SAINT 2012 Sitzung XI: Was die Radiologie noch im Köcher hat Björn Gemein, Krankenhaus Nordwest, Frankfurt am Main

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Kidney | Case 10
MWA
Acquired experience in ablation
Percutaneous thermal ablation has been performed
since 2001 by the team of interventional radiologists
working within the group of Prof. Düx. They have
a lot of experience in radiofrequency thermal ablation
and microwave thermal ablation of tumors located within
the lung, liver, kidney, lymph nodes, soft tissue as well as
skeleton. Primary tumors as well as metastatic diseases
are mainly treated palliatively to control tumor growth.
Since October 2009 microwave thermal ablation is mainly
performed because patients tolerate the procedure much
better (less pain, less postablation syndromes) and the
Information and background
Treatment
Organ treated Retroperitoneal lymph node
Type of tumour Renal cell carcinoma
Size of tumour 5 x 5 cm axial
Image guidance used CT
Patient selection criteria
After heminephrectomy, the patient was at risk of losing
the remaining kidney because of huge lymph node
metastasis compressing the vessels of the kidney.
The patient received chemotherapy. Microwave ablation
seemed to be a good method to reduce the size of the
metastasis and protect the kidney from damage
without causing too much stress to the patient.
Needle selection criteria
A needle length of 17 cm and an active needle tip of
3.7 cm was chosen to treat the tumor volume.
Needle insertion approach
Needle placement is performed under CT guidance and general
anaesthesia, using 3 needle positions dorsal paravertebral to get
a maximum ablation volume in acceptable time.
Anesthesia
General anaesthesia took an overall time of approx. 2 hours
including the time for intubation and extubation.
Procedural time
The procedural time took approx. 60 minutes between first
and last documentation of the needle’s position, approx.
90 minutes including pre-procedure and post-procedure
imaging.
Ablation time is 10 minutes for each position, using an
energy of 45 W. For the time of the CT guided positioning of
the needle, the anaethesiologist stops the ventilation which
provides an exact and constant position of the target volume.
Date of the procedure 4 March 2010
Country Germany
Hospital Krankenhaus Nordwest, Frankfurt am Main
Department Department of Radiology
Physician Dr med Björn H. Gemein
Email gemein.bjoern@khnw.de
size of ablation necrosis may be increased by using 2 or 3
antennas simultaneously. So far more than 130 procedures
of microwave thermal ablation have been performed at
Nordwest Hospital.
Materials and method
Female patient, 82 years old, urothelial carcinoma (pT3,
N2 (4/4), G2, R0) of the right kidney, nephro ureter ectomy
May 2008, chemotherapy (since July 2008: Gemcitabine +
Carboplatin; since December 2009: Paclitaxel), now suffering
from growing lymph nodes retroperitoneal on the opposite
side. Microwave ablation was performed in March 2010.
10. Protection of the Remaining Kidney After
Urothelial Carcinoma of the Contralateral Kidney

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Kidney | Case 10
Figure 1: Pre-treatment CT, 29 December 2009 Figure 2: 17 February 2010
Figure 3: 17 February 2010 Figure 4: Microwave ablation, 4 March 2010, 1st
position
Figure 5: Microwave ablation, 4 March 2010, 2nd
position Figure 6: Microwave ablation, 4 March 2010, 3rd
position

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Kidney | Case 10
Good result with significant size reduction of
the lymph nodes which saved the remaining
kidney from damage. The reduction of the size
was obvious in an MRI which was performed
5 weeks (April 2010) after ablation (March
2010) and became significant during the next
months (June 2010, September 2010). The
remaining kidney retained its function.
It is our experience that if you perform a
contract enhanced CT examination right
after the ablation, the result of the ablation
can immediately be seen in the portal venous
phase so it‘s easy to get an impression of the
ablated area, which helps to plan additional
needle positions, when necessary, in order to
ensure a good safety margin.
Our standard protocol for control is as follows:
1 day after the ablation we do an examination
to check for complications. When a high
tissue contrast or a detailed presentation of
structures is needed, for liver, liver cirrhosis
and for proof of vitality, we prefer an MRI,
in all other cases CT is chosen. Because this
first control is just to check for complications,
CT instead of MRI is sufficient at this point.
The next control will be done after 1 month
in order to check for success of the ablation,
and at this point MRI should be chosen in the
cases stated above (in all other cases still CT).
Follow-up controls are after 3 and 6 months.
Whenever vital tumor is seen in the control,
we plan the next ablation and start with
our standard protocol again right from the
beginning.
Hints for interpretation of the controls:
(Edge-)Enhancement within the first 4 weeks:
Reactive. (Edge-)Enhancement after the first
4 weeks: Remaining activity.
Regression (of size): Response.
Results and follow up
MWA
Figure 7: Post-treatment control MRI, 9 April 2010
Figure 8: Post-treatment control MRI, 9 April 2010
Figure 9: Follow-up control CT, 24 June 2010
Figure 10: Follow-up control CT, 15 September 2010

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Notes