Hybrid Imaging Reveals Improved Absorbed Dose from Selective Internal Radiation Treatment by Using an Anti-Reflux Catheter

Abstract Selective internal radiation therapy (SIRT) is a promising technique for patients with hepatic malignancies. Several image-based investigations, e.g. volumetric and absorbed dose assessment, are mandatory for SIRT planning and treatment verification based on national and international regulations.General treatment workflows are described in guidelines, recommendations, and the package inserts of the manufactures. But, guidance to tackle particular clinical conditions can be ill-defined and different centers practice their own workflow to analyze the treatment process. This case report includes an example of inconsistency between treatment simulation and observed treatment result, revealed by hybrid imaging. There is no universally accepted standard procedure defined in the literature for detecting and evaluating a possible mismatch between [99mTc]Tc-MAA-based simulation and distribution of the therapeutic microspheres. In this setting, more advanced multi-modal image-based analysis may be beneficial.A 78 year old patient with hepatocellular carcinoma underwent liver radioembolization with resin 90Y-microspheres. Tumoral and non-tumoral dose–volume histograms were evaluated for simulated activity distribution using [99mTc]Tc-MAA-SPECT and post-treatment activity measurement using 90Y-PET. During simulation workup, [99mTc]Tc-MAA particles were administered using a regular catheter. On the other hand, for the treatment session an anti-reflux catheter was used. Our result, suggests that the use of an anti-reflux catheter might improve tumor coverage, and as a result decrease non-tumoral liver uptake deposition.