title: Conductive interstitial thermal therapy (CITT) device evaluation in VX2 rabbit model.
abstract: We have developed a conductive interstitial thermal therapy (CITT) device to precisely and reliably deliver controlled thermal doses to the surgical margins at the cavity site following tumor resection, intraoperatively. The temperature field created by CITT ablation of a perfused tissue was modeled with a finite element package Femlab. The modeling suggested that a maximum probe temperature of 120 degrees C and an ablation time of 20 minutes were required to ablate highly perfused tissue such as the VX2 carcinoma. Deployable pins enable faster and more reliable thermal ablation. The model predictions were tested by thermal ablation of VX2 carcinoma tumors implanted in adult New Zealand rabbits. The size of the ablated region was confirmed with a viability stain, triphenyltetrazolium chloride (TTC). Histopathological examination revealed 3 regions in the ablated area: a carbonized region (1-3 mm); a region that contained thermally fixed cells; and an area of coagulated necrosis cells. Cells in the thermally fixed region stained for PCNA (proliferating cell nuclear antigen) and were bounded by the carbonized layer at the cavity wall, and by necrotic cells that exhibit nuclear fragmentation and cell dissociation, 5 to 10 mm away from the CITT probe. Adjacent tissue outside the target region was spared with a clear demarcation between ablated and normal viable tissue. It is suggested that the CITT device can be used, clinically, to inhibit local recurrence by creating negative surgical margins following the resection of a primary tumor in non-metastatic early staged tumors.
authors.affiliation: Dept. of Otolaryngology, Univ. of Arkansas, Medical Sciences, 4301 West Markham, Little Rock, AR, USA. Shafirsteingal@uams.edu
authors.forename: Gal
authors.initials: G
authors.lastname: Shafirstein
authors.forename: Leah
authors.initials: L
authors.lastname: Hennings
authors.forename: Yihong
authors.initials: Y
authors.lastname: Kaufmann
authors.forename: Petr
authors.initials: P
authors.lastname: Novak
authors.forename: Eduardo G
authors.initials: EG
authors.lastname: Moros
authors.forename: Scott
authors.initials: S
authors.lastname: Ferguson
authors.forename: Eric
authors.initials: E
authors.lastname: Siegel
authors.forename: Suzanne V
authors.initials: SV
authors.lastname: Klimberg
authors.forename: Milton
authors.initials: M
authors.lastname: Waner
authors.forename: Paul
authors.initials: P
authors.lastname: Spring
mesh_terms: D000818:Animals; D002277:Carcinoma / Q000737:chemistry / Q000473:pathology / Q000628:therapy*; D004195:Disease Models, Animal; D005260:Female; D006358:Hot Temperature; D006979:Hyperthermia, Induced / Q000295:instrumentation*; D007150:Immunohistochemistry; D008954:Models, Biological; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D011817:Rabbits; D016896:Treatment Outcome
chemical_list: D018809:Proliferating Cell Nuclear Antigen