Vascular Redistribution for SIRT—A Quantitative Assessment of Treatment Success and Long-Term Analysis of Recurrence and Survival Outcomes

Abstract

Aim Flow redistribution is not uncommonly performed as a treatment strategy to optimize delivery of radioembolization particles to the liver. We quantitatively evaluated the effect of vessel embolization to promote flow redistribution when performing selective internal radiation therapy (SIRT) for liver metastases, and assessed long-term outcomes of treatment. Materials and Methods One hundred and fifty-eight SIRT procedures over an 8-year period were retrospectively reviewed. Twenty-three patients who underwent partial/whole embolization of the left hepatic artery were compared to a control group of 18 patients who did not receive any hepatic embolization as part of their work up. Counts were measured for each patient on both the post-99mTcMAA injection, and the post-90Y microspheres injection imaging. Recurrence and survival rates were also measured. Results A statistically significant shift in the right:left ratio between planning and treatment procedures was seen in patients who had vessel embolization in favor of the embolized lobe (p = 0.014). There was no significant difference in the time to recurrence in the embolized lobes versus the nonembolized lobes. No significant difference in overall survival was detected between the two cohorts. Conclusion To facilitate safe whole liver treatment, it is sometimes necessary to partially or completely occlude main or accessory hepatic arteries. This study shows that the success of flow redistribution strategies can be quantitatively measured, and there is no adverse impact on time to recurrence or overall survival outcomes.

Factors impacting survival after transarterial radioembolization in patients with hepatocellular carcinoma: Results from the prospective CIRT study

“…40 The variations in the blood supply of the left liver lobe may require a more meticulous positioning of suited microcatheters to ensure a consistent and robust dose distribution compared to the right liver lobe, explaining differences in outcome if not considered thoroughly. [41] , [42] , [43] …”

Techniques to Optimize Radioembolization Tumor Coverage

“…For one group of patients with right lobe lesions, left hepatic artery coil embolization was performed prior to TARE treatment, whereas the control group received no pretreatment embolization (or flow redistribution). 14 Their analysis demonstrated no significant difference in time to recurrence or overall survival between the left hepatic artery pretreatment coil embolization group versus no pretreatment coil embolization group.…”

Ambulatory Same-Day Map-and-Treat Angiography for Selective Internal Radiation Therapy Using a Transradial Approach

“…The purpose of the first stage is to map and define the hepatic arterial anatomy to identify anatomical variance and assess flow in the vessels. Historically, a second key component of the mapping procedure was to coil-occlude/embolise any hepatic or gastric branches that might complicate treatment, or lead to inadvertent Y-90 delivery outside of the liver [3]. The final component of the mapping procedure was to produce a trial run of the eventual Y-90 delivery by administrating a non-harmful, surrogate marker for Y-90, in this case, technetium-99 macro-aggregated albumin ( 99m Tc MAA).…”