Interstitial laser-induced thermotherapy of the lung: evaluation of the influence of ablation continuity on ablation size in a swine model

Abstract

The purpose of this study was to assess the relationship between size and the continuity of energy application in interstitial laser-induced thermotherapy. Percutaneous computed tomography-guided laser ablation (30 W, 600 nm diode) of the lung was performed in 7 Yorkshire pigs; a total of 42 ablation zones were created. Twenty ablations were performed using a continuous cycle of 2 min (protocol A) and 22 ablations were performed using 4 intermittent cycles with a duration of 1 min for each cycle interrupted by a 10-s stop between the cycles (protocol B). The lung was harvested immediately after euthanasia for gross pathology and histopathologic evaluation. Statistical analysis was performed using the Student t test and the Spearman correlation coefficient. Laser ablation resulted in complete necrosis of variable size of lung. The mean ablation zone dimensions (±SD) were 1.9 (±0.4) cm × 1.4 (±0.3) cm for protocol A and 2.2 (±0.5) cm × 1.4 (±0.4) cm for protocol B. The size of the necrosis is not significantly different when comparing a continuous 2-min ablation to a 4-cycle intermittent ablation for 1 min each cycle interrupted by a 10-s stop between the cycles (P = 0.98 and 0.53, respectively).

Porphysome nanoparticles for enhanced photothermal therapy in a patient-derived orthotopic pancreas xenograft cancer model: a pilot study

“…The observed thermally induced morphological changes were found to be similar to those reported elsewhere for ablative therapies such as RFA and tissue resection procedures involving electrocautery. 37,38 Due to the invasiveness of pancreas PTT as administered under the current study design, induction of apoptosis or longterm expression of stress and proliferation markers could not be assayed. Unfortunately, this precluded the identification of the thermal treatment marginal zone, where local temperatures are raised but the therapeutic ablative threshold is not reached.…”