A complete instrumentation has been developed for photodynamic therapy (PDT) and combined PDT- hyperthermia in the upper aerodigestive tract and the bronchi. These instruments consist of several light distributors which permit optimal light dosage to "superficial" tumors, as well as an injector for laser beams into an optical fiber and a fiberoptic coupler for cw laser beam powers at least 100 Watts. PDT is carried out with HpD and Photofrin II at 630 nm, whereas occasional simultaneous hyperthermia is at 1.06 microns. PDT of 41 cases of "early" squamous cell carcinoma is reported with follow-up between 5 and 62 months. In the oesophagus and bronchi the results are good for cancers staged in situ or microinvasive at endoscopy (2 recurrences for 23 lesions treated). For more advanced cancers (submucosal in the oesopha- gus or invading the bronchial cartilage) the results are less satisfactory with 3 recurrences for 8 lesions treated. In the bronchi (1 case) and the oesophagus (1 case) the largest disease - free survival is now more than 5 years. We encountered 6 complications (3 cicatrical stenosis, 2 fistulae, 1 severe sunburn), most of them resulting from the lack of selectivity of PDT with these porphyrin mixtures at the applied conditions. These experiments show that PDT is efficient at destroying early squamous cell carcinomas in the pharynx, oesophagus and bronchi. Tumour selectivity of HpD and photofrin II is poor in the aerodigestive tract lined with squamous cell epithelium. The future lies in the synthesis of a more selective efficient photosensitizer.
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