Favorable outcome of patients treated by radioembolization of liver metastasis from uveal melanoma

Aim: Hepatic metastasis is the most frequent and prognostically relevant spread in uveal melanoma. At diagnosis, hepatic lesions are typically to wide-spread to be removed by surgery. Median survival has been reported to be only 4-15 month from first diagnosis of liver involvement. Radioembolization (RE), also referred to as selective internal radiotherapy (SIRT), may be considered as a palliative treatment. However, because uveal melanoma is a rare disease, scientific knowledge on the role of RE is still limited in this entity. We thus conceived this study to analyze feasibility and longtime outcome of RE.

Methods: 27 consecutive patients with known hepatic metastasis from uveal melanoma (mean age 69 y, range 52-83) were included into this study between 1/2014 and 4/2018. Decision to evaluate RE was made by the local multidisciplinary tumor board for management of cutaneous malignancies. In the majority of patients (74%), RE was considered as first-line treatment of liver metastases. The other patients had previously been treated by RFA/TACE (n=2), chemo- or immunotherapy (n=3) or by combined locoregional and systemic therapy (n=2). Overall survival was measured using the Kaplan-Meier estimator.

Results: As based on hepatic angiography and simulation of sphere distribution using MAA-SPECT/CT, 23/27 individuals were deemed to qualify for RE. In 4 patients RE was considered not feasible due to either insufficient targeting of tumor lesions (n=2) or non-correctable gastrointestinal shunting (n=2). 19/23 patients received RE of the whole liver, while RE could be restricted to a single liver lobe in 4 individuals. The mean hepatic tumor load accounted for 19% of the total liver volume (range 5-44%). RE was predominantly performed as a single time point intervention (n=17) while two procedures with approx. 6-week interval were applied in the remainder. Median overall survival was 14.8 month from RE and 20.7 month from the first diagnosis of hepatic metastases. In 3 cases RE was repeated after 11, 12 or 27 month due to progression after initial response.

Conclusions: Despite advanced hepatic metastatic spread, favorable survival can be achieved after RE in patients with uveal melanoma. In the view of other evolving treatment options (immunotherapy, chemosaturation) prognostic factors as well as treatment sequence and combination are to be evaluated.