Researchers at MD Anderson Cancer Center in Houston and Princeton Radiation Oncology reached that conclusion after evaluating 24 mesothelioma surgery patients between 2009 and 2013.
Study subjects underwent either lung-sparing pleurectomy/decortication (P/D) surgery or lung-removing extrapleural pneumonectomy (EPP). Both procedures aim to improve mesothelioma survival by removing the diseased pleural lining and other at-risk tissues such as the diaphragm and the pericardium around the heart.
Both sets of patients were then treated with intensity modulated radiation therapy (IMRT) to the affected side of their chest in an effort to kill any mesothelioma cells left behind after surgery. IMRT delivers beams of radiation in short bursts, giving it the ability to conform radiation dose to the irregular shape of a mesothelioma tumor.
Seventy-six percent of the study subjects were still living a year after their surgery/IMRT treatment and 56 percent lived for at least 2 years. (Average survival for mesothelioma patients is usually less than a year.) Patients who underwent the PD procedure had a median overall survival twice as long as those who had undergone EPP. The problem was that all of the patients, regardless of which type of surgery they had, experienced a steady decline in lung function after their IMRT.
“Pulmonary function declined from baseline to after surgery and declined still further after IMRT,” reports radiation oncologist William W. Chance, MD, of MD Anderson, lead author on the paper.
The good news is that, in addition to extending survival, hemithoracic IMRT appeared to produce few serious side effects, which is typically one of the chief difficulties of radiotherapy. The new study appears in a recent issue of the International Journal of Radiation Oncology, Biology, Physics.
Chance, WW et al, “Hemithoracic Intensity Modulated Radiation Therapy after Pleurectomy/Decortication for Malignant Pleural Mesothelioma: Toxicity, Patters of Failure, and a Matched Survival Analysis”, October 25, 2014, International Journal of Radiation Oncology, Biology, Physics, Epub ahead of print