Fluorescing cells in sputum after parenteral HpD

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.