Novel detector for portal imaging in radiation therapy

Ostling J., Wallmark M., Brahme A., Danielsson M., Iacobaeus C., Fonte P., ...More

Medical Imaging 2000 Conference, California, United States Of America, 13 - 17 February 2000, vol.3977, pp.84-95 identifier identifier

  • Publication Type: Conference Paper / Full Text
  • Volume: 3977
  • Doi Number: 10.1117/12.384550
  • City: California
  • Country: United States Of America
  • Page Numbers: pp.84-95
  • Bursa Uludag University Affiliated: No


We are developing a novel concept for portal imaging that would allow for on-line control and verification of the radiation treatment of cancer patients both at diagnostic and therapeutic energies. This device will consist of two consecutive detectors confined in one gas chamber: a KeV- photon detector, which can visualize the internal soft tissue of the patient, and an MeV-photon detector, which will measure the absolute intensity of the therapeutic beam and its position with respect to the tumor and normal tissues. Both detectors are based on gas and solid photon to electron converters combined with recently invented gas electron multipliers. The device will have a common charge collecting pad-type readout plate equipped with ASIC-based electronics for both detectors. A first simplified prototype device has recently been built and extensively tested. Special efforts were made to find conditions for a safe and reliable operation of the readout electronics' that can be damaged by plasma-type discharge effects induced specially at high dose rates. Results obtained so far indicate that our new detector concept may satisfy all requirements on advanced therapy beam monitoring systems.