Introduction
Developed early in the 1980’s, with the use of ethanol injection, as a palliative treatment to patients with unresectable tumors or with liver transplant contraindications or because of long waiting list times due to organ shortage.
During the 1990’s instruments using thermal energy appeared. Of theses the most widely used is Radiofrequency.
Treatment methods
These methods are based in the application of chemical or thermal ablation strategies into liver tumors, with the help of modern imaging techniques.
Chemical Methods
The most widely used is the ethanol (95%), which is injected using a 10-15 cm long needle, 20-22 G, that produces coagulation necrosis, and also because of the thrombogenic effect of ethanol, it induces local ischemia, potentializing its antitumoral effect.
Other chemical agents like the acetic acid, is used because of its better penetrance in the fibrous septa, diminishing the amount of chemical injected as well as the number of hospital admissions.
Physical Methods
Radiofrequency: Its currently the most widely used. The thermal effect is secondary to ionic vibration produced by a radiofrequency current delivered through electrodes attached to a power generator. The new electrodes can be used in the treatment of tumors up to 4 cm in diameter.
Cryotherapy: Because of the diameter of the cryodes, this technique is mostly used with laparoscopy or during a laparotomy. Currently, the cryodes have beed reduced in size and can now be used percutaneously.
Other methods are lasers and microwaves.
Procedure
Each procedure usually has a 24 to 48 hour period of hospitalization, use of antibiotic prophylaxis, and laboratory check-up, regarding any coagulation problems ( PLT <50.000;>10 seconds).
Contraindications to all of the latter procedures are: coagulation problems, tumors ill-defined with imaging techniques, and RFA has its own CI’s : Lesions located close to the biliary convergence, vessels and other intraabdominal organs.
The imaging control is done, usually, 1 month after the last treatment, with an arterial phase CT scan, and the values of AFP.
Results
Alcoholisation: The tumor diameter is the major factor affecting tumor necrosis. Studies have been performed taking into account pathological specimens vs CT scan results. 70% of tumors achieve total necrosis; 80-100% of tumors
Radiofrequency: Multiple reports appear in today’s literature regarding this procedure. Same as for ethanol, tumor diameter is the major determinant of treatment efficacity. Tumor <3> 3 cm, this percentage is 47,6%. The same goes for the infiltrative tumors which achieve necrosis only 35% of the times.
Complications
Ethanol: Fever and mild abdominal pain are the most common symptoms. Rarely, complications such as hemoperitoneum, portal thrombosis and injection into the pleural cavity, occur. Tumor seeding in the needle tract is now a cause of major concern and is reporte dto occur in 0,008 to 6% of the cases.
Radiofrequency: Thermal injury to other organs is a rare occurrence. Tumor seeding has been reported as well as with ethanol injection.
Recurrence
The most important factors associated with recurrence are: Tumor diameter, number of tumors, presence of a capsule or intratumoral septa, and the tumor’s differentiation.
Prognosis
The prognosis after ethanol injection is almost the same as for the RFA treatment. The 1, 3 and 5 year survival rate is 90-100%, 50-70% and 30-50% respectively, but the disease free survival is much better with RFA.
Conclusions
Even though RFA has been widely adopted worldwide, ethanol injection is still a good choice for the treatment of HCC. Even though the costs of RFA are high, the short hospitalization times and better DFS makes it a much better treatment. All these methods have been widely applied for different stages of HCC, for example, patients on the liver transplant waiting list, or it can also be used in conjunction with TACE to obtain a better patient survival.
Cancer 2001; 92: 1516-1524; Scand J Gastroenterol 1997; 32: 1168-1173; Eur Radiol
2001; 11: 914-921; Cancer 2000; 88: 2452-2463; Radiology 1999; 210: 655-661; Hepatology 2001; 33: 1124-1129; Cancer 1999; 86: 1682-1690; Gastroenterol Clin Biol 2002; 26: 570-577
Developed early in the 1980’s, with the use of ethanol injection, as a palliative treatment to patients with unresectable tumors or with liver transplant contraindications or because of long waiting list times due to organ shortage.
