carbon-11-methionine and Hyperparathyroidism--Primary

Primary hyperparathyroidism is a common endocrine disorder, with 80% of all cases usually caused by one single hyperfunctioning parathyroid adenoma. Conventional imaging modalities for the diagnostic work-up of primary hyperparathyroidism (PHPT) include ultrasound of the neck, 99mTc-sestamibi scintigraphy, and four-dimensional computed tomography (4D-CT). However, the role of other imaging modalities, such as 11C-methionine PET/CT, in the care pathway for PHPT is currently unclear. Here, we report our experience of the diagnostic utility of 11C-methionine PET/CT in a single-center patient cohort (n = 45).. Retrospective single-center cohort study.. The data of eligible patients that underwent 11C-methionine PET/CT between 2014 and 2022 at Addenbrooke's Hospital (Cambridge, UK) were collected and analyzed. The clinical utility of imaging modalities was determined by comparing the imaging result with histopathological and biochemical outcomes following surgery.. In patients with persistent primary hyperparathyroidism following previous surgery, 11C-methionine PET/CT identified a candidate lesion in 6 of 10 patients (60.0%), and histologically confirmed in 5 (50.0%). 11C-methionine PET/CT also correctly identified a parathyroid adenoma in 9 out of 12 patients (75.0%) that failed to be localized on other imaging modalities. 11C-methionine PET/CT had a sensitivity of 70.0% (95% CI 55.8 - 84.2%) for the detection of parathyroid adenomas.. This study highlights a diagnostic role for 11C-methionine PET/CT in patients that have undergone unsuccessful prior surgery or have equivocal or negative prior imaging results, aiding localization and a targeted surgical approach.

Topics: Adenoma; Cohort Studies; Humans; Hyperparathyroidism, Primary; Methionine; Parathyroid Glands; Parathyroid Neoplasms; Positron Emission Tomography Computed Tomography; Racemethionine; Retrospective Studies; Technetium Tc 99m Sestamibi; United Kingdom

The preferred nuclear medicine method for identification of hyperfunctioning parathyroid glands in hyperparathyroidism (HPT) develops continuously in relation to the technological progress. Diagnostic methods based on PET/CT have during recent years evolved with new tracer possibilities competing with traditional scintigraphic methods. This investigation is a head-to-head comparison of Tc-99m-sestamibi SPECT/CT gamma camera scintigraphy (sestamibi SPECT/CT) and C-11-L-methionin PET/CT imaging (methionine PET/CT) for preoperative identification of hyperfunctioning parathyroid glands.. The study is a prospective cohort study including 27 patients diagnosed with primary hyperparathyroidism (PHPT). Two nuclear medicine physicians assessed all examinations independently and blinded. All scanning assessments were matched to the final surgical diagnosis as confirmed by histopathology. Biochemical monitoring of the therapeutical effects was performed preoperatively by PTH-measurements and followed postoperatively for up to 12 months. Comparisons were made for differences in sensitivity and positive predictive value (PPV).. Twenty-seven patients (18 females, 9 males; mean age (range): 58.9 years (34.1-79)) were enrolled into the study. The 27 patients had a total of 33 identified sites of lesions of which 28 (85%) turned out to be histopathological verified hyperfunctioning parathyroid glands. The sensitivity and PPV for sestamibi SPECT/CT were 0.71 and 0.95; that of methionine PET/CT was 0.82 and 1, respectively. Both sensitivity and PPV were slightly lower for sestamibi SPECT/CT than for methionine PET PET/CT (-0.11, 95% confidence interval (95% CI): -0.29 to 0.08; -0.05, 95% CI: -0.14 to 0.04, respectively), but not to a statistically significant extent (p=0.38 and p=0.31). The sensitivity and PPV for diagnostic CT were 0.64 (95% CI: 0.44 to 0.81) and 1 (95% CI: 0.81 to 1).. Methionine PET/CT performed comparable to sestamibi SPECT/CT with respect to identification and localization of hyperfunctioning parathyroid glands prior to surgery.

Topics: Carbon Radioisotopes; Female; Humans; Hyperparathyroidism, Primary; Male; Methionine; Nitriles; Organotechnetium Compounds; Positron Emission Tomography Computed Tomography; Prospective Studies; Racemethionine; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Patients with PHPT, undergoing C-MET after an inconclusive pre-operative imaging and having a parathyroid surgery, were retrospectively included. C-MET visual and semi-quantitative assessment was performed. Parameters, as SUV. Thirty-eight patients (36 female, age: 57.69 ± 15.13 years) were included. Pre-operative median calcium and PTH values were 11.1 mg/dl [interquartile range (IQR) 10.6-11.5] and 154.6 pg/ml (IQR 101.8-227.0), respectively. C-MET showed a parathyroid uptake in 30 out of thirty-eight patients (78.9%). Among 42 nodules excised, C-MET correctly detected the side of the neck (right/left) in 30/42 with sensitivity, specificity and accuracy of 79, 75 and 79%, respectively. C-MET correctly identified the exact position (superior/inferior) in 27/42 with sensitivity, specificity and accuracy of 75, 50 and 71%, respectively. SUV. C-MET showed a good performance in detecting hyperfunctioning parathyroid glands in PHPT patients with inconclusive pre-operative imaging. Semi-quantitative PET-derived parameters closely correlated with PTH as well as with size and weight of the excised gland, thus reflecting some biochemical and histological characteristics of involved glands.

