cancer, further studies involving a larger study population are needed.

Negative Histopathological Prognostic Factors Affecting Morbidity in T1 Differentiated Thyroid Carcinoma.

Background: The aim was to evaluate: (i) if multifocality is a negative prognostic factor; and (ii) the association of diameter of the largest tumor, total tumor diameter, and the ratio of the largest tumor diameter to total tumor diameter (DR) with histopathological and clinical outcome parameters in T1 differentiated thyroid carcinoma (DTC). Materials and Methods: In 1014 T1N0/1Mx patients, correlation between multifocality, contralateral lobe involvement, capsular-vascular invasion, diameter of the largest tumor, total tumor diameter, DR, and follow-up results were investigated. Results: Persistent/recurrent disease and necessity for additional radioiodine treatment (RAIT) were more frequent in cases with multifocality and contralateral lobe involvement (p = 0.035, p = 0.015, p = 0.021, and p = 0.04). Persistence/recurrence, reoperation in the neck, and additional RAIT were more frequent in patients with the size of the largest tumor focus >1 cm (p = 0.024, p < 0.001, and p = 0.002) and N1 status (p < 0.001, p < 0.001, and p < 0.001). Mean total tumor diameter was higher in patients with capsular invasion, contralateral lobe, and lymph node involvement (p = 0.001, p = 0.003, and p = 0.013). Conclusion: Multifocality, contralateral lobe involvement, diameter of the largest tumor >1 cm, and N1 status are related with increased risk of disease persistence, recurrence, reoperation, and additional RAIT. Sum of diameter of all tumor foci are associated with capsular invasion.