title: The Advantages and Challenges of Using FDG PET/CT for Response Assessment in Melanoma in the Era of Targeted Agents and Immunotherapy.
abstract: The treatment of melanoma has been revolutionised in recent years by advances in the understanding of the genomic landscape of this disease, which has led to the development of new targeted therapeutic agents, and the ability to therapeutically manipulate the immune system through inhibition of cancer cell-T-cell interactions that prevent an adaptive immune response. While these therapeutic interventions have dramatically improved the prospects of survival for patients with advanced melanoma, they bring significant complexity to the interpretation of therapeutic response because their mechanisms and temporal profile of response vary considerably. In this review, we discuss the mode of action of these emerging therapies and their toxicities to provide a framework for the use of FDG PET/CT in therapeutic response assessment. We propose that the greatest utility of PET in assessment of response to agents that abrogate signalling related to BRAF mutation is for early assessment of resistance, while in anti-CTLA4 therapy, immunological flare can compromise early assessment of response but can identify potentially life-threatening autoimmune reactions. For anti-PD1/PDL1 therapy, the role of FDG PET/CT is more akin to its use in other solid malignancies undergoing treatment with conventional chemotherapy. However, further research is required to optimise the timing of scans and response criteria in this disease.
authors.affiliation: Cancer Medicine, The Peter MacCallum Cancer Centre, Melbourne, Australia.|The Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, Australia.
authors.forename: Annie N M
authors.initials: ANM
authors.lastname: Wong
authors.affiliation: Cancer Medicine, The Peter MacCallum Cancer Centre, Melbourne, Australia.|The Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, Australia.
authors.forename: Grant A
authors.initials: GA
authors.lastname: McArthur
authors.affiliation: Cancer imaging, The Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Hofman
authors.affiliation: The Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, Australia. rod.hicks@petermac.org.|Cancer imaging, The Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3000, Australia. rod.hicks@petermac.org.
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: Hicks
mesh_terms: D019788:Fluorodeoxyglucose F18; D006801:Humans; D007167:Immunotherapy / Q000379:methods*; D008545:Melanoma / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000276:immunology; D058990:Molecular Targeted Therapy / Q000379:methods*; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: BRAF; Immune response; Melanoma; PET; Therapeutic monitoring