Advances in radiotherapy are focussed on prescribing higher doses for better control of the tumour. For this reason quality assurance becomes more and more important. On 27 March, 12.00 Leah McDermott of The Netherlands Cancer Institute – Antoni van Leeuwenhoek Hospital will defend her PhD thesis on radiotherapy dose verification with a flat panel imager, also known as an electronic portal imaging device (EPID).
Normally this device, essentially an x-ray camera, is used for patient set-up verification. However it can also be used to acquire images of radiation fields before or while they are being delivered to the patient. Information from these images can be used to measure, and verify, the prescribed dose.
McDermott has established the relationship between the EPID signal and dose, and developed a method to determine the dose in the middle of the patient from images acquired behind the patient. As a result, 2-dimensional 'in vivo dosimetry' has been introduced in the clinic, a tool with which planned patient treatments can be measured individually.
This has provided the clinic with a check and record of the delivered dose. These advances have resulted in a large volume of verification data and providing an effective, efficient and accurate radiotherapy ‘safety net’. This net provides radiation oncologists and physicists with the confidence to raise dose prescriptions, introduce new techniques and advance radiotherapy to achieve better cure rates for cancer patients.
More information
Leah McDermott
Telephone: 020 512 2148, email l.mcdermott@nki.nl
PhD thesis defence
Date: 27 March 12.00 h
Location: Oude Lutherse Kerk (Aula), Singel 411, Amsterdam
Promoter: Prof. Marcel van Herk
Co-promoter: Dr. Ben Mijnheer