TY - JOUR
T1 - Targeting liver lesions for radiofrequency ablation
T2 - An experimental feasibility study using a CT-US fusion imaging system
AU - Crocetti, Laura
AU - Lencioni, Riccardo
AU - DeBeni, Stefano
AU - See, Teik Choon
AU - Pina, Clotilde Della
AU - Bartolozzi, Carlo
PY - 2008/1
Y1 - 2008/1
N2 - PURPOSE: To investigate the feasibility and validity of real-time guidance using a fusion imaging system that combines ultrasound (US) and computed tomography (CT) in the targeting and subsequent radiofrequency (RF) ablation of a liver target inconspicuous on US. METHODS AND MATERIALS: The study was designed as an experimental ex vivo study in calf livers with radiopaque internal targets, inconspicuous at US, simulating a focal liver lesion. The study included 2 phases. The initial phase was to examine the feasibility of matching preprocedural volumetric CT data of the calf livers with real-time US using a commercially available multimodality fusion imaging system (Virtual Navigator System, Esaote SpA, Genoa, Italy), and to assess the accuracy of targeting using a 22 gauge cytologic needle. The second phase of the study was to validate such a technique using a 15 gauge RF multitined expandable needle (RITA Medical Systems, Mountain View, CA) and to examine the accuracy of the needle placement relative to the target. The tip of the trocar of the RF needle had to be placed 1 cm from the target and then the hooks had to be deployed to 3 cm. Unenhanced CT of the liver and multiplanar reconstructions were performed to calculate accuracy of positioning, ie, the lateral distance between the needle and the target, the distance between the tip of the trocar of the RF electrode and the target, and the lateral distance between the central tine of the RF electrode and the target. RESULTS: All calf livers underwent successful CT-US registration with a mean registration error of 3.0 ± 0.1 mm and 2.9 ± 0.1 mm in the initial and second phase of the study, respectively. In the initial phase an overall number of 24 insertions were performed after the US-CT guidance. The mean needle to target distance was 1.9 ± 0.7 mm (range, 0.8-3.0 mm). In the second phase an overall number of 12 ablations were performed. The mean target-trocar distance was 10.3 ± 2.6 mm. The mean target-central tine lateral distance was 3.9 ± 0.7 mm (range, 2.9-5.1 mm). After the dissection of the specimen the target was found unchanged in the center of the ablation zone in all cases. CONCLUSION: Real-time registration and fusion of preprocedure CT volume images with intraprocedure US is feasible and accurate. The study was however conducted in an ideal experimental setting, without patient movements and breathing, and further studies are warranted to validate the system under clinical conditions.
AB - PURPOSE: To investigate the feasibility and validity of real-time guidance using a fusion imaging system that combines ultrasound (US) and computed tomography (CT) in the targeting and subsequent radiofrequency (RF) ablation of a liver target inconspicuous on US. METHODS AND MATERIALS: The study was designed as an experimental ex vivo study in calf livers with radiopaque internal targets, inconspicuous at US, simulating a focal liver lesion. The study included 2 phases. The initial phase was to examine the feasibility of matching preprocedural volumetric CT data of the calf livers with real-time US using a commercially available multimodality fusion imaging system (Virtual Navigator System, Esaote SpA, Genoa, Italy), and to assess the accuracy of targeting using a 22 gauge cytologic needle. The second phase of the study was to validate such a technique using a 15 gauge RF multitined expandable needle (RITA Medical Systems, Mountain View, CA) and to examine the accuracy of the needle placement relative to the target. The tip of the trocar of the RF needle had to be placed 1 cm from the target and then the hooks had to be deployed to 3 cm. Unenhanced CT of the liver and multiplanar reconstructions were performed to calculate accuracy of positioning, ie, the lateral distance between the needle and the target, the distance between the tip of the trocar of the RF electrode and the target, and the lateral distance between the central tine of the RF electrode and the target. RESULTS: All calf livers underwent successful CT-US registration with a mean registration error of 3.0 ± 0.1 mm and 2.9 ± 0.1 mm in the initial and second phase of the study, respectively. In the initial phase an overall number of 24 insertions were performed after the US-CT guidance. The mean needle to target distance was 1.9 ± 0.7 mm (range, 0.8-3.0 mm). In the second phase an overall number of 12 ablations were performed. The mean target-trocar distance was 10.3 ± 2.6 mm. The mean target-central tine lateral distance was 3.9 ± 0.7 mm (range, 2.9-5.1 mm). After the dissection of the specimen the target was found unchanged in the center of the ablation zone in all cases. CONCLUSION: Real-time registration and fusion of preprocedure CT volume images with intraprocedure US is feasible and accurate. The study was however conducted in an ideal experimental setting, without patient movements and breathing, and further studies are warranted to validate the system under clinical conditions.
KW - Fusion imaging
KW - Liver tumor ablation
KW - Targeting
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UR - http://www.scopus.com/inward/citedby.url?scp=37549012940&partnerID=8YFLogxK
U2 - 10.1097/RLI.0b013e31815597dc
DO - 10.1097/RLI.0b013e31815597dc
M3 - Article
C2 - 18097275
AN - SCOPUS:37549012940
VL - 43
SP - 33
EP - 39
JO - Investigative Radiology
JF - Investigative Radiology
SN - 0020-9996
IS - 1
ER -