1. The document discusses the history and mechanisms of radiofrequency ablation (RFA) for treating hepatic tumors. RFA uses alternating current within 200-1200 MHz to generate heat and coagulate tissue. 2. RFA can be performed percutaneously, laparoscopically, or during open surgery. Different ablation schemes and needle types are used depending on tumor size and location. 3. Complications of RFA include wound infection, bleeding, and abscesses. Studies show high rates of initial tumor necrosis but frequent recurrence within a year.

1. RADIOFREQUENCY IN THE TREATMENT OF HEPATIC TUMORS PROF. LIVIU VLAD Clinic of Surgery No. 3 University of Medicine Iuliu Hatieganu, Cluj,Romania

3. MECHANISM OF THERMAL INJURY: ENERGY TRANSFER RADIOFREQUENCY: THE FREQUENCY OF ALTERNATING CURRENT IS WITHIN FREQUENCY RANGE 200-1200 MHz The result: frictional heat desiccates the tissue, evaporation of intercellular water and coagulation necrosis

5. Computer representation of single-ablation model. Effective ablation must encompass tumor plus 360° 1-cm tumor-free margin. Computer drawing depicts tumor plus half of effective tumor-free margin ( red sphere). This 360° margin adds 2 cm to overall diameter of ablation sphere, depicting ablation volume encompassing tumor and tumor-free margin. NECROSIS THERMAL ZONE

6. 6-sphere model, treat tumors measuring 3 and 4.25 cm, respectively. 14-sphere model increased the treatable tumor size to 3, 4.6, or 6.3 cm For treating larger tumors, we need cylindrical model to be less efficient and easier to control. VARIOUS TYPES OF RFA ABLATION MODELS

7. ABLATION SCHEMES A , Solitary ablation completely envelops small tumor and circumferential rim of healthy liver. B , Six optimally placed overlapping spheres produce composite spherical thermal injury with diameter equal to 1.25 times diameter of a single ablation sphere. C , Overlapping thermal cylinders is effective way to treat large tumors. Each cylinder is created by overlapping serial ablations by 50% along a single needle path. Adjacent cylinders are overlapped by 50%. John P. McGahan Gerald D. Dodd III - AJR:176, January 2001

8. s. Nahum Goldberg I, G. Scott Gazelle, Peter R. Mueller AJR:174, February 2000 RF = radiofrequency. IlP = interstitial laser photocoagulation. MW = microwave. US =percutaneous ultrasound probes. HIFU = high-intensity focused ultrasound

9. TYPES OF NEEDLES FOR RFA

10. COOL TYPE NEEDLE RFA LESION IN LIVER Resected tumor after RFA

15. S. Mulier, P. Mulier, Y. Ni et al. British Journal of Surgery 2002, 89, 1206±1222 Complication rate of RFA according to approach

16. R E S U L T S after Chamberlain RS & Fong Y- in Blumgart Surgery of liver and biliary tract WB Saunders, 2000 94,68,40% survival at 1,3,5 years 50% recurred at less 1 year 67% 12 months free survival 83% complete initial necrosis 52% complete necrosis 6 months 93% complete CT necrosis 83% free assessment – 3 months 69% complete CT necrosis 13% recurrence 92% complete initial necrosis 50 11 16 15 19 10 25 20 HCC Metastatic tumors Metastatic tumors Metastatic tumors HCC Metastatic tumors HCC Metastatic tumors Metastatic tumors Rossi 1996 Solbiati 1997 Livraghi 1997 Dodd 1999 Rhim 1999 Bauer 1999 Results No. patients Diagnosis Author/year

17. Liver tumors treated by radiofrequency thermal ablation Open RFA – number of patients (n=1 4 ) Diagnosis N umber of patients N umber of tumors HC C 5 5 Meta stasis of colorectal carcinoma 5 16 Meta stasis of breast carcinoma 2 5 Primary unknown site 1 4 Meta stasis of uterine carcinoma 1 3 PERSONAL EXPERIENCE Sex ratio: M/ F  6  8 Age 41 –75 years

18. RFA PROCEDURES PERSONAL EXPERIENCE TOTAL INTRAOPERATIVE R F A n o = 14 INTRAOPERATIVE RFA associated with tumor resection n o = 5 INTRAOPERATIVE RFA only n o = 9

20. ULTRASOUND GUIDED INTRAOPERATIVE RFA PERSONAL EXPERIENCE

21. INTRAOPERATIVE RFA FOLLOWED BY TUMOR RESECTION PERSONAL EXPERIENCE

22. RFA OF HC C ASSOCIATED WITH CIRRHOSIS PERSONAL EXPERIENCE

23. RFA OF METASTASIS OF COLORECTAL CARCINOMA PERSONAL EXPERIENCE

25. BIOCH E MIC AL FOLLOW-UP INCLUDED TRANSAMINASES PERSONAL EXPERIENCE

26. Alkaline phosphatase and  GT PERSONAL EXPERIENCE

27. US assessment of RFA PERSONAL EXPERIENCE Follow-up 6 weeks postoperatively

28. CT assessment of RFA Follow-up 6 weeks postoperatively RFA for metastasis of breast carcinoma + resection RFA for HCC + resection PERSONAL EXPERIENCE

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