Postablation assessment using follow-up registration of CT images before and after radiofrequency ablation (RFA): prospective evaluation of midterm therapeutic results of RFA for hepatocellular carcinoma.
OBJECTIVE
The purpose of this study was to prospectively evaluate the diagnostic impact of prototypic software that allows registration of CT images before and after radiofrequency ablation (RFA) for safety margin assessment, as well as to determine the therapeutic impact of this software on local tumor progression in comparison with the conventional method of side-by-side CT comparison.


SUBJECTS AND METHODS
One-hundred fifty patients with a single hepatocellular carcinoma (HCC) referred for RFA were enrolled. CT scans were obtained before and after RFA, and all CT images were analyzed with and without the use of nonrigid registration software. Thereafter, local tumor progression in the study group (n = 150) was compared with that in a matched control group (n = 90) in which side-by-side comparison of CT images before and after RFA was used for safety margin assessment.


RESULTS
RFA using registration software-assisted diagnoses to decide whether additional RFA was necessary resulted in a 10.67% local tumor progression rate 42 months after the procedure, which was significantly better than that in the matched control group (23.33%) (p = 0.01). After registration software was used, 15.33% (23/150) of patients had conflicting assessments on the safety margin and the necessity for additional RFAs compared with the initial visual comparison of the CT scans.


CONCLUSION
The addition of follow-up registration of CT images before and after RFA resulted in significantly improved assessment of safety margins, simplifying the decision of whether to perform additional treatments and reducing local tumor progression of HCCs after RFA.
['Shin|Sooyoung|S|', 'Lee|Jeong Min|JM|', 'Kim|Kyung Won|KW|', 'Joo|Ijin|I|', 'Han|Joon Koo|JK|', 'Choi|Byung Ihn|BI|', 'Klotz|Ernst|E|']
D006528:Carcinoma, Hepatocellular D017115:Catheter Ablation D018450:Disease Progression D005260:Female D006801:Humans D008113:Liver Neoplasms D008297:Male D008875:Middle Aged D011446:Prospective Studies D011857:Radiographic Image Interpretation, Computer-Assisted D012984:Software D014057:Tomography, X-Ray Computed D016896:Treatment Outcome
registration CT radiofrequency ablation ablative margin liver