title: 18F-fluorodeoxyglucose positron emisson tomography/computed tomography guided conformal brachytherapy for cervical cancer.
abstract: OBJECTIVE
  To evaluate the feasibility of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT)-guided conformal brachytherapy treatment planning in patients with cervical cancer.
  
  
  METHODS
  Pretreatment FDG-PET/CT was performed for 12 patients with cervical cancer. Brachytherapy simulation was performed after an external-beam radiation therapy median dose of 4140 cGy. Patients underwent FDG-PET/CT scans with placement of tandem and ovoid applicators. The gross tumor volume (GTV) was determined by adjusting the window and level to a reasonable value and outlining the edge of the enhancing area, which was done in consultation with a nuclear medicine physician. A standardized uptake value profile of the tumor margin was taken for each patient relative to the maximum uptake value of each tumor and analyzed. The plan was designed to deliver 400 cGy to point A (point A plan) or to cover the clinical target volume (CTV) (PET/CT plan).
  
  
  RESULTS
  The median dose that encompassed 95% of the target volume (D95) of the CTV was 323.0 cGy for the point A plan vs 399.0 cGy for the PET/CT plan (P=.001). The maximum standardized uptake values (SUV(max)) of the tumors were reduced by a median of 57% (range, 13%-80%). All but 1 patient presented with discernable residual uptake within the tumors. The median value of the thresholds of the tumors contoured by simple visual analysis was 41% (range, 23%-71%).
  
  
  CONCLUSIONS
  In this study, the PET/CT plan was better than the conventional point A plan in terms of target coverage without increasing the dose to the normal tissue, making optimized 3-dimensional brachytherapy treatment planning possible. In comparison with the previously reported study with PET or CT alone, we found that visual target localization was facilitated by PET fusion on indeterminate CT masses. Further studies are needed to characterize the metabolic activity detected during radiation therapy for more reliable targeting.
authors.affiliation: Department of Radiation Oncology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Heerim
authors.initials: H
authors.lastname: Nam
authors.forename: Seung Jae
authors.initials: SJ
authors.lastname: Huh
authors.forename: Sang Gyu
authors.initials: SG
authors.lastname: Ju
authors.forename: Won
authors.initials: W
authors.lastname: Park
authors.forename: Jeong Eun
authors.initials: JE
authors.lastname: Lee
authors.forename: Joon Young
authors.initials: JY
authors.lastname: Choi
authors.forename: Byung-Tae
authors.initials: BT
authors.lastname: Kim
authors.forename: Chan Kyo
authors.initials: CK
authors.lastname: Kim
authors.forename: Byung Kwan
authors.initials: BK
authors.lastname: Park
mesh_terms: D001918:Brachytherapy / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D064847:Multimodal Imaging / Q000379:methods*; D058958:Organs at Risk / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden; D002583:Uterine Cervical Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18