Comparison of pinhole and SPECT 99mTc-MIBI imaging in primary hyperparathyroidism

Direct Comparison of Preoperative Imaging Modalities for Localization of Primary Hyperparathyroidism: A Systematic Review and Network Meta-analysis

Importance

Accurate preoperative localization of primary hyperparathyroidism (pHPT) is an important and challenging issue for a successful parathyroidectomy. Although new imaging modalities have been introduced during the past decade, direct comparative studies on advanced imaging techniques are limited.

Objective

To compare the performance of different preoperative imaging modalities for the localization of pHPT by performing a network meta-analysis (NMA).

Data Sources

PubMed, Embase, and the Cochrane Library were searched from the earliest available indexing date through September 28, 2020.

Study Selection

The inclusion criteria were diagnostic tests with sensitivities of 2 or more different preoperative imaging modalities for the same indivduals.

Data Extraction and Synthesis

Two researchers independently reviewed the literature according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension statement of health care intervention guidelines for network meta-analyses.

Main Outcomes and Measures

After classifying various imaging modalities into 8 representative imaging categories, the pooled estimation between the odds ratio and 95% credible intervals (CrIs) was calculated in the sensitivity for localization of pHPT. The surface under the cumulative ranking curve (SUCRA) values were obtained to calculate the probability of each imaging modality being the most effective diagnostic method.

Results

A total of 8495 patients from 119 direct comparative studies using 2 or more imaging modalities for localization of pHPT were included. The sensitivity of choline positron emission tomography and computed tomography (PET-CT) was significantly higher than that of technetium 99m sestamibi single-photon emission computed tomography (MIBI SPECT) in both patient-based and lesion-based analyses (patient-based analysis: odds ratio, 5.22; 95% CrI, 2.36-11.80; lesion-based analysis: odds ratio, 17.70; 95% CrI, 5.79-60.10). Among 8 representative imaging modality categories, choline PET-CT showed the highest SUCRA value in both patient-based and lesion-based analyses. In patient-based analysis after 2010, choline PET-CT showed the highest SUCRA value, followed by the CT category, although MIBI SPECT had the highest SUCRA value in analysis before 2009.

Conclusions and Relevance

The results from this network meta-analysis suggest that choline PET-CT showed the best performance in both patient-based and lesion-based analyses and that choline PET-CT would be the best preoperative imaging modality for localization of pHPT.

Number of Foci of Functioning Thyroid Tissue Remaining after Thyroidectomy for Differentiated Thyroid Cancer: Institutional Experience

Radioiodine imaging of the neck with a pinhole collimator (PinC) is frequently performed in differentiated thyroid cancer (DTC) patients for visualizing individual, and a total number of foci (NOF) of functioning residual thyroid tissue (FRTT) within the thyroid bed in postthyroidectomy patients. The objective of this study was to determine our experience regarding the NOF of FRTT visualized on pretherapy radioiodine PinC images. We performed a retrospective review of radioiodine PinC images of the neck of patients with very low-risk DTC and who had thyroidectomy performed by selected surgeons at MedStar Washington Hospital Center. For each patient's image, the NOF of FRTT was determined by two blind readers. Statistical analysis was performed. One hundred and twenty-six patients met the criteria. Surgeon (S1, S2, S3, and S4) performed 17, 10, 86, and 13 thyroidectomies, respectively. The analysis (mean, range, and standard deviation) of NOF of FRTT was: S1: (2.2, 0-5, 1.3); S2: (1.6, 1–3, 0.8); S3: (2.6, 0–7, 1.5); S4: (3.3, 1–5, 1.3). The percentages of < 2, ≤3, ≤4, and <5 foci remaining were 4.9%, 21.5%, 77.0%, and 91.3%, respectively. For the selected surgeons, the NOF of FRTT in the thyroid bed or neck in postthyroidectomy patients never exceeded 7, rarely exceeded 5 (2.4%), and infrequently exceeded 4 (8.7%). Based on these data, our thresholds of the NOF for which we perform further workup for possible locoregional disease are ≥5. Each facility is encouraged to establish their own criteria for their facility and preferably for each of their surgeons.

