title: Clinical comparison of dose calculation using the enhanced collapsed cone algorithm vs. a new Monte Carlo algorithm.
abstract: OBJECTIVE
  Comparison of the dosimetric accuracy of the enhanced collapsed cone (eCC) algorithm with the commercially available Monte Carlo (MC) dose calculation for complex treatment techniques.
  
  
  METHODS
  A total of 8 intensity-modulated radiotherapy (IMRT) and 2 stereotactic body radiotherapy (SBRT) lung cases were calculated with eCC and MC algorithms with the treatment planning systems (TPS) Oncentra MasterPlan 3.2 (Nucletron) and Monaco 2.01 (Elekta/CMS). Fluence optimization as well as sequencing of IMRT plans was primarily performed using Monaco. Dose prediction errors were calculated using MC as reference. The dose-volume histrogram (DVH) analysis was complemented with 2D and 3D gamma evaluation. Both algorithms were compared to measurements using the Delta4 system (Scandidos).
  
  
  RESULTS
  Recalculated with eCC IMRT plans resulted in lower planned target volume (PTV) coverage, as well as in lower organs-at-risk (OAR) doses up to 8%. Small deviations between MC and eCC in PTV dose (1-2%) were detected for IMRT cases, while larger deviations were observed for SBRT (up to 5%). Conformity indices of both calculations were similar; however, the homogeneity of the eCC calculated plans was slightly better. Delta4 measurements confirmed high dosimetric accuracy of both TPS.
  
  
  CONCLUSIONS
  Mean dose prediction errors < 3% for PTV suggest that both algorithms enable highly accurate dose calculations under clinical conditions. However, users should be aware of slightly underestimated OAR doses using the eCC algorithm.
authors.affiliation: Division of Medical Radiation Physics, Department of Radiotherapy, Medical University Vienna/AKH Wien, Vienna, Austria. irina.fotina@akhwien.at
authors.forename: Irina
authors.initials: I
authors.lastname: Fotina
authors.forename: Gabriele
authors.initials: G
authors.lastname: Kragl
authors.forename: Bernhard
authors.initials: B
authors.lastname: Kroupa
authors.forename: Robert
authors.initials: R
authors.lastname: Trausmuth
authors.forename: Dietmar
authors.initials: D
authors.lastname: Georg
mesh_terms: D000465:Algorithms; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000532:radiotherapy; D008297:Male; D009010:Monte Carlo Method; D010039:Otorhinolaryngologic Neoplasms / Q000532:radiotherapy; D011471:Prostatic Neoplasms / Q000532:radiotherapy; D011874:Radiometry; D016634:Radiosurgery / Q000295:instrumentation / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000295:instrumentation / Q000379:methods*