carbon-11-methionine and Parathyroid-Neoplasms

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

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

The purpose of this study was to compare the sensitivity of single-photon emission computed tomography/computed tomography (SPECT/CT) using 99mTc-sestamibi (MIBI) with that of PET/CT using 11C-methionine (MET) for localization of parathyroid adenomas/hyperplasia in primary hyperparathyroidism.. Twenty-three patients with primary hyperparathyroidism were analyzed. Fifteen patients underwent surgery, and the remaining eight did not, but these patients were clinically diagnosed as having primary hyperparathyroidism. Patients underwent both MET PET/CT and MIBI SPECT/CT scanning. The sensitivities of both modalities were evaluated on a per-patient basis, and on a per-lesion basis for parathyroid lesions detected by surgery. The size of the parathyroid adenoma/hyperplasia and serum intact parathyroid hormone levels were compared with the results of each of the two modalities.. Per-patient sensitivities of MET PET/CT and MIBI SPECT/CT were 65 and 61%, respectively. Per-lesion sensitivities of MET PET/CT and MIBI SPECT/CT were 91 and 73% for histologically confirmed adenomas and 30 and 30% for hyperplastic glands, respectively. No significant differences were observed between the two modalities. The size of uptake-positive lesions was significantly larger than that of uptake-negative lesions in both modalities. Intact parathyroid hormone levels showed no significant difference between uptake-positive and uptake-negative patients in both modalities.. The sensitivities of MET PET/CT and MIBI SPECT/CT were comparable. MET PET/CT has a complementary role in localizing parathyroid adenomas/hyperplasia when MIBI SPECT/CT is inconclusive.

Topics: Adenoma; Adult; Aged; Aged, 80 and over; Female; Humans; Hyperplasia; Male; Methionine; Middle Aged; Multimodal Imaging; Parathyroid Neoplasms; Positron-Emission Tomography; Retrospective Studies; Sensitivity and Specificity; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Tumor Burden

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

Topics: Adenoma; Choristoma; Female; Humans; Hyperparathyroidism; Methionine; Middle Aged; Obesity, Morbid; Parathyroid Glands; Parathyroid Neoplasms; Radionuclide Imaging; Radiopharmaceuticals

The aim of this study was to assess the utility of combined C-methionine and F-FDG PET/CT imaging in hyperparathyroidism.. We reviewed all scans performed for hyperparathyroidism with both C-methionine and F-FDG PET/CT or PET in our institution since 1993. Forty-three patients (47 pairs of scans) were included (13 men and 30 women) with a mean age of 63 years. C-methionine and F-FDG PET/CT scans were classified as positive or negative for localization of abnormal parathyroid tissue, and the site of uptake was noted in the positive scans. Other concurrent imaging (Tc-MIBI scintigraphy, ultrasonography, CT, or MRI) findings were also noted when performed. Clinical follow-up information was available in 27 patients (30 episodes).. Of the 47 PET scan episodes, 23 (49%) were positive. Twenty-two C-methionine scans showed abnormal focal localization of which 10 also showed concordant abnormal F-FDG uptake. One patient was positive with F-FDG and negative with C-methionine.Of the 16 patients who underwent subsequent surgery, 6 had concordant C-methionine, F-FDG, and surgical findings; 6 had concordant C-methionine and surgical findings; 1 had concordant F-FDG and surgical findings; and 3 had both PET scans negative but had adenomas excised during surgery.Of the 3 with both PET scans negative and discordant surgical findings, 1 had mediastinal parathyroid lipoadenoma excised and 2 had normally sited parathyroid adenoma excised.. F-FDG PET/CT rarely provides additional information and could be saved for patients in whom C-methionine PET/CT is negative.

