以激光进行的高温疗法称激光加热疗法,已成为肿瘤热疗的一种新的有效手段。主要使用近红外激光,采用直接照射或插入光纤的方法进行治疗。但应用时由于近红外波段激光对组织的穿透有限,热效应被局限在一个小的体积内,不同肿瘤组织光穿透情况又有很大差异,治疗的范围难以把握。另外,热疗时,难以区分肿瘤体和正常组织的边界,照射不当容易造成周围正常组织的伤害,因此实时地监测导向近红外光成为激光热疗的关键。研究表明运用上转换纳米探针[Yb/Er(NaYF4∶Yb,Er)]靶向定位到肿瘤,在980 nm近红外光的激发下可实现激光加热的同时进行上转换荧光的监测,从而确定照射的范围、分布、剂量以及肿瘤边界,最终达到导向热疗实现精确治疗肿瘤的目的。
The photothermal therapy which mainly uses near-infrared laser to heat tissue has become a new validated method for tumor treatment through direct surface irradiating or inserting light fibers in tumor.The near-infrared light transfer in tissue is limit and the thermal effect occurs only in a small volume during treatment.Thus the treating extent is difficult to control.Otherwise,it is difficult to distinguish the boundary of tumor and normal tissue in photothermal therapy.Improper heating will hurt the normal tissue.So it is important to guide the laser in time in thermal therapy.The results indicate that by using upconversion nanoparticles[Yb/Er(NaYF4∶Yb,Er)] to localize on tumor,the infrared light can be monitored in real time with the upconversion fluorescence.The light dosage,distribution,heating extent and the boundary of tumor can be detected to increase the effect of thermal therapy.