Use of PET tracers for parathyroid localization: a systematic review and meta-analysis

The great spatial and temporal resolution of positron emission tomography might provide the answer for patients with primary hyperparathyroidism (pHPT) and non-localized parathyroid glands. We performed a systematic review of the evidence regarding all investigated tracers.

A study was considered eligible when the following criteria were met: (1) adults ≥17 years old with non-familial pHPT, (2) evaluation of at least one PET isotope, and (3) post-surgical and pathological diagnosis as the gold standard. Performance was expressed in sensitivity and PPV.

Twenty-four papers were included subdivided by radiopharmaceutical: 14 studies investigated L-[¹¹C]Methionine (11C-MET), one [¹¹C]2-hydroxy-N,N,N-trimethylethanamium (11C-CH), six 2-deoxy-2-[¹⁸F]fluoro-D-glucose (18F-FDG), one 6-[¹⁸F] fluoro-L-DOPA (18F-DOPA), and three N-[(¹⁸F)Fluoromethyl]-2-hydroxy-N,N-dimethylethanaminium (18F-FCH). The 14 studies investigating MET included a total of 327 patients with 364 lesions. Sensitivity for the detection of a lesion in the correct quadrant had a pooled estimate of 69 % (95 % CI 60-78 %). Heterogeneity was overall high with I² of 51 % (p = 0.01) for all 14 studies. Pooled PPV ranged from 91 to 100 % with a pooled estimate of 98 % (95 % CI 96-100 %). Of the other investigated tracers, 18-FCH seems the most promising with high diagnostic performance.

The results of our meta-analysis show that 11C-MET PET has an overall good sensitivity and PPV and may be considered a reliable second-line imaging modality to enable minimally invasive parathyroidectomy. Our literature review suggests that 18F-FCH PET may produce even greater accuracy and should be further investigated using both low-dose CT and MRI for anatomical correlation.