Modelling SPECT auto-contouring acquisitions for Lu & I molecular radiotherapy using new developments in Geant4/GATE.

Purpose: Monte Carlo modelling of SPECT imaging in Molecular Radiotherapy can improve activity quantification. Until now, SPECT modelling with GATE only considered circular orbit (CO) acquisitions. This cannot reproduce auto-contour acquisitions, where the detector head moves close to the patient to improve image resolution.

Clinical implementation of PLANET® Dose for dosimetric assessment after [Lu]Lu-DOTA-TATE: comparison with Dosimetry Toolkit® and OLINDA/EXM® V1.0.

Background: The aim of this study was to compare a commercial dosimetry workstation (PLANET® Dose) and the dosimetry approach (GE Dosimetry Toolkit® and OLINDA/EXM® V1.0) currently used in our department for quantification of the absorbed dose (AD) to organs at risk after peptide receptor radionuclide therapy with [Lu]Lu-DOTA-TATE.

Methods: An evaluation on phantom was performed to determine the SPECT calibration factor variations over time and to compare the Time Integrated Activity Coefficients (TIACs) obtained with the two approaches.

Comparison of commercial dosimetric software platforms in patients treated with Lu-DOTATATE for peptide receptor radionuclide therapy.

Purpose: The aim of this study was to quantitatively compare five commercial dosimetric software platforms based on the analysis of clinical datasets of patients who benefited from peptide receptor radionuclide therapy (PRRT) with Lu-DOTATATE (LUTATHERA ).

Methods: The dosimetric analysis was performed on two patients during two cycles of PRRT with Lu. Single photon emission computed tomography/computed tomography images were acquired at 4, 24, 72, and 192 h post injection.

Monte Carlo dosimetry of a realistic multicellular model of follicular lymphoma in a context of radioimmunotherapy.

Purpose: Small-scale dosimetry studies generally consider an artificial environment where the tumors are spherical and the radionuclides are homogeneously biodistributed. However, tumor shapes are irregular and radiopharmaceutical biodistributions are heterogeneous, impacting the energy deposition in targeted radionuclide therapy. To bring realism, we developed a dosimetric methodology based on a three-dimensional in vitro model of follicular lymphoma incubated with rituximab, an anti-CD20 monoclonal antibody used in the treatment of non-Hodgkin lymphomas, which might be combined with a radionuclide.

OpenDose: Open-Access Resource for Nuclear Medicine Dosimetry.

Radiopharmaceutical dosimetry depends on the localization in space and time of radioactive sources and requires the estimation of the amount of energy emitted by the sources deposited within targets. In particular, when computing resources are not accessible, this task can be performed using precomputed tables of specific absorbed fractions (SAFs) or S values based on dosimetric models. The aim of the OpenDose collaboration is to generate and make freely available a range of dosimetric data and tools.