Original Research Incidence and Significance of Hypermetabolic PET-CT Findings in Unilateral TVF Motion Impairment Otolaryngology– Head and Neck Surgery 1–6 Ó American Academy of Otolaryngology–Head and Neck Surgery Foundation 2019 Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/0194599819866403 http://otojournal.org Luke Stanisce, MD 1,2 , Timothy Renzi 2 , Nikita Paripati 2 , Nadir Ahmad, MD 1,2 , Thomas C. Spalla, MD 1,2 , Howard L. Roth, MD 2,3 , and Yekaterina Koshkareva, MD 1,2 No sponsorships or competing interests have been disclosed for this article. Abstract Objective. To determine the incidence and significance of asym- metric hypermetabolic laryngeal findings on positron emission tomography–computed tomography (PET-CT) in patients with unilateral true vocal fold (TVF) motion abnormalities. Study Design. Retrospective cohort. Setting. Single-center tertiary care institution. Subjects and Methods. The medical records of patients with unilateral TVF motion abnormalities were reviewed. The incidence of normal and asymmetric hypermetabolic laryn- geal findings was calculated in patients who underwent PET- CT and laryngeal examination, operative laryngoscopy with biopsy, or injection medialization laryngoplasty. Results. A total of 135 patients with unilateral TVF motion abnormalities underwent PET-CT. After exclusion of patients who completed new or surveillance imaging for a laryngeal neoplasm (n = 27), asymmetric hypermetabolic findings in the larynx were noted in 21 (19%) cases: 13 (12%) on the con- tralateral side of the impaired TVF, 8 (7%) on the ipsilateral side. Two (25%) patients with ipsilateral hypermetabolism had concerning subsequent fiberoptic laryngeal examinations prompting operative biopsy. There was no evidence of inflam- matory or neoplastic disease in all patients with contralateral hypermetabolic findings. Fifteen patients completed PET-CT scans after injection medialization procedures; 6 (40%) dis- played avidity ipsilateral to the side of the injection. The median time from injection to scan was 27 days, as opposed to 193 days in the unremarkable scans (P = .011). Conclusion. Contralateral hypermetabolism in patients with uni- lateral TVF motion abnormalities may represent a false-positive finding. Ipsilateral hypermetabolic uptake without recent fold instrumentation warrants prompt diagnostic evaluation. Keywords vocal fold paralysis, PET-CT, false positive, laryngeal cancer Received April 2, 2019; accepted July 9, 2019. P ositron emission tomography–computed tomography (PET-CT) imaging plays a major role in the detection and surveillance of cancer in the head and neck region. While increased uptake of radioisotope-labeled fluorodeoxyglucose (FDG) is used to visually represent neo- plastic tissue, a variety of inflammatory conditions, benign lesions, and normal physiologic activity may also demon- strate hypermetabolic findings. 1-5 Resulting from an inher- ent lack of specificity, the predictive value and diagnostic accuracy of this modality have been a contemporary focus of head and neck investigation. 6-9 In the setting of a unilateral true vocal fold (TVF) motion impairment, the contralateral vocal fold may develop increased activity in a compensatory effort to achieve glottic closure. 10,11 Select reports have shown that this augmented activity can yield asymmetric increased FDG avidity on the contralateral side of the impaired vocal fold. 12,13 However, asymmetrical hypermetabolism in the larynx should also raise suspicion for a primary or meta- static glottic neoplasm. Otolaryngologists are often tasked with discerning the underlying cause for these incidental imaging findings. Despite the need to reconcile PET-CT scan interpretation difficulties, the rate of true- and false-positive findings attri- butable to TVF motion impairment has yet to be defined. Previous reports attempted to examine asymmetric laryngeal PET scans without considering the incidence of normal scans in this patient demographic, inaccurately drawing con- clusions about diagnostic efficacy. 14,15 To date, no studies have comprehensively determined the rate of normal, abnor- mal, or false-positive laryngeal PET-CT findings in patients 1 Division of Otolaryngology–Head and Neck Surgery, Cooper University Hospital, Camden, New Jersey, USA 2 Cooper Medical School at Rowan University, Camden, New Jersey, USA 3 Department of Radiology, Cooper University Hospital, Camden, New Jersey, USA Corresponding Author: Luke Stanisce, MD, Division of Otolaryngology–Head and Neck Surgery, Cooper University Hospital, Three Cooper Plaza, Suite 404, Camden, NJ 08103, USA. Email: lukestanisce@gmail.com