Prognostic significance of metabolic response by positron emission tomography after neoadjuvant chemotherapy for resectable malignant pleural mesothelioma

Abstract

Background: To select optimal candidates for extrapleural pneumonectomy (EPP), we retrospectively evaluated the usefulness of metabolic response by fluorodeoxyglucose-positron emission tomography/computed tomography (FDGPET/CT) after neoadjuvant chemotherapy to predict prognosis for patients with resectable malignant pleural mesothelioma (MPM) who underwent EPP in a multicenter study. Patients and methods: We carried out high-resolution CT (HRCT) and FDG-PET/CT before and after neoadjuvant platinum-based chemotherapy on 50 patients with clinical T1-3 N0-2 M0 MPM who underwent EPP ± postoperative hemithoracic radiotherapy. A decrease of ≥30% in the tumor maximum standardized uptake value (SUVmax) was defined as a metabolic responder. The radiologic response using the modified RECIST or metabolic response and surgical results were analyzed. Results: The median overall survival (OS) from diagnosis was 20.5 months. Metabolic responders significantly correlated to OS with median OS for metabolic responders not reached versus 18.7 months for non-responders. No correlation was observed between OS and radiologic response with median OS for radiologic responders and nonresponders. Based on the multivariate Cox analyses, decreased SUVmax and epithelioid subtype were significantly independent factors for OS. Conclusions: The metabolic response after neoadjuvant chemotherapy is an independent prognostic factor for patients with resectable MPM. Patients with metabolic responder or epithelioid subtype may be good candidates for EPP. © The Author 2012. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved.