title: Total Body Metabolic Tumor Response in ALK Positive Non-Small Cell Lung Cancer Patients Treated with ALK Inhibition.
abstract: In ALK-positive advanced NSCLC, crizotinib has a high response rate and effectively increases quality of life and survival. CT measurement of the tumor may insufficiently reflect the actual tumor load changes during targeted therapy with crizotinib. We explored whether 18F-FDG PET measured metabolic changes are different from CT based changes and studied the impact of these changes on disease progression.
  
  
  
  18F-FDG PET/CT was performed prior to and after 6 weeks of crizotinib treatment. Tumor response on CT was classified with RECIST 1.1, while 18F-FDG PET response was assessed according to the 1999 EORTC recommendations and PERCIST criteria. Agreement was assessed using McNemars test. During follow-up, patients received additional PET/CT during crizotinib treatment and second generation ALK inhibition. We assessed whether PET was able to detect progression earlier then CT.
  
  
  
  In this exploratory study 15 patients were analyzed who were treated with crizotinib. There was a good agreement in the applicability of CT and 18F-FDG PET/CT using the EORTC recommendations. During first line crizotinib and subsequent second line ALK inhibitors, PET was able to detect progression earlier then CT in 10/22 (45%) events of progression and in the others disease progression was detected simultaneously.
  
  
  
  In advanced ALK positive NSCLC PET was able to detect progressive disease earlier than with CT in nearly half of the assessments while both imaging tests performed similar in the others.
authors.affiliation: University of Groningen and Department of Pulmonary Diseases, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: Gerald S M A
authors.identifier: 0000-0003-3386-6831
authors.initials: GS
authors.lastname: Kerner
authors.affiliation: University of Groningen and Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: Michel J B
authors.initials: MJ
authors.lastname: Koole
authors.affiliation: University of Groningen and Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: Alphons H H
authors.initials: AH
authors.lastname: Bongaerts
authors.affiliation: University of Groningen and Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen, the Netherlands.|Department of Nuclear Medicine, Tygerberg Hospital, Stellenbosch University, Stellenbosch, South-Africa.
authors.forename: Jan
authors.initials: J
authors.lastname: Pruim
authors.affiliation: University of Groningen and Department of Pulmonary Diseases, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: Harry J M
authors.initials: HJ
authors.lastname: Groen
mesh_terms: D000328:Adult; D000368:Aged; D000077548:Anaplastic Lymphoma Kinase; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000201:enzymology / Q000378:metabolism*; D000077547:Crizotinib; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D047428:Protein Kinase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D011720:Pyrazoles / Q000494:pharmacology / Q000627:therapeutic use*; D011725:Pyridines / Q000494:pharmacology / Q000627:therapeutic use*; D020794:Receptor Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D047428:Protein Kinase Inhibitors; D011720:Pyrazoles; D011725:Pyridines; D000077547:Crizotinib; C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D020794:Receptor Protein-Tyrosine Kinases