Inter- and intra-fraction motion in stereotactic body radiotherapy for spinal and paraspinal tumours using cone-beam CT and positional correction in six degrees of freedom

Finnigan, Renee., Lamprecht, Brock., Barry, Tamara., Jones, Kimberley., Boyd, Joshua., Pullar, Andrew., Burmeister, Bryan. and Foote, Matthew. (2016) Inter- and intra-fraction motion in stereotactic body radiotherapy for spinal and paraspinal tumours using cone-beam CT and positional correction in six degrees of freedom. Journal of Medical Imaging and Radiation Oncology, 60 1: 112-118. doi:10.1111/1754-9485.12353


Author Finnigan, Renee.
Lamprecht, Brock.
Barry, Tamara.
Jones, Kimberley.
Boyd, Joshua.
Pullar, Andrew.
Burmeister, Bryan.
Foote, Matthew.
Title Inter- and intra-fraction motion in stereotactic body radiotherapy for spinal and paraspinal tumours using cone-beam CT and positional correction in six degrees of freedom
Journal name Journal of Medical Imaging and Radiation Oncology   Check publisher's open access policy
ISSN 1754-9485
1754-9477
Publication date 2016-02-01
Year available 2015
Sub-type Article (original research)
DOI 10.1111/1754-9485.12353
Open Access Status Not Open Access
Volume 60
Issue 1
Start page 112
End page 118
Total pages 7
Place of publication Richmond, Victoria, Australia
Publisher Wiley-Blackwell Publishing
Collection year 2016
Language eng
Formatted abstract
Introduction: Stereotactic body radiotherapy (SBRT) for spinal tumours delivers high doses per fraction to targets in close proximity to neural tissue. With steep dose gradients, small changes in position can confer significant dosimetric impact on adjacent structures. We analysed positioning error in consecutively treated patients on a strict image-guidance protocol with online correction in 6 degrees of freedom (6-DOF).

Methods: Set-up error, residual error post-correction and intra-fraction motion for 30 courses of spinal SBRT in 27 patients were assessed using cone-beam CT. Positional error was corrected in x, y and z translational planes and rotational axes using a robotic couch, applying 2 mm and 2° action levels. Linear mixed-effects model assessed whether positional error was influenced by factors such as vertebral level, immobilisation device and treatment duration.

Results: Sixty-two fractions were delivered with 225 image registrations. Median treatment duration was significantly longer for patients treated with static-field intensity-modulated radiotherapy compared with volumetric-modulated arc treatment – 40 min versus 28 min, respectively (P = 0.01). Across all fractions, the median residual positional error after initial correction was greatest in the x translational plane (0.5 mm; 95% confidence interval (CI) 0.3–0.6) and y rotational axis (0.25°; 95% CI 0.1–0.3). Median intra-fraction error was also greatest in the x-plane (0.7 mm; 95% CI 0.5–1.0) and y-axis (0.4°; 95% CI 0.2–0.5).

Conclusion: 
With strict immobilisation, image-guidance and 6-DOF correction, our current practice of applying 3-mm planning margins for target volumes and critical structures appears safe. Lower image-guidance action thresholds plus verification with end-to-end testing would be recommended before further reducing margins.
Keyword Cone-beam computed tomography
Image-guided radiotherapy
Radiosurgery
Spine
Stereotactic
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2016 Collection
School of Medicine Publications
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 1 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 3 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Tue, 15 Sep 2015, 13:07:56 EST by System User on behalf of Scholarly Communication and Digitisation Service