Quantitative study of the changes in brain white matter before and after radiotherapy by applying multi-sequence MR radiomics
Mingming Chen, Lizhen Wang, Guanzhong Gong, Yong Yin, Pengcheng Wang
Abstract
PURPOSE: To analyse the changes in brain white matter before and after radiotherapy (RT) by applying multisequence MR radiomics features and to establish a relationship between the changes in radiomics features and radiation dose. METHODS: Eighty-eight patients with brain tumours who had undergone RT were selected in this study, and MR images (T1, T1+C, T2FLAIR, T2, DWI, and ASL) before and after RT were obtained. The brain white matter was delineated as an ROI under dose gradients of 0-5 Gy, 5-10 Gy, 10-15 Gy, 15-20 Gy, 20-30 Gy, 30-40 Gy, and 40-50 Gy. The radiomics features of each ROI were extracted, and the changes in radiomics features before and after RT for different sequences under different dose gradients were compared. RESULTS: At each dose gradient, statistically significant features of different MR sequences were mainly concentrated in three dose gradients, 5-10 Gy, 20-30 Gy, and 30-40 Gy. The T1+C sequence held the most features (66) under the 20-30 Gy dose gradient. There were 20 general features at dose gradients of 20-30 Gy, 30-40 Gy, and 40-50 Gy, and the changes in features first decreased and then increased following dose escalation. With dose gradients of 5-10 Gy and 10-15 Gy, only T1 and T2FLAIR had general features, and the rates of change were - 24.57% and - 29.32% for T1 and - 3.08% and - 10.87% for T2FLAIR, respectively. The changes showed an upward trend with increasing doses. For different MR sequences that were analysed under the same dose gradient, all sequences with 5-10 Gy, 20-30 Gy and 30-40 Gy had general features, except the T2FLAIR sequence, which was concentrated in the FirstOrder category feature, and the changes in features of T1 and T1+C were more significant than those of the other sequences. CONCLUSIONS: MR radiomics features revealed microscopic changes in brain white matter before and after RT, although there was no constant dose-effect relationship for each feature. The changes in radiomics features in different sequences could reveal the radiation response of brain white matter to different doses.