PDT治疗BALB／c荷瘤小鼠喉癌中的激光剂量效应研究

目的 激光照射剂量和光敏剂的种类及浓度可明显影响光动力疗法（PDT）的治疗效果.本研究以BALB/c荷瘤小鼠为对象,探讨不同激光照射剂量对PDT治疗喉癌效果的影响.方法 取48只皮下接种人喉癌上皮细胞Hep-2的BALB/c荷瘤鼠,分成6组,其中1组为对照,其余5组尾静脉注射血卟啉单甲醚（HMME）后3h分别以30、60、120、240、480 J/cm^2能量的波长630 nm激光照射肿瘤组织.隔日观察肿瘤大小、体质量,并在PDT后30 d取肿瘤组织做病理切片.结果 与对照组相比,所有剂量组PDT都使肿瘤消除或部分消除,疗效与剂量呈正相关,120和480 J/cm^2组小鼠肿瘤完全治愈.瘤损部位在PDT作用后1d出现结痂,5d结痂变硬变黑,同时肿瘤开始消退,30 d左右肿瘤完全消失.结论 PDT是治疗小鼠喉癌非常有前景的方法,其最佳照射剂量是120 J/cm^2.

Dose effect of laser irradiation in photodynamic therapy for laryngocarcinoma in BALB/c mouse

Objective The dose and type of light and photosensitizer could seriously affect the curative effect of photodynamic therapy （PDT）.The purpose of this study was to observe whether or not PDT with hematoporphyrin monomethyl ether （HMME） can cure laryngocarcinoma in the solid tumor model,and to define the proper laser amount for killing the cancer cells.Methods Forty eight BALB/c mouse models with subcutaneous Hep-2 laryngeal carcinomas were prepared.Mice were divided into six groups depending on the amount of laser received from 30 J/cm^2 to 480 J/cm^2 including a control group,tumor size in each group was between 8 mm and 10 mm.Tail vein injection were given with HMME prior to applying the laser light,and then illumination was carried out on the tumor at 3 h after HMME administration.Tumor volume,animal weight and histopathologic changes were observed after PDT.Results All mice apparently showed positive results via PDT,and the cancer had been cured in 120 J/cm^2 and 480 J/cm^2 groups.The laryngeal cancer lesions began to form scab 1 d after PDT and the scab became hard and black after 5 d.The tumor regression began simultaneously and completed around 30 d after PDT.Conclusions PDT may treat laryngeal cancers which sized less than 10 mm in mouse models.The optimum energy to destruct the laryngeal cancer cells may be 120 J/cm^2.