Abstract
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.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Kwee TC, Basu S, Cheng G, Alavi A (2010) FDG PET/CT in carcinoma of unknown primary. Eur J Nucl Med Mol Imaging 37:635–644
Grau C, Johansen LV, Jakobsen J, Geertsen P, Andersen E, Jensen BB (2000) Cervical lymph node metastases from unknown primary tumours. Results from a national survey by the Danish Society for Head and Neck Oncology. Radiother Oncol 55:121–129
Johansen J, Buus S, Loft A et al (2008) Prospective study of 18FDG-PET in the detection and management of patients with lymph node metastases to the neck from an unknown primary tumor. Results from the DAHANCA-13 study. Head Neck 30:471–478
Rusthoven KE, Koshy M, Paulino AC (2004) The role of fluorodeoxyglucose positron emission tomography in cervical lymph node metastases from an unknown primary tumor. Cancer 101:2641–2649
Danish Head and Neck Cancer Group. https://www.dahanca.oncology.dk. Accessed 26 April 2016
R Core Team (2015) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. https://www.R-project.org/
National Comprehensive Cancer Network. http://www.nccn.org. Accessed 26 April 2016
Corrigan AJ, Schleyer PJ, Cook GJ (2015) Pitfalls and artifacts in the use of PET/CT in oncology imaging. Semin Nucl Med 45:481–499
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
This work was funded by a clinical short-term fellowship grant from the Norwegian Cancer Society (Grant Number 160907-2014).
Conflict of interest
All authors declare that they have no conflict of interest.
This study was approved by the institutional research committee as well as the hospital’s patient privacy ombudsman. Informed consent from the patients was not necessary according to Norwegian legislation and approval statement from the hospital’s patient privacy ombudsman.
Rights and permissions
About this article
Cite this article
Dale, E., Moan, J.M., Osnes, T.A. et al. Cervical lymph node metastases of squamous cell carcinoma of unknown origin: the diagnostic value of FDG PET/CT and clinical outcome. Eur Arch Otorhinolaryngol 274, 1015–1019 (2017). https://doi.org/10.1007/s00405-016-4318-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00405-016-4318-5