The purpose of this study was to determine if parameters derived from diffusion-weighted (DW-) and dynamic contrast-enhanced (DCE-) magnetic resonance imaging (MRI) can help to assess early response to peptide receptor radionuclide therapy (PRRT) with 90Y-DOTATOC in neuroendocrine hepatic metastases (NET-HM). Twenty patients (10 male; 10 female; mean age: 59.2 years) with NET-HM were prospectively enrolled in this single-center imaging study. DW-MRI and DCE-MRI studies were performed just before and 48 hours after therapy with 90Y-DOTATOC. Abdominal SPECT/CT was performed 24 hours after therapy. This MRI imaging and therapy session was repeated after a mean interval of 10 weeks. Up to four lesions per patient were evaluated. Response to therapy was evaluated using metastasis sizes at the first and second therapy session as standard for comparison (regressive, stable, and progressive). DW-MRI analysis included the apparent diffusion coefficient (ADC) and parameters related to intravoxel incoherent motion (IVIM), namely, diffusion (D), perfusion fraction (f) and pseudo-diffusion (D ∗ ). DCE-MRI analysis comprised Ktrans, v e and k ep. For statistical analysis of group differences, one-way analysis of variance (ANOVA) and appropriate post hoc testing was performed. A total of 51 lesions were evaluated. Seven of 51 lesions (14%) showed size progression, 18/51 (35%) regression, and 26/51 (51%) remained stable. The lesion-to-spleen uptake ratio in SPECT showed a decrease between the two treatment sessions that was significantly stronger in regressive lesions compared with stable (p = 0.013) and progressive lesions (p = 0.021). ANOVA showed significant differences in mean ADC after 48 h (p = 0.026), with higher ADC values for regressive lesions. Regarding IVIM, highest values for D at baseline were seen in regressive lesions (p = 0.023). In DCE-MRI, a statistically significant increase in v e after 10 weeks (p = 0.046) was found in regressive lesions. No differences were observed for the transfer constants Ktrans and k ep. Diffusion restriction quantified as ADC was able to differentiate regressive from progressive NET-HMs as early as 48 hours after PRRT. DW-MRI therefore may complement scintigraphy/SPECT for early assessment of response to PRRT. Assessment of perfusion parameters using IVIM and DCE-MRI did not show an additional benefit.

中文翻译：

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扩散加权和动态对比增强MRI预测90Y-DOTATOC肽受体放射性核素治疗后神经内分泌肝转移的治疗反应。

这项研究的目的是确定源自扩散加权（DW-）和动态对比增强（DCE-）磁共振成像（MRI）的参数是否可以帮助评估90Y对肽受体放射性核素治疗（PRRT）的早期反应-DOTATOC在神经内分泌肝转移（NET-HM）中。这项单中心影像学研究前瞻性招募了20例NET-HM患者（10例男性； 10例女性；平均年龄：59.2岁）。在90Y-DOTATOC治疗之前和之后48小时进行了DW-MRI和DCE-MRI研究。治疗后24小时进行腹部SPECT / CT检查。平均间隔10周后重复进行MRI成像和治疗。每个患者最多评估四个病变。在治疗的第一和第二阶段，以转移灶的大小作为比较的标准（回归，稳定和进行性），评估对治疗的反应。DW-MRI分析包括表观扩散系数（ADC）和与体素内非相干运动（IVIM）相关的参数，即扩散（D），灌注分数（f）和伪扩散（D ∗）。DCE-MRI分析包括Ktrans，ve和k ep。为了对组差异进行统计分析，进行了单向方差分析（ANOVA）和适当的事后检验。总共评估了51个病变。51个病灶中有7个（14％）表现出大小进展，18/51（35％）消退，26/51（51％）保持稳定。SPECT中病灶与脾脏的摄取比率显示，两次治疗之间的下降较稳定病灶（p = 0.013）和进行性病灶（p = 0.021）的退行性病灶明显更强。方差分析显示48小时后，平均ADC值存在显着差异（p = 0.026），回归病变的ADC值较高。关于IVIM，在退行性病变中基线时的D最高值（p = 0.023）。在DCE-MRI中，回归性病变在10周后ve的统计学上显着增加（p = 0.046）。没有观察到转移常数Ktrans和kep的差异。量化扩散限制是因为ADC能够在PRRT后48小时内区分出渐进性NET-HMs与渐进性NET-HMs。因此，DW-MRI可以补充闪烁显像/ SPECT，以早期评估对PRRT的反应。