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.
Department of Oncology, Oslo University Hospital, P.O. Box 4953, Nydalen, 0424, Oslo, Norway. einar.dale@ous-hf.no.
Einar
http://orcid.org/0000-0001-9483-2788
E
Dale
Department of Oncology, Oslo University Hospital, P.O. Box 4953, Nydalen, 0424, Oslo, Norway.
Jon M
JM
Moan
Department of Otorhinolaryngology, Head and Neck Surgery, Oslo University Hospital, Oslo, Norway.
Terje A
TA
Osnes
Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway.
Trond V
TV
Bogsrud
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000556:secondary; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000494:pharmacology*; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000556:secondary; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009333:Neck; D009382:Neoplasms, Unknown Primary; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D011379:Prognosis; D019275:Radiopharmaceuticals / Q000494:pharmacology; D012189:Retrospective Studies
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
18F-FDG; Cancer of unknown primary; Cervical lymph node metastases; Head and neck cancer; Positron emission tomography
Cancer. 2004 Dec 1;101(11):2641-9
15517576
Head Neck. 2008 Apr;30(4):471-8
18023031
Semin Nucl Med. 2015 Nov;45(6):481-99
26522391
Eur J Nucl Med Mol Imaging. 2010 Mar;37(3):635-44
19882152
Radiother Oncol. 2000 May;55(2):121-9
10799723