Radio-frequency ablation (RFA) to treat renal cell carcinoma

For a long time, the treatment of choice for renal cell carcinoma was complete surgical removal of the affected kidney. This safely and completely removed the tumour, but the patient then had only one kidney.

Over time, medical technology has advanced so much that renal cell carcinomas detected early can also be treated minimally invasively with RFA. For smaller tumours, radio-frequency ablation has achieved comparable long-term survival rates in studies to surgical treatment.

The tumour cells are killed by heating them.

Minimally-invasive RFA is intended to replace surgery – either because the tumour is still small enough or because the risks of surgery are too great.

RFA is suitable for patients whose renal tumour has been discovered early and which is still less than 4 cm in diameter. There must also not be any distant metastases. (Alternatively, in such cases kidney-sparing resection – partial nephrectomy – can also be used).

We also recommend RFA for patients with high surgical risks or patients who only have one kidney.

We admit the patient for around 3 to 4 days for treatment.

Beforehand

A precise determination of the indication and careful preparation are needed for RFA.

In preparation for the procedure, we evaluate the case history and any diagnostic results already available, such as CT images, MRI scans and, if available, PET-CT scans (positron emission computed tomography). To this end, we request that a detailed medical history is provided, with a list of the treatments already applied, an indication of the progression of the disease, and the most up-to-date diagnostic images available.

Based on the documents supplied, we can check whether the most important requirements for RFA are fulfilled. If this is the case, the patient will be invited for a further consultation and work-up at our outpatient clinic for minimally invasive tumour therapy.

During

During RFA of a renal cell carcinoma, an ultrasound or CT scanner is used to monitor the guidance of a thin needle (applicator) into the tumour (Figure 1).

Figure 1: Principle of radio-frequency ablation (RFA): By delivering a high-frequency alternating current (400 – 500 kHz), the charged particles close to the applicator inserted in the tumour start to move very rapidly. This movement generates heat in the surrounding tissue and therefore leads to cell destruction.

With an applied alternating current, the tip of the needle causes the charged particles (ions) to move around so that the tissue close to the tip of the needle is heated to up to 120°C. This heat kills the tumour cells immediately.

We carry out this procedure without a general anaesthetic but with strong pain relief.

The entire procedure takes around 90 minutes.

After

There are no restrictions to normal everyday activities following the procedure.

After 6 to 8 weeks and then every three months, we recommend an MRI scan of the kidneys since the tumour, just like with surgical treatment, can recur both at the treated site and at other sites in the body.

You can have the MRI scan done as an outpatient at our facility or elsewhere. If the CT/MRI scan is carried out elsewhere, we would be grateful if you could send us the image data via CD-ROM for further assessment.

The treatment-related complication rate for RFA is very low.

Thermal complications such as burns to the intestines or other adjacent organs are avoided thanks to the CT scan monitoring during the procedure. The same applies to mechanical injuries.

Where tumour volumes are large, the body’s own response to the tumour destruction approximately four to six hours after the procedure can cause fever, chills and nausea. These symptoms only last a few hours and can be treated with medication.

Finally, complications can be caused in the skin due to the introduction of the catheter.

Figure 2: The example shows the treatment of a renal cell carcinoma in the right kidney with RFA.

The contrast-enhanced MRI scan taken before treatment shows a renal cell carcinoma with contrast medium uptake (arrow).

To carry out the procedure, the RFA probe is advanced percutaneously under CT fluoroscopy guidance into the tumour. Once the probe is correctly positioned, the tumour is ablated.

The contrast-enhanced MRI scan taken 7 years after RFA shows successful ablation of the tumour with no signs of progress long-term.

Contact


Minimally Invasive Tumour Therapy (MITT)
Charité Campus Virchow-Klinikum (CVK)
Department of Radiology
Augustenburger Platz 1
13353 Berlin

http://www.rki.de/Krebs/DE/Content/Publikationen/Krebs_in_Deutschland/kid_2012/kid_2012_c64.pdf?__blob=publicationFile

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