A comparison between 11C-methionine PET/CT and MIBI SPECT/CT for localization of parathyroid adenomas/hyperplasia

OBJECTIVE

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

Dual-isotope 99mTc-MIBI/123I parathyroid scintigraphy in primary hyperparathyroidism: comparison of subtraction SPECT/CT and pinhole planar scan

PURPOSE

In patients with primary hyperparathyroidism, the preoperative imaging objective is to locate accurately and reliably uniglandular or multiglandular hyperfunctioning parathyroid, to guide surgery, particularly for minimally invasive method. Subtraction planar scintigraphy with dual-isotope (I/Tc-MIBI) is an efficient examination to specify abnormal parathyroid location, but without accurate anatomic reference. This lack should be avoided by a hybrid SPECT/CT image acquisition.

METHODS

We compared planar scans (neck and mediastinum parallel-hole, associated with anterior neck pinhole) to neck and mediastinum SPECT/CT, all with subtraction (I/Tc-MIBI) method, in exact location of abnormal parathyroid in 50 patients with sporadic primary hyperparathyroidism. Surgical and histological findings were used as the standard of comparison.

RESULTS

Sensitivity is equivalent for the 2 protocols (86% and 75% for SPECT/CT and planar protocol, respectively, P = 0.15), but SPECT/CT was highly specific (specificity 100% and 90% for SPECT/CT and planar protocol, respectively, P = 0.04). In patients with concomitant thyroid disease, subtraction SPECT/CT appeared to be more sensitive than planar protocol (88% and 62% for SPECT/CT and planar protocol, respectively, P = 0.04).

CONCLUSIONS

In preoperative assessment of primary hyperparathyroidism and to guide surgery, we propose to perform first subtraction SPECT/CT and to complete it with neck pinhole, only if tomoscintigraphy is negative.

Comparison of Tc-99m pertechnetate images with dual-phase Tc 99m MIBI and SPECT images in primary hyperparathyroidism

BACKGROUND

The purpose of this study was to evaluate the value of Tc-99m pertechnetate planar, dual-phase MIBI and MIBI-SPECT images in the determination and localization of parathyroid lesions.

MATERIALS AND METHODS

In this study, 38 patients who underwent operation for primary hyperparathyroidism were included. Tc-99m pertechnetate planar-pinhole imaging of the neck and then MIBI planar and SPECT images in supine position was performed. Late SPECT images were acquired 120 minutes after the injection. Early and late MIBI images were quantitatively evaluated.

RESULTS

Of the 38 patients, 30 of them had adenoma, 2 patients had hyperplasia and 6 of them were normal on planar images. Thirty-four of 38 patients were positive on SPECT images. SPECT images of the patients with positive results were matched with pathology results.

CONCLUSION

As a result, Tc-99m pertechnetate planar-pinhole, Tc-99m MIBI planar and SPECT images are useful for localization of parathyroid lesions especially in multinodular thyroid gland. However, US or CT images are necessary for more accurate localization and Tc-99m pertechnetate images are useful for interpreting and comparing with the early and late MIBI images.

Comparison of five parathyroid scintigraphic protocols

Objectives. We compared five parathyroid scintigraphy protocols in patients with primary (pHPT) and secondary hyperparathyroidism (sHPT) and studied the interobserver agreement. The dual-tracer method ((99m)Tc-sestamibi/(123)I) was used with three acquisition techniques (parallel-hole planar, pinhole planar, and SPECT/CT). The single-tracer method ((99m)Tc-sestamibi) was used with two acquisition techniques (double-phase parallel-hole planar, and SPECT/CT). Thus five protocols were used, resulting in five sets of images. Materials and Methods. Image sets of 51 patients were retrospectively graded by four experienced nuclear medicine physicians. The final study group consisted of 24 patients (21 pHPT, 3 sHPT) who had been operated upon. Surgical and histopathologic findings were used as the standard of comparison. Results. Thirty abnormal parathyroid glands were found in 24 patients. The sensitivities of the dual-tracer method (76.7-80.0%) were similar (P = 1.0). The sensitivities of the single-tracer method (13.3-31.6%) were similar (P = 0.625). All differences in sensitivity between these two methods were statistically significant (P < 0.012). The interobserver agreement was good. Conclusion. This study indicates that any dual-tracer protocol with (99m)Tc-sestamibi and (123)I is superior for enlarged parathyroid gland localization when compared with single-tracer protocols using (99m)Tc-sestamibi alone. The parathyroid scintigraphy was found to be independent of the reporter.

