title: Tumor Response After Stereotactic Body Radiation Therapy to Nonspine Bone Metastases: An Evaluation of Response Criteria.
abstract: OBJECTIVE
  To evaluate the applicability of the Response Evaluation Criteria in Solid Tumors (RECIST 1.1) and University of Texas MD Anderson (MDA) Cancer Center criteria in the setting of stereotactic body radiation therapy (SBRT) to nonspine bone metastases.
  
  
  METHODS
  Patients who were treated with SBRT to nonspine bone metastases were identified by retrospective chart review. An independent musculoskeletal radiologist evaluated response to treatment using computed tomography (CT) scans.
  
  
  RESULTS
  Thirty-three patients were treated to 42 nonspine bone metastases. The most common primary cancer cites were renal cell carcinoma (RCC) (33.3%), lung (24.2%), and prostate (18.2%). Bone metastases were either mainly lytic (57.1%), mainly sclerotic (28.6%), or mixed (14.3%). When lytic and sclerotic lesions were evaluated according to RECIST 1.1, local control (LC) was 83%, 85%, 88%, and 80% for those with CT imaging between months 1 to 3, 4 to 6, 7 to 9, and 10 to 12, respectively. When evaluated by the MDA criteria by density, LC within each time period was slightly greater. Overall LC decreased considerably when evaluated by MDA in terms of size.
  
  
  CONCLUSIONS
  Consensus definitions of response are required as they have implications on clinical trials and disease management. Without consistent response criteria, outcomes from clinical trials cannot be compared and treatment efficacy remains undetermined.
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Rachel
authors.initials: R
authors.lastname: McDonald
authors.affiliation: Department of Medical Imaging, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Linda
authors.initials: L
authors.lastname: Probyn
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Ian
authors.initials: I
authors.lastname: Poon
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Darby
authors.initials: D
authors.lastname: Erler
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Drew
authors.initials: D
authors.lastname: Brotherston
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Hany
authors.initials: H
authors.lastname: Soliman
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Patrick
authors.initials: P
authors.lastname: Cheung
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Hans
authors.initials: H
authors.lastname: Chung
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: William
authors.initials: W
authors.lastname: Chu
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Andrew
authors.initials: A
authors.lastname: Loblaw
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Nemica
authors.initials: N
authors.lastname: Thavarajah
authors.affiliation: Department of Medical Imaging, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Catherine
authors.initials: C
authors.lastname: Lang
authors.affiliation: Department of Physics, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Lee
authors.initials: L
authors.lastname: Chin
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada. Electronic address: Edward.Chow@sunnybrook.ca.
authors.forename: Edward
authors.initials: E
authors.lastname: Chow
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Arjun
authors.initials: A
authors.lastname: Sahgal
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary* / Q000601:surgery*; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging / Q000556:secondary / Q000601:surgery; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology; D008168:Lung / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000473:pathology; D016634:Radiosurgery / Q000379:methods*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome