1987 Fiscal Year Final Research Report Summary
Development of Photodynamic Therapy for Malignant Tumors
| Project/Area Number |
60440111
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
Thoracic surgery
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| Research Institution | TOKYO MEDICAL COLLEGE |
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Principal Investigator |
HAYATA Yoshihiro Dept. of Surgery, Tokyo Medical College Professor, 医学部, 教授 (30074470)
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| Co-Investigator(Kenkyū-buntansha) |
KAWATA Norihiko Dept. of Surgery. Tokyo Medical Colledge Assistant, 医学部, 助手 (70204740)
米山 一男 東京医科大学, 医学部, 助手
KONAKA Chimori Dept. of Surgery, Tokyo Medical College Assistant, 医学部, 助手 (70147180)
AIZAWA Kastuo Dept. of Physiology, Tokyo Medical College Assistant Professor, 医学部, 助教授 (40074645)
KATO Harubumi Dept. of Surgery, Tokyo Medical Colledge Lecturer, 医学部, 講師 (20074768)
YONEYAMA Kazuo Dept. of Surgery, Tokyo Medical Colledge Assistant
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| Project Period (FY) |
1985 – 1987
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| Keywords | Photodynamic therapy / Photosensitizer / Mono-L-aspartyl / chlorin e6 (NPe6) / Hematoporphyrin derivative (HpD) / Excimer dye laser Mitochondria / ミトコンドリア / ビデオ顕微鏡 |
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| Research Abstract |
Photodynamic therapy (PDT) is based on incorporation of a photosensitizer that has high affinity for malignant tissue and stimulation of the photosensitizer with a low power laser beam, with tumorcidal effects. Using the same principle fluorescence can also be elicited from the tumor by a laser beam of a different wavelength in order to detect the lesion. Our team has investigated this therapeutic modality in basic and clinical studies for ten years. Our initial studies employed hematoporphyrin derivative (HpD) as the photosensitizer for PDT with an argon dye laser and we have reported the first cases of five-year survival in a case of cancer treated only by PDT.
Mono-L-aspartyl chorin e (NPe ) is a photosensitizer newly developed in 1987. This material shows higher affinity to tumor and better light absorption than HpD. It has a strong absorption band at a wavelength longer than 600nm and consequently is not affected by hemoglobin. Further investigations are necessary for clinical application.
An excimer dye laser which more powerful than the argon dye laser has been developed for clinical applications. This laser equipment makes it possible to diagnose and treat in the same procedure by a wavelength-change device. Especially for diagnoses, the fiberscopic image, fluorescent light, and fluorescent wave length are shown in the same image.
The basic experiment of photodynamic therapy has been performed. HpD and NPe have been shown to have a high affinity for mitochondria. Damage to the mitochondria by photosensitizer was recognized by decrease in mitochondrial movement. This is in agreement with theories that the first step of photodynamic therapy is degeneration of mitochondria.
In 1987 the basic investigation, the laser equipment and the newly developed photosensitizer for photodynamic therapy were established. Our proposed project is a clinical trial and comparison with PDT using HpD and argon dye laser, as well as with other modalities.
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