Chemoembolization technique

Radioembolization with yttrium-90 ( Y) microspheres represents an innovative approach that has gained increasing awareness and clinical use over the past 5-10 years. The minimal toxicity of radioembolization and the ability to discharge the patient on an outpatient basis make the therapy an attractive alternative in the treatment of primary and metastatic liver malignancies. Patients are able to resume normal activities shortly following treatment, with minimal side effects, in contrast to the post-embolization syndrome often associated with current chemoembolic techniques. 

Chemoembolization Technique Several techniques must be considered when referring to chemoembo-... 

There have been few reports on the cUnical use of albumin microspheres for the delivery of drugs. The limited clinical trials, using chemotherapeutic agents, employ a technique referred to as arterial chemoembolism in which the drug-containing microspheres... 

The appropriate examination technique is critical for sensitive detection and specific characterization of focal liver lesions. A biphasic examination of the liver with a late-arterial and a portal venous phase can be regarded as standard today. For specific indications, like the follow-up of hepatocellular carcinoma (HCC) after transarterial chemoembolization (TACE) or for the depiction of the arterial vessels prior to angiography, an early arterial phase scan, which can be post-processed into CT angiography, is helpful (Fig. 3.2). The value of delayed scans (e.g. 5 min after contrast agent injection) is controversial in the literature mainly centers with a focus on imaging in liver cirrhosis consider the use of late phase images as necessary, whereas other authors see no added value for it [21,45]. 

Sodium tetradecyl sulfate (Sotradecol) Chemoembolization mixtures Miscellaneous techniques ... 

For many patients suffering from liver tumors, surgery may represent the only curative approach for others only palliative, interventional techniques are available for local tumor control (e.g., cryotherapy, chemoembolization, ethanol injection, and radio frequency ablation). 

It is our experience that the type of HCC seen at MDACC, and perhaps in the Western World, is different or at least more advanced from that more commonly treated by the interventional radiologist in Japan (Yamashita et al. 1993). Nodular HCC is seen in less than 25% of our patients, while it comprises 75% of the Japanese patient population. However, this is now changing due to the present influx of patients with positive hepatitis B and C. This type of tumor can be approached by surgery, by the direct injection of absolute ethanol, by direct percutaneous thermal ablation (radiofrequency or cryoablation), by chemoembolization, or the combination of these techniques (Figs. 9.4,9.5). 

Chemoembolization Chemoembolization with the combination of Ivalon and FUDR (800 mg), mitomycin C (10 mg), or cisplatin (150 mg) for colorectal hepatic metastases led to no significant improvement in response or survival. Yamashita et al. (1993), who treated 68 patients with various hepatic metastases using iodized oil and chemotherapeutic agents,noted a response rate of 22% and a median survival of 10 months. A similar result was observed by Inoue et al. (1989), i.e., a partial response rate of 16% and a median survival period of 11 months. We currently do not perform chemoembolization in patients with metastatic colorectal carcinoma because the survival rates have not improved compared to the less aggressive approach of intraarterial chemotherapy. However, Lang and Brown (1993) and Pentecost et al. (1992) are encouraged by their results for chemoembolization of hepatic metastases from colorectal cancer and they believe that the technique can be recommended as palliative treatment. More recently, Pajkos et al. (1998) treated 41 patients with metastatic colorectal carcinoma to the liver with chemoembolization consisting of Adriamycin (50 mg), mitomycin C (8 mg), cisplatin (50 mg), or carboplatin (150 mg), Lipiodol (10 ml), and starch microspheres every 6 weeks, as well as systemic 5FU (425 mg/m ) and leucovorin 20 mg/m for 5 days every 28 days. The response rate was 68% with a median survival time of 15 months. 

Chemoembolization has also been performed in an attempt to improve upon the results obtained with particulate embolization alone. Microencapsulated cisplatin particles (100 pm in diameter) were prepared at MDACC by a solvent evaporation technique and contained 46% by weight of cisplatin and poly(D,L)-lactide. In a 1 1 ratio of chemotherapeutic agent to capsular material, approximately 40% of the cisplatin was released within the first 4 h after delivery, as determined by in vitro studies. A Phase I/II Clinical study was performed at MDACC in 20 patients utilizing microcapsules containing cisplatin 100 mg/m as the maximum tolerated dose (MTD), delivered every 4-6 weeks. The median number of vascular occlusion procedures per patient was three. Of the 18 evaluable patients, 12 (67%) had a PR in their symptoms. Of the 15 patients with elevated 5-hydroxyindoleacetic acid, 11 (73%) had a median reduction of 64%. In 14 of 18 patients there was an objective decrease in the tumor, of which six (33%) were PR and eight (44%) were MR. One treatment-related death occurred from hepatorenal syndrome and five (25%) of the 20 patients died of the disease during the study (Diamandidou et al. 1998). 

Wallace et al. applied this technique from May 2005 to March 2006 in 86 out of 240 different fiver interventions (infusion, radioembolization, embolization and chemoembolization). They reported that C-arm CT added important information without impact on the procedure in 19% of the cases. In another 41%, C-arm CT, however, added information that had clear impact and might have even changed the carrying out of the procedure. Apart from all the other procedures, the... 

The techniques and agents used to treat liver tumors by chemoembolization are very heterogeneous (Tables 2.5.2, 2.5.3). To this day, there is no consensus on the best chemoembolization protocol. 

Vogl TJ, Zangos S, Balzer JO, Thalhammer A, Mack MG (2002b) Transarterial chemoembolization of liver metastases Indication, technique, results. Rofo Fortschr Geb Rontgenstr Neuen Bildgeb Verfahr 174 675-683... 

The results presented here must still be compared with a variety of other minimally invasive techniques. Transarterial chemoembolization is a procedure involving the injection of lipiodol and a chemotherapeutic agent into the hepatic artery. The intention is to produce selective ischemic injury to the tumor, which relies mainly on the arterial circulation. Ka nematsu et al. (1993) did the first comparative study between hepatic resection in 67 patients and transcatheter arterial embolization (TAB) in 20 patients with resectable disease. The 1-year, 3-year, and 5-year cumulative survival rates for 67 patients undergoing surgery were 89.1%, 74.6%, and 54.6% respectively and for the 20 patients treated with TAB, 90%, 50%, and 17.50% respectively. Surgery therefore provided more favorable results (Kanematsu et al. 1993). 

These include mainly thermal ablative techniques such as laser-induced thermotherapy, radiofrequency and microwave ablation, but also chemoembolization as well as selective internal irradiation therapy. 

Despite these encouraging preliminary results, there are no reports showing that RF ablation, performed alone or in combination with intra-arterial procedures, results in improved survival in patients with intermediate stage HCC. A randomized trial comparing an optimized RF technology with chemoembolization would be needed to establish the potential role of the technique in this patient population. 

Liver resection can therefore be offered only to a small number of patients with a good chance of success. There is a demand for additional treatments to improve the success of resection and to diminish the incidence of recurrence after surgery, particularly in patients for whom surgery is not an option. Alternative methods include oncologic strategies, such as systemic or locoregional chemotherapy, and interventional techniques, including percutaneous alcohol injection, transarterial chemoembolization, microwave ablation, and percutaneous laser treatment (Lin et al. 1997). 

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