Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
Department of General Surgery, Medical University of Vienna, Vienna, Austria.
Eur J Nucl Med Mol Imaging. 2022 Dec;50(1):205-217. doi: 10.1007/s00259-022-05936-0. Epub 2022 Sep 5.
The purpose of this study was to determine whether multiparametric positron emission tomography/magnetic resonance imaging (mpPET/MRI) can improve locoregional staging of rectal cancer (RC) and to assess its prognostic value after resection.
In this retrospective study, 46 patients with primary RC, who underwent multiparametric 18F-fluorodeoxyglucose (FDG) PET/MRI, followed by surgical resection without chemoradiotherapy, were included. Two readers reviewed T- and N- stage, mesorectal involvement, sphincter infiltration, tumor length, and distance from anal verge. In addition, diffusion-weighted imaging (DWI) and PET parameters were extracted from the multiparametric protocol and were compared to radiological staging as well as to the histopathological reference standard. Clinical and imaging follow-up was systematically assessed for tumor recurrence and death.
Locally advanced rectal cancers (LARC) exhibited significantly higher metabolic tumor volume (MTV, AUC 0.74 [95% CI 0.59-0.89], p = 0.004) and total lesion glycolysis (TLG, AUC 0.70 [95% CI 0.53-0.87], p = 0.022) compared to early tumors. T-stage was associated with MTV (AUC 0.70 [95% CI 0.54-0.85], p = 0.021), while N-stage was better assessed using anatomical MRI sequences (AUC 0.72 [95% CI 0.539-0.894], p = 0.032). In the multivariate regression analysis, depending on the model, both anatomical MRI sequences and MTV/TLG were capable of detecting LARC. Combining anatomical MRI stage and MTV/TLG led to a superior diagnostic performance for detecting LARC (AUC 0.81, [95% CI 0.68-0.94], p < 0.001). In the survival analysis, MTV was independently associated with overall survival (HR 1.05 [95% CI 1.01-1.10], p = 0.044).
Multiparametric PET-MRI can improve identification of locally advanced tumors and, hence, help in treatment stratification. It provides additional information on RC tumor biology and may have prognostic value.
本研究旨在确定多参数正电子发射断层扫描/磁共振成像（mpPET/MRI）是否能改善直肠癌（RC）的局部区域分期，并评估其切除后的预后价值。
在这项回顾性研究中，纳入了 46 名接受原发性 RC 多参数 18F-氟脱氧葡萄糖（FDG）PET/MRI 检查的患者，这些患者在没有放化疗的情况下接受了手术切除。两名读者对 T 期和 N 期、直肠系膜受累、括约肌浸润、肿瘤长度和距肛缘的距离进行了评估。此外，从多参数方案中提取了扩散加权成像（DWI）和 PET 参数，并与放射学分期以及组织病理学参考标准进行了比较。系统评估了临床和影像学随访的肿瘤复发和死亡情况。
局部晚期 RC（LARC）的代谢肿瘤体积（MTV，AUC 0.74[95%CI 0.59-0.89]，p=0.004）和总病变糖酵解（TLG，AUC 0.70[95%CI 0.53-0.87]，p=0.022）明显高于早期肿瘤。T 期与 MTV（AUC 0.70[95%CI 0.54-0.85]，p=0.021）相关，而 N 期则可以通过解剖学 MRI 序列更好地评估（AUC 0.72[95%CI 0.539-0.894]，p=0.032）。在多变量回归分析中，根据模型的不同，解剖学 MRI 序列和 MTV/TLG 都能够检测出 LARC。将解剖学 MRI 分期和 MTV/TLG 相结合，对检测 LARC 的诊断性能更优（AUC 0.81[95%CI 0.68-0.94]，p＜0.001）。在生存分析中，MTV 与总生存率独立相关（HR 1.05[95%CI 1.01-1.10]，p=0.044）。
多参数 PET-MRI 可以提高局部晚期肿瘤的检出率，从而有助于治疗分层。它提供了关于 RC 肿瘤生物学的额外信息，可能具有预后价值。
