Journal article
Cryosurgery of Dunning AT-1 Rat Prostate Tumor: Thermal, Biophysical, and Viability Response at the Cellular and Tissue Level
Cryobiology, Vol.34(1), pp.42-69
02/1997
Handle:
https://hdl.handle.net/2376/112836
PMID: 9028916
Abstract
This study investigates cryodestruction of the Dunning AT-1 rat prostate tumor at the single cell, tissue slice, andin vivolevels. The thermal history around a 3-mm-diameter cylindrical cryosurgical probe was predicted by solving the bioheat equation in a one-dimensional cylindrical geometry. At various radial positions in the iceball this thermal history was approximated by a constant cooling rate and a final, steady-state temperature (or end-temperature). The predicted cooling rates and end temperatures ranged from ≥1000°C/min to 5°C/min and −196°C to −20°C, respectively. These cooling rates and end-temperatures were then imposed on single AT-1 cells, AT-1 tissue slicesin vitroand AT-1 tumorsin vivo.The single cells and tissue slices were frozen by LN2immersion, copper block slam-freezing, or controlled cooling on a cryomicroscope or a directional solidification stage. LN2immersion is lethal to AT-1 cells (presumably due to intracellular ice formation), while cooling at 5–100°C/min leaves some viable cells (at end-temperatures ranging between −20 and −40°C). AT-1 tumor slices show extensive intracellular ice formation due to slam cooling, extensive dehydration at 100°C/min, and total dehydration at rates ≤10°C/min to end temperatures below −10°C. Postfreeze culture and histology of the AT-1 tissue show that extensive intracellular ice formation is lethal, while cellular dehydration and vascular engorgement leave viable cells (at end-temperatures between −20 and −40°C). Based solely on the single cell andin vitrotissue damage achieved by cooling rates and end-temperatures, a sizable portion of a cryosurgically frozen tumor would be expected to survive. However,in vivocryosurgery performed on AT-1 tumors demonstrated that the tissue was damaged throughout the cryolesion, even at the periphery where the thermal history would be expected to allow single cells and tissue slices to survivein vitro.Taken together, these results suggest that damage mechanisms other than those due to cooling rate and end-temperature may be responsible for the increased cellular destruction at the periphery of the iceballin vivoand that cooling rate is less important than end-temperature in determining cryosurgical damage in AT-1 tumors. Experiments are ongoing to determine if the time held at an end temperature, thawing rate, vascular response, or other mechanisms are primarily responsible for the enhanced destructive capabilityin vivo.
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Details
- Title
- Cryosurgery of Dunning AT-1 Rat Prostate Tumor: Thermal, Biophysical, and Viability Response at the Cellular and Tissue Level
- Creators
- J.C BISCHOF - Bioheat and Mass Transfer Laboratory, Department of Mechanical Engineering, University Hospitals, University Hospitals, University of MinnesotaD SMITH - Bioheat and Mass Transfer Laboratory, Department of Mechanical Engineering, University Hospitals, University Hospitals, University of MinnesotaP.V PAZHAYANNUR - Bioheat and Mass Transfer Laboratory, Department of Mechanical Engineering, University Hospitals, University Hospitals, University of MinnesotaC MANIVEL - Department of Mechanical Engineering, Department of Laboratory Medicine and Pathology, University Hospitals, University Hospitals, University of MinnesotaJ HULBERT - Department of Mechanical Engineering, University Hospitals, Department of Urologic Surgery, University Hospitals, University of MinnesotaK.P ROBERTS - Department of Mechanical Engineering, University Hospitals, Department of Urologic Surgery, University Hospitals, University of Minnesota
- Publication Details
- Cryobiology, Vol.34(1), pp.42-69
- Academic Unit
- Elson S. Floyd College of Medicine
- Publisher
- Elsevier Inc
- Identifiers
- 99900547890601842
- Language
- English
- Resource Type
- Journal article