Radiological changes on CT after stereotactic body radiation therapy to non-spine bone metastases: a descriptive series.
BACKGROUND
In recent years, stereotactic body radiation therapy (SBRT) has become increasingly used for the management of non-spine bone metastases. Few studies have examined the radiological changes in bone metastases after treatment with SBRT and there is no consensus about what constitutes radiologic response to therapy. This article describes various changes on CT after SBRT to non-spine bone metastases in eight selected cases.


METHODS
A retrospective review was conducted for patients treated with SBRT to non-spine bone metastases between November 2011 and April 2014 at Sunnybrook Health Sciences Centre. A musculoskeletal radiologist identified eight illustrative cases of interest and provided a description of the findings.


RESULTS
Different radiological changes following SBRT were described, including: remineralization of lytic bone metastases, demineralization of sclerotic bone metastases, pathologic fracture, size progression and response in different lesions, as well as lung fibrosis after SBRT to a rib metastasis.


CONCLUSIONS
We reviewed the radiological images of eight selected cases after SBRT to nonspine bone metastases and a number of characteristic findings were highlighted. We recommend future studies to correlate radiologic changes with clinical outcomes including pain relief, toxicity and long-term local control.
Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
Nicholas
N
Chiu
Department of Medical Imaging, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
Linda
L
Probyn
Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
Srinivas
S
Raman
Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
Rachel
R
McDonald
Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
Ian
I
Poon
Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
Darby
D
Erler
Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
Drew
D
Brotherston
Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
Hany
H
Soliman
Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
Patrick
P
Cheung
Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
Hans
H
Chung
Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
William
W
Chu
Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
Andrew
A
Loblaw
Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
Nemica
N
Thavarajah
Department of Medical Imaging, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
Catherine
C
Lang
Department of Physics, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
Lee
L
Chin
Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada. edward.Chow@sunnybrook.ca.
Edward
E
Chow
Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
Arjun
A
Sahgal
D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy* / Q000556:secondary; D001943:Breast Neoplasms / Q000473:pathology; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000556:secondary; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology; D008175:Lung Neoplasms / Q000473:pathology; D008297:Male; D011471:Prostatic Neoplasms / Q000473:pathology; D016634:Radiosurgery / Q000379:methods; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome
CT; Stereotactic body radiation therapy (SBRT); non-spine bone metastases