During the 1990’s instruments using thermal energy appeared. Of theses the most widely used is Radiofrequency.
Treatment methods
These methods are based in the application of chemical or thermal ablation strategies into liver tumors, with the help of modern imaging techniques.
Chemical Methods
The most widely used is the ethanol (95%), which is injected using a 10-15 cm long needle, 20-22 G, that produces coagulation necrosis, and also because of the thrombogenic effect of ethanol, it induces local ischemia, potentializing its antitumoral effect.
Other chemical agents like the acetic acid, is used because of its better penetrance in the fibrous septa, diminishing the amount of chemical injected as well as the number of hospital admissions.
Physical MethodsRadiofrequency: Its currently the most widely used. The thermal effect is secondary to ionic vibration produced by a radiofrequency current delivered through electrodes attached to a power generator. The new electrodes can be used in the treatment of tumors up to 4 cm in diameter.
Cryotherapy: Because of the diameter of the cryodes, this technique is mostly used with laparoscopy or during a laparotomy. Currently, the cryodes have beed reduced in size and can now be used percutaneously.
Other methods are lasers and microwaves.
ProcedureEach procedure usually has a 24 to 48 hour period of hospitalization, use of antibiotic prophylaxis, and laboratory check-up, regarding any coagulation problems ( PLT <50.000;>10 seconds).
Contraindications to all of the latter procedures are: coagulation problems, tumors ill-defined with imaging techniques, and RFA has its own CI’s : Lesions located close to the biliary convergence, vessels and other intraabdominal organs.
The imaging control is done, usually, 1 month after the last treatment, with an arterial phase CT scan, and the values of AFP.
Results
Alcoholisation: The tumor diameter is the major factor affecting tumor necrosis. Studies have been performed taking into account pathological specimens vs CT scan results. 70% of tumors achieve total necrosis; 80-100% of tumors
Radiofrequency: Multiple reports appear in today’s literature regarding this procedure. Same as for ethanol, tumor diameter is the major determinant of treatment efficacity. Tumor <3> 3 cm, this percentage is 47,6%. The same goes for the infiltrative tumors which achieve necrosis only 35% of the times.
Complications
Ethanol: Fever and mild abdominal pain are the most common symptoms. Rarely, complications such as hemoperitoneum, portal thrombosis and injection into the pleural cavity, occur. Tumor seeding in the needle tract is now a cause of major concern and is reporte dto occur in 0,008 to 6% of the cases.
Radiofrequency: Thermal injury to other organs is a rare occurrence. Tumor seeding has been reported as well as with ethanol injection.
Recurrence
The most important factors associated with recurrence are: Tumor diameter, number of tumors, presence of a capsule or intratumoral septa, and the tumor’s differentiation.
Prognosis
The prognosis after ethanol injection is almost the same as for the RFA treatment. The 1, 3 and 5 year survival rate is 90-100%, 50-70% and 30-50% respectively, but the disease free survival is much better with RFA.
Conclusions
Even though RFA has been widely adopted worldwide, ethanol injection is still a good choice for the treatment of HCC. Even though the costs of RFA are high, the short hospitalization times and better DFS makes it a much better treatment. All these methods have been widely applied for different stages of HCC, for example, patients on the liver transplant waiting list, or it can also be used in conjunction with TACE to obtain a better patient survival.
Cancer 2001; 92: 1516-1524; Scand J Gastroenterol 1997; 32: 1168-1173; Eur Radiol
2001; 11: 914-921; Cancer 2000; 88: 2452-2463; Radiology 1999; 210: 655-661; Hepatology 2001; 33: 1124-1129; Cancer 1999; 86: 1682-1690; Gastroenterol Clin Biol 2002; 26: 570-577
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