Local Ablative Procedures: RF, Microwave, TACE, TARE and SBRT

What is it?

Local ablative procedures are treatments that aim to destroy the tumour where it is, or to cut off its blood flow, without removing it surgically. They are discussed for a limited number of foci, especially in the liver and lung. Not every small tumour is suitable for these procedures.

Radiofrequency and microwave ablation, TACE and TARE are performed by the interventional radiologist. Stereotactic body radiotherapy is planned by the radiation oncologist. The medical oncologist evaluates these options at the same table as systemic treatment; the medical oncologist does not perform these procedures personally.

How does it work?

In radiofrequency ablation, alternating current delivered from the needle tip produces heat. Microwave ablation also destroys cells with heat and in some locations takes less time. The position of the needle is confirmed with ultrasound or tomography.

In TACE, chemotherapy and particles that block the vessel are delivered by catheter into the artery feeding the liver. TARE, also known as selective internal radiation therapy or SIRT, follows the same logic: radiation-emitting microspheres are released into the vessel. SBRT, in contrast, delivers a high dose to a narrow area from outside the body in a few sessions.

In which cancers is it used?

Primary liver tumours and limited spread of colorectal cancer to the liver are the most frequently discussed areas. Small lung foci, selected masses in the kidney and limited metastases in bone or lymph nodes can also be candidates for ablative treatment at the tumour board.

The number of foci, their diameter, proximity to a vessel or bile duct and the working reserve of the liver determine the decision. Which treatment is appropriate is discussed at the tumour board, with the relevant specialties taking part, by considering the type, stage and molecular features of the cancer and the person’s general condition together.

How is it given?

Thermal ablation and embolisation are most often performed in an angiography or tomography unit, with sedation or anaesthesia. The artery may be entered from the groin or the wrist. Observation in hospital for one night may be needed. SBRT, however, is completed as an outpatient on the radiotherapy machine in a few sessions.

Before the procedure, anticoagulant drugs, kidney function and allergy are asked about. Afterwards, imaging shows how much the focus has been affected. The systemic drug may be stopped or continued in the same period; the board decides this.

During follow-up, blood tests, imaging and symptom review are read together. The dose or date may be changed according to side effects and organ function. The list of medicines used at home is updated at every visit. Sudden fever, shortness of breath, uncontrolled diarrhoea or bleeding should be reported the same day.

Possible side effects

Pain at the procedure site, fever, fatigue and nausea may last a few days. Liver tests may rise temporarily. Rarely, bleeding, bile duct injury, an air leak around the lung or inflammation within the abdomen can develop. Before TARE a vessel map is made to prevent leakage to surrounding organs.

Persistent fever, jaundice, shortness of breath or pain that makes one faint should be reported the same day.