Abstract
Background: Immune checkpoint inhibitors (ICI) have achieved astonishing results and improved overall survival (OS) in several types of malignancies, including advanced melanoma. However, due to a peculiar type of anti-cancer activity provided by these drugs, the response patterns during ICI treatment are completely different from that with “old” chemotherapeutic agents.
Objective: To provide an overview of the available literature and potentials of 18F-FDG PET/CT in advanced melanoma during the course of therapy with ICI in the context of treatment response evaluation.
Method: Morphologic criteria, expressed by Response Evaluation Criteria in Solid Tumors (RECIST), immune-related response criteria (irRC), irRECIST, and, more recently, immune-RECIST (iRECIST), along with response criteria based on the metabolic parameters with 18F-Fluorodeoxyglucose (18FFDG), have been explored.
Results: To overcome the limits of traditional response criteria, new metabolic response criteria have been introduced on time and are being continuously updated, such as the PET/CT Criteria for the early prediction of Response to Immune checkpoint inhibitor Therapy (PECRIT), the PET Response Evaluation Criteria for Immunotherapy (PERCIMT), and “immunotherapy-modified” PET Response Criteria in Solid Tumors (imPERCIST). The introduction of new PET radiotracers, based on monoclonal antibodies combined with radioactive elements (“immune-PET”), are of great interest.
Conclusion: Although the role of 18F-FDG PET/CT in malignant melanoma has been widely validated for detecting distant metastases and recurrences, evidences in course of ICI are still scarce and larger multicenter clinical trials are needed.
Keywords: Melanoma, 18F-FDG PET, response evaluation, immunotherapy, solid tumors, ICI, PET/CT.
Graphical Abstract
[http://dx.doi.org/10.1056/NEJMoa1003466] [PMID: 20525992]
[http://dx.doi.org/10.1016/S0140-6736(15)01281-7] [PMID: 26712084]
[http://dx.doi.org/10.2217/imt-2017-0187] [PMID: 30008262]
[http://dx.doi.org/10.1056/NEJMoa1510665] [PMID: 26406148]
[http://dx.doi.org/10.1016/S0140-6736(16)32455-2] [PMID: 27939400]
[http://dx.doi.org/10.1200/JCO.2016.67.3467] [PMID: 27354476]
[http://dx.doi.org/10.1056/NEJMoa1602252] [PMID: 27718784]
[http://dx.doi.org/10.1146/annurev.immunol.26.021607.090331] [PMID: 18173375]
[http://dx.doi.org/10.1007/s00259-017-3802-5] [PMID: 28815334]
[http://dx.doi.org/10.1016/j.ejso.2016.07.145] [PMID: 27769635]
[http://dx.doi.org/10.1056/NEJMoa1503093] [PMID: 25891173]
[http://dx.doi.org/10.1056/NEJMoa1504030] [PMID: 26027431]
[http://dx.doi.org/10.3390/diagnostics7020023]
[http://dx.doi.org/10.1016/j.ejca.2008.10.026] [PMID: 19097774]
[http://dx.doi.org/10.1158/1078-0432.CCR-09-1624] [PMID: 19934295]
[http://dx.doi.org/10.1158/1078-0432.CCR-13-0895] [PMID: 23743568]
[http://dx.doi.org/10.1200/JCO.2015.64.0391] [PMID: 26951310]
[http://dx.doi.org/10.1056/NEJMoa1305133] [PMID: 23724846]
[http://dx.doi.org/10.1016/S0140-6736(14)60958-2] [PMID: 25034862]
[http://dx.doi.org/10.1016/S1470-2045(17)30074-8] [PMID: 28271869]
[http://dx.doi.org/10.1016/S0959-8049(99)00229-4] [PMID: 10673991]
[http://dx.doi.org/10.2967/jnumed.108.057307] [PMID: 19403881]
[http://dx.doi.org/10.1007/s00259-017-3687-3] [PMID: 28361188]
[http://dx.doi.org/10.2967/jnumed.116.188839] [PMID: 28360208]
[http://dx.doi.org/10.1007/s00259-017-3870-6] [PMID: 29124281]
[PMID: 15299056]
[http://dx.doi.org/10.1200/JCO.2005.03.5634] [PMID: 16505438]
[http://dx.doi.org/10.1007/s00259-018-3972-9] [PMID: 29478079]
[http://dx.doi.org/10.1007/s00259-014-2944-y] [PMID: 25359635]
[http://dx.doi.org/10.2967/jnumed.109.070946] [PMID: 20150263]
[http://dx.doi.org/10.1093/annonc/mdy330] [PMID: 30137228]
[http://dx.doi.org/10.1111/pcmr.12503] [PMID: 27333363]
[http://dx.doi.org/10.1200/JCO.2015.61.6870] [PMID: 26261262]
[http://dx.doi.org/10.1007/s00259-017-3691-7] [PMID: 28389693]
[http://dx.doi.org/10.1007/s00259-018-4171-4] [PMID: 30291373]
[http://dx.doi.org/10.1001/jamaoncol.2017.2925] [PMID: 28975219]
[http://dx.doi.org/10.1007/s11912-018-0722-x] [PMID: 30413981]
[http://dx.doi.org/10.1007/s00259-017-3813-2] [PMID: 28831583]
[http://dx.doi.org/10.1186/s13550-016-0216-5] [PMID: 27473846]
[http://dx.doi.org/10.2967/jnumed.116.177659] [PMID: 27980047]
[http://dx.doi.org/10.1007/s11307-017-1060-3] [PMID: 28247187]
[http://dx.doi.org/10.2967/jnumed.114.153338] [PMID: 25952734]
[http://dx.doi.org/10.1158/0008-5472.CAN-15-2784] [PMID: 27354381]