title: Comparison of CT and PET-CT based planning of radiation therapy in locally advanced pancreatic carcinoma.
abstract: BACKGROUND
  To compare computed tomography (CT) with co-registered positron emission tomography-computed tomography (PET-CT) as the basis for delineating gross tumor volume (GTV) in unresectable, locally advanced pancreatic carcinoma (LAPC).
  
  
  METHODS
  Fourteen patients with unresectable LAPC had both CT and PET images acquired. For each patient, two three-dimensional conformal plans were made using the CT and PET-CT fusion data sets. We analyzed differences in treatment plans and doses of radiation to primary tumors and critical organs.
  
  
  RESULTS
  Changes in GTV delineation were necessary in 5 patients based on PET-CT information. In these patients, the average increase in GTV was 29.7%, due to the incorporation of additional lymph node metastases and extension of the primary tumor beyond that defined by CT. For all patients, the GTVCT versus GTVPET-CT was 92.5 +/- 32.3 cm3 versus 104.5 +/- 32.6 cm3 (p = 0.009). Toxicity analysis revealed no clinically significant differences between two plans with regard to doses to critical organs.
  
  
  CONCLUSIONS
  Co-registration of PET and CT information in unresectable LAPC may improve the delineation of GTV and theoretically reduce the likelihood of geographic misses.
authors.affiliation: Department of Radiation Oncology, Baskent University Medical Faculty, Adana Medical and Research Center, Kisla Saglik Yerleskesi, Adana, Turkey. drerkantopkan@yahoo.com
authors.forename: Erkan
authors.initials: E
authors.lastname: Topkan
authors.forename: Ali A
authors.initials: AA
authors.lastname: Yavuz
authors.forename: Mehmet
authors.initials: M
authors.lastname: Aydin
authors.forename: Cem
authors.initials: C
authors.lastname: Onal
authors.forename: Fuat
authors.initials: F
authors.lastname: Yapar
authors.forename: Melek N
authors.initials: MN
authors.lastname: Yavuz
mesh_terms: D000328:Adult; D002277:Carcinoma / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D049268:Positron-Emission Tomography / Q000379:methods*; D020266:Radiotherapy, Conformal; D014057:Tomography, X-Ray Computed / Q000379:methods*