Patterns of disease progression on 18F-fluorodeoxyglucose positron emission tomography-computed tomography in patients with malignant pleural mesothelioma undergoing multimodality therapy with pleurectomy/decortication.

Introduction: The aim of this study was to evaluate the patterns of disease progression in patients treated with pleurectomy/decortication (P/D), hyperthermic pleural lavage with povidone-iodine, prophylactic radiotherapy and adjuvant chemotherapy, using F-fluorodeoxyglucose (18F-FDG) PET/computed tomography (PET/CT).

Materials And Methods: This was a retrospective study of 65 patients treated with a multimodality therapy including P/D between October 2004 and March 2012. Thirty-two patients underwent 18F-FDG PET/CT within 6 weeks of completion of adjuvant chemotherapy and 6-monthly thereafter at our institution. The first site of relapse on 18F-FDG PET/CT was recorded, and all scans were reviewed by an independent observer.

Results: Thirty-two patients (27 male, median age 61 years, range 45-73) underwent their 18F-FDG PET/CT scans at our institution. Eighteen of the 32 patients were alive at last follow-up (median follow-up 42 months, range 16-76). Nine patients were alive with disease recurrence. Fourteen patients died of disease progression (median survival 24.7 months, range 15-38). The median maximum standardized uptake value (SUVmax) in relapsing mesothelioma was 10.9 (range 4.9-27.3). There was a statistically significant correlation between the SUVmax and tumour lesion glycolysis of recurrent mesothelioma and overall survival (P=0.05). The site of disease recurrence was the pleura in the majority of the alive patients and was extrapleural in the dead patients. There was a statistically significant correlation between disease-free survival and complete macroscopic resection (P=0.02).

Conclusion: After P/D with hyperthermic pleural lavage with povidone-iodine, prophylactic radiotherapy and adjuvant chemotherapy, the most frequent site of recurrence is the pleural cavity. Peritoneal seeding is rare. The tumour SUVmax and tumour lesion glycolysis correlate significantly with overall survival.