open access

Vol 18, No 3 (2013)
Original research articles
Published online: 2013-05-01
Submitted: 2012-09-13
Get Citation

Initial evaluation of intrafraction motion using frameless CyberKnife VSI system

Alejandro Floriano, Icíar Santa-Olalla, Alberto Sanchez-Reyes
DOI: 10.1016/j.rpor.2013.03.004
·
Rep Pract Oncol Radiother 2013;18(3):173-178.

open access

Vol 18, No 3 (2013)
Original research articles
Published online: 2013-05-01
Submitted: 2012-09-13

Abstract

Aim

To analyze intrafraction movement in patients undergoing frameless robotic radiosurgery and evaluate the influence of image acquisition frequency on global accuracy.

Background

Stereotactic radiosurgery requires high spatial accuracy in dose delivery. In conventional radiosurgery, a rigid frame is used to guarantee a correct target alignment and no subsequent movement. Frameless radiosurgery with thermoplastic mask for immobilization cannot completely eliminate intrafraction patient movement. In such cases, it is necessary to evaluate its influence on global treatment accuracy.

Materials and methods

We analyzed the intrafraction motion of the first 15 patients undergoing intracranial radiosurgery (39 fractions) with the CyberKnife VSI system at our institution. Patient position was measured at a 15–90-s interval and was used to estimate intrafraction patient movement.

Results

With our acquisition image protocol and immobilization device, the 99% displacement error was lower than 0.85[[ce:hsp sp="0.25"/]]mm. The systematic movement components were lower than 0.05[[ce:hsp sp="0.25"/]]mm and the random component was lower than 0.3[[ce:hsp sp="0.25"/]]mm in the 3 translational axes. Clear linear time dependence was found in the random component.

Conclusions

Selection of the X-ray image acquisition time is necessary to meet the accuracy required for radiosurgery procedures with the CyberKnife VSI system. We verified that our image acquisition protocol met the 1-mm criterion.

Abstract

Aim

To analyze intrafraction movement in patients undergoing frameless robotic radiosurgery and evaluate the influence of image acquisition frequency on global accuracy.

Background

Stereotactic radiosurgery requires high spatial accuracy in dose delivery. In conventional radiosurgery, a rigid frame is used to guarantee a correct target alignment and no subsequent movement. Frameless radiosurgery with thermoplastic mask for immobilization cannot completely eliminate intrafraction patient movement. In such cases, it is necessary to evaluate its influence on global treatment accuracy.

Materials and methods

We analyzed the intrafraction motion of the first 15 patients undergoing intracranial radiosurgery (39 fractions) with the CyberKnife VSI system at our institution. Patient position was measured at a 15–90-s interval and was used to estimate intrafraction patient movement.

Results

With our acquisition image protocol and immobilization device, the 99% displacement error was lower than 0.85[[ce:hsp sp="0.25"/]]mm. The systematic movement components were lower than 0.05[[ce:hsp sp="0.25"/]]mm and the random component was lower than 0.3[[ce:hsp sp="0.25"/]]mm in the 3 translational axes. Clear linear time dependence was found in the random component.

Conclusions

Selection of the X-ray image acquisition time is necessary to meet the accuracy required for radiosurgery procedures with the CyberKnife VSI system. We verified that our image acquisition protocol met the 1-mm criterion.

Get Citation

Keywords

Robotic radiosurgery; Frameless; Intrafraction movement; Accuracy

About this article
Title

Initial evaluation of intrafraction motion using frameless CyberKnife VSI system

Journal

Reports of Practical Oncology and Radiotherapy

Issue

Vol 18, No 3 (2013)

Pages

173-178

Published online

2013-05-01

DOI

10.1016/j.rpor.2013.03.004

Bibliographic record

Rep Pract Oncol Radiother 2013;18(3):173-178.

Keywords

Robotic radiosurgery
Frameless
Intrafraction movement
Accuracy

Authors

Alejandro Floriano
Icíar Santa-Olalla
Alberto Sanchez-Reyes

Important: This website uses cookies. More >>

The cookies allow us to identify your computer and find out details about your last visit. They remembering whether you've visited the site before, so that you remain logged in - or to help us work out how many new website visitors we get each month. Most internet browsers accept cookies automatically, but you can change the settings of your browser to erase cookies or prevent automatic acceptance if you prefer.

By "Via Medica sp. z o.o." sp.k., ul. Świętokrzyska 73, 80–180 Gdańsk, Poland
tel.:+48 58 320 94 94, fax:+48 58 320 94 60, e-mail: journals@viamedica.pl