Fig. 1.

Strategies for the placement of six electrodes (40 mm active part) according to the location and the form of hepatocellular carcinoma (HCC) to treat with multibipolar radiofrequency ablation (with adaptors) tumors > 5 cm by limiting as much as possible full intraprocedural repositioning and intratumorous punctures. a Basic pentagonal configuration planning for the insertion of six electrodes according to roughly parallel courses (±30°) according as much as possible to the long axis of the tumor. b The cutting technique for the ablation of large tumors located at the periphery of the right or left lobe. Using the cutting strategy, the effect of the ablation extends from pure thermal effect for the safety margin and the proximal side of the tumor to ischemic effect for its opposite exo-hepatic side. c The no touch retronodular convergent technique is the safer strategy for the ablation of subcapsular tumor having a large liver side. This technique allows a strict extratumorous (no touch) ablation of subcapsular tumor up to 6 cm. Distances between the tips of two adjacent electrodes have to be within the 1–3 cm range. d The wedged ablation technique consisting of inserting electrodes according to the convergent course to the apex of the liver subsegment or a segment where the tumor is located is especially designed to treat poorly delineated infiltrative HCC (assumed to be not diffuse).