title: A new method for the placement of brachytherapy probes in paranasal sinus and nasopharynx neoplasms.
abstract: OBJECTIVE
  In afterloading therapy, the exact placement of the applicator is crucial for the result of radiotherapy. A deviation of few millimeters from the target leads to a significant reduction of radiation energy to the tumor.
  
  
  METHODS
  We present a new method using a computer-assisted device for three-dimensional placing of afterloading probes based on CT scans that allows for the exact placement.
  
  
  RESULTS
  Target points have been reached with an accuracy of 0.6 mm. Since 1991 we have used this technique for 24 clinical applications in 11 patients with recurrent neoplasms in the region of the paranasal sinuses and nasopharynx for palliative treatment.
  
  
  CONCLUSIONS
  The presented method is a reliable and precise procedure for the positioning of afterloading probes, avoiding the inaccuracy of the traditional methods.
authors: Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Maastricht, The Netherlands.
authors: B
authors: B
authors: Kremer
authors: L
authors: L
authors: Klimek
authors: D
authors: D
authors: Andreopoulos
authors: R
authors: R
authors: Mösges
mesh_terms: D000328:Adult; D000368:Aged; D001918:Brachytherapy / Q000295:instrumentation / Q000379:methods*; D002277:Carcinoma / Q000000981:diagnostic imaging / Q000532:radiotherapy; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000532:radiotherapy; D004867:Equipment Design; D006801:Humans; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D010255:Paranasal Sinus Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D011881:Radiotherapy, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed