Bal C S, Kumar A
Department of Nuclear Medicine & PET, AIIMS, New Delhi, India.
Trop Gastroenterol. 2008 Apr-Jun;29(2):62-70.
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.
大量肝细胞癌（HCC）患者会出现大的和/或多个无法手术切除的肿瘤，无法进行经皮消融，如经皮乙醇、乙酸或热盐水注射以及射频消融。同样，如果肿瘤无法经皮到达，或者肿瘤位于包膜下或膈下，经皮治疗也不适用。许多患者还会伴有门静脉血栓形成，这取决于血栓形成的部位和严重程度，从而使其不适合进行化疗栓塞。对于这类患者，可以采用内放射治疗来延长生存期并提高生活质量。放射治疗的目的是将放射性同位素输送到肝肿瘤，使其在肿瘤内停留足够长的时间以给予预定剂量的辐射。与此同时，输送到正常肝实质和其他器官的剂量应尽可能低。多种放射性同位素，如碘-131、钇-90、铼-188、钬-166等可用于此目的，治疗剂靶向肿瘤可通过以下方式实现：1）放射性同位素直接瘤内植入；2）胃肠外注射针对HCC抗原的放射性标记抗体（放射免疫治疗）；3）通过肝动脉将放射性同位素直接注入肿瘤或经动脉放射性同位素治疗（TART）。放射治疗似乎是一种非常合理且有效的治疗选择，a）用于治疗无法手术切除的大HCC，尤其是伴有门静脉血栓形成的情况；b）治疗因任何原因不适合经皮治疗的无法手术切除的小肿瘤；c）作为肝移植前的新辅助治疗以降低移植复发风险，或在肝切除术前缩小肿瘤大小；d）作为手术后或经皮消融治疗后的辅助治疗以降低复发风险。此外，如果使用发生器生产的铼-188，成本会非常低，它似乎与其他现有放射性同位素一样有效或更有效且有用。发生器形式的铼-188的可用性使其储存、运输、洗脱和使用非常方便且具有成本效益，特别是在偏远地区和发展中国家。使用发生器还能根据需要持续提供铼-188。
