[Potential advantages of the MRI for the radiofrequency ablation of liver tumors].
OBJECTIVE
To present first results of radiofrequency ablation of liver tumors using a new MR compatible applicator.


METHODS
We performed 37 interventions in 20 patients (mean age 58.6 years) with primary intrahepatic malignancies or metastases: colorectal carcinoma n = 6, hepatocellular carcinoma n = 3, pancreatic carcinoma n = 4, sarcoma n = 2, cholangiocellular carcinoma n = 1, carcinoma of the tonsil n = 1, breast carcinoma n = 1, gastric carcinoma n = 1, and gastrointestinal stroma tumor n = 1. Interventions were performed under CT-guidance with CT fluoroscopy (n = 32) and under MR-guidance (n = 5) using fast T1-weighted sequences in breath-hold technique. RFA was performed with the RF-generator (150 W) under local anesthesia and sedation using MR compatible applicators (Starburst XL, Rita Medical Systems, USA) together with the appropriate Soft Tissue Introducer System. Intra-interventional control was performed with intrahepatically or intralesionally placed introducer system or applicator. MRI was performed with plain breath-triggered T2-weighted turbo spin echo sequences (TSE T2) with fat saturation.


RESULTS
All interventions were performed without major events. The mean diameter of induced coagulation was 4.0 (+/- 0.7) cm. Repositioning was necessary in 8 interventions (21 %) after detection of residual tumor on an intra-interventional MRI. After a mean follow-up of 6.5 (+/- 1.2) months, the local tumor control rate was 92 %.


CONCLUSIONS
MR-compatible RF applicators offer the opportunity for intra-interventional detection of residual tumor during RF ablations by use of sensitive MRI sequences. These procedures may lead to a higher confidence in tumour ablation and may reduce the number of re-interventions and local recurrences of intrahepatic tumors.
Gaffke
G
G
Klinik für Strahlenheilkunde und Poliklinik, Charité, Universitätsmedizin Berlin. gunnar.gaffke@charite.de
Gebauer
B
B
Gnauck
M
M
Knollmann
F D
FD
Helmberger
T
T
Ricke
J
J
Oettle
H
H
Felix
R
R
Stroszczynski
C
C
D017115:Catheter Ablation / Q000379:methods; D005471:Fluoroscopy; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000556:secondary / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D012086:Reoperation; D012680:Sensitivity and Specificity; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome