[18F]-FDG–PET in clinical stage I/II non-seminomatous germ cell tumours: results of the German multicentre trial
[18F]-FDG-PET in clinical stage I/II non-seminomatous germ cell tumours: results of the German multicentre trial
M. de Wit 0 9
W. Brenner 9
M. Hartmann 8
J. Kotzerke 7
D. Hellwig 14
J. Lehmann 13
C. Franzius 12
S. Kliesch 11
M. Schlemmer 16
K. Tatsch 15
R. Heicappell 10
L. Geworski 5
H. Amthauer 6
B. M. Dohmen 3
H. Schirrmeister 4
U. Cremerius 1
C. Bokemeyer 9
R. Bares 2
0 Present address: Department of Internal Medicine, Hematology and Oncology, Vivantes Klinikum Neuko ̈lln , Berlin , Germany
1 Department of Nuclear Medicine , Klinikum Ingolstadt, Ingolstadt
2 Department of Nuclear Medicine, University Hospital Tu ̈bingen , Tu ̈bingen , Germany
3 Department of Nuclear Medicine, Diakonie Hospital Rotenburg (W) , Rotenburg
4 Department of Nuclear Medicine, University Schleswig-Holstein , Kiel
5 Department of Nuclear Medicine, Clinic for Nuclear Medicine , Campus Mitte, Charite ́, Berlin
6 Department of Radiology, Clinic for Radiology , Campus Virchow, Charite ́, Berlin
7 Department of Nuclear Medicine, University of Dresden , Dresden
8 Department of Urology, Military Hospital Hamburg , Hamburg
9 Department of Internal Medicine, University Clinic Hamburg-Eppendorf
10 Department of Urology, Clinic Uckermark , Schwedt/Oder
11 Department of Urology, University Hospital Mu ̈nster , Mu ̈nster
12 Department of Nuclear Medicine
13 Department of Urology, Saarland University , Saarland
14 Department of Nuclear Medicine, Saarland University Medical Center , Homburg
15 Department of Nuclear Medicine, Ludwig-Maximilian University , Mu ̈nchen
16 Department of Medicine
Purpose: The aim of this study was to determine the predictive values of 2-[fluorine-18]fluoro-2-deoxy-D-glucosepositron emission tomography (FDG-PET) in primary staging in patients with newly diagnosed non-seminomatous germ cell tumour (NSGCT) clinical stage I/II. Patients and methods: The hypothesis was that FDG-PET would improve the negative predictive value (NPV) from 70% to 90%, thus requiring a total of 169 patients. All scans underwent visual analysis by a reference team of nuclear medicine physicians. Results were validated by histology following retroperitoneal lymph node dissection. Results: Only 72 of the planned 169 patients were included, due to poor accrual. The prevalence of nodal involvement was 26%. Correct nodal staging by FDG-PET was achieved in 83% compared with correct computed tomography (CT) staging in 71%. CT had a sensitivity and specificity of 41% and 95%, respectively. Positive predictive value (PPV) and NPV were 87% and 67%, respectively. FDG-PET had a sensitivity and specificity of 66% and 98%, respectively. PPV was 95%. The primary end point was not reached, with an NPV of 78%. Conclusion: FDG-PET as a primary staging tool for NSGCT yielded only slightly better results than CT. Both methods had a high specificity while false-negative findings were more frequent with CT. FDG-PET is mostly useful as a diagnostic tool in case of questionable CT scan.
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introduction
Conventional radiological staging for retroperitoneal lymph
nodes in patients with germ cell tumour results in 20%–30%
false upstaging and about the same percentage of false
downstaging. Using spiral computed tomography (CT) and
lowering the threshold for lymph node size to <1 cm as
indicative for metastases improves sensitivity to >90% but
decreases specificity to 50% [1].
2-[Fluorine-18]fluoro-2-deoxy-D-glucose–positron
emission tomography (FDG–PET) as a functional rather than
a morphological tool is applied in order to improve staging
by exploiting the metabolic difference between normal cells
and cancer cells [2]. Compared with other non-invasive
diagnostic methods, improved sensitivity and specificity were
reported for FDG–PET in the detection of primary or
recurrent tumours [3–9].
Very few data are available for FDG–PET in early-stage germ
cell tumours. The aim of our study was to test if FDG–PET
increases staging accuracy in early-stage testicular germ cell
tumours compared with spiral CT.
patients and methods
In 1998, a German multicentre trial was initiated for FDG–PET staging of
germ cell tumour patients. Patients were stratified according to stage.
The study recruited patients with non-seminomatous germ cell tumours
(NSGCTs) at an early stage (I and II) undergoing primary
retroperitoneal lymph node dissection (RPLND).
As required by German law, the protocol was fully approved by the
ethical committees of each participating hospital and the national
radiation protection authorities and passed a review for quality control
by the German Cancer Society. The study was carried out in accordance
with the Declaration of Helsinki. Every patient signed a written fully
informed consent form before PET scanning.
inclusion criteria
Patients were included if they were diagnosed with NSGCT at the
clinical stage I or IIA/B according to tumour–node–metastasis
classification. FDG–PET and CT were carried out following orchiectomy.
Evaluation of PET scans took place in t (...truncated)