Henriksen Otto Mølby, Maarup Simone, Hasselbalch Benedikte, Poulsen Hans Skovgaard, Christensen Ib Jarle, Madsen Karine, Larsen Vibeke Andrée, Lassen Ulrik, Law Ian
Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark.
Department of Oncology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
Neurooncol Adv. 2024 Oct 24;6(1):vdae178. doi: 10.1093/noajnl/vdae178. eCollection 2024 Jan-Dec.
In the present study, early response assessment by o-(2-[F]fluoroethyl)-l-tyrosine (FET) positron emission tomography (PET) and contrast-enhanced magnetic resonance imaging (MRI) were investigated in a phase II open-label single-center study of nivolumab plus bevacizumab for recurrent high-grade astrocytic glioma.
Twenty patients with nonresectable first recurrence of high-grade astrocytic glioma after EORTC/NCIC protocol underwent [F]FET PET/MRI at baseline and after 2 cycles of treatment. Whole brain values of contrast-enhancing volume on MRI (CEV), of the mean (TBR) and maximal tumor-to-background ratio (TBR), and of metabolically active volume (MTV) on [F]FET PET were obtained. Regional changes in [F]FET uptake were assessed by parametric response mapping (PRM). Prediction of overall survival (OS) and response (OS > 11 months) were assessed by Cox and receiver operating characteristic (ROC) analysis, respectively. Also, MRI (response assessment in neuro-oncology [RANO] 2.0) and PET-based (PET RANO 1.0) response assessment criteria were compared.
In ROC analysis responders were separated ( < .05) from nonresponders by lower MTV at follow-up (AUC 0.771, cutoff 18.3 mL), larger decrease in MTV (AUC 0.757, cutoff -5.3 mL), larger decrease in both TBR (AUC 0.814, cutoff -0.53) and relative TBR (AUC 0.829, cutoff -11%) and smaller PRM progressive volume (AUC 0.843, cutoff 4.0 mL). Change in CEV did not predict response. RANO 2.0 and PET RANO response assessment criteria had similar and only borderline prognostic values.
The study indicates that [F]FET PET is superior to contrast-enhanced MRI for early response assessment in patients with recurrent high-grade astrocytic glioma treated with nivolumab and bevacizumab.
在本研究中，在一项关于纳武单抗联合贝伐单抗治疗复发性高级别星形细胞瘤的II期开放标签单中心研究中，对o-(2-[F]氟乙基)-L-酪氨酸（FET）正电子发射断层扫描（PET）和对比增强磁共振成像（MRI）的早期反应评估进行了研究。
20例按照欧洲癌症研究与治疗组织/加拿大国家癌症研究所方案治疗后首次复发且不可切除的高级别星形细胞瘤患者在基线和2个周期治疗后接受了[F]FET PET/MRI检查。获得了MRI上对比增强体积（CEV）的全脑值、[F]FET PET上的平均肿瘤与本底比值（TBR）和最大肿瘤与本底比值（TBR）以及代谢活性体积（MTV）。通过参数反应映射（PRM）评估[F]FET摄取的区域变化。分别通过Cox分析和受试者工作特征（ROC）分析评估总生存期（OS）和反应（OS>11个月）的预测情况。此外，还比较了MRI（神经肿瘤学反应评估[RANO]2.0）和基于PET（PET RANO 1.0）的反应评估标准。
在ROC分析中，通过随访时较低的MTV（AUC 0.771，临界值18.3 mL）、MTV的较大下降（AUC 0.757，临界值-5.3 mL）、TBR（AUC 0.814，临界值-0.53）和相对TBR（AUC 0.829，临界值-11%）的较大下降以及较小的PRM进展体积（AUC 0.843，临界值4.0 mL），可将反应者与无反应者区分开来（P<0.05）。CEV的变化不能预测反应。RANO 2.0和PET RANO反应评估标准具有相似且仅为临界的预后价值。
该研究表明，对于接受纳武单抗和贝伐单抗治疗的复发性高级别星形细胞瘤患者，[F]FET PET在早期反应评估方面优于对比增强MRI。
