Pilot Group – Dosimetry in nuclear medicine

Weibo Li
German Federal Office for Radiation Protection (BfS)
Email: wli [at] bfs [dot] de (wli[at]bfs[dot]de)

Lara Struelens
SCK CEN, Belgium
Email: lara [dot] struelens [at] sckcen [dot] be (lara[dot]struelens[at]sckcen[dot]be)

The Pilot Group has:

• 20 full members,
• approx. 20 corresponding members and
• approx. 20 observers.

Liaisons

The Pilot Group has 4 liaisons from EANM - Silvano Gnesin (Dosimetry) and Elena Prieto (Radiation Protection), SIG-FRID - Manuel Bardiès and ICRP - Augusto Giussani.

Task Group leader: Lara Struelens (SCK CEN, Belgium)

The growing use of nuclear medicine and the diversity of new radiopharmaceuticals, stimulate the need for a more comprehensive re-evaluation of the radiological risk for caregivers and general public coming into proximity of nuclear medicine patients. The objective of this task is to develop a more comprehensive dose calculation approach by using the most recent advancements in computational dosimetry, such as Monte Carlo simulations, realistic flexible human phantoms, and time activity distribution curves from the most recent biokinetic models. In addition to caregiver and medical staff dose assessment, this new dose calculation framework is particularly important for modelling some of the most concerning close contact exposure situations, such as an adult holding/comforting a child patient, or a mother breastfeeding her child.

Task Group leader: Kuangyu Shi (Universitätsspital Bern, Switzerland)

The objective of this task is to implement established AI techniques in the pharmacokinetic modelling and patient dosimetry, especially in the emerging radiopharmaceutical therapy. We are now working on a review on “AI practical application in dosimetry for radiopharmaceutical therapy” from a EURADOS view. In the same time, we are implementing and intercomparing machine learning algorithms in organ-level dosimetry prediction.

Task Group leader: Juan Ocampo Ramos (Memorial Sloan Kettering Cancer Center, USA)

Dosimetry intercomparison is important for evaluating and improving the accuracy and precision of radiation absorbed dose calculations, as well as for ensuring the safety and quality of nuclear medicine procedures. The task will try to identify the range of results and then investigate the origins of any potential discrepancies based on assumptions, methodologies, software, or tools used. Finally, the aim is to identify and develop EURADOS guidelines to harmonize clinical patient dosimetry in cooperation with other professional nuclear medicine associations.

Task Group leaders: Maria Carapinha (ESTeSL, Portugal) and Jan Taprogge (Royal Marsden Hospital, UK)

ICRP biokinetic models often only consider healthy reference populations. Iodine biokinetics are expected to differ in hyperthyroid patients and revised biokinetics models are essential for radiation protection purposes. This task will aim to collate biokinetic information available in the literature and attempt to create a disease-specific model for patients with Grave’s disease.

Task Group leader: Astrid Delker (Klinikum Ludwig-Maximilians-Universität München, Germany)

This task will focus on 3D dosimetry techniques in normal organs and tumor. In addition, we will implement this technique to improve, for example, correlation between bone marrow toxicity and response in case of presence of bone metastases.

Task Group leader: Philipp Ritt (Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany)

This task will utilize advanced dosimetric techniques, leveraging in-vitro and in-vivo imaging technologies, to evaluate absorbed doses at the sub-tissue and sub-organ levels, such as in the kidneys and bone marrow. The initial sub-task will involve an intercomparison exercise using a semi-artificial autoradiography dataset. This approach will allow all participants to work with realistic, voxelized data and also facilitate a better understanding of potential errors and variability in small-scale dosimetry.

The task group comprises scientists from various European hospitals and research organizations and is open to welcoming interested newcomers.

Task Group leader: Vladimir Spielmann (BfS, Germany)

The absorbed dose coefficients to the patients from administered radiopharmaceuticals are usually calculated according to the generalized schema recommended by the MIRD and ICRP. In these calculations, the mathematic models for the time-dependent activity curves in organs and tissues (pharmacokinetic models) and the mathematic and digital representations of the human body (voxel phantoms) are initially evaluated. Because of the uncertainties in the image acquisition chains and the variability of the patients, the image-based pharmacokinetic models and the reference human phantoms used for the estimation of absorbed doses to patients are subject to large sources of uncertainty. Hence, for an individual patient, the resulting dose coefficients are uncertain. In this task, general methods and programs will be developed for assess the uncertainty of organ absorbed dose to patients in diagnostics and treatments, furthermore, sensitivity analysis approach will be applied for identify the important model parameters in the dose calculation chain.