title: [Stable disease or complete response? : A critical evaluation of the radiologic response to immune checkpoint blockade in advanced melanoma].
abstract: BACKGROUND
  Rating the response of melanoma to immune checkpoint blockade (ICB) by conventional CT proves to be difficult, since response patterns and kinetics differ from the classical responses seen with other therapies. Hence, immune-related response criteria were developed. However, they are mainly based on the alteration of the diameter of lesions over time but do not include metabolic activity.
  
  
  OBJECTIVE
  The aim of this study was to search for additional criteria to improve the interpretation of the radiologic images of patients with metastatic melanoma after ICB.
  
  
  METHODS
  We retrospectively analysed 7 patients with metastatic melanoma over a period of 13-41 months after treatment with ICB using contrast enhanced CT scans from the neck region to the lower abdomen and compared the results in the follow ups with18F-FDG PET/CT.
  
  
  RESULTS
  Metastatic lesions in 5 of 7 patients rated as stable disease (SD) in CT staging showed no metabolic activity in18F-FDG PET/CT. The size of these lesions did not increase or show metabolic activity in the further follow-up, even after discontinuation of ICB. In contrast, tumor lesions in the other 2 patients rated as SD in CT staging showed metabolic activity in18F-FDG PET/CT. These tumor lesions expanded significantly in the further course of the disease.
  
  
  CONCLUSIONS
  In addition to the size of a tumor lesion, its metabolic activity adds important information regarding treatment response. Thus, we propose that the metabolic activity assessed with18F-FDG-PET/CT should be included in the immune response criteria. No FDG uptake in a lesion should be rated as inactive tumor rather than SD and further treatment may not be required.
authors.affiliation: Klinik und Poliklinik für Dermatologie und Allergologie, Ludwig-Maximilians-Universität (LMU) München, Frauenlobstr. 9-11, 80337, München, Deutschland. Julia.Tietze@med.uni-muenchen.de.
authors.forename: J K
authors.initials: JK
authors.lastname: Tietze
authors.affiliation: Klinik und Poliklinik für Dermatologie und Allergologie, Ludwig-Maximilians-Universität (LMU) München, Frauenlobstr. 9-11, 80337, München, Deutschland.
authors.forename: M
authors.initials: M
authors.lastname: Heppt
authors.affiliation: Klinik und Poliklinik für Dermatologie und Allergologie, Ludwig-Maximilians-Universität (LMU) München, Frauenlobstr. 9-11, 80337, München, Deutschland.
authors.forename: D
authors.initials: D
authors.lastname: Angelova
authors.affiliation: Klinik und Poliklinik für Dermatologie und Allergologie, Ludwig-Maximilians-Universität (LMU) München, Frauenlobstr. 9-11, 80337, München, Deutschland.
authors.forename: T
authors.initials: T
authors.lastname: Ruzicka
authors.affiliation: Klinik für Radiologie, Ludwig-Maximilians-Universität (LMU) München, Ziemssenstr. 1, 80336, München, Deutschland.
authors.forename: F
authors.initials: F
authors.lastname: Berger
authors.affiliation: Klinik und Poliklinik für Dermatologie und Allergologie, Ludwig-Maximilians-Universität (LMU) München, Frauenlobstr. 9-11, 80337, München, Deutschland.
authors.forename: C
authors.initials: C
authors.lastname: Berking
mesh_terms: D000328:Adult; D000368:Aged; D061067:Antibodies, Monoclonal, Humanized / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007167:Immunotherapy / Q000009:adverse effects / Q000592:standards*; D000074324:Ipilimumab / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000556:secondary / Q000628:therapy*; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D000072078:Positron Emission Tomography Computed Tomography; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D047368:Tumor Burden / Q000187:drug effects
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000074324:Ipilimumab; D019788:Fluorodeoxyglucose F18; C582435:pembrolizumab
keywords: Computed tomography; Ipilimumab; Metabolic activity; Pembrolizumab; Positron emission tomography; Stable disease