Messmann H, Szeimies R M, Bäumler W, Knüchel R, Zirngibl H, Schölmerich J, Holstege A
Dept. of Internal Medicine, University of Regensburg, Germany.
Endoscopy. 1997 May;29(4):275-80. doi: 10.1055/s-2007-1004189.
The fractionated application of laser light has been shown to enhance the effect of photodynamic therapy (PDT) on normal rat colon after photosensitization with 5-aminolevulinic acid. In a pilot study, we examined whether this modified laser treatment can also enhance the effect of PDT in patients with esophageal cancer after sensitization with hematoporphyrins.
Six patients (four cases of early esophageal carcinoma and two cases of advanced esophageal carcinoma, one of the latter patients having tumor overgrowth on a metal stent) were treated in nine sessions. In four sessions, laser energy was fractionated to enhance the PDT effect using a hematoporphyrin polyester. Irradiation was carried out 48 hours after sensitization. The total laser energy of 150 J/cm2 was applied either continuously or in fractions, with a single break of five minutes after 75 J/cm2.
Among the three patients who underwent continuous laser light irradiation, one patient experienced a complete remission of two of three superficial esophageal cancers. The patient with tumor overgrowth on an implanted metal stent showed a partial response, with improvement of dysphagia without destruction of the stent, while in another patient with advanced esophageal cancer, the dysphagia did not improve after continuous laser treatment. Fractionated laser therapy led to complete remission in all three patients with early cancers, one of whom had failed to respond to previous treatment with continuous PDT. A partial remission was obtained in a fourth patient with a uT2 cancer who had also shown no remission after continuous PDT treatment. However, after fractionated laser therapy, three mild esophageal stenoses occurred, in comparison with none after continuous PDT.
Light fractionation during PDT improved the effectiveness of the treatment in a small number of patients, and increased side effects such as the occurrence of mild esophageal stenosis. This modified treatment can be a promising approach in the effort to reduce the dose of hematoporphyrins or other sensitizers required, and to avoid prolonged skin sensitization or local stenosis.
已证明分次应用激光可增强光动力疗法（PDT）对经5-氨基酮戊酸光敏化后的正常大鼠结肠的治疗效果。在一项初步研究中，我们检测了这种改良激光治疗是否也能增强经血卟啉敏化后的食管癌患者的光动力治疗效果。
6例患者（4例早期食管癌和2例晚期食管癌，后者中有1例患者的肿瘤在金属支架上过度生长）接受了9次治疗。在4次治疗中，使用血卟啉聚酯对激光能量进行分次以增强光动力治疗效果。致敏后48小时进行照射。150 J/cm²的总激光能量以连续或分次方式施加，在75 J/cm²后单次中断5分钟。
在接受连续激光照射的3例患者中，1例患者的3处浅表食管癌中有2处完全缓解。植入金属支架上肿瘤过度生长的患者显示部分缓解，吞咽困难改善且支架未受损，而另1例晚期食管癌患者在连续激光治疗后吞咽困难未改善。分次激光治疗使所有3例早期癌症患者完全缓解，其中1例患者先前接受连续光动力治疗无效。第4例uT2期癌症患者在连续光动力治疗后也未缓解，但在分次激光治疗后获得部分缓解。然而，与连续光动力治疗后无狭窄相比，分次激光治疗后出现了3例轻度食管狭窄。
光动力治疗期间的光分次在少数患者中提高了治疗效果，并增加了如轻度食管狭窄等副作用。这种改良治疗可能是一种有前景的方法，有助于减少所需的血卟啉或其他敏化剂剂量，并避免长期皮肤致敏或局部狭窄。
