PURPOSE: To determine whether combining @entity1543 instillation before radiofrequency (RF) ablation can improve local tissue electrical conductivity, RF energy deposition, intratumoral heating, and @entity5 @entity39 in a large animal model. MATERIALS AND METHODS: Multiple hypovascular @entity235 @entity242 were implanted in 11 mildly immunosuppressed @entity235 (25 mg/kg @entity205 twice daily). @entity5 were incubated for 8-12 weeks to 4.2 cm +/- 0.6 in diameter. Treatment strategies included 10% and 15% @entity1543 diluted in distilled water, 10% and 15% @entity1543 diluted in saturated @entity4202 solution, 50% @entity1543 , and 100% @entity1068 , with 6 mL of each injected alone or in combination with RF ablation (internally cooled, 1-cm tip; 12 minutes). Two additional control groups were studied in which @entity5 received either RF alone or distilled water injected alone. Comparisons were also made with groups treated with 36% @entity4202 with and without RF ablation. Resultant coagulation for these ablative strategies, along with local temperatures and RF parameters such as impedance, current, and power, were compared. RESULTS: Increasing coagulation was observed with increasing @entity1543 concentrations (1.7 cm +/- 0.4, 2.8 cm +/- 0.6, and 3.5 cm +/- 0.3 for 10%, 15%, and 50% @entity1543 alone, respectively; P <.01). The combination of RF ablation with @entity1543 resulted in greater coagulation than with either therapy alone (P <.05). However, maximum heating and coagulation were observed with 10% @entity1543 diluted in @entity4202 , with which the entire @entity5 (diameter, 4.5 cm +/- 0.4) was completely ablated in every case. This was equivalent to results for @entity5 treated with 36% @entity4202 combined with RF. RF with a 50% @entity1543 concentration resulted in coagulation measuring only 3.7 cm +/- 0.3 (P <.01). Significantly greater RF heating (89.7 degrees C +/- 12.3 at 10 mm) was observed when the @entity5 were pretreated with 10% or 15% @entity1543 in saturated @entity4202 , compared with 67.9 degrees C +/- 13.7 observed when @entity1543 was diluted in water (P <.02). RF combined with @entity1068 produced less coagulation (2.8 cm +/- 0.3) than combinations with @entity1543 because rapid and irreversible impedance increases were observed. CONCLUSION: Addition of @entity1543 injections to RF ablation substantially increases @entity5 destruction compared with RF or injection therapy alone. However, lower @entity1543 concentrations in saturated @entity4202 produced greater @entity5 coagulation, suggesting that, in this @entity5 model, alterations in electrical conductivity play a more important role in increasing @entity5 ablation efficiency than do the additional ablative effects of @entity1543 .

Image-guided percutaneous chemical and radiofrequency XXXX ablation in an animal model.

@entity242 :: ('MESH:D012509', 'Disease') :: ['venereal sarcomas'] @entity39 :: ('MESH:D009336', 'Disease') :: ['necrosis'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor', 'Tumors', 'hypovascular tumor', 'tumors'] @entity235 :: ('9615', 'Species') :: ['canine', 'dogs'] @entity205 :: ('MESH:D016572', 'Chemical') :: ['cyclosporin A'] @entity1068 :: ('MESH:D000431', 'Chemical') :: ['ethanol'] @entity1543 :: ('MESH:D019342', 'Chemical') :: ['acetic acid'] @entity4202 :: ('D012965', 'Chemical') :: ['NaCl']
@entity5 :: (MESH:D009369,Disease) :: ['tumor']
