gms | German Medical Science

48th Meeting of the Particle Therapy Co-Operative Group

Particle Therapy Co-Operative Group (PTCOG)

28.09. - 03.10.2009, Heidelberg

Hybrid optoelectronic scintillating fibers for proton imaging

Meeting Abstract

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  • J. Seco - Radiation Oncology, Massachusetts General Hospital, Boston, USA
  • S. Danto - Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, USA
  • N. Depauw - Radiation Oncology, Massachusetts General Hospital, Boston, USA
  • Y. Fink - Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, USA

PTCOG 48. Meeting of the Particle Therapy Co-Operative Group. Heidelberg, 28.09.-03.10.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. Doc09ptcog180

doi: 10.3205/09ptcog180, urn:nbn:de:0183-09ptcog1806

Published: September 24, 2009

© 2009 Seco et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Background: Proton radiation therapy presents an advantage over conventional radiation therapy due to its finite range in patients, and it is thus bound for development. The use of proton radiography daily prior to proton therapy would then be of a great advantage. The overall goal is to design a novel proton imaging device utilizing the advantage of both fiber optics and scintillators, hence representing a great improvement in both image quality and manufacturing costs.

Materials and methods: A novel hybrid optoelectronic scintillating fiber has been designed and developed by MGH/MIT with the purpose of building a proton imaging device. The optoelectronic fiber consists of an As40Se52Te8 semi-conductor thin film in contact with four metallic electrodes and supported by some cladding, either polyether sulfone (PES) or polycarbonate (PC). The fiber is hollow-core allowing a scintillator to be added to it. Different type of scintillating materials are evaluated for their different characteristics; a fast decay time allows proton imaging on an event-by-event basis, leading to better spatial resolution, while a greater light output gives a better signal-to-noise ratio. The fiber can then be manufactured with different densities of scintillator in order to further improve the accuracy.

Results: Experiments have been made using the aforementioned fibers with different scintillators, both organic (Csl) and inorganic (BC-517H). While increasing the proton current, which regulates the intensity of the beam irradiating a patient, from 10nC to 150nC, the optoelectronic scintillating fibers responses were linear with R2>0.987. A linear response is vitally important in identifying, with millimeter precision, the localization of an interaction point.

Discussion and conclusion: The best scintillating material to use inside the optoelectronic fibers has to be assessed in order to obtain the best accuracy at a small cost. The implementation of a proton imaging device using optoelectronic scintillating fibers can therefore significantly improve the future of proton radiography by substantially enhancing image quality while considerably reducing manufacturing costs.