Morano José Antonio Carlos Otaviano David, Cordeiro Naylana, Guimarães Sergio Botelho, Jamacaru Francisco Vagnaldo Fechine, Moraes Filho Manoel Odorico de
Department of Surgery, Federal University of Ceara, Fortaleza-CE, Brazil.
Acta Cir Bras. 2011;26 Suppl 1:53-6. doi: 10.1590/s0102-86502011000700011.
To develop a model to evaluate the effects of focal pulsed ultrasound (US) waves as a source of heat for treatment of murine subcutaneous implanted Walker tumor.
An experimental, controlled, comparative study was conducted. Twenty male Wistar rats (160-300 g) randomized in 2 equal groups (G-1: Control and G-2: Hyperthermia) were inoculated with Walker-256 carcinosarcoma tumor. After 5 days G-2 rats were submitted to 45ºC hyperthermia. Heat was delivered directly to the tumor by an ultrasound (US) equipment (3 MHz frequency, 1,5W/cm³). Tumor temperature reached 45º C in 3 minutes and was maintained at this level for 5 minutes. Tumor volume was measured on days 5, 8, 11, 14 e 17 post inoculation in both groups. Unpaired t-test was used for comparison. P<0.05 was considered significant.
Tumor volume was significantly greater in day 5 and decreased in days 11, 14 and 17 in treated rats. Rats treated with hyperthermia survived longer than control animals. On the 29th day following tumor inoculation, 40% of control rats and 77.78% of hyperthermia-treated rats remained alive.
The proposed model is quite simple and may be used in less sophisticated laboratory settings for studying the effects of focal hyperthermia in the treatment of malignant implanted tumours or in survival studies.
建立一个模型，以评估聚焦脉冲超声波作为热源对小鼠皮下植入的Walker肿瘤的治疗效果。
进行了一项实验性、对照性、比较性研究。将20只雄性Wistar大鼠（体重160 - 300克）随机分为两组（G - 1：对照组和G - 2：热疗组），接种Walker - 256癌肉瘤肿瘤。5天后，G - 2组大鼠接受45℃热疗。通过超声设备（频率3MHz，功率1.5W/cm³）将热量直接传递到肿瘤。肿瘤温度在3分钟内达到45℃，并在此水平维持5分钟。在接种后的第5、8、11、14和17天测量两组的肿瘤体积。采用非配对t检验进行比较。P < 0.05被认为具有统计学意义。
治疗组大鼠在第5天肿瘤体积显著更大，而在第11、14和17天减小。接受热疗的大鼠比对照动物存活时间更长。在接种肿瘤后的第29天，40%的对照大鼠和77.78%的热疗大鼠仍然存活。
所提出的模型非常简单，可用于不太复杂的实验室环境，以研究聚焦热疗对恶性植入肿瘤的治疗效果或用于生存研究。
