Time-dependent diffusion MRI study of chemoradiation treatment response in patients with HPV positive oropharyngeal carcinoma

In this study, we evaluated the time-dependence of diffusivity and kurtosis in HPV-positive oropharyngeal squamous cell carcinoma patients before and during chemo-radiation treatment, as part of a study for adaptive de-escalation of the therapy. The non-deescalated patients with less than 40% nodal shrinkage had significantly higher diffusivity and lower kurtosis at pre-treatment than the de-escalated patients with more than 40% nodal volume shrinkage. The water exchange times were longer in the de-escalated patients than in the non-deescalated patients, although not significant. The prognostic accuracy of the pre-treatment imaging parameters was between 0.7 and 0.85.