Clinical usefulness of positron emission tomography-computed tomography in recurrent thyroid carcinoma.
OBJECTIVE
To determine the efficacy of combined positron emission tomography-computed tomography (PET-CT) in identifying recurrent thyroid cancer and to elucidate its role in the clinical management of thyroid carcinoma.


METHODS
Retrospective study.


METHODS
Tertiary care referral academic center.


METHODS
One hundred twenty-four patients with previously treated thyroid carcinoma who underwent PET-CT.


METHODS
PET-CT images were correlated with clinicopathologic information. The influence of PET-CT findings on disease status determination and the treatment plan was evaluated.


RESULTS
Among 121 patients undergoing iodine I 131 ((131)I) imaging (an (131)I image was unavailable for 3 patients), 80.6% had negative findings on (131)I imaging before undergoing PET-CT. Among 75 patients who had positive findings on PET-CT, 71 were true positive results. Among 49 patients who had negative findings on PET-CT, 32 were true negative results. Therefore, PET-CT demonstrated a sensitivity of 80.7%, specificity of 88.9%, positive predictive value of 94.7%, and negative predictive value of 65.3%. A significant difference was noted in the mean serum thyroglobulin levels between patients with positive vs negative PET-CT findings (192.1 vs 15.0 ng/mL, P = .01) (to convert thyroglobulin level to micrograms per liter, multiply by 1.0). Overall, distant metastases were detected in 20.2% of patients using PET-CT. There was an alteration of the treatment plan in 28.2% of patients as a result of added PET-CT information, and 21.0% of patients underwent additional surgery.


CONCLUSIONS
PET-CT is usually performed in patients with thyroid cancer having elevated thyroglobulin levels but non-(131)I-avid tumors and has high diagnostic accuracy for identifying local, regional, and distant metastases. Additional information from PET-CT in patients with (131)I-negative and thyroglobulin-positive tumors frequently guides the clinical management of recurrent thyroid carcinoma.
Department of Otolaryngology, University of Pittsburgh, PA, USA.
Ali
A
Razfar
Barton F
BF
Branstetter
Apostolos
A
Christopoulos
Shane O
SO
Lebeau
Steven P
SP
Hodak
Dwight E
DE
Heron
Edward J
EJ
Escott
Robert L
RL
Ferris
D018263:Adenocarcinoma, Follicular / Q000097:blood / Q000175:diagnosis; D000231:Adenocarcinoma, Papillary / Q000097:blood / Q000175:diagnosis; D018249:Adenoma, Oxyphilic / Q000097:blood / Q000175:diagnosis; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000175:diagnosis*; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013954:Thyroglobulin / Q000097:blood; D013964:Thyroid Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000556:secondary; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult
D013954:Thyroglobulin