Post-RT Head and Neck DCE-MRI: Association Between Mandibular Dose and v_e.

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) quantifies tissue permeability and blood flow.
• Radiation therapy (RT) alters vasculature, potentially changing DCE-MRI parameters in different dose regions.
• This study investigates DCE-MRI parameter differences in the mandible post-head and neck cancer (HNC) RT.

Purpose of the Study:

• To determine if significant differences exist in DCE-MRI quantitative parameters (K^trans and v_e) between high-dose (>60 Gy) and low-dose (≤60 Gy) regions of the mandible after HNC RT.
• To assess the utility of DCE-MRI in monitoring radiation-induced changes in mandible vasculature.

Main Methods:

• DCE-MRI data from HNC patients post-RT were analyzed.
• K^trans and v_e parameters were calculated using Tofts model fitting.
• Mandible regions (ramus and body, left and right) were delineated, and statistical tests (Friedman, Wilcoxon signed-rank) compared parameters between low-dose regions and between high-dose and low-dose regions.

Main Results:

• Analysis included 48 HNC subjects.
• No significant difference in v_e was found between mandible regions, but K^trans showed significant differences between ramus and body regions.
• A significant difference in v_e was observed between high-dose and low-dose mandible regions (p = 0.00013).

Conclusions:

• No inherent difference in v_e was found within the mandible, but significant differences exist between high- and low-radiation-dose regions.
• DCE-MRI is effective in monitoring mandible vasculature changes after HNC RT.
• Monitoring these changes can aid in early toxicity management and improve survivor quality of life.