Department of Diagnostic and Interventional Radiology, and Nuclear Medicine, Pisa University Hospital, Pisa, Italy.
Diagnostic and Interventional Radiology, University of Pisa, Pisa, Italy.
Colorectal Dis. 2023 May;25(5):905-915. doi: 10.1111/codi.16483. Epub 2023 Feb 20.
To assess the diagnostic value of apparent diffusion coefficient (ADC) on 3 T device for the prediction of tumoral response to neoadjuvant chemoradiotherapy (nCRT) and for the response assessment after nCRT in patients with locally advanced rectal cancer (LARC), using pathology as a reference.
Forty-one patients affected by LARC undergoing 3.0 T MRI before and after nCRT were retrospectively selected. After the conventional acquisition of high resolution T2-weighted sequences, diffusion-weighted MRI (DW-MRI) was performed using a spin-echo echo-planar sequence with multiple b values (150, 500, 1000, 1500 s/mm ). Fitted ADC values were calculated for each rectal lesion before and after nCRT by drawing a hand-made region of interest (ROI) around the tumour outline. All patients underwent surgery and pathological staging (classified according to tumour regression grading [TRG] and to tumour and node [TN]) represented the reference standard. Pretreatment ADC value (pre-ADC), ADC value obtained after nCRT (post-ADC) and the difference between post-ADC and pre-ADC (ΔADC) were correlated with both the TRG classes and the TN staging system in each patient.
The ADC values obtained in the post nCRT examination and the ΔADC were statistically related both to TRG (p = 0.0004; p = 0.0126, respectively) and TN (p = 0.0484; p = 0.0673, respectively) stages at histopathology. On the contrary, the pre-ADC was not related either to the TRG classes or to the lesion TN staging system (p > 0.05).
3 T DW-MRI using ADC value can be useful to assess the efficacy of nCRT in LARC; in fact, post-ADC and ΔADC values improve MR capability to evaluate tumour response.
在 3T 设备上评估表观扩散系数（ADC）对新辅助放化疗（nCRT）后预测肿瘤反应的诊断价值，并在局部晚期直肠癌（LARC）患者 nCRT 后评估反应，以病理为参考。
回顾性选择 41 例接受 nCRT 前后 3.0T MRI 的 LARC 患者。在进行高分辨率 T2 加权序列的常规采集后，使用自旋回波回波平面序列进行扩散加权 MRI（DW-MRI），使用多个 b 值（150、500、1000、1500s/mm）。通过在肿瘤轮廓周围手动绘制感兴趣区（ROI），计算 nCRT 前后每个直肠病变的拟合 ADC 值。所有患者均接受手术和病理分期（根据肿瘤消退分级[TRG]和肿瘤与淋巴结[TN]分类），代表参考标准。治疗前 ADC 值（pre-ADC）、nCRT 后 ADC 值（post-ADC）和 post-ADC 与 pre-ADC 之间的差异（ΔADC）与每位患者的 TRG 分级和 TN 分期系统相关。
nCRT 后检查获得的 ADC 值和 ΔADC 值与 TRG（p=0.0004；p=0.0126）和 TN（p=0.0484；p=0.0673）分期均有统计学意义。相反，pre-ADC 与 TRG 分级或病变 TN 分期系统均无相关性（p>0.05）。
3T DW-MRI 使用 ADC 值可用于评估 nCRT 治疗 LARC 的疗效；事实上，post-ADC 和 ΔADC 值提高了 MRI 评估肿瘤反应的能力。
