Cervical lymph node metastases of squamous cell carcinoma of unknown origin: the diagnostic value of FDG PET/CT and clinical outcome.
FDG PET/CT is perceived as a valuable diagnostic tool in addition to the standard diagnostic workup for patients with isolated neck lymph nodes of squamous cell carcinoma of unknown primary (SCCUP). For patients with SCCUP intended for primary radiotherapy, we hypothesize that the previously reported FDG PET/CT detection rates are too high. From 2008 to 2015, 30 SCCUP patients were examined with FDG PET/CT. The objective of the FDG PET/CT examination was twofold: (1) improve the radiotherapy target definition, and (2) identify the primary cancer. Before the FDG PET/CT, the patients had been through a standard workup consisting of CT of the neck and chest, examination with flexible endoscopy with patient awake, panendoscopy and examination under general anesthesia, tonsillectomy and sometimes blind sampling biopsies, and MRI (floor of the mouth). All FDG PET/CTs were performed applying a flat table, head support and fixation mask as part of the radiotherapy treatment planning. Diagnostic CT with contrast was an integrated part of the PET/CT examination. Only 1/30 patients (cancer of the vallecula) had their primary cancer detected by FDG PET/CT. In addition, a non-biopsied patient with high uptake in the ipsilateral palatine tonsil was included, giving a detection rate of ≤7 % (95 % CI 2-21 %). In this retrospective study, we found that the FDG PET/CT detection rate of the primary for SCCUP patients is lower than previously reported. It is questionable whether FDG PET/CT is necessary for these patients when improved, advanced workup is available.
['Dale|Einar|E|http://orcid.org/0000-0001-9483-2788', 'Moan|Jon M|JM|', 'Osnes|Terje A|TA|', 'Bogsrud|Trond V|TV|']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D002294:Carcinoma, Squamous Cell D005260:Female D019788:Fluorodeoxyglucose F18 D006258:Head and Neck Neoplasms D006801:Humans D008198:Lymph Nodes D008207:Lymphatic Metastasis D008297:Male D008875:Middle Aged D009333:Neck D009382:Neoplasms, Unknown Primary D000072078:Positron Emission Tomography Computed Tomography D011379:Prognosis D019275:Radiopharmaceuticals D012189:Retrospective Studies
Cervical lymph node metastases 18F-FDG Cancer of unknown primary Head and neck cancer Positron emission tomography