MR imaging-guided radio-frequency thermal ablation in the pancreas in a porcine model with a modified clinical C-arm system.
OBJECTIVE
To test the hypotheses that (a) magnetic resonance (MR) imaging-guided radio-frequency (RF) thermal ablation in the pancreas is safe and feasible in a porcine model and (b) induced thermal lesion size can be predicted with MR imaging monitoring.


METHODS
MR imaging-guided RF ablation was performed in the pancreas of six pigs. A 17-gauge monopolar RF probe was inserted into the pancreas with MR imaging guidance, and RF was applied for 10 minutes. After postprocedural imaging (T2-weighted, short inversion time inversion-recovery [STIR], and T1-weighted imaging before and after intravenous administration of gadodiamide), the pigs were observed for 7 days and follow-up MR images were acquired. The pigs were sacrificed, and pathologic examination was performed.


RESULTS
Successful RF probe placement was accomplished in all pigs; the interventional procedure took 46-80 minutes. Thermal lesions were 12-15 mm perpendicular to the probe track and were best seen on STIR and contrast material-enhanced T1-weighted images with a radiologic and/or pathologic mean difference in RF lesion diameter of 1.7 mm +/- 1.0 (SD) and 0.8 mm +/- 1.2, respectively. Diarrhea was the only side effect during the 1-week follow-up; no clinical signs of pancreatitis occurred.


CONCLUSIONS
MR imaging-guided RF thermal ablation in the pancreas is feasible and safe. Induced thermal lesion size can best be monitored with STIR and contrast-enhanced T1-weighted images. In the future, RF ablation may offer an alternative treatment option for pancreatic cancer.
Merkle
E M
EM
Department of Radiology, University Hospitals of Cleveland, Case Western Reserve University, OH 44106, USA.
Haaga
J R
JR
Duerk
J L
JL
Jacobs
G H
GH
Brambs
H J
HJ
Lewin
J S
JS
D000818:Animals; D003972:Diathermy; D004195:Disease Models, Animal; D005240:Feasibility Studies; D005260:Female; D008279:Magnetic Resonance Imaging; D010179:Pancreas / Q000473:pathology / Q000601:surgery*; D010180:Pancreatectomy / Q000379:methods*; D013552:Swine