Quantitative assessment of vasculature with DCE-MRI in nasopharyngeal carcinomas following radiotherapy and its value for efficacy evaluation
10.3969/j.issn.1673-4254.2015.07.05
- VernacularTitle:DCE-MRI定量参数评价放疗前后鼻咽癌肿瘤血管变化及其对预后评估的价值
- Author:
Weihua LIAO
1
;
Lifang YANG
;
Wuzhong JIANG
;
Lunquan SUN
;
Ya CAO
;
Xiaoyi WANG
Author Information
1. 中南大学湘雅医院放射科
- Keywords:
nasopharyngeal carcinoma;
radiotherapy;
tumor angiogenesis;
magnetic resonance imaging;
dynamic enhancement
- From:
Journal of Southern Medical University
2015;(7):954-959
- CountryChina
- Language:Chinese
-
Abstract:
Objective To study the changes in quantitative kinetic parameters in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) during radiotherapy and their value for efficacy evaluation in patients with nasopharyngeal carcinoma (NPC). Methods Twenty-four patients with NPC that had been pathologically confirmed as poorly differentiated squamous cell carcinoma underwent conventional MRI and DCE-MRI scans 1-2 days before radiotherapy (Pre-RT), during radiotherapy (RT 50 Gy), and upon completion of radiotherapy (RT 70 Gy). Based on the two-compartment model and using the arterial input function deconvolution technique, we calculated the quantitative kinetic parameters of DCE-MRI (Ktrans, kep, and Ve) of the tumor tissues, examined the correlation between the tumor regression rate (RS0-50) and the parameters on Pre-RT and RT 50 Gy, and compared the parameters for RT 70 Gy among the groups with different prognosis. Results The Ktrans value of the tumor tissue decreased after radiotherapy and showed a significant difference between Pre-RT and RT 70 Gy, but not between Pre-RT and RT 50 Gy. The kep value decreased and Ve value increased after radiotherapy. The tumor regression rate was found to be positively correlated with the Ktrans value for Pre-RT (P=0.005) but negatively with the Ktrans value for RT 50 Gy (P=0.001). During the follow-up for 3 years, 5 patients died and 3 patients had distant metastases. No statistical differences in Ktrans, kep, or Ve were found between the groups with different prognosis. Conclusions The kinetic parameters in DCE-MRI, which vary significantly during radiotherapy, allow monitoring of tumor angiogenesis and vascular permeability and quantitative assessment of treatment efficacy for NPC. Ktrans value for Pre-RT and RT 50 Gy can serve as an indicator for early efficacy assessment of radiotherapy and for treatment adjustment, but its relation with the long-term outcomes awaits further study.
