Bauckneht Matteo, Piva Roberta, Sambuceti Gianmario, Grossi Francesco, Morbelli Silvia
Matteo Bauckneht, Roberta Piva, Gianmario Sambuceti, Silvia Morbelli, Nuclear Medicine Unit, IRCCS San Martino-IST, University of Genoa, 16132 Genoa, Italy.
World J Radiol. 2017 Feb 28;9(2):27-33. doi: 10.4329/wjr.v9.i2.27.
Strategies targeting intracellular negative regulators such as immune checkpoint inhibitors (ICPIs) have demonstrated significant antitumor activity across a wide range of solid tumors. In the clinical practice, the radiological effect of immunotherapeutic agents has raised several more relevant and complex challenges for the determination of their imaging-based response at single patient level. Accordingly, it has been suggested that the conventional Response Evaluation Criteria in Solid Tumors assessment alone, based on dimensional evaluation provided by computed tomography (CT), tends to underestimate the benefit of ICPIs at least in a subset of patients, supporting the need of immune-related response criteria. Different from CT, very few data are available for the evaluation of immunotherapy by means of F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET). Moreover, since the antineoplastic activity of ICPIs is highly related to the activation of T cells against cancer cells, FDG accumulation might cause false-positive findings. Yet, discrimination between benign and malignant processes represents a huge challenge for FDG-PET in this clinical setting. Consequently, it might be of high interest to test the complex and variegated response to ICPIs by means of PET and thus it is worthwhile to ask if a similar introduction of immune-related PET-based criteria could be proposed in the future. Finally, PET might offer a new insight into the biology and pathophysiology of ICPIs thanks to a growing number of non-invasive immune-diagnostic approaches based on non-FDG tracers.
针对细胞内负调节因子的策略，如免疫检查点抑制剂（ICPI），已在多种实体瘤中显示出显著的抗肿瘤活性。在临床实践中，免疫治疗药物的放射学效应给在个体患者水平上确定基于成像的反应带来了更多相关且复杂的挑战。因此，有人提出，仅基于计算机断层扫描（CT）提供的维度评估的传统实体瘤反应评估标准，往往会低估ICPI至少在一部分患者中的益处，这支持了免疫相关反应标准的必要性。与CT不同，通过氟代脱氧葡萄糖正电子发射断层扫描（FDG-PET）评估免疫治疗的可用数据非常少。此外，由于ICPI的抗肿瘤活性与T细胞对癌细胞的激活高度相关，FDG积聚可能会导致假阳性结果。然而，在这种临床环境中，区分良性和恶性过程对FDG-PET来说是一个巨大的挑战。因此，通过PET测试对ICPI的复杂多样反应可能会非常有意义，因此值得探讨未来是否可以提出类似的基于PET的免疫相关标准。最后，由于越来越多基于非FDG示踪剂的非侵入性免疫诊断方法，PET可能会为ICPI的生物学和病理生理学提供新的见解。
