Guerreiro F, van Houdt P J, Navest R J M, Hoekstra N, de Jong M, Heijnen B J, Zijlema S E, Verbist B, van der Heide U A, Astreinidou E
Department of Radiation Oncology, Leiden University Medical Center, Leiden, the Netherlands.
Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, the Netherlands.
Phys Imaging Radiat Oncol. 2024 Jul 3;31:100608. doi: 10.1016/j.phro.2024.100608. eCollection 2024 Jul.
Radiation-induced damage to the organs at risk (OARs) in head-and-neck cancer (HNC) patient can result in long-term complications. Quantitative magnetic resonance imaging (qMRI) techniques such as diffusion-weighted imaging (DWI), DIXON for fat fraction (FF) estimation and T mapping could potentially provide a spatial assessment of such damage. The goal of this study is to validate these qMRI techniques in terms of accuracy in phantoms and repeatability in-vivo across a broad selection of healthy OARs in the HN region.
Scanning was performed at a 3 T diagnostic MRI scanner, including the calculation of apparent diffusion coefficient (ADC) from DWI, FF and T maps. Phantoms were scanned to estimate the qMRI techniques bias using Bland-Altman statistics. Twenty-six healthy subjects were scanned twice in a test-retest study to determine repeatability. Repeatability coefficients (RC) were calculated for the parotid, submandibular, sublingual and tubarial salivary glands, oral cavity, pharyngeal constrictor muscle and brainstem. Additionally, a linear mixed-effect model analysis was used to evaluate the effect of subject-specific characteristics on the qMRI values.
Bias was 0.009x10 mm/s for ADC, -0.7 % for FF and -7.9 ms for T. RCs ranged 0.11-0.25x10 mm/s for ADC, 1.2-6.3 % for FF and 2.5-6.3 ms for T. A significant positive linear relationship between age and the FF and T for some of the OARs was found.
These qMRI techniques are feasible, accurate and repeatable, which is promising for treatment response monitoring and/or differentiating between healthy and unhealthy tissues due to radiation-induced damage in HNC patients.
头颈部癌（HNC）患者中，辐射对危及器官（OARs）造成的损伤可导致长期并发症。定量磁共振成像（qMRI）技术，如扩散加权成像（DWI）、用于脂肪分数（FF）估计的DIXON和T值映射，有可能提供此类损伤的空间评估。本研究的目的是在体模准确性和针对HN区域广泛选择的健康OARs进行的体内重复性方面验证这些qMRI技术。
在3T诊断MRI扫描仪上进行扫描，包括从DWI、FF和T值映射计算表观扩散系数（ADC）。扫描体模以使用Bland-Altman统计方法估计qMRI技术偏差。在一项重测研究中对26名健康受试者进行了两次扫描以确定重复性。计算了腮腺、颌下腺、舌下腺和咽鼓管唾液腺、口腔、咽缩肌和脑干的重复性系数（RC）。此外，使用线性混合效应模型分析来评估个体特征对qMRI值的影响。
ADC的偏差为0.009×10⁻³mm²/s，FF为-0.7%，T为-7.9ms。ADC的RC范围为0.11 - 0.25×10⁻³mm²/s，FF为1.2 - 6.3%，T为2.5 - 6.3ms。发现年龄与某些OARs的FF和T之间存在显著的正线性关系。
这些qMRI技术是可行、准确且可重复的，这对于监测HNC患者的治疗反应和/或区分因辐射损伤导致的健康与不健康组织很有前景。
