title: An alternative parameter for early forecasting clinical response in NSCLC patients during radiotherapy: proof of concept study.
abstract: OBJECTIVE
  Positron emission tomography with (18)F fludeoxyglucose integrated with CT ((18)F-FDG PET/CT) is a recommended imaging procedure in the evaluation of non-small-cell lung cancers (NSCLCs). Radiochemotherapy (RCT) is a mainstay for treatment of locally advanced NSCLC, for which overall survival still remains poor. Early evaluation of treatment response may help in decision-making to complete radiotherapy (RT) or to switch to other treatment modalities. The present study aimed to evaluate the performance of new metabolic parameters based on a simplified kinetic analysis on a single time point (SKA-S)-derived mathematical method, as compared with standardized uptake value (SUV) measurement during RT.
  
  
  METHODS
  Four patients treated with RT or RCT for NSCLC were evaluated using (18)F-FDG PET/CT during RT and after treatment completion. Whole-body (18)F-FDG PET/CT was performed followed by four additional list-mode acquisitions centered over the target lesion. Response was evaluated at four times (i.e. PET1-PET4) by calculating standard SUV values and T80%, the time taken to reach 80% of (18)F-FDG metabolized fraction using a SKA-S-derived mathematical method.
  
  
  RESULTS
  Data from SUV and T80% calculations were found to be controversial. T80% was found to be more predictive of clinical outcome.
  
  
  CONCLUSIONS
  Although results from this pilot study should be further confirmed in a large prospective study, the data suggest that T80% is a promising metabolic biomarker for assessing early response to RT.
  
  
  CONCLUSIONS
  In this proof of concept study, we show that T80% defined from a mathematic model taking into account the net influx rate constant and vascular volume could be consider as a promising biomarker as compared with the maximum SUV.
authors.affiliation: 1 SMARTc, INSERM, UMR 911 CRO2, Aix Marseille Université, Marseille, France.|2 Assistance Publique des Hôpitaux de Marseille, Radiotherapy Department, Marseille, France.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Padovani
authors.affiliation: 2 Assistance Publique des Hôpitaux de Marseille, Radiotherapy Department, Marseille, France.
authors.forename: Aurelie
authors.initials: A
authors.lastname: Baret
authors.affiliation: 1 SMARTc, INSERM, UMR 911 CRO2, Aix Marseille Université, Marseille, France.
authors.forename: Joseph
authors.initials: J
authors.lastname: Ciccolini
authors.affiliation: 3 Aix Marseille Université; Assistance Publique Hôpitaux de Marseille, Nuclear Medical Department, Marseille, France.
authors.forename: David
authors.initials: D
authors.lastname: Taieb
authors.affiliation: 3 Aix Marseille Université; Assistance Publique Hôpitaux de Marseille, Nuclear Medical Department, Marseille, France.
authors.forename: Farman
authors.initials: F
authors.lastname: Bardia
authors.affiliation: 3 Aix Marseille Université; Assistance Publique Hôpitaux de Marseille, Nuclear Medical Department, Marseille, France.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Teissonnier
authors.affiliation: 1 SMARTc, INSERM, UMR 911 CRO2, Aix Marseille Université, Marseille, France.|2 Assistance Publique des Hôpitaux de Marseille, Radiotherapy Department, Marseille, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Muracciole
authors.affiliation: 1 SMARTc, INSERM, UMR 911 CRO2, Aix Marseille Université, Marseille, France.|4 Aix Marseille Université; Assistance Publique Hôpitaux de Marseille, Multidisciplinary Oncology and Therapeutic Innovations Department, Marseille, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Barlesi
authors.affiliation: 1 SMARTc, INSERM, UMR 911 CRO2, Aix Marseille Université, Marseille, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Barbolosi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D005240:Feasibility Studies; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D011379:Prognosis; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18