The CT appearance pattern of radiation-induced lung injury and tumor recurrence after stereotactic body radiation therapy in early stage non-small cell lung cancer

Qian Li; Yu Liu; Bin Su; Hongguang Zhao; Qingren Lin; Yaoyao Zhu; Lingnan Zhang; Denghu Weng; Xiaomei Gong; Xiaojiang Sun; Yaping Xu

doi:10.21037/tlcr-20-609

The CT appearance pattern of radiation-induced lung injury and tumor recurrence after stereotactic body radiation therapy in early stage non-small cell lung cancer

Transl Lung Cancer Res. 2020 Jun;9(3):713-721. doi: 10.21037/tlcr-20-609.

Authors

Qian Li¹, Yu Liu¹, Bin Su¹, Hongguang Zhao¹, Qingren Lin², Yaoyao Zhu¹, Lingnan Zhang³, Denghu Weng², Xiaomei Gong¹, Xiaojiang Sun², Yaping Xu¹

Affiliations

¹ Department of Radiation Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.
² Department of Radiation Oncology, Cancer Hospital of University of Chinese Academy of Sciences, Hangzhou, China.
³ Department of Radiology, Cancer Hospital of University of Chinese Academy of Sciences, Hangzhou, China.

Abstract

Background: Radiographic changes after stereotactic body radiation therapy (SBRT) have not been well studied. The purpose of this study was to investigate the computed tomography (CT) appearance pattern of radiation-induced lung injury (RILI) and recurrence after SBRT in patients with early stage non-small cell lung cancer (NSCLC).

Methods: We retrospectively analyzed clinical data of inoperable early stage NSCLC patients undergoing SBRT treatment from February 2012 to June 2018. All patients had undergone serial CT scanning before SBRT and after completion of SBRT. An experienced radiation oncologist and radiologist reviewed all CT images, and identified the RILI and CT high-risk features (HRFs).

Results: A total of 60 patients were enrolled in this study; 55 patients had RILI (91.67%) and 7 patients had local failure. In the early CT findings of observers 1 and 2, there were diffuse ground glass opacities (GGOs) in 3 and 4 patients, diffuse consolidation in 10 and 12 patients, patchy consolidation in 22 and 15 patients, patchy GGOs in 19 and 24 patients, and no changes in 5 and 4 patients, respectively (kappa =0.706). In the late CT findings of observer 1 and 2, there were modified conventional patterns in 37 and 37 patients, mass-like patterns in 10 and 9 patients, scar-like patterns in 7 and 8 patients, and no changes in 5 and 5 patients, respectively (kappa =0.726). In the results of the CT-based HRFs of disease local failure, there were ≥1 HRFs in 7 patients, ≥2 HRFs in 7 patients, ≥3 HRFs in 6 patients, ≥4 HRFs in 5 patients, and ≥5 HRFs in 3 patients, respectively. Patients with only 1 HRF showed high sensitivity (100%) and low specificity (52.80%), with the specificity increasing and the sensitivity decreasing as the number of HRFs increased.

Conclusions: The agreement of the CT appearance on RILI between 2 observers was good. Regular follow-up and attention to HRFs are vital for better identifying RILI and local disease failure.

Keywords: Radiation-induced lung injury (RILI); early stage non-small cell lung cancer; stereotactic body radiation therapy (SBRT); tumor recurrence.