Multidetector-row computed tomography of focal liver lesions treated by radiofrequency ablation: spectrum of findings at long-term follow-up.

OBJECTIVE: To assess serial changes in liver tumors after percutaneous radiofrequency ablation at follow-up multidetector-row computed tomography.

MATERIALS AND METHODS: Forty patients with 65 malignant lesions underwent multidetector-row computed tomography immediately, 1 month and every 3 months, up to a maximum of 15 months after radiofrequency ablation. The computed tomography (CT) appearance of the treated lesions (non-enhanced attenuation, enhancement pattern, shape and size) was assessed at each follow-up. The relationship between each CT finding and the treatment outcome was evaluated by chi2 test (P < 0.05).

RESULTS: No significant differences were found in lesion shape and in non-enhanced CT attenuation between successfully and unsuccessfully treated lesions, whereas over time change of lesion size was significantly different. The no enhancement and nodular enhancement pattern prevalence was significantly (P < 0.0001) different between successfully and unsuccessfully treated lesions, whereas non-nodular enhancement pattern did not show any relationship with the treatment outcome.

CONCLUSIONS: Lesion size increase and nodular enhancement pattern resulted significantly related to the treatment failure.