Authors (including presenting author) :
Lo M(1), Kwan KK(1)
Affiliation :
(1)Medical Physics Unit, Clinical Oncology, Tuen Mun Hospital
Introduction :
Treatment activity for yttrium-90 Transarterial Radioembolization (TARE) when calculated by using manufacturer-recommended empirical techniques estimate safely acceptable doses according to historical data only without patient specific risk factors. The currently utilized clinical dosimetric standards (e.g. partition method) do not reflect real-world non-uniform tumor dose or liver parenchymal dose. Emerging dosimetry methods overcame the mean dose approach in favor of the evaluation of dose distribution at voxel level. However, the multitude of microdosimetric calculations’ intertwining components lie disjointed within literatures.
Objectives :
Articles are reviewed to sort out possible paths to adopt the treatment dosimetry of TARE in microscale from current clinical settings. By considering radiobiological effect of the spatial and temporal varying dose rates in the microscale, knowledge available in external beam radiation therapy (EBRT), tumor control probability and normal liver dose constraints, can be applied to microsphere treatments to establish fundamental dose-response relationship for treatment efficacy and toxicity and to manage patient follow-up.
Methodology :
As a minimally invasive procedure, combining embolization and radiation, the microsphere treatment planning emphasized image-based pre-treatment simulations of injection and post-treatment evaluations of outcome; the review focused on the 3D implementations with physical and / or digital phantom validations. Keywords such as “radioembolization dose volume histogram”, “radioembolization local dose deposition”, “radioembolization microdosimetry”, “Y-90 predictive dosimetry” “radioembolization SPECT/CT”, “yttrium-90 PET/CT”, “yttrium-90 biologic effective dose”, “yttrium-90 NTCP TCP”, and “yttrium-90 radiomics radiogenomics ” were inputted into Google search.
