Task Group 116
Radiological Protection Aspects of Imaging in Radiotherapy

A Task Group under Committee 3

Modern radiotherapy equipment delivers radiation beams from multiple directions conformed to the shape of the target tumour to achieve a planned radiation distribution. Imaging is crucial for successful planning and delivery of this dynamic image guided radiation therapy, to provide additional accuracy in localisation of tumour volumes at the time of treatment. Imaging may be associated with each of the therapy fractions in order to adjust for tumour volumes and any movement in other organs. This is accomplished using either kV or MV orthogonal x-rays or cone beam computed tomography imaging systems integrated into linear accelerators, and enables radiation field margins surrounding the tumour to be reduced. However, if imaging is used frequently with little optimisation, doses to organs and tissues outside the planning target volume can reach tens of mGy per radiotherapy fraction and the imaging dose delivered to the tumour over the course of treatment is no longer insignificant. The use of radiography and fluoroscopy in planning brachytherapy treatment will also be considered. At the present time, practices vary between centres in imaging modalities used, the frequency of imaging, and the level of optimisation undertaken, so more guidance is needed.

This task group will provide guidance on radiological protection aspects in the use of imaging (e.g., cone beam CT, fluoroscopy) in radiotherapy. Advice will relate to optimisation of protocols for exposures carried out during the planning stages, and the frequency and level of optimisation for imaging performed for treatment guidance. The report will consider the trade-off between therapeutic advantages and additional radiation doses from imaging. The report will also examine the need for assessment of organ and tissue doses relating to imaging for communication to radiation oncologists and inclusion in the planning process.

Colin Martin (Chair), University of Glasgow, United Kingdom
William Small (Vice-Chair), USA
Sebastien Gros (Member), Loyola University Medical Center, USA
Aurelie Isambert (Member), IRSN, France
Stine Korreman (Member), Denmark
Tomas Kron (Member), Peter MacCallum Cancer Centre, Australia
Choonsik Lee (Member), National Cancer Institute, USA
Thomas Merchant (Member), USA
Ngie Min Ung (Member), University of Malaya, Malaysia
Tim Wood (Member), Hull University Teaching Hospitals, United Kingdom
Habib Abdulmohsen Alsaleh (Member-Mentee), Saudi Arabia
Abdullah Abuhaimed (Member-Mentee), King Abdulaziz City for Science and Technology, Saudi Arabia
Buthaina Al Ameri (Member-Mentee), Federal Authority for Nuclear Regulation, United Arab Emirates
Zakiya Al Rahbi Al Rahbi (Member-Mentee), Oman
Anson Cheung Ho Yin (Member-Mentee),
Ana Cravo S (Member-Mentee), Portugal
Mario Djukelic (Member-Mentee), Sir Charles Gairdner Hospital, Australia
Mirta Dumancic (Member-Mentee), Gerald Bronfman Department of Oncology, McGill University, Montral QC, Canada
Hein Fourie (Member-Mentee),
Marianna Koutrouli (Member-Mentee), Newcastle upon Tyne Hospitals NHS Foundation Trust, United Kingdom
Anja Lazovic (Member-Mentee), Serbia & Montenegro
Runcheng Liang (Member-Mentee), China Institute for Radiation Protection, China
Aliaksandr Miadzvetski (Member-Mentee), International Sakharov Environmental Institute of Belarusian State University, Belarus
Francisco Mosquera-Pena Snchez (Member-Mentee),
Lavanya Murugan (Member-Mentee), Medical Physicist, Rajiv Gandhi Government General Hospital and Madras Medical College, Chennai, India
Isabelle Nilsson (Member-Mentee), Sweden
Piotr Pankowski (Member-Mentee), Department of Nuclear Physics and Radiation Safety, Faculty of Physics and Applied Informatics University of Lodz, Poland
Maria Cristina Plazas (Member-Mentee), Universidad Nacional de Colombia, Colombia
Samara Prass dos Santos (Member-Mentee), Brazil
Hossam Ragab (Member-Mentee), Senior Medical Physicist at Warith International Cancer Institute, Iraq
Yiannis Roussakis (Member-Mentee), German Oncology Center, Cyprus
Snezana Vostinic (Member-Mentee), Serbia & Montenegro
Suryakanta Acharya (Technical Secretary), PAY-W Clinic, Assam Cancer Care Foundation, India
Daniel Berger (Representative), International Atomic Energy Agency, AUSTRIA
Jenia Vassileva (Representative), International Atomic Energy Agency (IAEA), Austria