Radionuclide therapy for hepatocellular carcinoma: indication, cost and efficacy.

ABSTRACT

A large number of patients with hepatocellular carcinoma (HCC) will have large and/or multiple inoperable tumours, precluding percutaneous ablation, such as percutaneous ethanol, acetic acid or hot saline injection, and radiofrequency ablation. Similarly, if the tumour is not accessible percutaneously or the tumour is subcapsular or subdiaphragmatic, percutaneous therapy is ruled out. Many patients will also have associated portal vein thrombosis, making them unsuitable for chemoembolisation, depending upon the level and severity of thrombosis. Such patients can be offered internal radioisotope therapy to prolong their survival and improve the quality of life. The aim of radioisotope therapy is to deliver the radioisotope to the hepatic tumour, where it must reside for a period sufficient to deliver the scheduled dose of radiation. At the same time the amount delivered to the normal liver parenchyma and other organs should be as low as possible. A variety of radioisotopes, such as lodine-131, Yttrium-90, Rhenium-188, Holmium-166 etc. can be used for this purpose and targeting of the therapeutic agent to the tumour may be achieved by 1) direct intra-tumour implantation of the radioisotope, 2) parenteral injection of radiolabelled antibodies specific to HCC antigens (radioimmunotherapy) or, 3) injecting the radioisotope through the hepatic artery directly into the tumour or trans-arterial radioisotope therapy (TART). The radioisotope therapy appears to be a very reasonable and effective therapeutic alternative, a) for the treatment of large inoperable HCC, particularly with portal vein thrombosis, b) treatment of small inoperable tumours unsuitable for percutaneous therapy because of any reason, c) as a neoadjuvant therapy before hepatic transplantation to reduce the risk of recurrence in the graft or before hepatic resection to shrink the tumour size, and d) as an adjuvant therapy, after surgery or percutaneous ablative therapy to reduce the risk of recurrence. Further, it can be very affordable if generator produced Re-188 is used, which appears to be equally or more effective and useful than other currently available radioisotopes. The availability of Re-188 in a generator form makes its storage, transportation, elution and usage very convenient and cost-effective, particularly at remote places and in developing countries. The use of generator also makes Re-188 available on a constant and need to need basis.