Photodynanic therapy (PDT), is a treatment modality for many cancers, and uses a tumor-specific photosensitizer and laser irradiation. Recently, we have developed a new minimally invasive laser device using a 1.0 mm in diameter composite-type optical fiberscope (COF), which could transmit laser energy and images for observation in parallel.In this study, we aimed to develop a new endobronchial treatment for peripheral cancer using PDT and a COF, and we evaluated the feasibility of PDT using COF for peripheral lung cancer. This phase I study enrolled 3 patients with peripheral lung cancers (primary tumor< 20 mm, stage IA), which were definitively diagnosed by bronchoscopic modalities such as EBUS-GS and brocnhoscopic navigation system. We conducted irradiation using a diode laser (664 nm) and a COF 4 hours after the administration of NPe6 40 mg/m2. We evaluated the tumor lesions using EBUS, and then we introduced the COF into the peripheral lung cancer, and irradiated of red light 664 nm (120 mW, 50 J/cm2 or 100J/cm2). We performed PDT for 3 patients with c-stage IA peripheral lung cancer, using a laser dose (120mW, 50J/cm2), and confirmed the feasibility of the dose. We escalated the laser dose and performed 4 patients using a laser dose (120mW, 100J/cm2). Seven patients met our criteria, and 5 cases were adenocarcinoma and 2 case squamous cell carcinoma. We were able to observe the cancer lesions at the peripheral lung by the COF, and feasibly irradiated. Two weeks and 3 months after NPe6-PDT, complications such as pneumonia and pneumothorax were not found, but one mildly found light skin-photosensitivity. Six months later, we found CR in 3 cases and SD in 4 cases. The 1.0 mm COF was a very useful device of NPe6-PDT for peripheral lung cancers, and PDT was a feasible and non-invasive treatment for a peripheral type early lung cancer. In the future, for non-invasive adenocarcinoma such as AIS, NPe6-PDT will become a treatment modality.
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