Rui J, Tatsutani K N, Dahiya R, Rubinsky B
Department of Mechanical Engineering, University of California, Berkeley 94720, USA.
Breast Cancer Res Treat. 1999 Jan;53(2):185-92. doi: 10.1023/a:1006182618414.
There is a growing interest in the use of cryosurgery to treat breast cancer, following recent breakthroughs in noninvasive imaging and in cryotechnology, as well as the recent success of cryosurgery in treating various types of cancer. However, since haphazard freezing does not guarantee tissue destruction, in order to apply this technique effectively it is essential to determine the thermal parameters that produce complete destruction of malignant tissue. This study seeks to quantitatively identify the relationship between thermal variables and the degree of freezing damage to human breast cancer cells. In order to do this, human breast cancer and normal cells were frozen with controlled thermal parameters using a directional solidification apparatus. Cell viability was determined after thawing using trypan blue, and correlated to the thermal variables used during freezing. Cellular damage is observed to increase with increasing cooling rates, due to the higher probability of intracellular ice formation. A double freeze thaw cycle significantly increases the extent of cell damage, and is sufficient to ensure complete cell destruction at final freezing temperatures of -40 degrees C for a 25 degrees C/min cooling rate, and -20 degrees C for a 50 degrees C/min cooling rate. The correlations between cell death and thermal parameters are qualitatively identical for all the cell types in this study, although there is some variation from one cell type to another in the overall susceptibility to freezing damage. The correlations established in this study can be used to design systematic and optimal breast cryosurgery protocols.
随着非侵入性成像和冷冻技术的最新突破，以及冷冻手术在治疗各种类型癌症方面的近期成功，人们对使用冷冻手术治疗乳腺癌的兴趣日益浓厚。然而，由于随机冷冻不能保证组织破坏，为了有效应用该技术，确定产生恶性组织完全破坏的热参数至关重要。本研究旨在定量确定热变量与人类乳腺癌细胞冷冻损伤程度之间的关系。为了做到这一点，使用定向凝固装置以受控的热参数冷冻人类乳腺癌细胞和正常细胞。解冻后使用台盼蓝测定细胞活力，并将其与冷冻过程中使用的热变量相关联。由于细胞内结冰的可能性更高，观察到细胞损伤随着冷却速率的增加而增加。双冻融循环显著增加了细胞损伤程度，并且足以确保在 -40℃ 的最终冷冻温度下以 25℃/min 的冷却速率以及在 -20℃ 下以 50℃/min 的冷却速率时细胞完全破坏。尽管不同细胞类型对冷冻损伤的总体敏感性存在一些差异，但本研究中所有细胞类型的细胞死亡与热参数之间的相关性在定性上是相同的。本研究中建立的相关性可用于设计系统且最佳的乳腺冷冻手术方案。
