title: Pre-Radiation Therapy Fluorine 18 Fluorodeoxyglucose PET Helps Identify Patients with Esophageal Cancer at High Risk for Radiation Pneumonitis.
abstract: OBJECTIVE
  To examine the association between pre-radiation therapy (RT) fluorine 18 fluorodeoxyglucose (FDG) uptake and post-RT symptomatic radiation pneumonitis (RP).
  
  
  METHODS
  In accordance with the retrospective study protocol approved by the institutional review board, 228 esophageal cancer patients who underwent FDG PET/CT before chemotherapy and RT were examined. RP symptoms were evaluated by using the Common Terminology Criteria for Adverse Events, version 4.0, from the consensus of five clinicians. By using the cumulative distribution of standardized uptake values (SUVs) within the lungs, those values greater than 80%-95% of the total lung voxels were determined for each patient. The effect of pre-chemotherapy and RT FDG uptake, dose, and patient or treatment characteristics on RP toxicity was studied by using logistic regression.
  
  
  RESULTS
  The study subjects were treated with three-dimensional conformal RT (n = 36), intensity-modulated RT (n = 135), or proton therapy (n = 57). Logistic regression analysis demonstrated elevated FDG uptake at pre-chemotherapy and RT was related to expression of RP symptoms. Study subjects with elevated 95% percentile of the SUV (SUV95) were more likely to develop symptomatic RP (P < .000012); each 0.1 unit increase in SUV95 was associated with a 1.36-fold increase in the odds of symptomatic RP. Receiver operating characteristic (ROC) curve analysis resulted in area under the ROC curve of 0.676 (95% confidence interval: 0.58, 0.77), sensitivity of 60%, and specificity of 71% at the 1.17 SUV95 threshold. CT imaging and dosimetric parameters were found to be poor predictors of RP symptoms.
  
  
  CONCLUSIONS
  The SUV95, a biomarker of pretreatment pulmonary metabolic activity, was shown to be prognostic of symptomatic RP. Elevation in this pretreatment biomarker identifies patients at high risk for posttreatment symptomatic RP.
authors.affiliation: From the Department of Radiation Oncology, The University of Texas Medical Branch, Galveston, Tex (R.C.); Department of Radiation Oncology, Baylor College of Medicine, Houston, Tex (N.P.); Department of Radiation Oncology, Beaumont Health System, 3601 W Thirteen Mile Rd, Royal Oak, MI 48073-6769 (E.C., T.M.G.); Department of Computational and Applied Mathematics, Rice University, Houston, Tex (E.C., T.M.G.); Department of Pulmonology, Bellvitge Hospital, University of Barcelona, Barcelona, Spain (S.A.G.); Department of Radiation Oncology, University of Chicago, Chicago, Ill (S.A.); and Divisions of Quantitative Sciences (B.H.), Diagnostic Imaging (D.P.), and Radiation Oncology (H.S.), The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Richard
authors.initials: R
authors.lastname: Castillo
authors.forename: Ngoc
authors.initials: N
authors.lastname: Pham
authors.forename: Edward
authors.initials: E
authors.lastname: Castillo
authors.forename: Samantha
authors.initials: S
authors.lastname: Aso-Gonzalez
authors.forename: Sobiya
authors.initials: S
authors.lastname: Ansari
authors.forename: Brian
authors.initials: B
authors.lastname: Hobbs
authors.forename: Diana
authors.initials: D
authors.lastname: Palacio
authors.forename: Heath
authors.initials: H
authors.lastname: Skinner
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Guerrero
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004938:Esophageal Neoplasms / Q000532:radiotherapy*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D017564:Radiation Pneumonitis / Q000175:diagnosis*; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D018570:Risk Assessment; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18