AUTHOR=Li Junmeng , Zhang Chao , Guo Huihui , Li Shuang , You Yang , Zheng Peiming , Zhang Hongquan , Wang Huanan , Bai Junwei 

TITLE=Non-invasive measurement of tumor immune microenvironment and prediction of survival and chemotherapeutic benefits from 18F fluorodeoxyglucose PET/CT images in gastric cancer

JOURNAL=Frontiers in Immunology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.1019386

DOI=10.3389/fimmu.2022.1019386

ISSN=1664-3224

ABSTRACT=Background The tumor immune microenvironment could provide prognostic and predictive information. We aimed to develop a noninvasive radiomics-based biomarker of a previously validated tumor immune microenvironment signature of gastric cancer (GC) with immunohistochemistry staining. 
Methods: A total of 230 patients (training (n = 153) or validation (n = 77) cohort) with gastric cancer were subjected to radiomics feature extraction (80 features). A radiomics tumor immune microenvironment score (RTIMS) was developed to predict the tumor immune microenvironment signature by using LASSO logistic regression. We further evaluated its association with prognosis and chemotherapy benefits.
Results: A 8-feature radiomics signature was developed and validated (area under the curve=0.692 and 0.713). The RTIMS signature were significantly associated with disease-free survival and overall survival both in the training and validation cohort (all P<0.001). Multivariate analysis revealed that the RTIMS was an independent prognostic factor. Further analysis revealed that patients with a high RTIMS derived survival benefit from adjuvant chemotherapy (for DFS, stage II: HR 0.208(95% CI 0.061-0.711), p=0.012; stage III: HR 0.321(0.180-0.570), p<0.001, respectively); while those with a low RTIMS did not.
Conclusion This imaging predictor provided a promising way to assess the tumor immune microenvironment and to infer clinical outcomes and chemotherapy response. The RTIMS signature could be useful in estimating tumor immune microenvironment and predicting survival and chemotherapy benefit for patients with gastric cancer, when validated by further prospective randomized trials.