Abstract 2576: Radiomic features of intrathoracic lesions can predict the mixed response in non-small cell lung cancer treated with immunotherapy

Abstract

Abstract Background: Although immunotherapy has emerged as a promising treatment for lung cancer, the decision to continue immunotherapy becomes challenging when mixed response (MR) occurs. This study is aimed to evaluate whether radiomic features from pre-treatment intrathoracic images can predict MR. Methods: 127 consecutive patients with NSCLC who received first line systemic treatment containing immunotherapy were included in this study. Chest CT scans were obtained at baseline and 1-3 times from 11 different CT scanners and harmonization method was applied to minimize scanner-related bias. The durable response of intrathoracic lesions (n=266) at least 24 weeks was evaluated based on RECIST 1.1 and irRECIST. MR was defined as the simultaneous presence of at least one lesion that increased and decreased in a single patient during immunotherapy and two different criteria of MR for the change of tumor lesions were applied: Definition-A (MR-A), Δ [baseline - first follow-up] ≥ 5 mm; Definition-B (MR-B), any change of Δ [baseline - first follow-up]. All intrathoracic lesions were identified and segmented by four different physicians. Radiomic features, including morphological, intensity, GLCM, GLRLM, GLSZM, and NGTDM, were extracted using LIFEX software (IMIV/CEA, Orsay, France). Confusion matrix was used to assess tumor responses, and area under the curve (AUC) for intrathoracic lesions was calculated. Results: Tumor responses based on irRECIST were CR (n=1, 0.8%), PR (n=33, 26.0%), SD (n=55, 43.3%), and PD (n=39, 30.7%). There were 10 cases (7.9%) of MR-A and 25 cases (19.7%) of MR-B. While the median progression-free survival (PFS) and overall survival (OS) in MR-A group were 22.9 (range, 0.5-50.6) and 23.5 (range, 1.1-42.2) months, those in MR-B group were 2.0 (range, 0.5-50.6) and 3.3 (range, 0.7-49.0) months respectively. While the overall sensitivity (SN) and specificity (SP) for MR-A in intrathoracic lesions were 0.55 and 0.87, those for MR-B were 0.52 and 0.71, respectively. The AUC for MR-A and MR-B were 0.71 and 0.62 respectively, and the AUC for durable response was 0.56. In the SD group, median PFS and OS were 3.3 (1.4-18.9) and 6.1 (4.8-26.2) in the MR-A group and 9.7 (0.7-18.9) and 23.9 (0.7-26.2) respectively in the MR-B group. Median PFS and OS were 18.2 (0.5-65.2) and 23.9 (0.9-55.3) respectively in the non-MR-A group and 18.2 (0.5-65.2) and 23.9 (0.9-55.3) respectively in the non-MR-B group. In the PD group, median PFS and OS were 23.5 (0.5-41.3) and 24.7 (1.1-42.2) respectively in the MR-A group and 5.1 (0.5-41.3) and 11.5 (1.1-49.0) respectively in the MR-B group. Median PFS and OS were 20.3 (0.7-71.4) and 37.1 (1.0-72.9) respectively in the non-MR-A group and 20.3 (0.7-71.4) and 37.1 (1.0-72.9) respectively in the non-MR-B group. Conclusion: The radiomic features in NSCLC patients who received immunotherapy may help predict MR in NSCLC patients treated with immunotherapy. Citation Format: Monica Yadav, Jeeyeon Lee, Peter Haseok Kim, Maria J. Chuchuca, Taegyu Um, Liam Il-Young Chung, Yury S. Velichko, Young Kwang Chae. Radiomic features of intrathoracic lesions can predict the mixed response in non-small cell lung cancer treated with immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2576.