Risk factors linked to pleural effusion after thoracic radiation

This study examined the incidence of pleural effusion in lung cancer patients after treatment with thoracic radiation therapy and identified risk factors associated with it. They concluded that patients treated with 5 Gy of radiation to over 41.5% of the lung were at the greatest risk of developing pleural effusion after treatment.

Thoracic radiation therapy (TRT) is a cancer treatment that involves radiation delivered to the lung area. It is commonly used for patients with earlier stage non-small-cell lung cancer and limited stage small cell lung cancer who are not eligible for surgery. There are toxic side effects from the treatment, however, including pleural effusion (PE). PE is a build-up of fluid in the chest or on the lung. Between 10-30% of patients treated with TRT have some form of toxic side effect. Therefore it is important to identify risk factors which might predict whether a patient is more likely to be affected.

This study looked at the rate of PE from TRT and its associated risk factors in patients with lung cancer.

175 lung cancer patients who had been treated with TRT and had no evidence of disease progression were included in the study. These patients had a 6 month follow up and the rate of PE was recorded.

Overall, 51 patients had PE after TRT. Of these, 40 patients had symptoms including chest pain, cough and shortness of breath.

Females had a 62% lower risk of developing PE and Caucasians had a 3.5-fold lower risk of developing PE. Patients with later stage cancer had a 60% higher risk and patients also being treated with chemotherapy had a 2.5 fold higher risk of developing PE. However, these did not meet statistical significance.

Patients receiving a radiation dose of 5 Gy over more than 41.5% of the total lung had a much greater risk of PE.

The authors identified factors that indicated a higher or lower risk of PE. They emphasized that patients treated with 5 Gy to over 41.5% of the lung had a very high risk of PE.