Photodynamic therapy (PDT) is a local treatment that consists of a photosensitizer (PS) and irradiation with a laser with appropriate wavelength of the PS absorbed tumor tissue. In 2015, second generation PDT using talaporfin sodium and diode laser was approved for clinical use in Japan to treat local failure esophageal cancer after radiotherapy (NT) or chemoradiotherapy (CRT), based on the favorable results obtained from our clinical trial in Japan. The indication criteria for PDT to treat local failure esophageal cancer after CRT are as follows : 1) absence of lymph node or distant metastasis, 2) lesion depth limited within T2, 3) maximum lesion length of 3 cm or less, 4) cancer affects 1 2 the circumference of the lumen or less, and 5) no invasion to the cervical esophagus. PDT is a local treatment using laser
therefore, the operator should face the lesion so that the laser can be applied perpendicular to the lesion, and should maintain the appropriate distance between the tip of the laser probe and the target lesion for maximum treatment efficacy. The PS may be absorbed in the patient's skin and eyes, and patients need to be protected from sunlight after PDT. Before introduction of PDT at each institution, investigators must participate in a training seminar in which they learn about the physical properties of lasers and their effect on the human body. In the seminar, investigators can learn clinical tips through hands on training. We hope that PDT will become more widely used by gastrointestinal endoscopists as a safe and effective treatment for esophageal cancer.