Lymph Node Metastasis of Squamous Cell Carcinoma from an Unknown Primary in the Upper and Middle Neck: Impact of ¹⁸F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

Abstract

Purpose: The purpose of this study was to assess the potential of 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) imaging for detection of the primary tumor and its impact on treatment planning in patients presenting with cancer of unknown primary and squamous cell carcinoma (SCC)-positive cervical lymph nodes of the upper and middle neck. Methods: The study population consisted of 18 consecutive patients with biopsy-proven SCC involving lymph nodes of the upper and middle neck region and negative conventional diagnostic procedures with regard to the location of the primary. All patients underwent FDG-PET/CT according to a standard procedure in search for the primary, unidentified tumor. Results: In none of the patients FDG-PET/CT was able to indicate a primary tumor localization. Although FDG-PET/CT did identify all sites of known lymph node involvement, neither additional sites of lymph node involvement nor sites of distant metastases were identified. Accordingly, FDG-PET/CT did not impact patient treatment planning. Conclusions: In this series, including patients suffering from lymph node metastases by an SCC of unknown primary in the upper and middle neck, FDG-PET/CT was unable to identify a primary tumor. In addition, FDG-PET/CT did not modify the treatment planning in any of the patients studied.

The added value of18F-fluorodeoxyglucose positron emission tomography computed tomography in patients with neck lymph node metastases from an unknown primary malignancy

“…The fusion of PET and CT, first described by Beyer et al, 32 enables the anatomical detail provided by CT to be combined with the functional information provided by FDG PET, and has been shown to increase the specificity and accuracy of tumour detection and to improve the diagnostic yield from targeted biopsy. 2,[10][11][12][13][14][15][16][17][18] In our cohort, the diagnostic performance of PET-CT in primary tumour detection was 50 per cent; combining this result with those of 10 previous studies gave an overall primary tumour detection rate of 37 per cent. These figures highlight the added value of PET-CT in the diagnostic investigation of patients with cervical lymph node metastases from an unknown primary.…”

Orbital Metastases as Presenting Sign of Lung Carcinoma: Detection of Primary Malignancy and Disease Burden by F-18 FDG PET/CT

“…Advantages of FDG PET/CT in this kind of case are that the whole body is imaged in one session and with high sensitivity. The use of FDG PET/CT has been widely evaluated for detecting the primary malignancy in both cervical and extracervical carcinoma of unknown primary site [7,8]. We have previously reported use of FDG PET/CT in patients with choroidal metastases [9], and this case demonstrates …”

Combined positron emission tomography/computed tomography (PET/CT) for imaging of orbital tumours and tumours extending into the orbit

“…This has been widely evaluated for the head and neck region in cervical carcinoma of unknown primary 21. PET/CT has the potential to improve the management of patients with carcinoma in the sinus/nasal area and orbit 2.…”