Prophylactic radiotherapy to intervention sites in mesothelioma: A systematic review and survey of UK practice

Background and purposePatients with malignant pleural mesothelioma (MPM), who undergo chest instrumentation, may develop seeding at the site of intervention, leading to subcutaneous tumour. This is believed to be reduced by the common practice of prophylactic irradiation to intervention tracts (PIT). However, evidence to support PIT is currently inadequate and contentious.Materials and methodsWe carried out a systematic search of published literature for articles relating to the incidence of chest wall intervention tract metastases and the use of PIT in mesothelioma. In addition, a survey of current practice was conducted in 54 UK oncology centres.ResultsFourteen studies revealed an incidence of chest wall intervention tract metastases of 0–48% with a trend toward a higher rate of metastases for more invasive procedures. Three randomised controlled trials (RCTs), two prospective non-randomised studies and five retrospective series met the eligibility criteria to evaluate the role of PIT in MPM. Of the three RCTs, two did not support the use of PIT. None of the RCTs included patients who had received systemic chemotherapy. Of the oncology centres responding to the survey, 75% practiced PIT, and 80% would be interested in a trial to determine the efficacy of PIT.ConclusionsNo consensus has been reached to support the use of PIT. However, most centres in the UK still offer PIT. There was widespread interest in a randomised controlled trial to establish PIT efficacy in the era of effective systemic chemotherapy for malignant pleural mesothelioma.