Diagnostic Performance of 18F-Choline Positron Emission Tomography/Contrast-Enhanced Computed Tomography in Adenoma Detection in Primary Hyperparathyroidism after Inconclusive Imaging: A Retrospective Study of 215 Patients

Abstract

This large, retrospective, single-centre study evaluated the diagnostic performance of ¹⁸F-choline positron emission tomography/contrast-enhanced computed tomography (PET/ceCT) in preoperative parathyroid adenoma detection in primary hyperparathyroidism cases after negative/inconclusive ultrasound or other imaging findings. We included patients who underwent surgery and ¹⁸F-choline PET/ceCT for inconclusive imaging results between 2015 and 2020. We compared the ¹⁸F-choline PET/ceCT results with surgical and histopathological findings and identified the variables influencing the correlation between ¹⁸F-choline PET/ceCT and surgical findings. Of 215 enrolled patients, 269 glands (mean lesion size, 10.9 ± 8.0 mm) were analysed. There were 165 unilocular and 50 multilocular lesions; the mean preoperative calcium level was 2.18 ± 0.19 mmol/L. Among 860 estimated lesions, 219 were classified as true positive, 21 as false positive, and 28 as false negative. The per-lesion sensitivity was 88.66%; specificity, 96.57%; positive predictive value, 91.40%; and negative predictive value, 95.39%. The detection and cure rates were 82.0% and 95.0%, respectively. On univariate and multivariate analyses, the maximum standardised uptake value (SUVmax), lesion size, and unilocularity correlated with the pathologic findings of hyperfunctioning glands. ¹⁸F-choline PET/ceCT presents favourable diagnostic performance as a second-line imaging method, with SUVmax, lesion size, and unilocularity predicting a high correlation between the ¹⁸F-choline PET/ceCT and surgical findings.

Keywords: 18F-choline PET/CT; diagnostic performance; minimally invasive surgery; parathyroid adenoma; primary hyperparathyroidism.

Figure 1

Example of true positive bilateral pathologic gland. ¹⁸F-choline positron emission tomography/contrast-enhanced computed tomography shows two nodular areas with hypermetabolism: left maximum standardised uptake value (SUVmax), 5.16; right SUVmax, 7.10. Pathology showed two adenomas: right weighing 4620 mg and left weighing 610 mg.

Figure 2

Example of false positive left paraoesophageal lymph node fixing ¹⁸ F-choline. ¹⁸F-choline positron emission tomography/contrast-enhanced computed tomography shows left latero-oesophageal nodular hypermetabolism (maximum standardised uptake value, 6.41). Pathology showed a lymph node 1 cm in size.

Figure 3

Example of false negative right retro-thyroid gland with insufficient ¹⁸F-choline fixation. ¹⁸F-choline positron emission tomography/contrast-enhanced computed tomography shows no nodular hypermetabolism. Pathology showed hyperplasic parathyroid weighing 80 mg.

Figure 4

Gland sizes (in mm) in the well-correlated group (n = 220) and uncorrelated group (n = 49).

Figure 5

Maximum standardised uptake values (SUVmax) in the well-correlated group (n = 220) and uncorrelated group (n = 49).

Figure 6

Number of glands detected by ¹⁸F-choline positron emission tomography/contrast-enhanced computed tomography in the well-correlated group (n = 220) and uncorrelated group (n = 49).