Technique thermal ablation

Combination therapy The use of local-interventional procedures is restricted to a maximum tumour size of 5 cm in diameter. Therefore, a combination of two local techniques is seen as promising. The joint application of PEI and TAB has proved its efficacy for some time. (177) Similarly, there have been reports about the successful use of TACE following laser thermal ablation. (136) Further encouraging options include a combination of TACE and RFTA, TACE with microwave coagulation (149) or TACE with cryotherapy. Using TACE, the size of the HCC can be reduced in some cases, making it possible to carry out subsequent ablation with better results. 

Ricke J, Wust P, Stohlmann A et al (2004) CT-guided interstitial brachytherapy of liver malignancies alone or in combination with thermal ablation phase I-II results of a novel technique. Int J Radiat Oncol Biol Phys 58 1496-... 

One of the application segments that is commonly associated with polymer blends is that of surgical instruments. As surgical techniques have proliferated, so has the need for increasingly specialized instruments. The drive toward minimally invasive surgeries has created the need for miniaturization, which in turn drives the need for smaller components with sufficient strength and durability. Access devices that are appropriate for polymer blends include trocars, retractors, and speculums. Hand instruments include staplers and forceps. Thermal ablation and electrosurgi-cal techniques require powered instruments. 

MNP-based hyperthermia is the most prominent method to conduct this noninvasive technique, without affecting healthy tissues. In an alternating magnetic field (AMF), MNPs vibrate and produce heat energy and their efficiency to produce heat is measured in terms of specific absorption rate (SAR) [34]. MNPs are good candidates since they have high MR T2 relaxivity and SAR and MRI-guided thermal ablation for cancer can be achieved [35]. 

Lencioni R, Cioni D, Bartolozzi C (2001) Percutaneous radio-frequency thermal ablation of liver malignancies techniques, indications, imaging findings, and clinical results. Abdom Imaging 26 345-360... 

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). 

The introduction of minimally invasive thermal ablation techniques offers a safe and accurate alternative to open or laparoscopic surgery in the treatment of renal tumors. Experimental as well as clinical studies proved RF ablation to be a safe and effective treatment option for small RCCs. It is well tolerated in patients with percutaneously accessible lesions. However, the long-term outcome remains to be determined. Until then its use is limited to selected patients. Despite these limitations, published experience with renal RF ablation is continuously growing. As soon as its long-term effectiveness is proven, this technique holds the potential to replace surgery as first-line therapy in small RCCs. 

Radiofrequency is the most widespread percutaneous thermal ablation technique used in liver tumors. In the few studies in vdiich it was used in lung tumors it achieved a morphological response of up to 100% with a mean survival of up to 19.7 months (Lee et al. 2004). 

The position of LITT among other treatment modalities is not yet settled. It is one of several thermal ablation techniques which share broadly the same indications and contraindications. These can play the same complementary role to surgery, and systemic chemotherapy as well as transarterial chemotherapy in the near future. These ablation techniques differ, however, in their physical nature and this leads to some differences in technical aspects and local effects. If these differences are thoroughly evaluated, the actual effectiveness can be compared. Still, the lack of adequate patient series does not allow the final results of these modalities to be demonstrated in a way to favor one of them completely above the rest. 

LITT represents an innovative promising technique for thermal ablation of lung metastases and primary lung cancers. Still, some methodical and physical problems have to be tackled to achieve better results. 

Endovenous thermal ablation has become an accepted option to eliminate the reflux caused by incompetent saphenous veins. In this chapter, a review of the clinical problems and anatomy precedes a review of this exciting new venous occlusion technique. 

These disappointing results coupled with the poor response of HCC to traditional chemotherapy have provided the impetus for the development of a variety of nonsurgical techniques for the treatment of hepatic neoplasms (Table 10.1). Such techniques are generally divided into transarterial interventions versus percutaneous ones. The latter group is further subdivided into thermal ablation techniques versus chemical ablation techniques. 

All of the percutaneous techniques are limited by the size and number of the lesions (up to three lesions each measuring up to 4 cm) as well as their location. Subdiaphragmatic lesions may be percutaneously inaccessible, and lesions close to large vascular structures respond poorly to thermal ablation techniques (RFA, MCT, Cryo, and LIPC). On the contrary, intra-arterial techniques are not limited by the number, size, or location of the lesions rather by the hepatic function reserve, as shown in Table 10.2. TACE, trans-arterial chemo-embolization TARE, trans-arterial radio-embolization MCT, microwave coagulation therapy RFA, radio frequency ablation LIPC, laser interstitial photocoagulation Cryo, cryo-ablation PEI, percutaneous ethanol injection PAAI, percutaneous acetic acid injection PCI, percutaneous chemotherapy injection... 

Different papers have reported different time-scales for the detection of recurrence. Mean time to recurrence in one series of patients with hepatocellular carcinoma treated with a range of ablation techniques was 4 months (Catalano et al. 2001). In our experience using thermal ablation techniques the median time to recurrence is 8 months but in some slow growing tumours or patients who respond to chemotherapy recurrence may be delayed until as late as 20 months. Other authors have also seen examples of late recurrence up to 14 months post treatment (Chopra et al. 2001). 

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