Cone Beam CT Shading Correction
Research type
Research Study
Full title
Making cone beam CT imaging fit for aggressive targeting & adaptive re-planning of photon and proton radiotherapy
IRAS ID
167091
Contact name
Thomas Marchant
Contact email
Sponsor organisation
The Christie NHS Foundation Trust
Duration of Study in the UK
2 years, 3 months, 29 days
Research summary
In-treatment cone-beam CT (CBCT) imaging is widely used in radiotherapy (RT) to provide 3D anatomical data for patient positioning and tumour targeting. However, because of X-ray scatter, non-ideal detectors and large regions of interest, CBCT cannot be used for essential re-calculation of delivered X-ray dose when anatomical changes are observed following pre-treatment planning and during daily delivery.
The purpose of this study is to develop and validate a software based method to improve the uniformity and calibration of CBCT images, so that they can be used for accurate assessment of changes to delivered dose in radiotherapy as a result of changes observed during the treatment course. Following peer-review this study has been awarded funding from the Medical Research Council.
The study will use anonymised patient images, acquired as a routine part of radiation therapy. The images will be used for "offline" testing of the methods developed, in order to determine the accuracy of dose calculations based on the processed CBCT images. The research team will have no access to identifiable patient data and the results will not be linked back to the original patients, or used to affect their treatment in any way.
The performance of the method will be studied for three anatomical sites: pelvis, thorax and head. For each anatomical site the success of the method will be tested by comparing the accuracy of CBCT-based dose calculations before and after applying the developed correction software. The primary objective of the study is to show that the software correction produces a significant improvement in dose calculation accuracy. This would demonstrate a potential for clinical application of the software, and lead to its further development as a standalone medical device.
REC name
London - Westminster Research Ethics Committee
REC reference
15/LO/0146
Date of REC Opinion
21 Jan 2015
REC opinion
Favourable Opinion