Purpose
Conventional imaging fails to localize parathyroid adenomas in a substantial amount of patients withprimary hyperparathyroidism (pHPT).Preliminary data has shown superior results for 18F-Fluorocholine (FCH)PET/CT1,2,3.No studies have yet investigated the performance of FCH PET/MRI.
Methods and materials
We conducted a prospective pilot study to investigate the performance of FCH PET/MRI in patients with pHPT and inconclusive 99mTc-sestamibi scintigraphy and ultrasound.
Directly after administration of 3MBq/kg FCH,
PET imaging was acquired simultaneously with MRI,
with both pre- and post gadolinium sequences.
Intraoperative localization and histology were used as gold standard for calculating diagnostic performance.
Paired t-test was used to compare the difference in SUVmax between abnormal parathyroids and physiologic thyroid uptake.
Results
Ten patients so far are scanned of whom 9 with histological confirmation.
FCH PET/MRI correctly localized 8/9 adenomas (89% sensitivity),
without any false positive results (100% PPV).
One patient had 4-gland hyperplasia,
of which three hyperplastic glands were not localized.
The mean SUVmax of the nine preoperatively identified pathological glands was 5.6 (range 3.3-9.9),
which was significantly higher than the 3.5 SUV (range 2.1-7.1) of the thyroid (p=0.002).
All patients had a higher SUVmax of the parathyroid compared to the thyroid,
with a ratio ranging...
Conclusion
These preliminary results show that FCH PET/MRI is able to localize adenomas with very high accuracy when conventional imaging fails to do so,
while concurrently providing the surgeon with detailed anatomic information.
More patients need to be investigated to confirm our initial results.
The accuracy of FCH PET/MRI for localizing glands in patients with 4-gland hyperplasia remains to be investigated.
Personal information
Dr.
Kluijfhoutreceived his MSc in Medicine in 2014 from the University of Utrecht,
The Netherlands.
He continued his medical training as a surgical intern at the St.
Antonius hospital,
Nieuwegein,
while concurrently working on his thesis regarding parathyroid imaging.
In 2015 heconducted researchas a Fulbright - PhD student at the University of California,
San Francisco and currently he is finishing his thesis as endocrine research fellow at the University ofToronto,
Canada.
References
1Kluijfhout WP,
Vorselaars WMCM,
Vriens MR,
et al.
Enabling minimal invasive parathyroidectomy for patients with primary hyperparathyroidism using Tc-99m-sestamibi SPECT–CT,
ultrasound and first results of 18F-fluorocholine PET–CT.
Eur J Radiol. 2015;84:1745-1751.
2Lezaic L,
Rep S,
Sever MJ,
et al.
18F-Fluorocholine PET/CT for localization of hyperfunctioning parathyroid tissue in primary hyperparathyroidism: a pilot study.
Eur J Nucl Med Mol Imaging. 2014;41:2083-2089.
3Michaud L,
Burgess A,
Huchet V,
et al.
Is (18)f-fluorocholine-positron emission tomography/computerized tomography a new imaging tool for detecting hyperfunctioning parathyroid glands in primary or...