title: PET/CT-guided treatment planning for paediatric cancer patients: a simulation study of proton and conventional photon therapy.
abstract: OBJECTIVE
  To investigate the impact of including fluorine-18 fludeoxyglucose ((18)F-FDG) positron emission tomography (PET) scanning in the planning of paediatric radiotherapy (RT).
  
  
  METHODS
  Target volumes were first delineated without and subsequently re-delineated with access to (18)F-FDG PET scan information, on duplicate CT sets. RT plans were generated for three-dimensional conformal photon RT (3DCRT) and intensity-modulated proton therapy (IMPT). The results were evaluated by comparison of target volumes, target dose coverage parameters, normal tissue complication probability (NTCP) and estimated risk of secondary cancer (SC).
  
  
  RESULTS
  Considerable deviations between CT- and PET/CT-guided target volumes were seen in 3 out of the 11 patients studied. However, averaging over the whole cohort, CT or PET/CT guidance introduced no significant difference in the shape or size of the target volumes, target dose coverage, irradiated volumes, estimated NTCP or SC risk, neither for IMPT nor 3DCRT.
  
  
  CONCLUSIONS
  Our results imply that the inclusion of PET/CT scans in the RT planning process could have considerable impact for individual patients. There were no general trends of increasing or decreasing irradiated volumes, suggesting that the long-term morbidity of RT in childhood would on average remain largely unaffected.
  
  
  CONCLUSIONS
  (18)F-FDG PET-based RT planning does not systematically change NTCP or SC risk for paediatric cancer patients compared with CT only. 3 out of 11 patients had a distinct change of target volumes when PET-guided planning was introduced. Dice and mismatch metrics are not sufficient to assess the consequences of target volume differences in the context of RT.
authors.affiliation: 1 Section of Radiotherapy, Department of Oncology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: J S
authors.initials: JS
authors.lastname: Kornerup
authors.forename: N P
authors.initials: NP
authors.lastname: Brodin
authors.forename: T
authors.initials: T
authors.lastname: Björk-Eriksson
authors.forename: C
authors.initials: C
authors.lastname: Birk Christensen
authors.forename: A
authors.initials: A
authors.lastname: Kiil-Berthelsen
authors.forename: M C
authors.initials: MC
authors.lastname: Aznar
authors.forename: C
authors.initials: C
authors.lastname: Hollensen
authors.forename: E
authors.initials: E
authors.lastname: Markova
authors.forename: P
authors.initials: P
authors.lastname: Munck Af Rosenschöld
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003198:Computer Simulation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D017785:Photons / Q000627:therapeutic use; D049268:Positron-Emission Tomography / Q000379:methods*; D061766:Proton Therapy; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D061089:Radiotherapy, Image-Guided / Q000379:methods*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D011522:Protons
chemical_list: D011522:Protons