Integrated FDG PET-CT imaging improves staging in malignant pleural mesothelioma

Summary

Aim of this study was to investigate, how often TNM staging is changed in patients with malignant pleural mesothelioma (MPM) by the application of integrated PET-CT compared to computed tomography alone and how often these changes are clinically relevant. Patients, methods: We studied 17 patients (68 ± 6 years, 8 women) with MPM. Integrated PET-CT scan and histological confirmation were performed in all patients. Results: Final histological diagnosis confirmed 9 epithelial type, 2 sarcomatoid type and 6 biphasic type MPM. Mean standardized uptake value (SUV) was 5.9 ± 1.9 in epithelial MPM and 15.1 ± 10.2 in sarcomatoid MPM. CT and PET-CT revealed discordances in 8/17 (47%) patients in TNM classification with 4/8 (50%) being clinically relevant. PET-CT led to downstaging in 5 (29%) and upstaging in 3 (18%) patients. Mean survival time tended to be higher in the subgroup of patients with lower mean SUV. Conclusions: PET-CT seems to be a valuable tool in staging of MPM and leads to discordant findings in almost every second patient compared to CT alone. In many cases these differences are clinically relevant and have therapeutic consequences.

Zusammenfassung

Ziel dieser Studie war zu untersuchen, wie oft das TNMStaging bei Patienten mit einem malignen Pleuramesotheliom (MPM) durch die Anwendung des integrierten PET-CT im Vergleich zur Computertomographie alleine geändert wird und wie oft diese änderungen zu klinisch relevanten Therapieentscheidungen führen. Patienten, Methoden: Wir untersuchten 17 Patienten (68 ± 6 Jahre, 8 Frauen) mit MPM. Integriertes PET-CT und histologische Sicherung erfolgten bei allen Patienten. Ergebnisse: Die histologische Diagnose bestätigte 9 epitheliale, 2 sarkomatöse und 6 biphasische Typen des MPM. Der mean standardized uptake value (SUV) betrug 5,9 ± 1,9 bei epithelialen MPM und 15,1 ± 10,2 bei sarkomatösen MPM. Das CT und die PET-CT zeigten bei 8/17 (47%) Patienten in der TNM-Klassifikation Unterschiede, wobei 4/8 (50%) davon klinisch relevant waren. Das PET-CT führte zu einem downstaging bei 5 (29%) und einem upstaging bei 3 (18%) Patienten. In der Subgruppe der Patienten mit einem niedrigeren mittleren SUV bestand ein Trend zu längeren überlebenszeiten. Schlussfolgerungen: Das PET-CT scheint eine wertvolle Methode im Staging des MPM zu sein und führt bei fast jedem zweiten Patienten zu diskordanten Befunden verglichen mit dem CT allein. In vielen Fällen sind diese Unterschiede klinisch relevant und haben therapeutische Konsequenzen.

Keywords

Positron emission tomography - computed tomography - malignant pleural mesothelioma

Schlüsselwörter

Positronenemissionstomographie - Computertomographie - malignes Pleuramesotheliom

^* Both authors contributed equally.

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