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Lewis Lung carcinomas in B6D2 mice have been treated by photoradiation therapy (PRT). All irradiations were performed at 630 nm. The optical power levels were typically varied from 45-100 mW with a radiation duration of 60 min. This gave an optical energy of 160-360 J delivered through a centrally inserted optical fiber into the tumor during treatment. The optical power density and the temperature were monitored during exposure. After treatment the animals were observed for at least two days before sacrifice. Biopsies have been taken for the histological follow-up. The experimental series were composed of non-treated controls and treated cases with variations in the chemical and optical dose scheme. Only the high (50 mg/kg) Hematoporphyrin derivative (HpD)-dose gave curative response from the tumors. The low dose (5 mg/kg) gave no significantly different response from the control case by visual observation; however, histologically there was some difference.

Cells exfoliated into sputum were examined for fluorescence after the intravenous injection of HpD. Malignant and non-malignant cells were seen to fluoresce up to 9 days post injection of HpD. Not all exfoliated squamous cell cancer cells or non-malignant cells fluoresced. Implications are discussed relative to imaging diagnostic fluorescence bronchoscopy and photoradiation therapy of obstructing endobronchial cancers and bronchial carcinoma in situ.