Photodynamic therapy for localised inoperable endobronchial cancer

Localised endobronchial (non-small-cell) lung cancer describes disease in which malignancy is confined within the bronchial wall, with no radiographic or endoscopic evidence of lymph node involvement. Patients for whom surgical resection may be considered unsuitable include those with bilateral lung cancer, impaired respiratory function because of chronic obstructive pulmonary disease or other conditions posing high operative risk, those who have had previous resection for lung cancer, and those who refuse surgery.

The range of treatment options for lung cancer depends on the type and stage of the disease and the suitability of major surgery for the individual patient. Treatment options include laser ablation, endobronchial brachytherapy and external-beam radiation.

Photodynamic therapy (PDT) involves injection of a photosensitising agent, followed a few days later by photoradiation of the affected area through a bronchoscope. This aims to reduce tumour bulk, so reducing symptoms caused by bronchial obstruction. Endobronchial debridement of necrotic tumour is required, commonly 48 hours after each treatment. The procedure can be repeated if necessary.

There were no randomised controlled or comparative trials comparing the efficacy of PDT with other treatment modalities. There was considerable heterogeneity among the studies included in the systematic reviews, with regard to both outcome measurements used and follow-up times reported. The complete remission rates following PDT ranged from 62% (16/26) to 85% (50/59) of lesions in different case series. Some subgroup analyses suggested that small lesions (in terms of diameter or surface area) respond to PDT better than larger lesions.

Where reported in case series, 5-year survival ranged from 43% among 36 patients with poor pulmonary or cardiac function to 72% among 21 patients who were surgical candidates. Other studies reported reduction of airway obstruction and improvement in self-reported quality of life after PDT. For more details, refer to the Sources of evidence.

The Specialist Advisors stated that there were no long-term comparative data on the efficacy of this procedure.

In one systematic review, eight studies reported adverse events. Mild to moderate symptoms of photosensitivity were reported in all studies. Very severe toxicity resulting from photosensitivity occurred in a minority of patients undergoing PDT.

Fatal haemoptysis within 1 month of treatment was recorded in 8% (3/38) of patients in one case series. Hypercapnic respiratory failure (requiring mechanical ventilation) occurred in 5% (2/38) and 4% (1/24) of patients following PDT. Some effects may be due to pre-existing pulmonary disease rather than the procedure. Other case series reported mild to moderate pulmonary events including short-term productive cough following PDT (the proportion of patients was not reported). For more details, refer to the Sources of evidence.

The Specialist Advisors listed photosensitivity as the main complication. Other potential adverse events were tissue necrosis leading to bleeding, and fistula formation.

It was noted that a variety of laser systems is available and different dosage schedules may be used. These variations may have an effect on safety and efficacy.

This procedure may be used in combination with other treatment modalities.

The heterogeneous groups of patients included in the studies and reviews made interpretation of the data difficult.