title: Dummy run and conformity indices in the ongoing EORTC low-grade glioma trial 22033-26033: First evaluation of quality of radiotherapy planning.
abstract: OBJECTIVE
  Early assessment of radiotherapy (RT) quality in the ongoing EORTC trial comparing primary temozolomide versus RT in low-grade gliomas.
  
  
  METHODS
  RT plans provided for dummy cases were evaluated and compared against expert plans. We analysed: (1) tumour and organs-at-risk delineation, (2) geometric and dosimetric characteristics, (3) planning parameters, compliance with dose prescription and Dmax for OAR (4) indices: RTOG conformity index (CI), coverage factor (CF), tissue protection factor (PF); conformity number (CN = PF x CF); dose homogeneity in PTV (U).
  
  
  RESULTS
  Forty-one RT plans were evaluated. Only two (5%) centres were requested to repeat CTV-PTV delineations. Three (7%) plans had a significant under-dosage and dose homogeneity in one deviated > 10%. Dose distribution was good with mean values of 1.5, 1, 0.68, and 0.68 (ideal values = 1) for CI, CF, PF, and CN, respectively. CI and CN strongly correlated with PF and they correlated with PTV. Planning with more beams seems to increase PTV(Dmin), improving CF. U correlated with PTV(Dmax).
  
  
  CONCLUSIONS
  Preliminary results of the dummy run procedure indicate that most centres conformed to protocol requirements. To quantify plan quality we recommend systematic calculation of U and either CI or CN, both of which measure the amount of irradiated normal brain tissue.
authors.affiliation: Radiation-Oncology Department, Institute Curie - René Huguenin Hospital, Saint-Cloud, France. musat@crh1.org
authors.forename: Elena
authors.initials: E
authors.lastname: Musat
authors.forename: Erik
authors.initials: E
authors.lastname: Roelofs
authors.forename: Raquel
authors.initials: R
authors.lastname: Bar-Deroma
authors.forename: Paul
authors.initials: P
authors.lastname: Fenton
authors.forename: Akos
authors.initials: A
authors.lastname: Gulyban
authors.forename: Laurence
authors.initials: L
authors.lastname: Collette
authors.forename: Roger
authors.initials: R
authors.lastname: Stupp
authors.forename: Damien C
authors.initials: DC
authors.lastname: Weber
authors.forename: J
authors.initials: J
authors.lastname: Bernard Davis
authors.forename: Edwin
authors.initials: E
authors.lastname: Aird
authors.forename: Brigitta G
authors.initials: BG
authors.lastname: Baumert
mesh_terms: D000328:Adult; D018906:Antineoplastic Agents, Alkylating / Q000627:therapeutic use*; D016543:Central Nervous System Neoplasms / Q000532:radiotherapy*; D003606:Dacarbazine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D005260:Female; D005910:Glioma / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D020266:Radiotherapy, Conformal; D000077204:Temozolomide; D016896:Treatment Outcome
chemical_list: D018906:Antineoplastic Agents, Alkylating; D003606:Dacarbazine; D000077204:Temozolomide