title: Image guidance and stabilization for stereotactic ablative body radiation therapy (SABR) treatment of primary kidney cancer.
abstract: OBJECTIVE
  Stereotactic ablative body radiation therapy for primary kidney cancer treatment relies on motion management that can quantify both the trajectory of kidney motion and stabilize the patient. A prospective ethics-approved clinical trial of stereotactic treatment to primary kidney targets was conducted at our institution. Our aim was to report on specific kidney tumor motion and the inter- and intrafraction motion as seen on treatment.
  
  
  METHODS
  Patients with tumor size <5 cm received a dose of 26 Gy in 1 fraction and those with tumor size ≥5 cm received 42 Gy in 3 fractions. All patients underwent a 4-dimensional computed tomography planning scan, immobilized in a dual-vacuum system. A conventional linear accelerator cone beam computed tomography scan was used for pre-, mid-, and posttreatment imaging to verify target position.
  
  
  RESULTS
  Between July 2012 and October 2014, 33 targets from 32 consecutive patients (24 males/8 females) were treated. Seventeen targets were prescribed 26 Gy/1 fraction and the remaining 16 targets received 42 Gy/3 fractions. Kidney motion at each of the poles was not affected by the presence of tumor (P = .875), nor was the motion statistically different from the corresponding contralateral kidney pole (P = .909). The mean 3-dimensional displacement of the target at mid- and posttreatment was 1.3 mm (standard deviation ± 1.6) and 1.0 mm (standard deviation ± 1.3), respectively. The maximum displacement in any direction for 95% of the fractions at mid- and posttreatment was ≤3 mm.
  
  
  CONCLUSIONS
  In summary, stereotactic ablative body radiation therapy of primary kidney targets can be accurately delivered on a conventional linear accelerator with protocol that has minimal intrafractional target motion.
authors.affiliation: Department of Radiation Therapy Services, Peter MacCallum Cancer Centre, Melbourne, Australia; Department of Medical Imaging and Radiation Sciences, Monash University, Melbourne, Australia. Electronic address: Daniel.Pham@radiotherapy.edu.au.
authors.forename: Daniel
authors.initials: D
authors.lastname: Pham
authors.affiliation: Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia.
authors.forename: Tomas
authors.initials: T
authors.lastname: Kron
authors.affiliation: Department of Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, Melbourne, Australia.
authors.forename: Mathias
authors.initials: M
authors.lastname: Bressel
authors.affiliation: Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia; Department of Radiation Oncology, Olivia Newton-John Cancer Centre/Austin Health, Melbourne, Australia.
authors.forename: Farshad
authors.initials: F
authors.lastname: Foroudi
authors.affiliation: Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Australia.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Hardcastle
authors.affiliation: Department of Medical Imaging and Radiation Sciences, Monash University, Melbourne, Australia.
authors.forename: Michal
authors.initials: M
authors.lastname: Schneider
authors.affiliation: Department of Radiation Therapy Services, Peter MacCallum Cancer Centre, Melbourne, Australia.
authors.forename: Sally
authors.initials: S
authors.lastname: Soteriou
authors.affiliation: Department of Radiation Therapy Services, Peter MacCallum Cancer Centre, Melbourne, Australia.
authors.forename: Jayson
authors.initials: J
authors.lastname: Innes
authors.affiliation: Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia; Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Australia.
authors.forename: Shankar
authors.initials: S
authors.lastname: Siva
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D054893:Cone-Beam Computed Tomography; D019583:Dose Fractionation, Radiation; D005260:Female; D056973:Four-Dimensional Computed Tomography; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009068:Movement; D058958:Organs at Risk; D010315:Particle Accelerators; D011446:Prospective Studies; D016634:Radiosurgery; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D025321:Surgery, Computer-Assisted; D047368:Tumor Burden