Lang David, Wahl Gerald, Poier Nikolaus, Graf Sebastian, Kiesl David, Lamprecht Bernd, Gabriel Michael
Johannes Kepler University Hospital Linz, Department of Pulmonology Altenberger Strasse 69, Kepler University Hospital GmbH, 4040 Linz and Krankenhausstrasse 9, 4020 Linz, Austria.
Department of Dermatology and Venerology, Johannes Kepler University Hospital Linz, Kepler University Hospital GmbH, Altenberger Strasse 69, 4040 Linz and Krankenhausstrasse 9, 4020 Linz, Austria.
J Clin Med. 2020 Oct 28;9(11):3483. doi: 10.3390/jcm9113483.
Cancer immunotherapy using immune-checkpoint inhibitors (ICI) has revolutionized the therapeutic landscape of various malignancies like non-small-cell lung cancer or melanoma. Pre-therapy response prediction and assessment during ICI treatment is challenging due to the lack of reliable biomarkers and the possibility of atypical radiological response patterns. Positron emission tomography/computed tomography (PET/CT) enables the visualization and quantification of metabolic lesion activity additional to conventional CT imaging. Various biomarkers derived from PET/CT have been reported as predictors for response to ICI and may aid to overcome the challenges clinicians currently face in the management of ICI-treated patients. In this narrative review, experts in nuclear medicine, thoracic oncology, dermatooncology, hemato- and internal oncology, urological and head/neck tumors performed literature reviews in their respective field and a joint discussion on the use of PET/CT in the context of ICI treatment. The aims were to give a clinical overview on present standards and evidence, to identify current challenges and fields of research and to enable an outlook to future developments and their possible implications. Multiple promising studies concerning ICI response assessment or prediction using biomarkers derived from PET/CT alone or as composite biomarkers have been identified for various malignancies and disease stages. Of interest, additional major incentives in the field may evolve from novel tracers specifically targeting immune-checkpoint molecules which could allow not only response assessment and prognosis, but also visualization of histological tumor cell properties like programmed death-ligand (PD-L1) expression in vivo. Despite the broad range of existing literature on PET/CT-derived biomarkers in ICI therapy, implications for daily clinical practice remain elusive. High-quality prospective data are urgently warranted to determine whether patients benefit from the application of PET/CT in terms of prognosis. At the moment, the lack of such evidence as well as the absence of standardized imaging methods and biomarkers still precludes PET/CT imaging to be included in the relevant clinical practice guidelines.
使用免疫检查点抑制剂（ICI）的癌症免疫疗法彻底改变了非小细胞肺癌或黑色素瘤等各种恶性肿瘤的治疗格局。由于缺乏可靠的生物标志物以及存在非典型放射学反应模式的可能性，ICI治疗前的反应预测和治疗期间的评估具有挑战性。正电子发射断层扫描/计算机断层扫描（PET/CT）除了能进行传统的CT成像外，还能实现代谢病变活动的可视化和量化。据报道，源自PET/CT的各种生物标志物可作为ICI反应的预测指标，可能有助于克服临床医生目前在管理接受ICI治疗的患者时面临的挑战。在这篇叙述性综述中，核医学、胸科肿瘤学、皮肤肿瘤学、血液学和内科肿瘤学、泌尿肿瘤学以及头颈肿瘤学领域的专家在各自领域进行了文献综述，并就PET/CT在ICI治疗中的应用进行了联合讨论。目的是提供当前标准和证据的临床概述，确定当前的挑战和研究领域，并展望未来的发展及其可能的影响。对于各种恶性肿瘤和疾病阶段，已经确定了多项关于单独使用源自PET/CT的生物标志物或作为复合生物标志物进行ICI反应评估或预测的有前景的研究。有趣的是，该领域的其他主要激励因素可能来自专门针对免疫检查点分子的新型示踪剂，这不仅可以进行反应评估和预后判断，还能在体内可视化组织学肿瘤细胞特性，如程序性死亡配体（PD-L1）表达。尽管关于PET/CT衍生生物标志物在ICI治疗方面已有大量现有文献，但对日常临床实践的影响仍不明确。迫切需要高质量的前瞻性数据来确定患者是否能从PET/CT应用中在预后方面获益。目前，缺乏此类证据以及标准化成像方法和生物标志物的缺失仍然妨碍PET/CT成像被纳入相关临床实践指南。
