Percutaneous radiofrequency ablation therapy for hepatocellular carcinoma: a proposed new grading system for the ablative margin and prediction of local tumor progression and its validation

Background In the present study we classified the radicality of percutaneous radiofrequency thermal ablation (RFA) therapy according to the extent of the ablated margin. We measured the local recurrence rate for each radicality grade to evaluate the significance of the grading system in assessing the therapeutic effectiveness of RFA and predicting local tumor progression.