Aims: 

Radiotherapy of tumours in the chest and neck regions may have serious pulmonary side-effects. Inflammation is an essential manifestation of radiation-induced injury and it may progress up to irreversible pulmonary fibrosis. To prevent such complications it would be useful to have simple non-invasive sensitive method for monitoring the course of airway and lung post-irradiation inflammation. We suppose that cough reaction intensity (CRI) could be the method that will be able to detect early postirradiation changes in airways.

Methods: 

Guinea pigs (Trick strain, n = 32) were used in the study. Animals were divided into two subgroups – non-treated (NT) group (n = 14; M = 7, F = 7) were submitted to sham chest irradiation; animals of treated (XRT) group (n = 18; M = 9, F = 9) were exposed to single dose of gamma rays. Cough was provoked by citric acid aerosol (CA, increasing concentrations). CRI testing was performed two days before sham/real chest irradiation, on 1^st, 3^rd, 10^th, 15^th, 21^st and 28^th days following irradiation. CRI was quantified by counting the number of coughs induced by all used CA concentrations.

Results: 

Significantly higher values of CRI were found in animals of XRT group on 10^th and 21^st days when compared to animals of NT group. Significant increase of CRI was also found within the XRT group on the 10th day after irradiation when compared to pre-irradiation values of CRI.

Conclusion: 

We conclude that CRI testing could provide a sensitive marker of post-irradiation changes in airways.