Intratumor Heterogeneity Characterized by Textural Features on Baseline ¹⁸F-FDG PET Images Predicts Response to Concomitant Radiochemotherapy in Esophageal Cancer

Abstract

18 F-FDG PET is often used in clinical routine for diagnosis, staging, and response to therapy assessment or prediction. The standardized uptake value (SUV) in the primary or regional area is the most common quantitative measurement derived from PET images used for those purposes. The aim of this study was to propose and evaluate new parameters obtained by textural analysis of baseline PET scans for the prediction of therapy response in esophageal cancer. Methods: Forty-one patients with newly diagnosed esophageal cancer treated with combined radiochemotherapy were included in this study. All patients underwent pretreatment whole-body 18 F-FDG PET. Patients were treated with radiotherapy and alkylatinlike agents (5-fluorouracil-cisplatin or 5-fluorouracil-carboplatin). Patients were classified as nonresponders (progressive or stable disease), partial responders, or complete responders according to the Response Evaluation Criteria in Solid Tumors. Different imagederived indices obtained from the pretreatment PET tumor images were considered. These included usual indices such as maximum SUV, peak SUV, and mean SUV and a total of 38 features (such as entropy, size, and magnitude of local and global heterogeneous and homogeneous tumor regions) extracted from the 5 different textures considered. The capacity of each parameter to classify patients with respect to response to therapy was assessed using the Kruskal-Wallis test (P , 0.05). Specificity and sensitivity (including 95% confidence intervals) for each of the studied parameters were derived using receiver-operatingcharacteristic curves. Results: Relationships between pairs of voxels, characterizing local tumor metabolic nonuniformities, were able to significantly differentiate all 3 patient groups (P , 0.0006). Regional measures of tumor characteristics, such as size of nonuniform metabolic regions and corresponding intensity nonuniformities within these regions, were also significant factors for prediction of response to therapy (P 5 0.0002). Receiver-operating-characteristic curve analysis showed that tumor textural analysis can provide nonresponder, partialresponder, and complete-responder patient identification with higher sensitivity (76%-92%) than any SUV measurement. Conclusion: Textural features of tumor metabolic distribution extracted from baseline 18 F-FDG PET images allow for the best stratification of esophageal carcinoma patients in the context of therapy-response prediction.

Reproducibility of F18‐FDG PET radiomic features for different cervical tumor segmentation methods, gray‐level discretization, and reconstruction algorithms

“…We investigated the reproducibility of several subtypes of GLCM entropy feature as they were reported as one the highest reproducible and predictive radiomic features 21, 27, 30. We included: Entropy, Summation Entropy, Difference Entropy in addition to first‐order Entropy (Intensity Histogram Entropy) .…”

Intratumoral heterogeneity of F-18 FDG uptake differentiates between gastrointestinal stromal tumors and abdominal malignant lymphomas on PET/CT

“…In many previous F-18 FDG PET studies, the tumor characteristics were usually evaluated by the 3D-SUV max , which reflected only a single voxel with the maximum uptake, and few PET studies have focused on the intratumoral distribution of F-18 FDG [1,3,15]. The CSH method that we applied in our study was recently reported for parameterizing heterogeneous intratumoral F-18 FDG uptake in non-small cell lung cancer PET studies [3].…”

“…Thus, evaluation of the intratumoral heterogeneity of F-18 FDG uptake may provide us with additional information about the tumor characteristics. A recent study reported that the detection of intratumoral metabolic heterogeneity on baseline F-18 FDG-PET is useful for predicting the response to concomitant radiochemotherapy in esophageal cancer [1]. However, no study has reported evaluation of the intratumoral distribution of F-18 FDG on PET to differentiate among tumors of unknown origin.…”

The precision of textural analysis in 18F-FDG-PET scans of oesophageal cancer

“…There are early reports that textural analysis, an additional tool quantifying intratumoural heterogeneity of 18 FDG-PET tracer uptake, may improve prediction of response and prognosis and it is hypothesised that image heterogeneity may be related to underlying biology and reflect the behaviour of malignant tumours [3][4][5][6][7].…”