Institutional Research Information Service
UCL Logo
Please report any queries concerning the funding data grouped in the sections named "Externally Awarded" or "Internally Disbursed" (shown on the profile page) to your Research Finance Administrator. Your can find your Research Finance Administrator at https://www.ucl.ac.uk/finance/research/rs-contacts.php by entering your department
Please report any queries concerning the student data shown on the profile page to:

Email: portico-services@ucl.ac.uk

Help Desk: http://www.ucl.ac.uk/ras/portico/helpdesk
Publication Detail
Characterisation of a Novel Radiation Detector and Demonstration of a Novel Error Detection Algorithm for Application in Radiotherapy
  • Publication Type:
  • Authors:
    Alzahrani H
  • Date awarded:
  • Awarding institution:
    UCL (University College London)
  • Language:
  • Keywords:
    DQE, EGSnrc, radiation detectors, dose verification
Radiation detectors play an important role in radiology departments, particularly in relation to imaging and dosimetry. The significant advances achieved in material properties and high-quality electronic systems during previous decades has led to a continual expansion of their role and usage. In turn, this has had a concomitant impact upon the rapid progress of radiation detector technologies, specifically those utilised in medical imaging and dosimetry. This thesis aims to evaluate a radiation detector for a particular function, and to assess its suitability for said function within radiology and radiotherapy departments. Two novel radiation detectors, one for low energy imaging (kV) and another for radiotherapy (MV), are named Lassena (kV) and Lassena (MV) respectively. These detectors underwent an evaluation for the first time in order to assess their performance. Lassena (kV) was assessed in terms of image resolution and noise level to obtain the detective quantum efficiency (DQE) values representing image quality. DQE (0.5) values were 0.46-0.59 for three beam energies. Lassena (MV) was evaluated regarding its dosimetric properties, including linearity based on dose rate, reproducibility, and uniformity. Lassena (MV) has a high degree of short-term reproducibility, an acceptable pixel uniformity-response at high dose rates, and acceptable linearity with a coefficient of determination of 0.8624. Lassena (kV) displayed promising results whilst Lassena (MV) exhibited high sensitivity to radiation. A Monte Carlo system consisting of a linear accelerator and radiation detector was built and calibrated in order to assess dose verification applications within radiotherapy using a radiation detector. Anatomical changes during radiation therapy (such as parotid shrinkage and sinusitis for a nasopharyngeal case) were replicated. Analysis of computational EPID images started to warn of a risk of deviation from the planned dose at -26.3% volume loss of the parotid gland. This is most likely to happen in the third week of the treatment, however, the user must be aware of the limitations present due to anatomical overlapping and gamma analysis.
Publication data is maintained in RPS. Visit https://rps.ucl.ac.uk
 More search options
There are no UCL People associated with this publication
University College London - Gower Street - London - WC1E 6BT Tel:+44 (0)20 7679 2000

© UCL 1999–2011

Search by