Incidental uptake of ¹⁸F-fluorodeoxyglucose in the prostate gland

Summary

Aim: To perform a systematic review and meta-analysis of published data on the prevalence and risk of malignancy of pros- tatic incidental uptake (PIU) detected by flu- orine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) or PET/computed tomography (PET/CT). Patients, material, methods: A comprehensive literature search of studies published up to February 2014 was performed. Pooled prevalence and malignancy risk of PIU were calculated on a per patient-based analysis including 95% confidence interval (95%CI). Furthermore, we assessed some parameters as potential predictors of malignant PIU. Results: Six studies including 47925 patients who underwent ¹⁸F-FDG PET/CT were selected. Pooled prevalence of PIU was 1.8% (95%CI: 1.3–2.3%). Overall, 444 patients with PIU were further evaluated and 121 underwent biopsy. The pooled risk of malignancy in patients with PIU further evaluated or verified by biopsy were 17% (95%CI: 12–23%) and 62% (95%CI: 54–71%), respectively. A higher mean age was observed in the group of malignant PIUs compared to benign PIUs. There was a trend towards a higher mean SUV_max in the group of malignant PIUs but without a statistically significant difference compared to benign PIUs. Peripheric site of PIU but not presence or absence of calcification was a predictor of malignancy. Conclusions: PIU is observed in about 1.8% of ¹⁸F-FDG PET/CT scans performed in male patients carrying a significant risk of malignancy. Therefore, whenever a PIU is detected further investigation is warranted to exclude malignancy, in particular when PIU is located in the peripheric site of prostate gland.

Zusammenfassung

Ziel: Review und Metaanalyse publizierter Daten zu Prävalenz und Malignitätsrisiko von zufälligem Uptake in der Prostata (ZUP), entdeckt durch Fluor-18-Fluordeoxyglukose (¹⁸F-FDG) Positronenemissionstomographie (PET) oder PET/Computed Tomography (PET/ CT). Patienten, Material, Methoden: Eine umfassende Literatursuche publizierter Studien bis Februar 2014 wurde durchgeführt. Gezielte Prävalenz und Malignitätsrisiko von ZUP wurden anhand patientenbasierter Analysen, inklusive 95% Konfidenzintervall (95% KI) berechnet. Außerdem beurteilten wir einige Parameter als mögliche Prädiktoren von ZUP. Ergebnisse: Sechs Studien mit 47 925 Patienten, die sich ¹⁸F-FDG-PET/CT unterzogen, wurden ausgewählt. Gezielte Prävalenz von ZUP betrug 1,8% (95% KI: 1,3–2,3%). Insgesamt wurden 444 Patienten mit ZUP weiterführend abgeklärt und 121 wurden bioptisch untersucht. Das Malignitätsrisiko in den Patienten, die mit ZUP weiterführend abgeklärt oder bioptisch verifiziert wurden, betrug 17% (95% KI: 12–23%) bzw. 62% (95% KI: 54–71%). Ein höheres Durchschnittsalter wurde in der Gruppe maligner ZUP im Vergleich zur Gruppe benigner ZUPs beobachtet. Dabei zeigte sich ein starker Trend in Richtung eines höheren durchschnittlichen SUV-_max in der Gruppe maligner ZUPs allerdings ohne statistischen signifikanten Unterschied verglichen mit der Gruppe benigner ZUPs. Periphere Lokalisation von ZUP allerdings ohne Präsenz oder Absenz von Kalzifikationen war ein Malignitätsprädiktor. Schlussfolgerungen: ZUP wurde in ungefähr 1,8% der ¹⁸F-FDG-PET/CT-Untersuchungen beobachtet bei männlichen Patienten, die ein signifikantes Malignitätsrisiko tragen. Wann immer ein ZUP entdeckt wird, sollte eine weiterführende Abklärung gewährleistet sein, um Malignität auszuschließen, besonders wenn ZUP in der peripheren Prostataloge lokalisiert ist.

Keywords

Prostate - incidental uptake - PET/CT - metaanalysis

Schlüsselwörter

Prostata - Zufallsuptake - PET/CT - Metaanalyse

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