Progress of Photodynamic Therapy in Gastric Cancer

Abstract

Progress of photodynamic therapy (PDT) in gastric cancer and the clinical outcome are described in this paper. (1) We included the whole lesion and a 5 mm margin in the field for irradiation. Marking by injection of India-ink showing the irradiation field was performed beforehand. (2) We established the standard light dose to be 90 J/cm2 for an argon dye laser and 60 J/cm2 for a pulse wave laser. (3) The size of cancerous lesion curable by PDT was expanded from 3 cm in diameter, i.e. 7 cm2 in area to 4 cm in diameter, i.e. 13 cm2 by employing a new excimer dye laser model, which could emit 4mJ/pulse with 80 Hz pulse frequency. (4) The depth of cancer invasion which could be treated by PDT was increased from about 4 mm, i.e. the superficial part of the submucosal layer (SM-1) to more than 10 mm in depth, i.e. the proper muscular layer. These improvements owe much to the pulse laser, the photodynamic action induced by which permits deeper penetration than that of a continuous wave laser. (5) We employed a side-viewing fiberscope for gastric PDT to irradiate the lesion from an angle of 90°. (6) We designed a simple cut quartz fiber for photoradiation with a spiral spring thickened toward the end. (7) We developed an endoscopic device for photoradiation in PDT which achieves accurate and efficient irradiation. As a result of these improvements a higher cure rate was obtained even with a lower light dose of irradiation.

Photodynamic Therapy Using Novel Zinc Phthalocyanine Derivatives and a Diode Laser for Superficial Tumors in Experimental Animals

“…In recent years, photodynamic therapy (PDT) using a photosensitizing agent and several light sources has been shown to have nonspecific effects upon malignant diseases. Considerable antitumor effects of PDT have been demonstrated in patients with superficial cancers such as central-type early-stage lung cancer, early-stage gastric cancer, skin cancer, mucosal intraepithelial neoplasia, melanoma, and prostate cancer [1]- [4].…”

Photodynamic therapy using intra‐articular photofrin for murine MRSA arthritis: Biphasic light dose response for neutrophil‐mediated antibacterial effect

“…A photosensitizer, such as Photofrin®, accumulates in proliferative tissues such as tumors. After accumulation, the photosensitizer is activated by visible light and induces the generation of singlet oxygen, which damages unwanted cells 5–10. Over the past decade, there have been an increasing number of reports on therapeutic applications of PDT for bacterial infections, especially for infections with multidrug‐resistant bacteria.…”

Influence of Intra‐articular Neutrophils on the Effects of Photodynamic Therapy for Murine MRSA Arthritis

“…Photodynamic therapy (PDT) is a promising therapeutic modality for proliferating diseases. A photosensitizer, such as Photofrin ® , accumulates in proliferating cells such as cancer cells and is activated by visible light, resulting in the generation of singlet oxygen, which damages proliferative tissue (5–9). A photosensitizer also accumulates in inflammatory lesions as well as proliferating tissues (10), and it has been reported that the therapeutic efficacy of PDT is achieved by efficient accumulation in infectious lesions of bacteria.…”