OBJECTIVETo investigate the value of B-ultrasonography, CT and MRI in the evaluation of efficacy of radiofrequency ablation (RFA) for hepatic cancer.

METHODSOne hundred patients with hepatic cancer were treated by ultrasound-guided RFA between October 1999 and September 2000. All patients had been examined by serum AFP, B-ultrasound, CT or MRI before and within one month after RFA.

RESULTSBefore RFA, 34 patients who had had CT, the tumor showed hypo- or iso-density un-enhancement and enhancement on dynamic scanning. After RFA, 14 patients were examined by CT scan. Compared with the density on CT scan before RFA, 5 patients showed lower density lesion without any enhancement on dynamic scanning, but the other 9 patients showed similar images to the previous CT scan before RFA in some parts of their tumor. Before RFA, 66 patients examined by MRI showed hypo-intensity on T(1)-weighted image, hyper-intensity on T(2)-weighted image and enhancement on dynamic scanning. After RFA, among 86 patients examined by MRI, 44 showed iso- or hyper-intensity on T(1)-weighted image, iso- or hypo-intensity on T(2)-weighted image and no enhancement on dynamic scanning. But 42 patients showed similar images to the previous MRI imaging performed before RFA in some parts of their tumor.

CONCLUSIONBoth CT and MRI can be used as imaging evaluation tool on the effect of radiofrequency ablation for hepatic cancer. However, MRI is better than CT to detect whether the tumor is necrotic or still partly viable after radiofrequency ablation. Patients can be regarded as clinically cured provided that the serum AFP declines to the normal level from abnormally high level and/or MRI or CT scans show a complete necrotic lesion after RFA.