Maier A, Anegg U, Tomaselli F, Rehak P, Sankin O, Fell B, Renner H, Pinter H, Smolle-Jüttner F M, Friehs G B
Department of Thoracic and Hyperbaric Surgery, University Medical School, Graz, Austria.
Endoscopy. 2000 Jan;32(1):42-8. doi: 10.1055/s-2000-132.
Experimental studies have shown that the cytotoxicity of porphyrins and related substances is mediated mainly by singlet oxygen and that hypoxic cells are less affected by porphyrins and light. In a clinical pilot study we assessed the use of photodynamic therapy (PDT) under hyperbaric oxygen (HBO), compared with PDT under normobaric conditions, in patients with advanced esophageal carcinoma.
After diagnostic work-up and staging, photosensitization in all patients was carried out using hematoporphyrine derivate (HpD) (2 mg/kg bodyweight 48 hours prior to PDT). We then applied light at 630 nm (KTP-Nd: YAG laser with DYE box) at dose of 300 J/cm, delivered by a fiber with a radial light-diffusing cylinder (length 1 cm), inserted through the biopsy channel of the endoscope. Of the patients, 14 (12 with stage III cancers, and two with stage IV cancers) were treated by PDT alone, and 17 patients (15 with stage III cancers, and two with stage IV cancers) received PDT under HBO at a level of 2 absolute atmospheric pressures (ATA). Transcutaneous PO2 levels of 500-750 mm Hg under HBO, compared with transcutaneous PO2 levels of 60-75 mm Hg under normobaric conditions, were measured.
Improvements regarding dysphagia and stenosis diameter were obtained in both treatment arms with no significant differences (P = 0.36 and 0.14, respectively). The tumor length also decreased in both groups and showed a significant difference in favour of the PDT/ HBO group (P = 0.002). Kaplan-Meier statistics showed median overall survival for the PDT group and the PDT/HBO group as 7.0 and 12 months respectively. The 12-month survival rate was 28.6% for the PDT group and 41.2% for the PDT/HBO group. Logrank test showed a difference in survival in favor of the PDT/HBO group (P = 0.059). No major treatment-related complication occurred, and the 30-day mortality rate was 0%.
Combined PDT/HBO represents a new approach in the treatment of esophageal cancer which, in this pilot study, appears to have enhanced the efficiency of PDT.
实验研究表明，卟啉及相关物质的细胞毒性主要由单线态氧介导，且缺氧细胞受卟啉和光的影响较小。在一项临床初步研究中，我们评估了高压氧（HBO）下光动力疗法（PDT）与常压条件下PDT相比，在晚期食管癌患者中的应用情况。
在进行诊断检查和分期后，所有患者均使用血卟啉衍生物（HpD）进行光敏化处理（在PDT前48小时，按2mg/kg体重给药）。然后，我们使用配有染料盒的KTP - Nd:YAG激光，通过一根带有径向光扩散圆柱体（长度1cm）的光纤，经内镜活检通道插入，以300J/cm的剂量施加630nm的光。其中，14例患者（12例III期癌症患者和2例IV期癌症患者）仅接受PDT治疗，17例患者（15例III期癌症患者和2例IV期癌症患者）在2个绝对大气压（ATA）的HBO水平下接受PDT治疗。测量了HBO下经皮氧分压水平为500 - 750mmHg，而常压条件下经皮氧分压水平为60 - 75mmHg。
两个治疗组在吞咽困难和狭窄直径方面均有改善，且无显著差异（分别为P = 0.36和0.14）。两组的肿瘤长度也均减小，且PDT/HBO组有显著差异（P = 0.002）。Kaplan - Meier统计显示，PDT组和PDT/HBO组的中位总生存期分别为7.0个月和12个月。PDT组的12个月生存率为28.6%，PDT/HBO组为41.2%。对数秩检验显示生存差异有利于PDT/HBO组（P = 0.059）。未发生与治疗相关的重大并发症，30天死亡率为0%。
PDT/HBO联合治疗是食管癌治疗的一种新方法，在本初步研究中，似乎提高了PDT的疗效。
