OBJECTIVES To assess the value of 18F-FDG PET and MR-IVIM parameters before and during concurrent chemoradiotherapy (CCRT) for evaluating early treatment response and predicting tumor recurrence in patients with locally advanced cervical cancer (LACC) using a hybrid PET/MR scanner. METHODS Fifty-one patients with LACC underwent pelvic PET/MR scans with an IVIM sequence at two time-points (pretreatment [pre] and midtreatment [mid]). Pre- and mid-PET parameters (SUVmax, MTV, TLG) and IVIM parameters (D, F, D*) and their percentage changes (Δ%SUVmax, Δ%MTV, Δ%TLG, Δ%D, Δ%F, Δ%D*) were calculated. We selected independent imaging parameters and built a combined prediction model incorporating imaging parameters and clinicopathological risk factors. The performance of the combinative evaluation for tumor early shrinkage rates (TESR) and the prediction model for tumor recurrence was assessed. RESULTS Thirty-two patients were classified into the good response (GR) group with TESR ≥ 50%, and 19 patients were categorized into the poor response (PR) group with TESR < 50%. Δ%D (p = 0.013) and Δ%F (p = 0.006) are independently related to TESR with superior combined diagnostic ability (AUC = 0.901). Pre-TLG, Δ%D, and suspicious lymph node metastasis (SLNM) were selected for the construction of the combined prediction model. The model for identifying the patients with high risk of tumor recurrence reached a moderate predictive ability and good stability with c-index of 0.764 (95% CI, 0.672-0.855). CONCLUSION The combined prediction model based on pretreatment PET metabolic parameter (pre-TLG), IVIM-D percentage changes, and LNs status provides great potential to identify the LACC patients with high risk of recurrence at early stage of CCRT. KEY POINTS • PET/MR plus IVIM offers various complementary information for LACC. • IVIM-D and IVIM-F percentage changes are independently related to tumor early shrinkage rates. • The combined prediction model can help identify the LACC patients with high risk of tumor recurrence.

中文翻译：

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多参数PET / MR（PET和MR-IVIM）用于评估局部晚期宫颈癌患者的早期治疗反应并预测肿瘤复发。

目的在同时放化疗（CCRT）之前和期间评估18F-FDG PET和MR-IVIM参数的价值，以使用混合PET / MR扫描仪评估局部晚期宫颈癌（LACC）患者的早期治疗反应并预测肿瘤复发。方法51例LACC患者在两个时间点（预处理[pre]和中期[mid]）接受了IVIM序列的盆腔PET / MR扫描。PET前后的参数（SUVmax，MTV，TLG）和IVIM参数（D，F，D *）及其百分比变化（Δ％SUVmax，Δ％MTV，Δ％TLG，Δ％D，Δ％F，计算出Δ％D *）。我们选择了独立的成像参数，并建立了一个结合了成像参数和临床病理风险因素的组合预测模型。评估了肿瘤早期缩小率（TESR）的综合评估和肿瘤复发预测模型的性能。结果将32例患者分为TESR≥50％的良好反应（GR）组，将19例患者分为TESR <50％的不良反应（PR）组。Δ％D（p = 0.013）和Δ％F（p = 0.006）独立地与具有良好综合诊断能力（AUC = 0.901）的TESR相关。选择前TLG，Δ％D和可疑淋巴结转移（SLNM）来构建组合预测模型。识别具有高肿瘤复发风险的患者的模型具有中等预测能力和良好稳定性，c指数为0.764（95％CI，0.672-0.855）。结论基于预处理PET代谢参数（pre-TLG）的组合预测模型，IVIM-D百分比变化和LN状况为识别CCRT早期复发高风险的LACC患者提供了巨大的潜力。要点•PET / MR plus IVIM为LACC提供了各种补充信息。•IVIM-D和IVIM-F百分比变化与肿瘤早期缩小率独立相关。•组合的预测模型可以帮助识别患有肿瘤复发高风险的LACC患者。