title: Comparison of imaging-based gross tumor volume and pathological volume determined by whole-mount serial sections in primary cervical cancer.
abstract: OBJECTIVE
  To investigate the accuracy of imaging-based gross tumor volume (GTV) compared with pathological volume in cervical cancer.
  
  
  METHODS
  Ten patients with International Federation of Gynecology and Obstetrics stage I-II cervical cancer were eligible for investigation and underwent surgery in this study. Magnetic resonance imaging (MRI) and fluorine-18 fluorodeoxyglucose positron emission tomography ((18)F-FDG PET)/computed tomography (CT) scans were taken the day before surgery. The GTVs under MRI and (18)F-FDG PET/CT (GTV-MRI, GTV-PET, GTV-CT) were calculated automatically by Eclipse treatment-planning systems. Specimens of excised uterine cervix and cervical cancer were consecutively sliced and divided into whole-mount serial sections. The tumor border of hematoxylin and eosin-stained sections was outlined under a microscope by an experienced pathologist. GTV through pathological image (GTV-path) was calculated with Adobe Photoshop.
  
  
  RESULTS
  The GTVs (average ± standard deviation) delineated and calculated under CT, MRI, PET, and histopathological sections were 19.41 ± 11.96 cm(3), 12.66 ± 10.53 cm(3), 11.07 ± 9.44 cm(3), and 10.79 ± 8.71 cm(3), respectively. The volume of GTV-CT or GTV-MR was bigger than GTV-path, and the difference was statistically significant (P < 0.05). No significant difference was observed between GTV-PET and GTV-path (P > 0.05). Spearman correlation analysis showed that GTV-CT, GTV-MRI, and GTV-PET were significantly correlated with GTV-path (P < 0.01). There was no significant difference in the lesion coverage factor among the three modalities.
  
  
  CONCLUSIONS
  The present study showed that GTV defined under 40% of maximum standardized uptake value in PET images was very similar to the pathological volume of cervical cancer. This result should be replicated in a larger number of patients with cervical cancer in a future study of ours.
authors.affiliation: Department of Radiation Oncology, , Xijing Hospital, Xi'an, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jing
authors.initials: J
authors.lastname: Hu
authors.forename: Jianping
authors.initials: J
authors.lastname: Li
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.forename: Weiwei
authors.initials: W
authors.lastname: Li
authors.forename: Yongchun
authors.initials: Y
authors.lastname: Zhou
authors.forename: Junyue
authors.initials: J
authors.lastname: Liu
authors.forename: Lichun
authors.initials: L
authors.lastname: Wei
authors.forename: Mei
authors.initials: M
authors.lastname: Shi
authors.forename: Shengjun
authors.initials: S
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.forename: Wanling
authors.initials: W
authors.lastname: Ma
keywords: 18F-FDG PET/CT; MRI; cervical cancer; gross tumor volume; pathological tumor volume