Marcon N E
Division of Gastroenterology, Wellesley Hospital, Toronto, Ontario, Canada.
Semin Oncol. 1994 Dec;21(6 Suppl 15):20-3.
Esophageal carcinoma usually is diagnosed at an advanced, incurable stage. In patients with good operative risk, surgery is still considered the ideal treatment. Patients with coexisting major medical conditions in whom resective surgery is precluded may benefit from several therapeutic options, including photodynamic therapy (PDT) with porfimer sodium (Photofrin; manufactured by Lederle Parenterals, Carolina, Puerto Rico, under license from Quadra Logic Technologies, Inc, Vancouver, British Columbia, Canada), dilation, thermal destruction, Nd:YAG laser ablation, injection therapy, and placement of prosthetic tubes. Photodynamic therapy with porfimer sodium is thought to have a direct toxic effect on malignant cells via the production of singlet oxygen, which damages the microvasculature of the tumor and renders it ischemic. The 630 nm wavelength used for clinical PDT exhibits the greatest relative degree of light penetration into tissue, with corresponding activation of retained photosensitizer. The efficacy of PDT with porfimer sodium is closely related to stage of disease. It should be emphasized that PDT has been shown to be potentially curative in patients with early, noninvasive tumors of both squamous and glandular (adenocarcinoma) histologies. Eighty-three patients with esophageal carcinoma were treated using PDT. At presentation, 60% of patients had recurrence following previous radiotherapy or chemotherapy. Patients with less advanced disease had a better response to PDT with regard to relief of dysphagia and prolongation of survival. Photodynamic therapy was found to be more useful than Nd:YAG laser therapy for high, upper third lesions, especially circumferential ones. For tumors larger than 8 cm, PDT was twice as effective as Nd:YAG laser therapy in establishing prolonged lumen patency, especially for adenocarcinomas. Photodynamic therapy appears to have the added advantages of fewer treatments and less pain. The role of PDT in gastrointestinal malignancies continues to evolve.
食管癌通常在晚期、无法治愈的阶段被诊断出来。对于手术风险低的患者，手术仍然被认为是理想的治疗方法。存在严重基础疾病而无法进行手术切除的患者可能从多种治疗选择中获益，包括使用卟吩姆钠（光卟啉；由Lederle Parenterals公司在加拿大不列颠哥伦比亚省温哥华的Quadra Logic Technologies公司授权下于波多黎各卡罗来纳生产）的光动力疗法（PDT）、扩张、热消融、钕钇铝石榴石（Nd:YAG）激光消融、注射治疗以及放置人工管。使用卟吩姆钠的光动力疗法被认为通过产生单线态氧对恶性细胞具有直接毒性作用，单线态氧会破坏肿瘤的微血管并使其缺血。用于临床PDT的630纳米波长在组织中具有最大相对光穿透程度，并能相应激活保留的光敏剂。使用卟吩姆钠的PDT疗效与疾病分期密切相关。应当强调的是，PDT已被证明对早期非侵袭性的鳞状和腺（腺癌）组织学肿瘤患者具有潜在的治愈作用。83例食管癌患者接受了PDT治疗。就诊时，60%的患者曾接受过放疗或化疗后复发。病情较轻的患者在吞咽困难缓解和生存期延长方面对PDT的反应更好。对于高位、食管上段病变，尤其是环形病变，发现光动力疗法比Nd:YAG激光疗法更有用。对于大于8厘米的肿瘤，在建立长期管腔通畅方面，PDT的效果是Nd:YAG激光疗法的两倍，尤其是对于腺癌。光动力疗法似乎还具有治疗次数少和疼痛轻的额外优势。PDT在胃肠道恶性肿瘤中的作用仍在不断演变。
