10 Postradioembolization imaging using bremsstrahlung90Y SPECT/CT

Radioembolization is a therapy during which radioactive microspheres are administered through a microcatheter placed in the hepatic arterial vasculature to irradiate liver tumors from within. is therapy is based on the principle that liver tumors are almost exclusively vascularized by the hepatic artery, whereas the healthy liver tissue receives the majority of its blood supply from the portal vein. erefore, following the administration in the hepatic artery, microspheres will be carried preferentially toward the distal arterioles 1.1 General introduction 3 1.1.1 What is radioembolization? 3 1.1.2 A brief history of radioembolization 4 1.1.3 Indications for radioembolization 6 1.1.4 Comparison of radioembolization and external beam radiation therapy principles 7 1.2 Types of microspheres and radionuclides used 8 1.2.1 Yttrium-90 microspheres 8 1.2.2 Holmium-166 microspheres 10 1.3 Pretreatment workup 11 1.3.1 Laboratory and clinical investigations 11 1.3.2 Pretreatment imaging: liver CT/MRI and 18F-FDG-PET 11 1.3.3 Assessing the individual hepatic arterial anatomy 12 1.3.4 Preparatory angiography and intraprocedural imaging 13 1.3.5 Imaging of the scout dose distribution 15 1.3.6 Pretreatment activity calculations 16 1.4 Treatment 17 1.4.1 Medication and periprocedural care 17 1.4.2 Treatment technique 17 1.4.3 Catheter types and particle- fluid dynamics 18 1.4.4 Imaging of the therapeutic microsphere distribution 18 1.4.5 Dose-response relationship 19 1.5 Treatment-related laboratory and clinical toxicity 19 1.5.1 Complaints during treatment 19 1.5.2 Laboratory toxicity 19 1.6 Tumor response assessment 21 1.6.1 Anatomical tumor response assessment 22 1.6.2 Functional tumor response assessment 22 1.7 Conclusion 23 References 23 in and around tumors. Clusters of microspheres are formed inside and in the periphery of tumors, where they emit high-energy β-radiation to induce cell death, while relatively sparing the healthy liver tissue (Braat et al., 2015). Radioembolization is a minimally invasive, image-guided, locoregional alternative, or adjunct to more conventional therapies such as surgery, systemic chemotherapy, and external beam radiation therapy for patients with liver-dominant malignancy. e advantages of this treatment are the targeted delivery of a very high radiation-absorbed dose to tumors, with limited systemic side eects and hepatotoxicity (Kennedy, 2014).