Initial study of radiological and clinical efficacy radioembolization using 188Re-human serum albumin (HSA) microspheres in patients with progressive, unresectable primary or secondary liver cancers.

Background: The aim of this initial study was to evaluate the clinical and radiological effectiveness of radioembolization (RE) using 188Re-Human Serum Albumin (HSA) microspheres in patients with advanced, progressive, unresectable primary or secondary liver cancers, not suitable to any other form of therapy.
Material/methods: Overall, we included 13 patients with 20 therapy sessions. Clinical and radiological responses were assessed at 6 weeks after therapy, and then every 3 months. The objective radiological response was classified according to Response Evaluation Criteria in Solid Tumors (RECIST) v.1.0 by sequential MRI. Adverse events were evaluated using NCI CTCAE v.4.03.
Results: There were 4 patients with hepatocellular carcinoma (HCC), 6 with metastatic colorectal cancer (mCRC), 2 with neuroendocrine carcinoma (NEC), and 1 patient with ovarian carcinoma. Mean administered activity of 188Re HSA was 7.24 GBq (range 3.8-12.4) A high microspheres labeling efficacy of over 97±2.1% and low urinary excretion of 188Re (6.5±2.3%) during first 48-h follow-up. Median overall survival (OS) for all patients was 7.1 months (CI 6.2-13.3) and progression-free survival (PFS) was 5.1 months (CI 2.4-9.9). In those patients who had a clinical partial response (PR), stable disease (SD), and disease progression (DP) as assessed 6 weeks after therapy, the median OS was 9/5/4 months, respectively, and PFS was 5/2/0 months, respectively. The treatment adverse events (toxicity) were at an acceptable level. Initially and after 6 weeks, the CTC AE was grade 2, while after 3 months it increased to grade 3 in 4 subjects. This effect was mostly related to rapid cancer progression in this patient subgroup.
Conclusions: The results of this preliminary study indicate that RE using 188Re HSA is feasible and a viable option for palliative therapy in patients with extensive progressive liver cancer. It was well tolerated by most patients, with a low level of toxicity during the 3 months of follow-up.