A Prospective Randomized Study of Prophylactic Irradiation of Tracts in Patients with Malignant Pleural Mesothelioma

Abstract

Background: Procedure tract metastasis (PTM) may complicate pleural procedures in malignant pleural mesothelioma (MPM) patients and cause significant morbidity. Aim: To evaluate the effectiveness of prophylactic radiotherapy (RTH) in preventing PTM and reducing pain. Methods: Forty patients with MPM, who had a pleural invasive procedure within the preceding 15 days, were randomized in a 1:1 ratio to receive prophylactic RTH to the procedure site (21 Gy in three consecutive daily fractions using 9MeV) vs. no RTH. During a 12-month follow up period, patients were examined monthly for PTM, toxicities and pain at the procedure site. Results: Patients receiving RTH had lower incidence of PTM than the control group (2/20, 10% vs. 5/20, 25%); however, this difference was not statistically significant. The proportion of patients who experienced pain at the pleural procedure site was significantly less in the RTH group compared with the control group (2/20, 10% vs. 12/20, 60%; p=0.001). Pain scores were significantly less in the RTH group compared with the control group (mean pain score 1.6 vs. 2.8, respectively; p=0.014). Conclusion: Prophylactic RTH to the pleural procedure site in MPM was not significantly effective in preventing or delaying PTM. However, prophylactic RTH reduced significantly the rate and severity of pain at the procedure site. Future studies may be needed to assess the effect of prophylactic RTH timing and its technique on preventing PTM.