title: Prognostic Value of Metabolic Tumor Volume Measured by 18F-FDG PET/CT in Esophageal Cancer Patients.
abstract: OBJECTIVE
  In this study, we aimed to explore prognostic importance of definition of preoperative metabolic tumor volume in esophageal cancer patients.
  
  
  METHODS
  22 patients who have histologically proven stage IIA-III esophageal cancer and underwent (18)F-FDG PET/CT for preoperative staging of disease were included to the study. After (18)F-FDG PET/CT, all the patients underwent surgery within 4 weeks period. Patients have been followed up until death or Sept 15(th), 2012. Dates of death were recorded for survival analysis. During evaluation of (18)F-FDG PET/CT images, metabolic tumor volumes were calculated by drawing the isocontour region of interests from all visually positive FGD uptake lesions.
  
  
  RESULTS
  22 patients (15M, 7F; mean age: 65.1±8.4, min-max:48-80) underwent (18)F-FDG PET/CT for preoperative staging of esophageal cancer. Preoperative diagnosis was squamous cell and adeno cancer in 17 (%77) and 5 (%23) patients, respectively. Location of primary tumor is distal, proximal and mid-esophagus in 13 (%59), 6 (%27) and 3 (%13) patients, respectively. Primary tumor of all the patients were FDG avid (mean SUVmax: 18.85±7.0; range: 5.5-35.1). Additionally, (18)F-FDG uptake was seen in mediastinal lymph nodes in 13 patients (5.45±8.15; range: 2.6-29.9). Mean metabolic tumor volumes of primary esophageal lesions were calculated as 8.77±8.46cm(3) (range: 2.3-34.2). Mean MTV of lymph nodes was 2.44±1.01cm(3) (range: 0.4-3.6). Mean total metabolic tumor volume was calculated as 9.99±8.58cm(3) (range: 2.3-27.3). 10 patients died during 447±121 days follow-up period. Mean survival time was 11.9±1.5 months (95%CI: 8.99-14.74) for entire patient group. Total metabolic tumor volume had a significant effect on survival (p=0.045) according to Cox proportional hazards regression analysis. One unit increase in MTV caused 1.1 (95%CI:1.003-1.196) fold increase in hazard, at any time.
  
  
  CONCLUSIONS
  Definition of preoperative metabolic tumor volume has a prognostic value in the prediction of postoperative survival times. Patients who have higher preoperative metabolic tumor volumes could be good candidates for more aggressive chemo-radiation therapy regiments.
  
  
  BACKGROUND
  None declared.
authors.affiliation: Ankara University Medical School, Department of Nuclear Medicine, Ankara, Turkey.
authors.forename: Ciğdem
authors.initials: C
authors.lastname: Soydal
authors.affiliation: Ankara University Medical School, Department of Thoracic Surgery, Ankara, Turkey.
authors.forename: Cabir
authors.initials: C
authors.lastname: Yüksel
authors.affiliation: Ankara University Medical School, Department of Nuclear Medicine, Ankara, Turkey.
authors.forename: Nuriye Özlem
authors.initials: NÖ
authors.lastname: Küçük
authors.affiliation: Ankara University Medical School, Department of Thoracic Surgery, Ankara, Turkey.
authors.forename: Ilker
authors.initials: I
authors.lastname: Okten
authors.affiliation: Ankara University Medical School, Department of Nuclear Medicine, Ankara, Turkey.
authors.forename: Elgin
authors.initials: E
authors.lastname: Ozkan
authors.affiliation: Ankara University Medical School, Department of Biostatistics, Ankara, Turkey.
authors.forename: Beyza
authors.initials: B
authors.lastname: Doğanay Erdoğan
keywords: Esophageal cancer; positron-emission tomography/computed tomography; tumor volume