PhD defense Remco Bastiaannet

On Tuesday 8 December 2020, Remco Bastiaannet will defend his thesis entitled: “Radioembolization: Toward the optimal dose.”


Radioembolization is a treatment for primary and metastatic liver tumors that cannot be removed surgically and are resistant to chemotherapy. The treatment consists of the infusion of millions of tiny radioactive spheres (i.e. microspheres) into the liver vasculature through a catheter. Because liver tumors and healthy liver tissue have different blood supplies, the microspheres tend to mostly lodge into tumorous tissue. Once implanted they irradiate the tumors from within, whilst mostly sparing healthy liver tissue.

The biodistribution of microspheres, and thus absorbed dose, is highly variable between patients and tumor types. Current methods for treatment planning mostly ignore this individual component. At the same time, these methods aim to prevent the occurrence of treatment-induced toxicity in all patients. As a result, current methods are thought to result in an overly conservative treatment for many patients. In other words, we are currently treating with the worst-case scenario in mind, which might result in undertreatment for most patients. Quantitative nuclear imaging allows for in vivo estimation of the microsphere biodistribution, which can guide therapy planning.

This thesis is split into two parts. Part I describes issues and technical advances in quantitative imaging that are meant to contribute to more accurate and faster dose estimations. The theme of Part II is how to best measure treatment response and how these insights can be applied to the optimization of individual treatment planning.