We carried out photodynamic therapy using pheophorbide (Pha) to pancreatic carcinoma of Syrian golden hamster. We injected N-nitroso-bis- (2-oxypropyl) amine (BOP) subcutaneously in a dose of 10mg/kg 8 times every week to female twenty-nine hamsters which were 8 weeks old. Pha was injected intervenously to nine of those. They were sacrificed at 6, 12, and 24 hours after injection of Pha and the concentration of it in each organ such as liver, pancreatic tumor, lung, kidney. pancreas, and skin was examined. Ten hamsters were treated by laser hyperthermia (the first group) and the other ten by photodynamic therapy using Pha (the second-group) to the pancreatic carcinoma at 19th-20th week after BOP injection. Their abdomens were opend under anesthesia and interstitial probe was punctured directly into the pancreatic carcinoma. The first group was treated by controlling temperature at 42-43°C, 5mm apart from the probe with 2W for 3-5 minutes with contineous wave, and the second group was treated with 2W for 3-5 minutes with pulse wave using Q switch. Seven days after treatment they were sacrificed and examined histo-pathlogically. Though the concentration of Pha in the pancreatic tumor at 6.12, 24 hours was recognized, it was almost none in normal pancreatic tissue at 24 hour after Pha injection. Therefore we carried out photodynamic therapy 24 hour after Pha injection. Histopathological changes of the pancreatic tumor treated by photodynamic therapy showed a marked amount of coagulated necrosis and in almost all cases disappearance of tumor cells was recognized. The therapeutic effects by photodynamic therapy were more extensive than those of laser hyperthermia. The effects of photodynamic therapy itself were minimal in surrounding area of the pancreatic tumor though the findings of secondary pancreatitis followed by pancreatic carcinoma were recognized. These results suggest that photodynamic therapy with Pha may become one of the safe and effective treatments to the solid carcinoma.

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Thoracoscopic treatment of spontaneous pneumothorax has been performed mainly with electrocautery ablation technique. But electrocautery has a risk of rupture of blebs. We employed carbon monoxide laser (CO laser: wavelength 5.4m) photocoagulation through thoracoscopy. CO laser light was delivered by a As-S glass fiber with 2-4W laser power at the output end. Nd: YAG laser (wavelength 1.06m) was also used for comparizon. Good contraction of bleb was obtained with non-contact method. Depth of coagulation and carbonization of CO laser was shallower than that of Nd: YAG laser. The risk of rupture by CO laser was small. We conclude that the laser photocoagulation therapy can play an important role in patient with spontaneous pneumothorax, especially CO laser is more useful than Nd: YAG laser.

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