Nasopharyngeal Cancer

• Fast Facts:  Covered here.
• Indications for PET/CT: Covered here.
• Imaging Protocol: Covered here.

Patient Presentations:

• The majority of patients with nasopharyngeal cancer have a biopsy-proven diagnosis prior to PET/CT scanning. In such cases, any focus of FDG uptake in the nasopharynx typically represents the cancer (prior to therapy).
• Many patients will present with the diagnosis of metastatic SCCA of unknown primary.  A nasopharyngeal primary must be excluded in these patients.
• Lastly, on rare occasion, an incidental nasopharyngeal cancer will be identified.

Assessing FDG-Avid Nasopharyngeal Soft Tissue Density: 

As previously addressed (here), FDG-avid nasopharyngeal soft tissue fullness is not an uncommon finding, and is usually inflammatory in nature.

• If the soft tissue fullness is mild, midline, posterior and symmetric, it is typically inflammatory in nature – even if intensely avid.  In these cases, we generally report:

  • “While a neoplastic process cannot be entirely excluded, this is typically physiologic or inflammatory in nature.” 

• If FDG-avid nasopharyngeal soft tissue density is prominent, eccentric or mass-like in CT appearance, we must raise a suspicion for malignancy. In such cases, we generally report:

  • Ill-defined and intensely avid soft tissue density is noted to involve the left aspect of the nasopharynx, measuring up to 1.8 x 1.2 cm (SUV 4.1). While this can be inflammatory in nature, direct visualization is recommended to exclude a neoplastic process.”

• Intense uptake in the lateral pharyngeal recess (bilateral or unilateral), without an accompanying soft tissue density, is typically inflammatory. 
• CAVEAT: The presence of associated hypermetabolic cervical nodes dramatically increases the likelihood of malignancy (and the confidence of your reporting).