Thermal ablation therapy

C.J. Lightdale, S.K. Heier, N.E. Marcon, et al. (1995). Photodynamic therapy with porfimer sodium versus thermal ablation therapy with Nd YAG laser for palliation of esophageal cancer a multicenter randomized trial. Gastrointest. Endoscopy, 42(6), 507-512. 

Percutaneous thermal ablation therapies have been receiving increasing attention as a potential primary treatment for focal HCC and fiver metastases. Possible advantages of ablative therapies as compared to surgical resection include a lower morbidity and mortality... 

In early thermal ablation therapy, electrode placement was typically performed under direct visualization using preoperative CT data. Variations in ablation size and shape during therapy could not be predicted and were not recognized during therapy, and had to wait until follow-up image scans were performed. 

The need of designing probes for measuring in vivo temperature is primarily dictated by therapeutical purposes. In fact, useful therapies against tumors like hypertermia or thermal ablation are based on localized heating which selectively kills tumor cells. Such therapies require the achievement of well-defined temperatures that, moreover, have to be maintained constant for a given time. Therefore, a continuous temperature monitoring is essential for the success of the therapy 136). 

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. 

In order to be eligible for RF thermal ablation, patients must meet certain requirements. As RF ablation is a form of local therapy, the disease to be treated must be confined to the liver, without vascular invasion or extrahepatic metastases (Lencioni et al. 2001) (Figs. 8.3,8.4). Other desirable attributes needed for successful treatment include focal, nodular type... 

Since the first description of interstitial tumor thermal ablation using laser therapy by Sown in 1983, experimental studies have shown that a reproducible... 

Fig. 11.10. Thyroid cancer with painiril unique bone metastasis. Radiofrequency ablation of the tumor. Laige necrosis of the metastasis was obtained and the thermal ablation was completed by radioiodine therapy with complete necrosis of the tumor...

The main advantage of thermal ablation is the abihty to create a well-controlled focal thermal injury with minimal morbidity and mortality to date. Unlike alcoholization (ethanol ablation), thermal ablation creates a well-demarcated lesion. Radiofrequency is particularly useful as a tumor therapy, while alcoholization is preferred in palliative bone metastases pain management because of its simplicity and low cost. 

Neoadjuvant TACE - Frankfurt Protocol (TACE Followed by LITT) 114 Combined Interventional Therapies Combination of TACE and PEI 116 Combination of TACE and Radiation Combination of TACE and Thermal Ablation (LITT / RE) 118 Combination of TACE and Microwave Coagulation 118 Combination of TACE and Cryotherapy 119 Conclusion 119 References 119... 

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. 

CT guidance affords the best available visualization of needle and probe placement in the lesion nidus. Helical CT with low-dose and CT fluoroscopy makes for a quicker procedure and a lower patient dose (Silverman et al. 1999 Teeuwisse et al. 2001). Lesion size and the configuration of the thermal lesion in particular can he controlled directly during the procedure. Therapy strategy can he adjusted hy the operator during the procedure and provides an effective thermal ablation and therapy result. However, the complication rate is reduced... 

Indications and contraindications for thermal ablation in the therapy of bone metastases are as follows ... 

In this setting, thermal ablation will be mainly a symptomatic, supportive (palliative) therapy, which can also be applied in conjunction with other therapies such as resection, radiotherapy or chemotherapy. In contrast to the treatment of malignant tumours, local thermal ablation is considered the method of choice in treatment of symptomatic benign bone tumours such as osteoid osteomas. 

It remains unclear whether the combination therapy of thermal ablation together with cemen-toplasty, for example, is superior to a single therapy (Fig. 9.3). Nevertheless, there are a few cases of painful bone tumours with a dense stroma that hinders cement injection. In cases such as these, thermal ablation may soften the tumour s stroma allowing subsequent cement instillation (Schaefer et al. 2002 Fourney et al. 2003 Hierholzer et al. 2003 Masala et al. 2003 Wenger 2003 Halpin et al. 2004 Masala et al. 2004 Halpin et al. 2005 Mont Alverne et al. 2005 Cheung et al. 2006 Brodano et al. 2007 Calmels et al. 2007 Jakobs et al. 2007). 

Simon CJ, Dupuy DE (2006) Percutaneous minimally invasive therapies in the treatment of bone tumors thermal ablation. Semin Musculoskelet Radiol 10(2) 137-144 Toyota N, Naito A, Kakizawa H et al (2005) Radiofrequency ablation therapy combined with cementoplasty for painful bone metastases initial experience. Cardiovasc Interv Radiol 28(5) 578-583... 

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... 

Interstitial laser therapy (ILT) A form of thermal ablation using a laser as the heat source. 

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