title: Prospective randomized double-blind pilot study of site-specific consensus atlas implementation for rectal cancer target volume delineation in the cooperative group setting.
abstract: OBJECTIVE
  Variations in target volume delineation represent a significant hurdle in clinical trials involving conformal radiotherapy. We sought to determine the effect of a consensus guideline-based visual atlas on contouring the target volumes.
  
  
  METHODS
  A representative case was contoured (Scan 1) by 14 physician observers and a reference expert with and without target volume delineation instructions derived from a proposed rectal cancer clinical trial involving conformal radiotherapy. The gross tumor volume (GTV), and two clinical target volumes (CTVA, including the internal iliac, presacral, and perirectal nodes, and CTVB, which included the external iliac nodes) were contoured. The observers were randomly assigned to receipt (Group A) or nonreceipt (Group B) of a consensus guideline and atlas for anorectal cancers and then instructed to recontour the same case/images (Scan 2). Observer variation was analyzed volumetrically using the conformation number (CN, where CN = 1 equals total agreement).
  
  
  RESULTS
  Of 14 evaluable contour sets (1 expert and 7 Group A and 6 Group B observers), greater agreement was found for the GTV (mean CN, 0.75) than for the CTVs (mean CN, 0.46-0.65). Atlas exposure for Group A led to significantly increased interobserver agreement for CTVA (mean initial CN, 0.68, after atlas use, 0.76; p = .03) and increased agreement with the expert reference (initial mean CN, 0.58; after atlas use, 0.69; p = .02). For the GTV and CTVB, neither the interobserver nor the expert agreement was altered after atlas exposure.
  
