Photodynamic therapy, a curative local treatment for esophageal squamous cell carcinoma, involves a photosensitizing drug (photosensitizer) with affinity for tumors and a photodynamic reaction triggered by laser light. Previously, photodynamic therapy was used to treat superficial esophageal squamous cell carcinoma judged to be difficult to undergo endoscopic resection. Recently, photodynamic therapy has mainly been performed for local failure after chemoradiotherapy. Although surgery is the most promising treatment for local failure after chemoradiotherapy, its morbidity and mortality rates are high. Endoscopic resection is feasible for local failure after chemoradiotherapy but requires advanced skills, and its indication is limited to within the submucosal layer by depth. Photodynamic therapy is less invasive than surgery and has a wider indication than endoscopic resection. Porfimer sodium (a first-generation photosensitizer) causes a high frequency of side effects related to photosensitivity and requires the long-term sun-shade period. Talaporfin (a second-generation photosensitizer) requires a much shorter sun-shade period than porfimer sodium. Photodynamic therapy will profoundly change treatment strategies for local failure after chemoradiotherapy.
Keywords: Endoscopic mucosal resection; Endoscopic submucosal dissection; Endoscopic treatment; Esophageal squamous cell carcinoma; Photodynamic therapy.