Changes in apparent diffusion coefficient radiomics features during dose-painted radiotherapy and high dose rate brachytherapy for prostate cancer

• Published in: Physics and imaging in radiation oncology 2019-01, Vol.9, p.1-6
• Main Authors: Lee, Sangjune Laurence, Lee, Jenny, Craig, Tim, Berlin, Alejandro, Chung, Peter, Ménard, Cynthia, Foltz, Warren D.
• Format: Article
• Language: English
• Subjects: Apparent diffusion coefficient; Diffusion-weighted MRI; Dose-painted radiotherapy; High dose rate brachytherapy; Original; Prostate cancer; Radiomics
• ISSN: 2405-6316; 2405-6316
• DOI: 10.1016/j.phro.2018.11.006

Dose escalation has improved cancer outcomes for patients with localized prostate cancer. Targeting subprostatic tumor regions for dose intensification may further improve outcomes. Apparent Diffusion Coefficient (ADC) maps may enable early radiation response assessment and dose adaptation. This study was a proof-of-principle investigation of early changes in ADC radiomics features for patients undergoing radiotherapy with dose escalation to the gross tumor volume (GTV). Fifty-nine patients were enrolled on a prospective tumor dose-escalation trial. Multi-parametric MRI was performed at baseline and week six, corresponding to the time of peak ADC change. GTV and prostate contours were deformably registered between baseline and week six T2-weighted images, and applied to ADC maps, to account for diminished image contrast post-EBRT and possible differences in prostate gland volume, shape, and orientation. A total of 101 radiomics features were tested for significant change post-EBRT using two-tailed Student’s t-test. All ADC features of the prostate and GTV volumes were correlated using Pearson’s coefficient (p