title: Case report of a near medical event in stereotactic radiotherapy due to improper units of measure from a treatment planning system.
abstract: OBJECTIVE
  The authors hereby notify the Radiation Oncology community of a potentially lethal error due to improper implementation of linear units of measure in a treatment planning system. The authors report an incident in which a patient was nearly mistreated during a stereotactic radiotherapy procedure due to inappropriate reporting of stereotactic coordinates by the radiation therapy treatment planning system in units of centimeter rather than in millimeter. The authors suggest a method to detect such errors during treatment planning so they are caught and corrected prior to the patient positioning for treatment on the treatment machine.
  
  
  METHODS
  Using pretreatment imaging, the authors found that stereotactic coordinates are reported with improper linear units by a treatment planning system. The authors have implemented a redundant, independent method of stereotactic coordinate calculation.
  
  
  RESULTS
  Implementation of a double check of stereotactic coordinates via redundant, independent calculation is simple and accurate. Use of this technique will avoid any future error in stereotactic treatment coordinates due to improper linear units, transcription, or other similar errors.
  
  
  CONCLUSIONS
  The authors recommend an independent double check of stereotactic treatment coordinates during the treatment planning process in order to avoid potential mistreatment of patients.
authors.affiliation: Division of Radiation Oncology, Department of Medicine, Dartmouth-Hitchcock Medical Center, Norris Cotton Cancer Center, Lebanon, New Hampshire 03756, USA. david.gladstone@dartmouth.edu
authors.forename: D J
authors.initials: DJ
authors.lastname: Gladstone
authors.forename: S
authors.initials: S
authors.lastname: Li
authors.forename: L A
authors.initials: LA
authors.lastname: Jarvis
authors.forename: A C
authors.initials: AC
authors.lastname: Hartford
mesh_terms: D001932:Brain Neoplasms / Q000150:complications / Q000601:surgery*; D006801:Humans; D019300:Medical Errors / Q000517:prevention & control*; D011832:Radiation Injuries / Q000209:etiology* / Q000517:prevention & control*; D016634:Radiosurgery / Q000009:adverse effects*