Topics: Adult; Aged; Aged, 80 and over; Female; Humans; Hyperparathyroidism, Primary; Image Processing, Computer-Assisted; Male; Methionine; Middle Aged; Parathyroid Glands; Positron Emission Tomography Computed Tomography; Reproducibility of Results; Retrospective Studies; Sensitivity and Specificity

Patients with primary hyperparathyroidism (pHPT) and a negative preoperative Tc-99 sestamibi (MIBI) scintigraphy are considered to have a higher risk of persistent disease. The aim of this study was to assess whether additional imaging with C-11 methionine positron emission tomography/computed tomography (Met-PET/CT) is able to localise sestamibi-negative hyperfunctioning parathyroid glands.. In 50 patients (38 females, 12 males, age 13-81 years) with pHPT and negative localisation procedures such as ultrasound and sestamibi, a Met-PET/CT was performed before parathyroid surgery. The results of Met-PET/CT were analysed prospectively and compared with intraoperative and histopathological findings. 22% of the patients underwent previous parathyroid and/or thyroid surgery.. Met-PET/CT correctly located a single-gland adenoma in 33 of 45 (73%) patients with pHPT. In 5 patients with multiglandular disease, Met-PET/CT detected at least one hyperfunctional parathyroid gland in 4 patients (80%). In 3 patients with double adenomas, 5 of 6 parathyroids were correctly located. Overall, 40 of 57 (70%) hyperfunctioning glands were identified with Met-PET/CT. Met-PET/CT was false-negative in 12 of 50 (24%) patients and false-positive in only one case (2%). Postoperatively, 48 of 50 patients (96%) were cured.. Additional pre-interventional imaging with Met-PET/CT was able to identify hyperfunctioning parathyroid glands in 74% of patients with pHPT and negative sestamibi scans, thus enabling successful parathyroid surgery.

Topics: Adenoma; Adolescent; Adult; Aged; Aged, 80 and over; Female; Humans; Hyperparathyroidism, Primary; Male; Methionine; Middle Aged; Parathyroid Neoplasms; Parathyroidectomy; Positron Emission Tomography Computed Tomography; Prospective Studies; Radiopharmaceuticals; Technetium Tc 99m Sestamibi; Young Adult

To investigate the efficacy of PET/CT with 11C-methionine for localizing parathyroid adenomas in patients with suspected primary hyperparathyroidism and inconclusive results of cervical ultrasonography and 99mTc-MIBI-SPECT/CT.. Retrospective analysis of imaging data of 18 patients and correlation with clinical outcome, in particular intraoperative findings and histopathology of excised tissue.. 12 of 18 patients received surgery. In 10 patients single parathyroid adenomas were found (diameter: 5-20 mm), 2 patients presented parathyroid hyperplasia (5 excised hyperplastic glands (diameter: 2-12 mm). PET/CT correctly localized all adenomas and 1 of 5 hyperplastic glands. The sensitivity per patient was 91.7% (11 of 12), the sensitivity per lesion 73.3% (11 of 15). All lesions missed by PET/CT had a size smaller than 9 mm and a volume of less than 0.2 ml. In 6 patients no surgery was performed. Five of them had a negative or atypical PET/CT. Further follow-up indicated familial hypocalciuric hypercalcemia in 3 of them (thus, PET/CT true negative), in the remaining 2 patients no validation is available. One patient with 2 highly suggestive lesions rejected surgery so far.. PET/CT with 11C-methionine is a very sensitive method for the detection of parathyroid adenomas, even if they are too small to be visualized by 99mTc-MIBI-SPECT/CT.

Topics: Adenoma; Adult; Aged; Female; Humans; Hyperparathyroidism, Primary; Male; Methionine; Middle Aged; Multimodal Imaging; Parathyroid Neoplasms; Positron-Emission Tomography; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

In patients with primary hyperparathyroidism (pHPT), positive preoperative localization studies enable to perform a minimally invasive approach for parathyroid surgery. However, current imaging techniques are not always successful. We therefore conducted a study to determine the sensitivity of C-11 methionine positron emission tomography/computed tomography (Met-PET/CT) in localizing parathyroid adenomas in pHPT. Met-PET/CT scans of the neck and mediastinum of 33 patients undergoing parathyroidectomy for primary HPT were compared with intraoperative and histological findings. Primary HPT was caused by a single gland adenoma in 30 patients, while another 3 patients had multiglandular disease. Met-PET/CT scan correctly located a single gland adenoma in 25 out of 30 (83%) patients with pHPT, among them 2 patients with persistent disease, 7 patients with prior neck surgery, and 8 patients with concomitant thyroid nodules. In 3 patients with multiglandular disease, Met-PET/CT showed only one enlarged parathyroid gland in two individuals and was negative in the third patient. Statistical analysis found a significant correlation between true-positive results and the weight (2.42+/-4.05 g) and diameter (2.0+/-1.18 cm) of parathyroid adenomas while the subgroup with false negative findings had significantly smaller (0.98+/-0.54 cm) and lighter (0.5+/-0.38 g) glands. Sensitivity was 83% for single gland adenomas and 67% for multiglandular disease. Met-PET/CT correctly localized 83% of single gland parathyroid adenomas in patients with pHPT. However, preoperative localization of multiglandular disease due to double adenomas or parathyroid hyperplasia remained difficult.

Topics: Adenoma; Adult; Aged; Aged, 80 and over; Female; Humans; Hyperparathyroidism, Primary; Intraoperative Care; Male; Methionine; Middle Aged; Neck; Parathyroid Neoplasms; Positron-Emission Tomography; Preoperative Care; Tomography, X-Ray Computed; Young Adult