Prospective evaluation of solitary thyroid nodule on 18F-FDG PET/CT and high-resolution ultrasonography

Abstract

Routine use of 18F-FDG PET/CT with SUV(max) at 60 min as the sole diagnostic criterion does not appear to have a significant advantage over high-resolution ultrasound in the evaluation of thyroid nodules. Incorporation of dual time point imaging enhances image interpretation, and yields a higher diagnostic performance, yet it is not statistically significant. Bearing in mind the cost, limited availability and radiation exposure, routine use of 18F-FDG PET/CT for distinguishing benign from malignant thyroid nodules cannot be recommended.

Usefulness of different ultrasound features of malignancy in predicting the type of thyroid lesions: a meta‑analysis of prospective studies

“…According to Azizi et al, 10 solid nodules had a statistically insignificantly increased risk of malignancy (73.3% of malignant and 66.0% of benign nodules were solid; OR, 1.4; 95% CI, 0.9-2.3). D'Souza et al 17 reported similar results (65.4% of cancers and 59.2% of benign nodules were solid; OR, 1.3; 95% CI, 0.5-3.1). However, unlike cancers, 10.3% of benign lesions were purely cystic.…”

“…However, the available data suggest a rather low diagnostic value of this parameter. According to Azizi et al, 10 macrocalcifications were insignificantly more prevalent in cancers (OR, 1.6; 95% CI, 0.7-3.6), while in the study performed by D'Souza et al, 17 they occurred slightly less frequently in malignancies (OR, 0.12; 95% CI, 0.02-1.02). The data on nodule composition were also insufficient to perform a meta-analysis.…”

Clinical significance of primary lesion FDG uptake for choice between oesophagectomy and endoscopic submucosal dissection for resectable oesophageal squamous cell carcinomas

“…Dual time point imaging based on these characteristics has been used to enhance the differential diagnostic accuracy between malignant and benign lesions and the detection of malignant tumours compared to the single point imaging. Although the early imaging point is relatively constant and around 1 h after FDG injection, the delayed imaging point after FDG injection differs among investigators or institutions: the delayed imaging was performed around 2 h [38,[40][41][42][43][44][45][46][47][48][49], around 3 h [50-54], 2 and 3 h [55], 1.5 and 3 h after 40 min dynamic acquisition [36] and 4 and 6 h after 2 h dynamic acquisition [35]. Although, as mentioned above, it seems ideally better to perform the delayed imaging at an interval as long as possible from the early imaging, we performed it at 2 h after FDG injection because the administered FDG activity was limited and relatively low (3.7 MBq/kg) and more delayed imaging might suffer from the poorer counting statistics, increased noise, increased imaging time and decreased throughput of PET/CT examinations per day.…”

“…There was no significant difference in SUVmax percentage change among T stages, suggesting that it may not help differentiation among T stages. Although the SUVmax decreased in 2 (−12.7% and −12.1%) of 3 T1 lesions, the remaining 15 early visible lesions (88%) showed increased SUVmax (mean percentage change: 22.2±10.5%, range: 1.8 to 38.6%) like other cancers including pulmonary , breast and thyroid and miscellaneous cancers which were imaged at 1 and 2 h post injection [38,[40][41][42][43][44][45][46][47][48][49]. The SUVmaxs of oesophagi with non-visible lesions did not differ between early and delayed imaging and ranged from 1.8 to 2.5 (mean: 2.2±0.2) at early imaging and from 1.7 to 3.0 (mean: 2.3±0.4) at delayed imaging.…”

Alterações da PET-FDG na avaliação pré-operatória de pacientes com nódulos tireoidianos e correlação com marcadores imuno-histoquímicos

“…É reconhecido que as características dos nódulos à ultrassonografia relacionam-se com risco de malignidade de um nódulo 3,5,43,53 . No presente estudo, houve apenas uma tendência, dentre os nódulos completamente sólidos, daqueles hipoecogênicos terem um risco maior de malignidade do que aqueles isoecogênicos ou hiperecogênicos.…”