Contrast-enhanced ultrasound improves real-time imaging of ablation region during radiofrequency ablation: preliminary results.
OBJECTIVE
To assess the added value of depicting tumour microvascularisation, using dynamic contrast enhanced (CEUS), during radiofrequency ablation, as a means of achieving a complete ablation (CA) of malignant liver lesions.


METHODS
18 consecutive patients (2 female, 16 male, age range 52-79 years, mean 64.1 ± 9.9 years) with 22 histologically confirmed hepatic malignancies (HCC: n = 10, liver metastases: n = 12) underwent RFA. Before RFA treatment, conventional US, CEUS and contrast enhanced CT (ceCT) of the liver were performed. During the CT-guided RFA procedure, CEUS was performed to asses the ablation defect. In case of partial ablation a subsequent ablation was performed with a corrected electrode position and evaluated again using CEUS. This procedure was repeated until a CA was achieved. The number of ablations per patient was recorded. Secondary efficacy parameters assessed were lesion detectability in the different imaging modalities and contrast phases.


RESULTS
Overall intraprocedural CEUS led to a change in therapeutic management in 59% of cases, resulting in 17 additional ablation cycles. Lesion detectability during CT Fluoroscopy was the sole statistical significant predictor of incomplete ablations (p = 0.008). The mean number of ablations for detectable lesions was 1.27 vs. 2.27 ablations for not detectable lesions (p = 0.002). The combined CT and CEUS RFA procedure led to a CA for all treated lesions in follow up 3 month post intervention.


CONCLUSIONS
CEUS does allow a reliable and immediate assessment of therapeutic efficacy of percutaneous RFA procedures of malignant liver lesions, through the continuous dynamic evaluation of tumour microcirculation.
Department of Radiology, University Hospital Regensburg, Regensburg, Germany. Philipp.Wiggermann@klinik.uni-regensburg.de
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P
Wiggermann
I
I
Zuber-Jerger
Y
Y
Zausig
M
M
Loss
M N
MN
Scherer
A G
AG
Schreyer
C
C
Stroszczynski
E M
EM
Jung
D000368:Aged; D002277:Carcinoma / Q000098:blood supply / Q000000981:diagnostic imaging / Q000556:secondary* / Q000601:surgery; D006528:Carcinoma, Hepatocellular / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000556:secondary / Q000601:surgery; D017115:Catheter Ablation; D003199:Computer Systems; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D005471:Fluoroscopy / Q000379:methods; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008113:Liver Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000556:secondary / Q000601:surgery; D008297:Male; D045423:Microbubbles; D008833:Microcirculation; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D010743:Phospholipids; D015641:Radiography, Interventional / Q000379:methods; D013459:Sulfur Hexafluoride; D016896:Treatment Outcome; D018615:Ultrasonography, Doppler, Color / Q000379:methods; D018084:Ultrasonography, Interventional / Q000379:methods*
D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride