title: A one-step cone-beam CT-enabled planning-to-treatment model for palliative radiotherapy-from development to implementation.
abstract: OBJECTIVE
  To develop a cone-beam computed tomography (CT)-enabled one-step simulation-to-treatment process for the treatment of bone metastases.
  
  
  METHODS
  A three-phase prospective study was conducted. Patients requiring palliative radiotherapy to the spine, mediastinum, or abdomen/pelvis suitable for treatment with simple beam geometry (≤2 beams) were accrued. Phase A established the accuracy of cone-beam CT images for the purpose of gross tumor target volume (GTV) definition. Phase B evaluated the feasibility of implementing the cone-beam CT-enabled planning process at the treatment unit. Phase C evaluated the online cone-beam CT-enabled process for the planning and treatment of patients requiring radiotherapy for bone metastases.
  
  
  RESULTS
  Eighty-four patients participated in this study. Phase A (n = 9) established the adequacy of cone-beam CT images for target definition. Phase B (n = 45) established the quality of treatment plans to be adequate for clinical implementation for bone metastases. When the process was applied clinically in bone metastases (Phase C), the degree of overlap between planning computed tomography (PCT) and cone-beam CT for GTV and between PCT and cone-beam CT for treatment field was 82% ± 11% and 97% ± 4%, respectively. The oncologist's decision to accept the plan under a time-pressured environment remained of high quality, with the cone-beam CT-generated treatment plan delivering at least 90% of the prescribed dose to 100% ± 0% of the cone-beam CT planning target volume (PTV). With the assumption that the PCT PTV is the gold-standard target, the cone-beam CT-generated treatment plan delivered at least 90% and at least 95% of dose to 98% ± 2% and 97% ± 5% of the PCT PTV, respectively. The mean time for the online planning and treatment process was 32.7 ± 4.0 minutes. Patient satisfaction was high, with a trend for superior satisfaction with the cone-beam CT-enabled process.
  
  
  CONCLUSIONS
  The cone-beam CT-enabled palliative treatment process is feasible and is ready for clinical implementation for the treatment of bone metastases using simple beam geometry, providing a streamlined one-step process toward palliative radiotherapy.
authors.affiliation: Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario, Canada. rebecca.wong@rmp.uhn.on.ca
authors.forename: Rebecca K S
authors.initials: RK
authors.lastname: Wong
authors.forename: Daniel
authors.initials: D
authors.lastname: Letourneau
authors.forename: Anita
authors.initials: A
authors.lastname: Varma
authors.forename: Jean Pierre
authors.initials: JP
authors.lastname: Bissonnette
authors.forename: David
authors.initials: D
authors.lastname: Fitzpatrick
authors.forename: Daniel
authors.initials: D
authors.lastname: Grabarz
authors.forename: Christine
authors.initials: C
authors.lastname: Elder
authors.forename: Melanie
authors.initials: M
authors.lastname: Martin
authors.forename: Andrea
authors.initials: A
authors.lastname: Bezjak
authors.forename: Tony
authors.initials: T
authors.lastname: Panzarella
authors.forename: Mary
authors.initials: M
authors.lastname: Gospodarowicz
authors.forename: David A
authors.initials: DA
authors.lastname: Jaffray
mesh_terms: D002985:Clinical Protocols; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D005240:Feasibility Studies; D006801:Humans; D009369:Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D010166:Palliative Care / Q000379:methods; D011446:Prospective Studies; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods* / Q000592:standards; D013997:Time Factors