Comparison of pinhole and high-resolution parallel-hole imaging for nodular thyroid disease

INTRODUCTION AND OBJECTIVE

Pinhole has been the main standard collimator to be used for thyroid imaging. There has been a gradually increasing trend to replace pinhole with the use of high-resolution low-energy parallel-hole collimator with zoom in thyroid imaging. The objective of this study is to compare parallel-hole collimator acquisition of thyroid gland with that obtained by pinhole collimator to find the effect on the diagnostic information in nodular thyroid disease.

MATERIAL AND METHODS

A total of 29 patients, 24 women and 5 men, aged 18 to 70 years who were routinely referred for thyroid imaging for the assessment of nodular disease were studied. Each patient was injected with 185 MBq (5 mCi) of Tc-99m sodium pertechnetate intravenously. After 20 minutes, acquisition using pinhole followed by parallel-hole collimators was obtained. For pinhole acquisition, a 3-mm insert was used, and 3 images were obtained in the anterior and anterior oblique projections. For parallel-hole acquisition, anterior view was obtained for 250 K. The collimator was placed as close as possible to the patient. The image quality, number, and definition of nodules were evaluated by 2 independent, qualified nuclear medicine physicians. Differences were resolved by consensus.

RESULTS

There were 14 patients who had nodular patterns and 15 had no apparent nodules. There were 40 nodules of different sizes detected by pinhole imaging. Only 10 (25%) of these nodules were observed on parallel-hole images.

CONCLUSION

Pinhole imaging must be used for thyroid imaging particularly in patients suspected of having nodular disease.

4D parathyroid CT as the initial localization study for patients with de novo primary hyperparathyroidism

BACKGROUND

Preoperative localization of parathyroid tumors of primary hyperparathyroidism (pHPT) is required for minimally invasive parathyroidectomy (MIP). Parathyroid four-dimensional computed tomography (4DCT) has mainly been used as an adjunct to other imaging modalities in the remedial setting. 4DCT was evaluated as the initial localization study in de novo patients with pHPT.

MATERIALS AND METHODS

A total of 87 consecutive patients underwent parathyroidectomy for pHPT from August 2008 to November 2009. 4DCT was introduced as the preferred imaging modality instead of sestamibi with SPECT (SeS) in April 2009. Results of the imaging studies [4DCT, SeS, and ultrasonography (US)], operative and, pathologic findings, and biochemical measurements were evaluated.

RESULTS

In this study, 84% of patients (73 of 87) underwent an US, 59.8% (52 of 87) a SeS, and 38.0% (33 of 87) had a 4DCT. 4DCT had improved sensitivity (85.7%) over SeS (40.4%) and US (48.0%) to localize parathyroid tumors to the correct quadrant of the neck (P < 0.005) as well as to localize (lateralize) the parathyroid lesions to one side of the neck (93.9% for 4DCT vs. 71.2% for US and 61.5% for SeS; P < 0.005). 4DCT correctly predicted multiglandular disease (MGD) in 85.7% (6 of 7) patients, whereas US and SeS were unable to detect MGD in any case. All patients achieved cure based on intraoperative parathyroid hormone (PTH) measurements and normalization of intact PTH and S-Ca during follow-up.

CONCLUSIONS

4DCT provides significantly greater sensitivity than SeS and US for precise localization of parathyroid tumors of pHPT. Additionally, it correctly predicted MGD in a majority of patients.

Imaging of parathyroid glands

Preoperative imaging studies have an important role in facilitating successful localization of adenomas for surgeons. Their use has increased and parallels the recent growth of minimally invasive parathyroidectomy. Based on findings that scintigraphy is reported to have the highest accuracy for localization of adenomas when compared with anatomic imaging techniques, this article discusses the current role and limitations of imaging, with a focus on scintigraphy, in the evaluation of patients before surgery for hyperparathyroidism.