Radioembolization for Colorectal Liver Metastases after Ablation: a Prospective study

Ablation therapy permits an alternative treatment option for patients with
irresectable colorectal liver metastases (CRLM). However, local liver
recurrence is a frequent phenomenon, which jeopardizes disease free survival
(DFS) of these patients. The rate of liver recurrence confined to the liver is
up to 60%, whereas after liver surgery, liver only recurrence is reported in
approximately 30 to 35% of patients. Experimental data demonstrated a
stimulating effect of ablation on the outgrowth of remaining tumor cells
surrounding the lesion. Selective internal Yttrium-90 (Y-90) radioembolization
is a form of brachytherapy in which radioactive microspheres are injected into
the hepatic artery in order to destroy malignant tissue. A combination of
ablation therapy and radioembolization may therefore reduce the local liver
recurrence rate and prolong DFS in patients with CRLM. In this study we will
assess the feasibility of this approach in patients with CRLM treated with Y-90
radioembolization after ablation.

Primary objective is to assess the efficacy of ablation therapy in combination
with Y-90 radioembolization in patients with CRLM.
Secondary objectives are:
1) Assessment of occurrence of any treatment related adverse events following
ablation in combination with Y-90 radioembolization in patients with CRLM.
2) Intrahepatic recurrences within 12 months after the ablation procedure.
3) To assess the impact of Y-90 radioembolization additional to the ablation
therapy on the quality of life of patients.

The proposed study is a multicenter, phase II prospective cohort study.

Patients will undergo radiofrequency ablation or microwave ablation followed by
Y-90 radioembolization.

Combining Y-90 radioembolization with ablation therapy requires pre-procedure
screening and four nights of extra hospitalization in two sessions. Although
minimally invasive, Y-90 radioembolization is not without adverse events.
Related adverse events are symptoms of the post-embolization syndrome and in
general, these symptoms emerge within 24 hours post-procedure and fade within 5
to 7 days. Grade II clinical adverse events were reported in 68% of patients
and grade III toxicities in 6% of patients. Grade II and grade III biochemical
adverse events were reported in respectively 16% and 2% of patients. Most
adverse events can be treated when necessary and for severe adverse events,
clinical guidelines are determined in order to minimize the occurrence of these
events. The addition of Y-90 radioembolization to ablation in treatment of
patients with CRLM may decrease the recurrence rate, which could be an
important step towards increased survival of these patients.