title: Comparison of tumor volumes as determined by pathologic examination and FDG-PET/CT images of non-small-cell lung cancer: a pilot study.
abstract: OBJECTIVE
  To determine the cut-off standardized uptake value (SUV) on (18)F fluoro-2-deoxy-glucose (FDG) positron emission tomography/computed tomography (FDG-PET/CT) images that generates the best volumetric match to pathologic gross tumor volume (GTV(path)) for non-small-cell lung cancer (NSCLC).
  
  
  METHODS
  Fifteen patients with NSCLC who underwent FDG-PET/CT scans followed by lobectomy were enrolled. The surgical specimen was dissected into 5-7-mum sections at approximately 4-mm intervals and stained with hematoxylin and eosin. The tumor-containing area was outlined slice by slice and the GTV(path) determined by summing over all the slices, taking into account the interslice thickness and fixation-induced volume reduction. The gross tumor volume from the PET images, GTV(PET), was determined as a function of cut-off SUV. The optimal threshold or optimal absolute SUV was defined as the value at which the GTV(PET) was the same as the GTV(path).
  
  
  RESULTS
  The fixation process induced a volumetric reduction to 82% +/- 10% (range, 62-100%) of the original. The maximal SUV was 10.1 +/- 3.6 (range, 4.2-18.7). The optimal threshold and absolute SUV were 31% +/- 11% and 3.0 +/- 1.6, respectively. The optimal threshold was inversely correlated with GTV(path) and tumor diameter (p < 0.05), but the optimal absolute SUV had no significant correlation with GTV(path) or tumor diameter (p > 0.05).
  
  
  CONCLUSIONS
  This study evaluated the use of GTV(path) as a criterion for determining the optimal cut-off SUV for NSCLC target volume delineation. Confirmatory studies including more cases are being performed.
authors.affiliation: Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan, China. jn7984729@public.jn.sd.cn
authors.forename: Jinming
authors.initials: J
authors.lastname: Yu
authors.forename: Xinke
authors.initials: X
authors.lastname: Li
authors.forename: Ligang
authors.initials: L
authors.lastname: Xing
authors.forename: Dianbin
authors.initials: D
authors.lastname: Mu
authors.forename: Zheng
authors.initials: Z
authors.lastname: Fu
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Sun
authors.forename: Xiangyu
authors.initials: X
authors.lastname: Sun
authors.forename: Guoren
authors.initials: G
authors.lastname: Yang
authors.forename: Baijiang
authors.initials: B
authors.lastname: Zhang
authors.forename: Xindong
authors.initials: X
authors.lastname: Sun
authors.forename: C Clifton
authors.initials: CC
authors.lastname: Ling
mesh_terms: D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D049268:Positron-Emission Tomography / Q000379:methods*; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed / Q000379:methods*; D047368:Tumor Burden
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18