title: Accurate prediction of target dose-escalation and organ-at-risk dose levels for non-small cell lung cancer patients.
abstract: OBJECTIVE
  To develop a method to predict feasible organ-at-risk (OAR) and tumour dose levels of non-small cell lung cancer (NSCLC) patients prior to the start of treatment planning.
  
  
  METHODS
  Included were NSCLC patients treated with volumetric modulated arc therapy according to an institutional isotoxic dose-escalation protocol. A training cohort (N=50) was used to calculate the average dose inside the OARs as a function of the distance to the planning target volume (PTV). These dose-distance relations were used in a validation cohort (N=39) to predict dose-volume histograms (DVHs) of OARs and PTV as well as the maximum individualized PTV dose escalation.
  
  
  RESULTS
  The validation cohort showed that predicted and achieved MLD were in agreement with each other (difference: -0.1±1.9 Gy, p=0.81). The spinal cord was dose limiting in only two patients, which was correctly predicted. The achieved mean PTV dose varied from 52 to 73 Gy and was predicted correctly with an accuracy better than 2 Gy (i.e. 1 fraction) for 79% of the patients.
  
  
  CONCLUSIONS
  We have shown that the MLD and the prescribed PTV dose could be accurately predicted for NSCLC patients. This method can guide the treatment planner to achieve optimal OAR sparing and tumour dose escalation.
authors: Department of Radiation Oncology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands. Electronic address: s.petit@erasmusmc.nl.
authors: Steven F
authors: SF
authors: Petit
authors: Department of Radiation Oncology (MAASTRO), GROW - School for Oncology and Developmental Biology, Maastricht University Medical Centre, The Netherlands.
authors: Wouter
authors: W
authors: van Elmpt
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000532:radiotherapy*; D006801:Humans; D008175:Lung Neoplasms / Q000532:radiotherapy*; D058958:Organs at Risk / Q000473:pathology; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods; D012307:Risk Factors
keywords: Dose prediction; Dose–distance relation; Knowledge based treatment planning; NSCLC dose escalation; Treatment planning QA