Photodiagnosis (PD) and Photodynamic Therapy (PDT) in oncology with particular reference to lung cancer

PDT is a treatment which uses a light-sensitive chemical, an appropriate wavelength light and tissue oxygen to achieve tumour necrosis. Its originates at the beginning of the 20" Century but in the last 10-15 years PD and PDT become real clinical practicalities. PDT has been shown to be an effective cancer treatment method in all common human cancers. In lung cancer its aims are palliation with survival benefit in advanced stage disease and curative intent in early stage tumours. At the Yorkshire Laser Centre (YLC), PD has been used for endoscopic diagnosis particularly lung cancer. PDT has been used in all major specialities particularly with lung and oesophageal cancer. The major work of the YLC has related to the prospective study of PDT in lung and oesophageal cancer. Our experience in lung cancer suggests indications for PD to be: diagnosis of early superficial cancer, to aid mapping of bronchoscopic extent of tumour allowing complete resection, monitoring treatment, and surveillance of operated patients. Our PDT results in lung cancer confirm: good palliation in advanced stage cancer with survival benefit in some subsets of patients, and long survival/cure of disease in early stage disease (>70% 5 year survival).