Hemithoracic Irradiation With Proton Therapy in Malignant Pleural Mesothelioma

Who May Qualify: - Patients ≥18 years of age, with biopsy confirmed MPM and histological subtyping (epithelioid or non-epithelioid) - N0 or N1 and M0 disease - Written willing to sign a consent form - Patient and local/regional MDT opt for active surveillance and deferral of SACT until clinical or radiological progression - WHO Performance Status 0-1 - Disease confined to one hemithorax based on CT assessment - Adequate pulmonary function - ≥ 40% predicted post-FEV1; - ≥ 40% predicted DLCO/TLCO - Agreement to travel to either proton beam therapy centres (i.e. UCLH or The Christie) if randomised to arm 2 - Agreement to be followed up at a local HIT-Meso trial site - Patient likely able to complete PBT planning based on local assessment Who Should NOT Join This Trial: - Presence of metastatic or contralateral disease - Cytological diagnosis and/or undetermined histological subtype - Prior thoracic radiotherapy, chemotherapy, immunotherapy for MPM - Prior radical surgery for MPM (extrapleural pneumonectomy or extended pleurectomy decortication or pleurectomy decortication) - Initial systemic therapy or surgery is required and the patient and local/regional MDT do not opt for active surveillance - Involvement of contralateral or supraclavicular lymph nodes - T4 disease with invasion of the myocardium - N2 and/or M1 disease - Presence of new effusion that is not amenable to drainage - WHO Performance Status ≥ 2 - Women who are pregnant or breast feeding - Current or previous malignant disease which may impact on the patient's life expectancy - Patient fitted with a pacemaker or implantable cardioverter-defibrillator (ICD)\\ - Diagnosis of clinically significant interstitial lung disease (ILD), excluding mild fibrosis or incidental findings - Chronic non-malignant disease with an estimated three-year survival rate of less than 20% - Patient with prior thoracic / abdominal radiotherapy for malignancy who was not discussed with sponsor before recruitment Always talk to your doctor about whether this trial is right for you.