  
  CONCLUSIONS
  Consensus guideline atlas implementation resulted in a detectable difference in interobserver agreement and a greater approximation of expert volumes for the CTVA but not for the GTV or CTVB in the specified case. Visual atlas inclusion should be considered as a feature in future clinical trials incorporating conformal RT.
authors.affiliation: Department of Radiation Oncology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA. fullercd@uthscsa.edu
authors.forename: Clifton D
authors.initials: CD
authors.lastname: Fuller
authors.forename: Jasper
authors.initials: J
authors.lastname: Nijkamp
authors.forename: Joop C
authors.initials: JC
authors.lastname: Duppen
authors.forename: Coen R N
authors.initials: CR
authors.lastname: Rasch
authors.forename: Charles R
authors.initials: CR
authors.lastname: Thomas
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Wang
authors.forename: Paul
authors.initials: P
authors.lastname: Okunieff
authors.forename: William E
authors.initials: WE
authors.lastname: Jones
authors.forename: Daniel
authors.initials: D
authors.lastname: Baseman
authors.forename: Shilpen
authors.initials: S
authors.lastname: Patel
authors.forename: Carlo G N
authors.initials: CG
authors.lastname: Demandante
authors.forename: Anna M
authors.initials: AM
authors.lastname: Harris
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Smith
authors.forename: Alan W
authors.initials: AW
authors.lastname: Katz
authors.forename: Camille
authors.initials: C
authors.lastname: McGann
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Harper
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Chang
authors.forename: Stephen
authors.initials: S
authors.lastname: Smalley
authors.forename: David T
authors.initials: DT
authors.lastname: Marshall
authors.forename: Karyn A
authors.initials: KA
authors.lastname: Goodman
authors.forename: Niko
authors.initials: N
authors.lastname: Papanikolaou
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Kachnic
mesh_terms: D004311:Double-Blind Method; D006801:Humans; D008488:Medical Illustration; D015588:Observer Variation; D010865:Pilot Projects; D011446:Prospective Studies; D018787:Radiation Oncology; D011859:Radiography; D020266:Radiotherapy, Conformal / Q000379:methods; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy; D047368:Tumor Burden
references.citation: Int J Radiat Oncol Biol Phys. 2009 Mar 1;73(3):944-51
references.pmid: 19215827
references.citation: Radiother Oncol. 2009 Aug;92(2):202-9
references.pmid: 19454365
references.citation: J Med Phys. 2008 Oct;33(4):136-40
references.pmid: 19893706
references.citation: Anticancer Res. 2007 Jul-Aug;27(4C):2965-71
references.pmid: 17695480
references.citation: Int J Radiat Oncol Biol Phys. 2006 Feb 1;64(2):333-42
references.pmid: 16414369
references.citation: Int J Radiat Oncol Biol Phys. 1997 Nov 1;39(4):841-8
references.pmid: 9369132
references.citation: Int J Radiat Oncol Biol Phys. 2007 Aug 1;68(5):1512-21
references.pmid: 17674982
references.citation: Radiother Oncol. 2008 Jul;88(1):10-9
references.pmid: 18514340
references.citation: Br J Radiol. 2010 Jan;83(985):44-51
references.pmid: 19620177
references.citation: Strahlenther Onkol. 2003 Jan;179(1):21-30
references.pmid: 12540981
references.citation: Int J Radiat Oncol Biol Phys. 2009 Feb 1;73(2):416-23
references.pmid: 18538494
references.citation: Int J Radiat Oncol Biol Phys. 2003 Oct 1;57(2):573-9
references.pmid: 12957271
references.citation: Radiother Oncol. 2003 Nov;69(2):189-94
references.pmid: 14643957
references.citation: Radiother Oncol. 1999 Dec;53(3):247-55
references.pmid: 10660205
references.citation: Radiother Oncol. 2004 Jan;70(1):21-30
references.pmid: 15036848
references.citation: Int J Radiat Oncol Biol Phys. 2009 Jun 1;74(2):383-7
references.pmid: 18947938
references.citation: Int J Radiat Oncol Biol Phys. 2008 Apr 1;70(5):1423-6
references.pmid: 17931795
references.citation: Int J Radiat Oncol Biol Phys. 2009 Jul 1;74(3):824-30
references.pmid: 19117696
references.citation: Int J Radiat Oncol Biol Phys. 2002 Jul 1;53(3):766-74
references.pmid: 12062623
references.citation: Int J Radiat Oncol Biol Phys. 2008 Jun 1;71(2):428-34
references.pmid: 18037584
references.citation: Acta Oncol. 2008;47(7):1317-24
references.pmid: 18661433
references.citation: Int J Radiat Oncol Biol Phys. 1999 Jan 1;43(1):57-66
references.pmid: 9989514
references.citation: Radiother Oncol. 2005 Nov;77(2):182-90
references.pmid: 16256231
references.citation: Strahlenther Onkol. 2006 Aug;182(8):450-7
references.pmid: 16896591
references.citation: Int J Radiat Oncol Biol Phys. 2009 Nov 15;75(4):990-3
references.pmid: 19345515
references.citation: Behav Res Methods. 2007 May;39(2):175-91
references.pmid: 17695343
references.citation: Int J Radiat Oncol Biol Phys. 1997 Feb 1;37(3):731-6
references.pmid: 9112473
references.citation: Int J Radiat Oncol Biol Phys. 1998 Jul 1;41(4):929-31
references.pmid: 9652859
references.citation: Int J Radiat Oncol Biol Phys. 2006 Jul 15;65(4):1129-42
references.pmid: 16750329
references.citation: Radiother Oncol. 2009 Jun;91(3):455-60
references.pmid: 19339069
references.citation: Radiother Oncol. 2003 Dec;69(3):227-36
references.pmid: 14644481
references.citation: Int J Radiat Oncol Biol Phys. 2007 Jun 1;68(2):592-600
references.pmid: 17498571
references.citation: Radiother Oncol. 2009 May;91(2):166-72
references.pmid: 19062118
references.citation: Int J Radiat Oncol Biol Phys. 2005 Oct 1;63(2):334-9
references.pmid: 16168828
references.citation: Neuroimage. 2006 Jul 1;31(3):1116-28
references.pmid: 16545965
references.citation: Int J Radiat Oncol Biol Phys. 2006 Feb 1;64(2):435-48
references.pmid: 16198064
references.citation: Int J Radiat Oncol Biol Phys. 2006 Oct 1;66(2):372-6
references.pmid: 16965989
references.citation: Radiother Oncol. 2005 May;75(2):217-23
references.pmid: 15885831
references.citation: Int J Radiat Oncol Biol Phys. 2005 Jul 1;62(3):893-900
references.pmid: 15936575
references.citation: Radiother Oncol. 2007 Aug;84(2):121-7
references.pmid: 17706307