Marginal Recurrence after Radiofrequency Ablation of Hepatocellular Carcinoma: Relationship between Distance from Hepatic Capsule to Tumor and Recurrence Period

Lee, Jin Hwa; Nam, Kyung Jin

Abstract

PURPOSE
To examine the relationship between distance from hepatic capsule to tumor and recurrence among hepatocellular carcinoma patients in whom marginal recurrence was noted after radiofrequency ablation therapy.
MATERIALS AND METHODS
Between January 2000 and December 2001, hepatocellular carcinoma patients with a tumor 5 cm or less in size and located 2 cm or less from the hepatic capsule underwent radiofrequency ablation therapy. We subsequently selected 37 patients (41 tumors) in whom immediate CT demonstrated complete tumor ablation and follow-up CT showed marginal recurrence. Tumors were grouped according to their distance from the hepatic capsule: Group I, adhered to the capsule; Group II, less than 1 cm from it; Group III, 1-2 cm distant. Of the 41 tumors, 22 were assigned to Group I, six to Group II, and 13 to Group III. Mean tumor size was 3.2 cm, and inter-group variation was small (Group I, 3.3 cm; Group II, 2.9 cm; Group III, 3.1 cm). Follow-up CT was used to determine marginal recurrence, and for inter-group comparison and the assessment of statistical significance, the t test was employed.
RESULTS
Marginal recurrence was noted at mean 5.5 months (2.7 months in Group I, 3.0 months in Group II, and 10.5 months in Group III). The t test revealed significant difference between Group I and III (p<0.0001) but not between Groups I and II, or II and III. If '1 cm from hepatic capsule' was the criterion for classification, and Group I and II were combined and compared with Group III, there was significant difference between the two groups (<0.0001).
CONCLUSION
Tumors which adhered to the hepatic capsule or were less than 1 cm from it recurred sooner than those situated 1-2 cm away.