TY - GEN
T1 - Thermal analysis for cryosurgery of nodular basal cell carcinoma
AU - Sun, Feng
AU - Aguilar, G.
AU - Kelly, K. M.
AU - Wang, G. X.
PY - 2006
Y1 - 2006
N2 - Basel cell carcinoma (BCC) is the most common human skin malignancy. Its incidence has increased significantly in Australia, Europe and North America over the past decade. A number of modalities are currently used for treatment of BCC, including cryosurgery which offers a potential for high cure rate, low cost, minimal bleeding and good cosmetic effect. However, cryosurgery is not used frequently for BCC because no current method exists to design adequate treatment parameters. We present a numerical analysis on the thermal history of the target tissue during cryosurgery of a nodular BCC using liquid nitrogen (LN2) spray. The model uses Pennes equation to describe the heat transfer within the target tissue. A convective thermal boundary is used to describe the heat interaction between the tissue and LN2, and the apparent heat capacity method is applied to address the tissue phase change process. A parametric study is conducted on the convective heat transfer coefficient (hs: 104-106 W/m 2·K), cooling site area (rs/R0: 0.5-1.0) and spray time (t: 0-30 sec.), with the objective to understand the thermal history during tissue freezing, including lethal temperature (-50°C) and cooling rate (CR). Results demonstrate that propagation of the lethal isotherm is sensitive to the convective heat transfer coefficient, hs, with a range of 104-5×104 W/m2·K. Increasing the cooling site area can significantly enhance cooling efficiency, producing dramatic increase in the amount of tissue encompassed by the lethal isotherm. The cooling rate (CR) shows a highly dynamic distribution during the cooling process: the highest CR drops quickly from 140°C/sec. (t=0.5 sec.) to 20°C/sec. (t=5 sec.). The highest CR is initially located close to the cooling site but moves toward the inside of the tissue as treatment proceeds. The model presented herein provides a simulation tool for treatment planning of cryosurgery using LN2 spray, in which the protocol parameters, e.g. cooling site area and spray time, can be determined for an optimal outcome. The quantitative predictions on the propagation of lethal isotherm and the distribution of CR should help to optimize cryosurgery efficacy.
AB - Basel cell carcinoma (BCC) is the most common human skin malignancy. Its incidence has increased significantly in Australia, Europe and North America over the past decade. A number of modalities are currently used for treatment of BCC, including cryosurgery which offers a potential for high cure rate, low cost, minimal bleeding and good cosmetic effect. However, cryosurgery is not used frequently for BCC because no current method exists to design adequate treatment parameters. We present a numerical analysis on the thermal history of the target tissue during cryosurgery of a nodular BCC using liquid nitrogen (LN2) spray. The model uses Pennes equation to describe the heat transfer within the target tissue. A convective thermal boundary is used to describe the heat interaction between the tissue and LN2, and the apparent heat capacity method is applied to address the tissue phase change process. A parametric study is conducted on the convective heat transfer coefficient (hs: 104-106 W/m 2·K), cooling site area (rs/R0: 0.5-1.0) and spray time (t: 0-30 sec.), with the objective to understand the thermal history during tissue freezing, including lethal temperature (-50°C) and cooling rate (CR). Results demonstrate that propagation of the lethal isotherm is sensitive to the convective heat transfer coefficient, hs, with a range of 104-5×104 W/m2·K. Increasing the cooling site area can significantly enhance cooling efficiency, producing dramatic increase in the amount of tissue encompassed by the lethal isotherm. The cooling rate (CR) shows a highly dynamic distribution during the cooling process: the highest CR drops quickly from 140°C/sec. (t=0.5 sec.) to 20°C/sec. (t=5 sec.). The highest CR is initially located close to the cooling site but moves toward the inside of the tissue as treatment proceeds. The model presented herein provides a simulation tool for treatment planning of cryosurgery using LN2 spray, in which the protocol parameters, e.g. cooling site area and spray time, can be determined for an optimal outcome. The quantitative predictions on the propagation of lethal isotherm and the distribution of CR should help to optimize cryosurgery efficacy.
UR - https://www.scopus.com/pages/publications/84920630486
U2 - 10.1115/IMECE2006-15963
DO - 10.1115/IMECE2006-15963
M3 - 会议稿件
AN - SCOPUS:84920630486
SN - 0791837904
SN - 9780791837900
T3 - ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE)
BT - Proceedings of 2006 ASME International Mechanical Engineering Congress and Exposition, IMECE2006 - Biomedical and Safety Systems
PB - American Society of Mechanical Engineers (ASME)
T2 - 2006 ASME International Mechanical Engineering Congress and Exposition, IMECE2006
Y2 - 5 November 2006 through 10 November 2006
ER -