We read with interest the editorial by Davies et al1 and were pleased to learn that talc is preferred by most respiratory physicians worldwide as an effective pleurodesing agent. Based on scientific data, the authors recognise that the talc currently used in the UK and USA has serious side effects because of systemic dissemination of small particles. They omitted, however, an important experimental study which used larger talc particles (ie, the talc currently used in Europe for >70 years) and clearly showed that this talc does not disseminate in organs,2 unlike previous studies using American or Brazilian talc. This explains why many European respiratory physicians have used talc as a pleurodesing agent for >50 years without experiencing serious side effects.3

We thank the authors for referring to our European prospective study showing that talc poudrage under medical thoracoscopy is safe.4 There is, however, some misunderstanding of our results. In our paper we reported that we did not find any significant difference in oxygen saturation after the procedure. Physicians had a free choice of patient follow-up after thoracoscopy. There was, indeed, an increase in supplemental oxygen saturation, but we should not forget that routine use of oxygen by nasal prongs is often performed after thoracoscopy, as is done after many interventional procedures such as bronchoscopy. We agree that 7/558 patients developed radiographic pulmonary infiltrates after talc poudrage. However, this does not prove that talc was responsible for this rare infiltrate, which might have been the result of lung re-expansion after pleurodesis.

On the other hand, we are not sure that control of the calibre of talc particles will increase the cost of graded talc. The current graded talc used in Europe since 1930 is safe, but has a unique drawback. It is very cheap and does not interest pharmaceutical companies because of the lack of potential for financial benefit.

We agree that more research needs to be done into the mechanism of pleurodesis. However, in the meantime, the talc debate should be clarified; many patients suffering from lasting and severe dyspnoea related to malignant pleural effusion are relieved by thoracoscopic talc poudrage performed without intubation, under local anaesthesia with moderate sedation.5