At BNMS Hermes Medical Solutions will be demonstrating its latest software for radionuclide therapy dosimetry. “We recognise the need for commercial applications to facilitate compliance with the IR(ME)R 2017 legislation,” states the company. “This requires that all hospitals individually plan and verify the radiation dose delivered to target volumes and organs at risk. Hybrid dosimetry with Olinda/EXM 2.1 is designed with a simple user workflow and allows non-experts access to the tools required to measure and report radiation dose from radionuclide therapies.”
In the latest release features include lesion dosimetry, whereby lesion doses can be calculated with the sphere model and displayed in a report. It is also possible to remove lesion activity from healthy organ activity if the lesion is inside the organ.
Personalisation of dosimetry calculations based on individual patient anatomy is available. MIRD s-factors can be scaled by organ mass as defined by the SPECT volumes of interest, assuming an average tissue density of 1g/cm3. External dose rate measurements from a whole-body probe can be used to define the time-activity curve.
The SPECT reconstruction software has benefitted from advances to meet the demands of imaging therapy radionuclides accurately. Hybrid Recon now includes full collimator modelling for I-123, I-131, Y-90 and Ho-166 imaging; Monte Carlo simulation of the true collimator interactions of these higher energy isotopes gives more accurate quantification of patient uptake. Collimator scatter, absorption with fluorescence, and septal penetration (photons B, C, and D respectively in figure) are modelled as well as geometric collimation (photon A).
Photo: Photon interaction types in a collimator: (A) geometrically collimated photon, (B) scattered photon, (C) lead x-ray fluorescence photon and (D) penetrated photon.
Published on page 16 of the March 2019 issue of RAD Magazine.