The effect of hyperthermia on cervical lymph node metastasis

本文报道了热疗对仓鼠口腔黏膜鳞状细胞癌O-1N颈部淋巴结转移的影响。材料与方法将O-1N植入金仓鼠50只分为3组：加热组（21只）每周2次，每次43ºC射频热疗40分钟，假组（15只）每周2次，在肿瘤内插入传感器40分钟，未治疗组（14只）。当肿瘤直径达到7mm时，用13.56MHz射频电容加热系统对肿瘤进行加热。一对分别由直径15毫米的电极板组成的涂抹器应用于皮肤和粘膜表面进行加热。用C-C热电偶温度计连续测量瘤内温度。实验后2周、3周和4周分别切除颈部淋巴结和颊部肿瘤。对淋巴结转移发生率进行组织学评估，并将淋巴结转移分为边缘窦转移型、髓样窦转移型、全淋巴结转移型和淋巴结外转移型(3)。结果加热组转移灶发生率降至38%（21只动物中有8只），转移灶在LN囊内，而假手术组转移灶发生率为60%（15只动物中有9只），未治疗组转移灶发生率为71%（14只动物中有10只），对照组均为淋巴结外转移灶。当加热后口腔肿瘤消失时，组织学上发现的LNs转移很少（8%），而口腔癌再生组的转移率增加到77.8%。因此，由于口腔癌的热效应，热疗似乎抑制了颈部LN转移。

(1). IntroductionThis paper reports the effect of hyperthermia on cervical lymph node metastases of buccal mucosa squamous cell carcinoma O-1N in hamsters.(2). Materials and MethodsFifty golden hamsters in which O-1N was transplanted into the cheek pouch were divided into 3 groups : a heating group (21 animals) subjected to RF hyperthermia at 43ﾟC for 40 minutes twice a week, a sham group (15 animals) in which a sensor was inserted into the tumor for 40 minutes twice a week, and an untreated group (14 animals). When the tumor reached 7mm in diameter, it was heated with a 13.56MHz RF capacitive heating system. A pair of applicators each consisting of a 15-mm-diameter electrode plate was applied to the cutaneous and mucosal surfaces for heating. Intratumoral temperature was measured continuously by the C-C thermocouple thermometer. Cervical lymph nodes (LNs) and buccal tumors were removed two, three and four weeks after the experiment, respectively. LNs were histologically evaluated for the incidence of metastases and classified into a marginal-sinus metastatic type, a medullary-sinus metastatic type, an entire-node metastatic type and an extra-node metastatic type.(3). ResultsIn the heating group, incidence of metastases were reduced to 38% (8 of 21 animals) and metastases were seen within the LN capsule, whereas metastases were observed in 60% (9 of 15 animals) in the sham group and 71% (10 of 14 animals) in the untreated group and the extra-node metastatic type was found in both control groups. When the buccal tumor disappeared after heating, very few (8%) LNs metastases were found histologically, whereas matastases increased to 77.8% in the oral cancer regrowth group. Thus hyperthermia appeared to inhibit cervical LN metastasis as a result of the thermal effect on oral carcinoma.