Laser-induced thermotherapy (LITT)—evaluation of a miniaturised applicator and implementation in a 1.0-T high-field open MRI applying a porcine liver model

Abstract

The miniaturised 6-F applicator can create comparable coagulation sizes to those of the 9-F system. Applicator guidance and online-thermometry in high-field open MRI are feasible.

Comparison of four radiofrequency ablation systems at two target volumes in an ex vivo bovine liver model

“…The tissue up to the macroscopically visible hemorrhagic rim has repeatedly been postulated in the literature to correspond to a transitional zone from inner coagulation necrosis to outer normal hepatic tissue (15). Other previous studies likewise included the transitional zone of necrosis in the calculation of necrotic lesion volumes because the histopathological correlation with NADH dehydrogenase, as the vitality marker revealed irreversible cell damage at the necrotic margins and the histological assessment of in vivo specimens revealed irreversibly damaged cells within the hemorrhagic margins (16).…”

MRI-guided laser ablation of neuroendocrine tumor hepatic metastases

“…MRI is particularly well suited for thermal therapy monitoring as it enables multiplanar thermal monitoring during the ablation using either T1 effect or PRF-method. Also the novel development of miniaturized instruments (30,31) to achieve thermal laser ablation make the procedure less invasive and comparable to other thermal therapy methods, such as radiofrequency ablation, cryotherapy, interstitial electroporation, microwave, and brachytherapy. It must be acknowledged that most of these methods, apart from cryotherapy, do not facilitate seamless utilization of intraoperative MRI monitoring.…”

Volume comparison of radiofrequency ablation at 3- and 5-cm target volumes for four different radiofrequency generators: MR volumetry in an open 1-T MRI system versus macroscopic measurement

“…As several studies [21,30] investigated the tissue condition between the coagulation zone next to the RF needle and the pink rim around the lesion detected irreversible cell death and hepatocyte atrophy, we included the transitional zone (TZ) in calculating the ablated volume.…”