Questions on TACE
Q1. Which of the following is not true for patient selection in Transarterial chemoembolization (TACE) in hepatocellula carcinoma?
a) HCC, Cholangiocarcinomas, Metastaic colorectal tumors and gastric metastatic tumors are more responsive to TACE
b) TACE can be safely given in patients with compromised liver function
c) Patency of portal vein should be evaluated carefully
d) Liver function has to be taken into account while instituting TACE
Q2. One of the following is not an indication of Radiofrequency Abalation (RFA) in Hepatocellular Carcinoma?
b) Close proximity of the lesion to bile duct
c) Unresectable disease
d) As a bridge to liver transplant
Q 3. One of the following is not the mechanism of action of Ethnaol when used in ablation of liver tumors?
a) Coagulation necrosis of tissues
b) Heat dissipation
c) Thrombosis of blood vessels
d) Decreased platelet function
Q4. Which one is the contraindication for Radiofrequency Abalation of Hepatocellular Carcinoma Liver
a) Close proximity of the tumor to bile duct or portal vein
b) Radiofrequency abalation (RFA) has been used as a bridge for liver transplantation
c) RFA is given in multiple lesions less than 3 in number
d) The upper size limit of a single lesion is 5-7 cm
Q5. Contraindication for Therasphere (Yttrium 90) radiotherapy is
a) Bridge to liver transplant
b) Neoadjuvant before resection
c) Portal vein thrombosis
d) Excessive hepatopulmonary shunting
Caution is advised when giving Transarterial Chemoebolization (TACE) in patients with compromised liver function.. It actually means that chemotherapeutic agent such as Doxorubicin is mixed with lipoidal oil, I 131 and a selective or superselectivehepatic arterial branch supplying the tumor is embolized with particles such as gelfoam or Poly vinyl alcohol. The mixture remains there for a longer time and exerts its therapeutic benefit.
Obviously tumors with increased blood supply such as HCC, cholangiocarcinoma and gastric metastasis will be benefited more. Portal vein thrombosis also leads to compromised liver function and is a relative contraindication for TACE.
Hepatocellular carcinoma receives about 90% of blood supply from hepatic artery. CT characters of HCC are described here
Radiofrequency abalation of Hepatocellular carcinoma is not an option when tumor lies with in 1 cm of the portal vein or bile duct. this is because of the heat sink effect in the fluid takes away the heat generated by the radiofrequency probe.
Newer methods to over come these effects include portal vein clamping during open RFA or balloon occlusion of the branch of hepatic artery.
Ethanol causes coagulative necrosis of the tissue and not heat dissipation. Heat is generated by the Radio Frequency probes. Other mechanism of etahnol injection include platelet dysfunction and thrombosis of small blood vessels
Radiofrequency Ablation (RFA) is not used when the tumor is in close proximity to the bile duct ie within a distance of 1 cm. This is because of the risk of heat injury to the bile duct. RFA is also not effective when the tumor is within 1 cm of a large portal vein because of the heat sink effect.