title: [Tumor growth during the waiting period for radiotherapy in patients with oropharyngeal carcinoma].
abstract: OBJECTIVE
  To quantify the potential increase in tumour volume during the waiting time for radiotherapy in patients with oropharyngeal squamous cell carcinoma.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  The tumour volumes as assessed on the diagnostic CT scan and the planning CT scan were compared. Thirteen patients with oropharyngeal carcinoma were included in this study. Both their diagnostic CT scan (CT-1) and their planning CT scan (CT-2) were performed in the Utrecht university medical centre. Tumour volume was calculated by delineating the tumour on CT slices and multiplying the surface area by the inter-slice distance. Tumour volumes were delineated by three independent observers. Tumour growth during the waiting time was defined as the difference in tumour volume on CT-2 and CT-1, calculated as the average of three observations.
  
  
  RESULTS
  The mean time between CT-1 and CT-2 was 33 days. The mean waiting period between the histopathological diagnosis and the start of radiotherapy was 56 days. Three groups could be distinguished: in one group the growth was less than 25% (n = 4), in one group the growth varied between 25 and 100% (n = 5), and in a third group there was growth of more than 100% (n = 4). Apart from this, in three cases the TNM stage had to be adjusted as a result of tumour progression.
  
  
  CONCLUSIONS
  This study showed that the tumour volume increased by more than 50% during the waiting time for radiotherapy in 8 out of 13 patients with squamous cell carcinoma of the oropharynx.
authors.affiliation: Afd. Kinderheelkunde, Universitair Medisch Centrum Utrecht, Postbus 85.500, 3508 GA Utrecht.
authors.forename: A
authors.initials: A
authors.lastname: Waaijer
authors.forename: C H
authors.initials: CH
authors.lastname: Terhaard
authors.forename: H
authors.initials: H
authors.lastname: Dehnad
authors.forename: G J
authors.initials: GJ
authors.lastname: Hordijk
authors.forename: M S
authors.initials: MS
authors.lastname: van Leeuwen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000473:pathology* / Q000532:radiotherapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009959:Oropharyngeal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000532:radiotherapy; D012189:Retrospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed