Impact of 3T multiparametric MRI and FDG-PET-CT in the evaluation of occult primary cancer with cervical node metastasis.
BACKGROUND
This study aimed to determine the ability of multimodal evaluation with multiparametric 3T-MRI (MPMRI) and positron emission tomography - computed tomography (PET/CT) to detect cancer of unknown primary origin (CUP) with neck lymph node (LN) metastasis.


METHODS
The study group comprised 38 retrospectively analysed consecutive patients with LN metastasis in the head and neck (HN) region without known primary tumours (PTs). Statistical values of 3T-MRI and of FDG-PET/CT scans were evaluated.


RESULTS
Of the 38 CUPs, conventional native T1-, T2-weighted and STIR sequences detected 6 PTs. Native sequences plus diffusion-weighted imaging (DWI) found 14-, and with fat suppression contrast-enhanced T1-weighted measurement as well as with the complex MPMRI found 15 primaries and with PET/CT 17 CUPs could be evaluated, respectively. The detection rates were 15.8, 36.8, 39.5, 39.5 and 44.7 % for conventional native MRI, native plus DWI, native with contrast-enhanced MRI (CE-MRI), for MPMRI, and for PET/CT, respectively. The overall detection rate proved by histology was 47.4 %. PET/CT provided the highest sensitivity (Sv: 94.4 %) but a lower specificity (Sp: 65.0 %), using MPMRI (Sv: 88.2 %) the specificity increased to 71.4 %. DWIincreased specificity of the native sequences (Sp: 76.2 %). Conventional native sequences plus DWI as well as 3T-MPMRI and PET/CT were same accurate (Acc: 79.0 %) and had similar likelihood ratio (LR: 3.42, 3.03 and 2.62) in detecting unknown PT sites.


CONCLUSIONS
The accuracy of FDG-PET/CT and MPMRI in case of CUP in finding the primary cancer in the neck regions is identical. While using PET/CT whole body information can be obtained in one examination. MPMRI shows the local soft tissue status more accurately. In cases of CUP PET/CT should be the first method of choice if it is available. MPMRI can clarify the exact primary tumor stage, and it can be advantageous in clarifying the prognostic factors, which is necessary in case of advanced tumor stage and when surgery is under consideration. In case low N stage is likely after the clinical examination and wait and see policy can be considered, MPMRI is recommended, and in this case the significance the of radiation free MPMRI is increasing.
Department of Diagnostic Radiology, National Institute of Oncology, Ráth György street 7-9, Budapest, 1122, Hungary. godeny.maria@oncol.hu.|Department of Postgraduate Education and Scientific Research, University of Medicine and Pharmacy, Tirgu Mures, Romania. godeny.maria@oncol.hu.
Mária
M
Gődény
Pozitron Diagnostics LTD, Hunyadi János street 9, Budapest, 1117, Hungary.
Zsolt
Z
Lengyel
Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, Szigony u.36, Budapest, 1083, Hungary.
Gábor
G
Polony
Department of Radiotherapy, National Institute of Oncology, Ráth György street 7-9, Budapest, 1122, Hungary.
Zoltán Takácsi
ZT
Nagy
Department of Diagnostic Radiology, National Institute of Oncology, Ráth György street 7-9, Budapest, 1122, Hungary.
Gergely
G
Léránt
Head and Neck Surgery Department, National Institute of Oncology, Ráth György street 7-9, Budapest, 1122, Hungary.
Orsolya
O
Zámbó
Head and Neck Surgery Department, National Institute of Oncology, Ráth György street 7-9, Budapest, 1122, Hungary.
Éva
É
Remenár
Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, Szigony u.36, Budapest, 1083, Hungary.
László
L
Tamás
Head and Neck Surgery Department, National Institute of Oncology, Ráth György street 7-9, Budapest, 1122, Hungary.|Department of Postgraduate Education and Scientific Research, University of Medicine and Pharmacy, Tirgu Mures, Romania.
Miklós
M
Kásler
D000328:Adult; D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000494:pharmacology*; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009333:Neck; D009382:Neoplasms, Unknown Primary / Q000175:diagnosis*; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000494:pharmacology; D012189:Retrospective Studies
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
Carcinoma of unknown primary origin; Diffusion-weighted imaging; High-field MRI; Magnetic resonance imaging; Positron emission tomography