Electronic portal imaging using Cherenkov radiation

Isuru C. Silva; G. Pang

doi:10.1117/12.772023

18 March 2008 Electronic portal imaging using Cherenkov radiation

Isuru C. Silva, G. Pang

Proceedings Volume 6913, Medical Imaging 2008: Physics of Medical Imaging; 69130A (2008) https://doi.org/10.1117/12.772023
Event: Medical Imaging, 2008, San Diego, California, United States

Abstract

Most electronic portal imaging devices (EPIDs) developed so far use a Cu plate/phosphor screen to absorb x rays. The main problem with this approach is that the Cu plate/phosphor screen must be thin (~ 2 mm) in order to obtain a high spatial resolution, resulting in a low quantum efficiency (QE) for megavoltage (MV) × rays (typically 2-4%). In addition, the phosphor screen contains high atomic number (high-Z) materials, resulting in an over-response of the detector to low energy x rays in dosimetric verification. Our overall goal is to develop a new high QE MV x-ray detector made of a low-Z material for both geometric and dosimetric verification in radiotherapy. Our approach is based on radiation-induced light (Cherenkov radiation) in optical fibers to convert x-ray energy into light. With our approach, a thick (~ 10-30 cm) fiber-optic taper (FOT) consisting of a matrix of optical fibers aligned with the incident x rays is used to replace the thin Cu plate/phosphor screen to dramatically improve the QE. In this work, we demonstrated that the predominant light source in optical fibers under irradiation of a MV beam is indeed Cherenkov radiation, and thus validated the feasibility of using Cherenkov radiation as the primary light source in our proposed Cherenkov detector. A prototype Cherenkov detector array was also built and images were obtained.

Citation Download Citation

Isuru C. Silva and G. Pang "Electronic portal imaging using Cherenkov radiation", Proc. SPIE 6913, Medical Imaging 2008: Physics of Medical Imaging, 69130A (18 March 2008); https://doi.org/10.1117/12.772023

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available