Clinical Usefulness of 18F-FDG PET/CT for Staging Cancer of the External Auditory Canal.

OBJECTIVE: Our objective was to evaluate the clinical usefulness of positron emission tomography/computed tomography using 2-deoxy-2-[F-18]fluoro-D-glucose (FDG-PET/CT) for staging cancer of the external auditory canal (EAC).

STUDY DESIGN: Retrospective case review.

SETTING: Tertiary referral center.

PATIENTS: Twenty-three patients (seven men, 16 women, mean age of 59.6-year-old) who underwent FDG-PET/CT and high-resolution CT within 1 month for staging cancer of the EAC between July 2006 and December 2014 were enrolled in this study.

INTERVENTION: FDG-PET/CT, high-resolution CT.

MAIN OUTCOME MEASURES: Sensitivity, specificity, and accuracy for diagnosing nodal metastases.

RESULTS: Most primary tumors were FDG-avid and maximum standardized uptake values were 7.72 ± 3.04 and 9.06 ± 3.94 for the early (60 min) and delayed (120 min) phases of FDG-PET/CT, respectively. FDG-PET/CT was capable of detecting small nodal metastases (short axis <10 mm), and patient-based sensitivity, specificity, and accuracy of FDG-PET/CT for the N staging were 71.4, 81.3, and 78.3%, respectively. There were no patients with distant metastases in our cohort. Compared with the combination of clinical examination and conventional imaging methods, additional FDG-PET/CT resulted in a change in the surgical strategy in five patients (21.7%).

CONCLUSIONS: Most primary cancers of the EAC are FDG-avid, and FDG-PET/CT is useful for detecting small nodal metastases, followed by the change in the surgical strategy.