Photodynamic therapy in advanced tracheobronchial cancers

Photodynamic therapy (PDT) has been introduced in the early eighties for treating patients with malignancies in the tracheobronchial tract. After intravenous injection of the photosensitizers, the tumor area in the tracheobronchial tree is illuminated bronchoscopically using a laser fiber to transmit light of a specific wavelength during the procedure. Secondary tissue necrosis ensues, because of the thrombosis of the tumor vasculature leading to late tissue hypoxia. Ample data have shown that PDT is effective to obtain full depth tissue necrosis with relative sparing of the normal tissue. Local tumor control can be achieved. Competitive endoscopic techniques such as lasers and electrocautery are applicable to debulk tumor in a less selective but more immediate manner. Skin photosensitivity is a potential morbidity of PDT, especially in using the first generation photosensitizers. This limits its palliative potential. More selective and more phototoxic sensitizers in combination with the use of portable diode laser, may improve the clinical usefulness of PDT in the management of lung cancer patients. However, cost-effectiveness studies comparing PDT and other local bronchoscopic treatment modalities such as thermal lasers, electrocautery, cryotherapy, brachytherapy, whether or not in addition to external radiotherapy and chemotherapy, should be conducted to define its definite role in the palliative treatment of advanced obstructive bronchial cancers.