Fielding D I, Buonaccorsi G, Cowley G, Johnston A M, Hughes G, Hetzel M R, Bown S G
National Medical Laser Centre, Institute of Surgical Studies, Royal Free and University College Medical School, London, UK.
Lasers Med Sci. 2001;16(1):26-33. doi: 10.1007/pl00011333.
Interstitial laser photocoagulation (ILP) and interstitial photodynamic therapy (PDT) involve delivery of light to lesions in solid organs using thin fibres passed through needles inserted percutaneously under image guidance. In ILP, the laser energy heats the tissue, whereas in PDT it activates a previously administered photosensitising agent. This study looks at their potential for treating localised, small, peripheral lung cancers in patients unsuitable for surgery. Experiments were undertaken on nine normal pigs, up to four fibres being inserted into the lung parenchyma percutaneously under X-ray guidance (ILP: 2-3 W, 1000 q/fibre, from 805 nm diode laser, PDT, 100-200 J/fibre from 652 nm diode laser at 50-100 W, 3 days after 0.15 mg/kg mTHPC). Animals were killed from 3 days to 3 months later and the treated areas examined macroscopically and microscopically. Both techniques were well tolerated, producing well-defined, localised lesions, typically 3.5 x 2 x 2 cm using four fibres. Histology showed thermal coagulative necrosis after ILP and haemorrhagic necrosis after PDT. Early small haematomas and late cavitation were sometimes seen after ILP, but not after PDT. PDT lesions healed with preservation of larger arteries and bronchi in the treated area. A few small pneumothoraces were seen which resolved spontaneously, probably related to the chest wall puncture. It was concluded that ILP and PDT lesions of a size large enough to cover a small tumour can be made safely in the lung parenchyma, although healing was better after PDT. Pilot clinical studies with both techniques are now justified on carefully selected patients.
间质激光光凝术（ILP）和间质光动力疗法（PDT）是通过在图像引导下经皮插入的细针将光传递到实体器官中的病变部位。在ILP中，激光能量加热组织，而在PDT中，它激活先前给予的光敏剂。本研究探讨了它们在治疗不适于手术的局部小周围型肺癌患者中的潜力。对9只正常猪进行了实验，在X射线引导下经皮将多达4根光纤插入肺实质（ILP：2 - 3瓦，每根光纤1000焦耳，来自805纳米二极管激光；PDT，在给予0.15毫克/千克的间四（羟基苯基）氯卟啉（mTHPC）3天后，每根光纤给予100 - 200焦耳，来自652纳米二极管激光，功率为50 - 100瓦）。在3天至3个月后处死动物，并对治疗区域进行宏观和微观检查。两种技术耐受性良好，产生界限清晰的局部病变，使用4根光纤时通常为3.5×2×2厘米。组织学显示ILP后为热凝固性坏死，PDT后为出血性坏死。ILP后有时可见早期小血肿和晚期空洞形成，而PDT后未见。PDT病变愈合后，治疗区域的较大动脉和支气管得以保留。可见少量小气胸，可自行缓解，可能与胸壁穿刺有关。得出的结论是，虽然PDT后愈合更好，但在肺实质中可以安全地制造出足以覆盖小肿瘤大小的ILP和PDT病变。现在有理由对精心挑选的患者进行这两种技术的初步临床研究。
