Task Group 117 Workshop

Radiological Protection in PET and PET/CT

18 September 2023  |  Virtual Event

Over the next decade, ICRP will be hosting several Digital Events each year as we look to review and revise the System of Radiological Protection for the next generation. 


ICRP Task Group 117 has prepared a report that describes the radiological protection in PET and PET/CT, which is out for public consultation until 29 December 2023.

The workshop will be concerned with the topics addressed in the report through presentations by Task Group members. There will be a panel discussion on the Implementation in Different Parts of the World as well as time allocated for Questions and Answers from the audience.

Participants who attend at least 50% of the workshop will receive a Certificate of Attendance via email within 48 hours of the event.


Publication Abstract

Positron Emission Tomography (PET) is a nuclear medicine imaging procedure used today almost exclusively in multimodal imaging particularly with computed tomography (CT) but also with magnetic resonance (MR), rather than alone. Its utilisation rates are growing as clinical indications expand with the addition of new PET radiopharmaceuticals. In some countries, PET/CT scans currently make up about 10% of all nuclear medicine examinations and about 20% of the patient effective dose delivered in nuclear medicine. Radiation doses depend not only on the administered activity, but also on the CT scan utilisation. Shorter half-lives of PET radionuclides and the high energies of annihilation photons emitted present particular challenges for staff radiological protection, which are compounded because patients are required to rest for an extended period between administration and imaging. Occupational doses in PET can be of few mSv per year, and skin doses to the fingers from manipulating PET radiopharmaceuticals can exceed the annual skin dose limit of 500 mSv if proper protection measures are not followed. Public exposure is not a cause for concern, and no special recommendations are needed to limit the release of the patient after the PET scan. However, patients and clinicians remain concerned and therefore, this report provides guidance on not only occupational, but also patient, and public radiological protection in PET and PET/CT. A brief section on PET/MR is also provided.

The technology involved and the way in which it is used together with the facility design has a direct impact on patient and staff dose. Consequently, the principles of operation of both the cyclotron used for production of the radionuclides and of the scanner are reviewed in this report; the report describes optimal facility design, equipment life cycle considerations, and work flow for the radiopharmaceutical agents.

The justification of the PET procedure should be established considering also the technology available, and when performed in a PET/CT scanner, the CT protocol should correspond to the objective of the CT examination. Distinct considerations are provided for the radiological protection related to the medical exposure of patients, carers/comforters, and research volunteers, including patient dose estimation, strategies to reduce the dose, and the special cases of patients who are breast feeding or pregnant, and paediatric patients.

Sources of exposure to staff working in PET facilities have been reviewed, and records show that dose depends not only on the protective methods but also on the individual practices, education, and quality assurance program. Therefore, procedures to reduce staff dose are provided together with guidance for staff monitoring. Optimisation of radiological protection for PET should be within the frame of a dose management and quality assurance program, which describes the radiological protection program and includes metrics to evaluate the degree of achievement. In addition, the health professionals that perform the procedures must obtain proficiency in radiological protection and safety through formal, accredited education, training, and continuous professional development.








Donna Newman (ICRP, USA)
Overview of TG 117 Report
Josep M. Martí-Climent (ICRP/Clínica Universidad de Navarra, Spain)


PET and PET/CT principles
Sören Holm (ICRP, Denmark)


How to Design a PET/CT Facility
Mario Marengo (ICRP/University of Bologna, Italy)


Justification and Optimisation Related to the Medical Exposure
Keon Kang (ICRP/Seoul National University, South Korea)
Optimisation for Staff
Colin Martin (ICRP/University of Glasgow, UK)


How to Control Staff Doses
Filip Vanhavere (ICRP/SCK-CEN, Belgium)


The Importance of Education and Training
Ana I. Santos (ICRP/Hospital Garcia de Orta, E.P.E., Portugal)


Moderator: Makoto Hosono (ICRP/Kindai University, Japan)
Panel: Application in Different Parts of the World and Feedback on the Draft Document
Moderator: Donna Newman (ICRP, USA)
Kwan Ng


Boris Brkljačić
Rafael Lopes