Lee L K, Whitehurst C, Pantelides M L, Moore J V
Laser Oncology Programme, CRC Department of Experimental Radiation Oncology, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Manchester, UK.
BJU Int. 1999 Nov;84(7):821-6. doi: 10.1046/j.1464-410x.1999.00314.x.
To develop an interstitial laser light delivery system using multiple optical fibres for photodynamic therapy (PDT) in the treatment of prostate cancer.
A laser beam was divided equally with a 1 x 4 fibre splitter to deliver PDT simultaneously through four 2-cm long, flexible cylindrical optical diffusers. Biplanar transrectal ultrasonography (TRUS) and a template were used to position the optical fibres percutaneously. In vivo measurements of light penetration depth (1/micro[eff] ) in prostate tissue were made in seven patients, using a sheathed isoprobe to measure light fluence rates at varying radial distances from the diffuser. The prostate was fixed with stabilization needles to minimize displacement during needle placement.
The mean (sd, range) micro(eff) in the prostates of the seven patients was 0.35 (0.07, 0.22-0.44) mm-1, which produced closely parallel slopes of light attenuation. However, there was up to a 10-fold variation in absolute light levels at the same diffuser-detector separation distances amongst the seven patients, probably caused by blood pooling around the diffuser light source. A similar problem around the isoprobe detector was overcome by sheathing the probe in clear plastic tubing. By stabilizing the prostate, the optical fibre positioning was precise to within 2 mm.
Although this light delivery and TRUS assembly were developed for clinical PDT in the prostate, the same instrumentation can be used reliably for in vivo light-penetration studies. Haemorrhage was unpredictable and highlighted one of the main problems which needs to be overcome.
开发一种使用多根光纤的间质激光传输系统，用于前列腺癌的光动力疗法（PDT）。
用一个1×4光纤分束器将激光束均匀分开，通过四根2厘米长的柔性圆柱形光扩散器同时进行PDT治疗。采用双平面经直肠超声检查（TRUS）和模板经皮定位光纤。在7名患者体内测量前列腺组织中的光穿透深度（1/μ[eff]），使用带鞘等探头在距扩散器不同径向距离处测量光通量率。用固定针固定前列腺，以尽量减少置针过程中的移位。
7名患者前列腺中的平均（标准差，范围）μ（eff）为0.35（0.07，0.22 - 0.44）mm-1，产生了紧密平行的光衰减斜率。然而，在相同的扩散器 - 探测器分离距离处，7名患者的绝对光水平变化高达10倍，这可能是由扩散器光源周围的血液聚集引起的。通过将探头套在透明塑料管中，克服了等探头探测器周围的类似问题。通过固定前列腺，光纤定位精确到2毫米以内。
尽管这种光传输和TRUS组件是为前列腺临床PDT开发的，但相同的仪器可可靠地用于体内光穿透研究。出血情况不可预测，突出了需要克服的主要问题之一。
