Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan, USA.
Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA.
J Magn Reson Imaging. 2024 Mar;59(3):929-938. doi: 10.1002/jmri.28831. Epub 2023 Jun 27.
Apparent diffusion coefficient is not specifically sensitive to tumor microstructure and therapy-induced cellular changes.
To investigate time-dependent diffusion imaging with the short-time-limit random walk with barriers model (STL-RWBM) for quantifying microstructure parameters and early cancer cellular response to therapy.
Prospective.
Twenty-seven patients (median age of 58 years and 7.4% of females) with p16+/p16- oropharyngeal/oral cavity squamous cell carcinomas (OPSCC/OCSCC) underwent MRI scans before therapy, of which 16 patients had second scans at 2 weeks of the 7-weeks chemoradiation therapy (CRT).
FIELD STRENGTH/SEQUENCE: 3-T, diffusion sequence with oscillating gradient spine echo (OGSE) and pulse gradient spin echo (PGSE).
Diffusion weighted images were acquired using OGSE and PGSE. Effective diffusion times were derived for the STL-RWBM to estimate free diffusion coefficient D , volume-to-surface area ratio of cellular membranes V/S, and cell membrane permeability κ. Mean values of these parameters were calculated in tumor volumes.
Tumor microstructure parameters were compared with clinical stages of p16+ I-II OPSCC, p16+ III OPSCC, and p16- IV OCSCC by Spearman's rank correlation and with digital pathological analysis of a resected tissue sample. Tumor microstructure parameter responses during CRT in the 16 patients were assessed by paired t-tests. A P-value of <0.05 was considered statistically significant.
The derived effective diffusion times affected estimated values of V/S and κ by 40%. The tumor V/S values were significantly correlated with clinical stages (r = 0.47) as an increase from low to high clinical stages. The in vivo estimated cell size agreed with one from pathological analysis of a tissue sample. Early tumor cellular responses showed a significant increase in D (14%, P = 0.03) and non-significant increases in κ (56%, P = 0.6) and V/S (10%, P = 0.1).
Effective diffusion time estimation might impact microstructure parameter estimation. The tumor V/S was correlated with OPSCC/OCSCC clinical stages.
1 TECHNICAL EFFICACY STAGE: 1.
表观扩散系数对肿瘤微结构和治疗引起的细胞变化并不敏感。
利用限时随机游走障碍模型（STL-RWBM）研究扩散成像的时间依赖性，以定量测量微结构参数和癌症早期的细胞对治疗的反应。
前瞻性。
27 例（中位年龄 58 岁，女性占 7.4%）患有 p16+/p16-口咽/口腔鳞状细胞癌（OPSCC/OCSCC）的患者在治疗前进行了 MRI 扫描，其中 16 例患者在 7 周放化疗（CRT）的第 2 周进行了第二次扫描。
磁场强度/序列：3-T，扩散序列采用振荡梯度自旋回波（OGSE）和脉冲梯度自旋回波（PGSE）。
采用 OGSE 和 PGSE 采集扩散加权图像。利用 STL-RWBM 推导出有效扩散时间，以估计自由扩散系数 D、细胞膜的体积-表面积比 V/S 和细胞膜通透性 κ。在肿瘤体积中计算这些参数的平均值。
采用 Spearman 秩相关分析将肿瘤微结构参数与 p16+I-II OPSCC、p16+III OPSCC 和 p16- IV OCSCC 的临床分期进行比较，并与切除组织样本的数字病理分析进行比较。对 16 例患者 CRT 期间的肿瘤微结构参数变化进行配对 t 检验。P 值<0.05 被认为具有统计学意义。
推导出的有效扩散时间会影响 V/S 和 κ 的估计值，影响幅度为 40%。肿瘤 V/S 值与临床分期显著相关（r=0.47），从低到高的临床分期呈递增趋势。体内估计的细胞大小与组织样本的病理分析结果一致。早期肿瘤细胞反应表现为 D 显著增加（14%，P=0.03），κ 略有增加（56%，P=0.6），V/S 略有增加（10%，P=0.1）。
有效扩散时间的估计可能会影响微结构参数的估计。肿瘤 V/S 与 OPSCC/OCSCC 的临床分期相关。
1 技术功效分期：1。