Topics: Adult; Aged; Aged, 80 and over; Female; Fluorodeoxyglucose F18; Follow-Up Studies; Humans; Hyperparathyroidism; Male; Methionine; Middle Aged; Parathyroid Neoplasms; Positron-Emission Tomography; Radiography

Focused unilateral or minimally invasive parathyroidectomy for primary hyperparathyroidism (pHPT) depends on the successful preoperative localization of parathyroid adenomas. The aim of this prospective study was to determine the accuracy of C-11 methionine positron emission tomography/computed tomography (Met-PET/CT), a novel localization procedure for hyperfunctional parathyroid tissue.. Preoperative Met-PET/CT scans of the neck and mediastinum of 102 patients undergoing parathyroidectomy for pHPT were preoperatively evaluated by a radiologist and a nuclear medicine physician and prospectively documented. The results of Met-PET/CT were compared with intraoperative and histopathological findings.. pHPT was caused by a single-gland adenoma in 97 patients, whereas 5 patients had multiglandular disease. Met-PET/CT correctly located a single-gland adenoma in 83 of 97 (86%) patients with pHPT (sensitivity 91%). The positive predictive value of Met-PET/CT in localizing a single-gland adenoma was 93%. Of the 5 patients with multiglandular disease, Met-PET/CT identified 2 hyperfunctioning parathyroid glands in 1 patient, 1 gland in 3 individuals, and was negative in the fifth patient (sensitivity 80%). A highly significant correlation was observed between true-positive findings and the size (mean = 1.81 ± 0.84 cm) and weight (mean = 1.50 ± 2.56 g) of parathyroid adenoma, whereas patients with false-negative findings had significantly smaller (mean = 1.09 ± 0.41 cm) and lighter (mean = 0.37 ± 0.29 g) glands (P < 0.001 and P = 0.001, respectively).. This study demonstrates the high accuracy of Met-PET/CT in the preoperative localization of parathyroid adenomas in a large series of patients with pHPT.

Topics: Adenoma; Adolescent; Adult; Aged; Aged, 80 and over; Contrast Media; Female; Humans; Iohexol; Male; Methionine; Middle Aged; Multimodal Imaging; Parathyroid Neoplasms; Parathyroidectomy; Positron-Emission Tomography; Prospective Studies; Sensitivity and Specificity; Statistics, Nonparametric; Tomography, X-Ray Computed

To compare the accuracy of planar scintigraphy, single photon emission computed tomography (SPECT), SPECT-CT, and positron emission tomography (PET) with C-11 methionine for the pre-operative detection of parathyroid adenomas.. We retrospectively evaluated the pre-operative studies of 60 patients with primary (n=56) and secondary (n=4) hyperparathyroidism. In 25/60 patients (Group 1), only planar scans were obtained, and additional SPECT and SPECT-CT were carried out in 35/60 patients (Group 2). PET or PET-CT with C-11 methionine was conducted in 8/60 patients (Group 3).. The results of the planar scans (Group 1) were true positive in 19/25 patients and false negative in 6/25 patients (sensitivity per patient, 76%). Histopathology confirmed 27 adenomas and two hyperplasia. Planar imaging identified 20/29 of these pathologies, whereas 9/29 were missed (sensitivity per adenoma, 69%). SPECT (Group 2) results were true positive in 34/35 patients and false negative in only one case (sensitivity per patient, 97%). On a lesion-based analysis, 38 adenomas were identified, and two were missed (sensitivity per adenoma, 95%). The sensitivities of SPECT and SPECT-CT were equal; however, SPECT-CT provided superior topographic information. C-11 methionine PET (Group 3) results were true positive in all eight patients. In one case, surgery confirmed two ipsilateral adenomas, only one of which was identified by PET (sensitivity per patient, 100%; per adenoma, 88.9%).. SPECT is superior to planar imaging. SPECT-CT has identical sensitivity compared to SPECT alone, but it provides additional topographic information. The sensitivity of PET appears to be even higher compared to SPECT. In the case of negative scintigraphic findings and proven hyperparathyroidism, additional C-11 methionine PET or PET-CT is recommended.

