Abstract
Objectives To study positive (PPV) and negative predictive value (NPV) of positron emission
tomography with computed tomography (PET-CT) scans in determining malignancy in skull
base lesions and perform a systematic literature review for optimal PET-CT interpretation.
Design Retrospective case series and systematic literature review of the current English
literature.
Setting Tertiary referral academic medical center.
Participants All patients with skull base lesions that underwent PET-CT and tissue biopsy from
2010 to 2013.
Main Outcome Measures PPV and NPV of radiologist's report and standardized uptake value (SUV) cutoff of
2.5 and 3, biopsy with pathologic interpretation, clinical follow-up.
Results A total of 31 PET-CT scans of 16 patients were studied; 10 PET-CT were performed
upfront for diagnostic purposes and 21 were post-treatment surveillance scans. The
PPV of radiologist's interpretation, SUV cutoff of 2.5, and SUV cutoff of 3.0 was
80%, 60%, and 68.4%, with a NPV of 100%, 83.3%, and 75%, respectively. Literature
search yielded 500 abstracts; 7 studies met inclusion criteria for detailed review.
No consensus or guidelines for optimal SUV cutoff value was found.
Conclusions PET-CT based on SUV cutoff criteria alone has high NPV but low PPV in determining
malignancy in skull base lesions. Interpretation by a radiologist experienced in nuclear
medicine and neuroradiology, synthesizing clinical, SUV, and radiologic data are of
superior value.
Keywords
PET-CT - skull base - SUV
