Feasibility of High Activity Rhenium-188-Microsphere in Hepatic Radioembolization

Background This paper describes the feasibility of intra-arterial high-activity administration of (188)Re-microspheres. Methods Patients with unresectable colorectal liver metastases or hepatocellular cancer (HCC) received single treatments with (188)Re-microspheres. The administered activity was calculated to give a liver dose of 100 Gy. From post-therapeutic scans and urine sampling, the dose to the liver, metastases and bladder was calculated. Toxicity was assessed up to 3 months after administration by means of the Common Terminology Criteria for Adverse Events v3.0 (Trotti et al. CTCAE v3.0: development of a comprehensive grading system for the adverse effects of cancer treatment. Semin Radiat Oncol 2003;13(3):176-81). Response was evaluated on CT. Results 13.6 +/- 4.7 GBq (188)Re-microspheres was administered selective in the feeding artery of the tumour to 10 patients (3 x HCC and 7 x colorectal liver metastases). There was a low urinary excretion rate of 8.9 +/- 3.8% of administered activity within 96 h. The absorbed dose to the tumour, normal liver (excluding the tumour) and bladder was 10.24 +/- 5.02 Gy/GBq (128 +/- 47 Gy), 3.94 +/- 2.52 Gy/GBq (50 +/- 33 Gy) and 0.27 +/- 0.20 Gy/GBq (2.4 +/- 1.9 Gy), respectively. There was an acceptable rate of toxicity in 30% of grades I and II, respectively, and 10% with grade III. There was reversible in the most patients within 14 days after treatment. The response was assessed on CT: two patients had a partial response (PR), five patients had stable disease and three patients had disease progression. Conclusion Treatment of colorectal liver metastases or HCC using high activities of (188)Re-microspheres was well tolerated and a PR was seen in 2 of 10 patients. The treatment represents a therapeutic option in these patients.