Topics: Adenoma; Adult; Aged; Aged, 80 and over; False Negative Reactions; Female; Humans; Hyperplasia; Male; Methionine; Middle Aged; Multimodal Imaging; Parathyroid Glands; Parathyroid Neoplasms; Positron-Emission Tomography; Radiopharmaceuticals; Retrospective Studies; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Young Adult

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

In symptomatic hyperparathyroidism, pre-surgical localization of the suspected site of adenoma is desirable. All widely available techniques may have difficulty in localizing the site. The aim of this study was to determine whether 11C-methionine positron emission tomography (PET) could accurately localize parathyroid adenomas in patients in whom conventional imaging had failed.. Fifty-one patients presenting with hyperparathyroidism, and in whom other imaging techniques had failed to definitely identify the site of adenoma, were reviewed retrospectively after 11C-methionine PET scanning. Patients were followed up by surgical histology, or clinically if surgery was not performed.. 11C-Methionine PET scanning was found to have a sensitivity of 83%, a specificity of 100% and an accuracy of 88% in successfully locating parathyroid adenomas. Most false negatives were due to adenomas in the lower mediastinum that was outside the area of scanning.. 11C-Methionine PET is a reliable and highly accurate technique for localizing parathyroid adenomas in patients in whom conventional imaging techniques have failed. It is necessary to image to the level of the lower mediastinum.

Topics: Adenoma; Adult; Aged; Aged, 80 and over; Female; Humans; Hyperthyroidism; Male; Methionine; Middle Aged; Parathyroid Neoplasms; Positron-Emission Tomography; Reproducibility of Results; Retrospective Studies; Sensitivity and Specificity

Topics: Adenoma; Aged; Diagnosis, Differential; False Positive Reactions; Granuloma; Humans; Male; Methionine; Parathyroid Diseases; Parathyroid Neoplasms; Positron-Emission Tomography; Radiopharmaceuticals; Sarcoidosis

Topics: Adenoma; Diagnosis, Differential; Female; Humans; Image Enhancement; Methionine; Middle Aged; Parathyroid Neoplasms; Radiopharmaceuticals; Subtraction Technique; Tomography, Emission-Computed; Tomography, X-Ray Computed

The study was designed to characterize L-[methyl-11 C]methionine accumulation in abnormal parathyroid tissues of hyperparathyroidism (HPT).. Thirty-four patients with primary (n = 32) or secondary HPT were investigated with PET before primary or reoperative (n = 25) parathyroid surgery. Parathyroid 11C-methionine accumulation was analyzed for integrated uptake values in defined tissue volumes standardized for the injected dose and body weight (SUV), four contiguous pixels of maximal accumulation (SUVhs), SUV multiplied by area of region of interest (SUVr) and by the excised tissue weight (SUVw). Transport rate constants (slope, slopehs) were calculated according to Patlak's formula using plasma 11C activity corrected for 11C-methionine metabolites.. True-positive localization was achieved in 85% of patients in whom 81% of the excised parathyroid lesions were visualized; no false-positive results were obtained. Corresponding proportions were 59% and 57% for CT and 55% and 52% for ultrasound, respectively. In the true-positive cases, parathyroid SUV, SUVhs and transport rate constants were consistently higher (p < 0.01) than in the thyroid, pharynx-esophagus, neck muscle and apical lung. Parathyroid SUV, SUVhs and SUVr increased with intact serum parathyroid hormone and calcium values (p = 0.0001-0.031), and weight of the excised tissue correlated with SUV and SUVhs (p = 0.024, 0.044). Parathyroid SUVhs varied strongly with the transport rate constants (p = 0.0008), and SUVr as well as s-calcium values differed significantly between parathyroid adenomas (n = 11), chief cell hyperplasias (n = 13), inadvertent implants (n = 3) and parathyroid cancers (n = 3).. Carbon-11-methionine PET has potential application in preoperative localization and metabolic characterization of abnormal parathyroid tissues in human HPT.

Topics: Adenoma; Adult; Aged; Aged, 80 and over; Choristoma; Female; Humans; Hyperparathyroidism; Hyperplasia; Male; Methionine; Middle Aged; Parathyroid Glands; Parathyroid Neoplasms; Sensitivity and Specificity; Tomography, Emission-Computed