Abstract
Background and purpose: Regarding the altered tumor immune status following cytotoxic treatment, this study aims to develop a radiomic signature to predict CD8+ tumor-infiltrating lymphocyte (TIL) density changes in chemoradiotherapy (CRT) of rectal cancer. Materials and methods: We used the magnetic resonance imaging (MRI) and immunohistochemistry data before and after neoadjuvant CRT. The discovery datasets consisted of pre-CRT dataset A1 (n = 113), post-CRT datasets A2 (n = 32; predominance of tumor) and A3 (n = 20; pure fibrosis). The developed model was validated in dataset B (n = 28). Thirty-eight radiomic features from T2-weighted MRI scans were incorporated into the least absolute shrinkage and selection operator method. Results: In pre-CRT dataset A1, the area under the receiver operating characteristic curve (AUC) values of radiomic score for predicting CD8+ TILs were 0.760 and 0.729 for training and validation subsets, respectively. A significant correlation was observed between the signature and CD8+ TIL density in the post-CRT dataset A2 (Pearson's R = −0.372, P = 0.036), whereas no association was found in dataset A3 (Pearson's R = −0.069, P = 0.77). The association was also observed in the validation dataset B (Pearson's R = −0.374, P = 0.049). In dataset A2, the radiomic score difference predicted changes in CD8+ TIL density (AUC = 0.824). Conclusion: We established the MRI-derived radiomic signature for predicting CRT-induced alterations in CD8+ TILs. This study suggests the clinical utility of radiomics-immunophenotype modeling to evaluate tumor immune status following neoadjuvant chemoradiation in rectal cancer.
Original language | English |
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Pages (from-to) | 124-131 |
Number of pages | 8 |
Journal | Radiotherapy and Oncology |
Volume | 162 |
DOIs | |
State | Published - Sep 2021 |
Bibliographical note
Publisher Copyright:© 2021 Elsevier B.V.
Keywords
- CD8-positive T-lymphocytes
- Chemoradiotherapy
- Neoadjuvant therapy
- Radiomic score
- Radiomics
- Rectal neoplasms