Influence of talc pleurodesis on FDG PET and CT imaging in malignant pleural mesothelioma (MPM)

  • Dr Tatiana Segard, Sir Charles Gairdner Hospital, Australia
  • Dr Ros Francis, Sir Charles Gairdner Hospital, Australia
  • A/Prof Anna Nowak, University Western Australia, Australia
  • Dr Agatha vanderSchaaf, Sir Charles Gairdner Hospital, Australia
  • Michael Phillips, Western Australia Institute of Medical Research, Australia
  • Prof Michael Millward, University Western Australia, Australia
  • Jan Boucek, Sir Charles Gairdner Hospital, Australia
  • Dr Peter Robins, Sir Charles Gairdner Hospital, Australia

    • Objective: To study the influence of talc pleurodesis on FDG PET and CT imaging in MPM.

    Methods: Newly-referred, consenting, untreated patients with MPM underwent CT and FDG PET scans within 14 days of each other. Tumour stage was derived for FDG PET and CT scans using UICC TNM staging. Quantitative FDG PET was performed using semi-automated 3D region-growing software (J Nucl Med (48) 1449-58; 2007) to derive total glycolytic volume (TGV) and SUVmax. Patients were treated as clinically indicated and followed for survival.

    Results: 29 (32%) of 92 eligible patients had pleurodesis prior to imaging. No difference in baseline characteristics or overall survival was observed between the pleurodesis (P) and non-pleurodesis (NP) groups, although the pleurodesis group experienced more chest pain (p=0.02). CT nodal disease was more advanced in the P group compared to the NP group (p = 0.03), but no difference was observed between groups for PET staging (p = 0.6). Quantitative PET analysis showed a higher mean TGV for the P group than the NP group (1,796 vs 506 respectively, p = 0.003) and a higher SUVmax (9.1 vs 6.7, p = 0.02). Cox regression demonstrated baseline TGV was a significant prognostic factor in both NP (HR=1.25, p=0.004) and P (HR=1.54, p=0.01) patients.

    Conclusions: CT nodal stage was higher in patients with prior talc pleurodesis, whereas no significant difference was found in PET TNM stage. Baseline TGV is higher is patients with prior pleurodesis, but remains predictive of survival, irrespective of a history of pleurodesis.