Clinical Utility of Tc-99m MIBI SPECT/CT for Preoperative Localization of Parathyroid Lesions

68Ga-Trivehexin PET/CT: a promising novel tracer for primary hyperparathyroidism

INTRODUCTION

This study aims to assess 68Ga-Trivehexin PET/CT for detecting hyperfunctioning parathyroid tissue in comparison to [99mTc]Tc-MIBI scintigraphy-SPECT/CT (MIBI scan) in patients with primary hyperparathyroidism (PHPT).

METHODS

The cohort comprised 13 patients diagnosed with PHPT based on biochemical analyses, including serum calcium, phosphorus, and parathyroid hormone (PTH) levels. Each participant underwent cervical ultrasonography, MIBI scan, and 68Ga-Trivehexin PET/CT imaging. Complementary 4D-CT and [18F]fluorocholine PET/CT were conducted in 7 patients. Ten lesions of 7 patients underwent PTH wash-out (WO) procedure. 68Ga-Trivehexin PET/CT findings were compared with other modalities and PTH-WO results.

RESULTS

Ten patients had sporadic PHPT, while 3 were diagnosed with MEN-1 syndrome-associated PHPT. One patient did not have any identifiable parathyroid lesion across the imaging modalities. On a patient-based analysis, MIBI scan and 68Ga-Trivehexin PET/CT identified parathyroid lesions in 10 and 11 patients, respectively. However, 68Ga-Trivehexin PET/CT detected 7 additional parathyroid lesions that were negative on the MIBI scan. Consequently, 17 lesions were identified and confirmed as hyperfunctioning parathyroid tissue through imaging, PTH-WO, or a combination of both modalities. In lesion-based evaluation, 68Ga-Trivehexin identified 16 lesions compared to 10 by MIBI scan, resulting in a detection rate of 94.1% and 58.8%, respectively. Notably, in three patients who underwent [18F]fluorocholine PET/CT, no lesions were detected; yet 68Ga-Trivehexin PET/CT successfully identified parathyroid lesions in two of these patients.

CONCLUSION

Our study provides the first evidence that 68Ga-Trivehexin PET/CT can effectively identify hyperfunctioning parathyroid tissue with a high detection rate warranting further investigations to comprehensively explore its potential in PHPT management.

The role of preoperative ultrasound, contrast-enhanced ultrasound, and 99mTc-MIBI scanning with single-photon emission computed tomography/X-ray computed tomography localization in refractory secondary hyperparathyroidism

OBJECTIVE

The aim of our study was to evaluate the role of preoperative US, CEUS, and 99mTc-MIBI scanning with SPECT/CT in localizing diseased parathyroid glands in cases of refractory secondary hyperparathyroidism (SHPT).

MATERIAL AND METHODS

Using pathological results as the gold standard, we compared the operative findings with the preoperative localization of each modality in 73 nodules and evaluated the accuracy, and sensitivity of each modality and combinations of the four modalities.

RESULTS

The sensitivity of US, CEUS, 99mTc-MIBI and SPECT/CT was 98.59%, 94.37%, 50.70% and 78.87%, respectively. US had the highest sensitivity of the four imaging methods and the diagnostic sensitivity of US and CEUS was superior to that of 99mTc-MIBI (p < 0.001 and p < 0.001) and SPECT/CT (p = 0.001 and p = 0.012). In addition, we found that the sensitivity of the combination of US with CEUS, US with 99mTc-MIBI and/or SPECT/CT, CEUS with 99mTc-MIBI and/or SPECT/CT, US with CEUS and two other imaging modalities (99mTc-MIBI and/or SPECT/CT) was 98.59%, 100%, 95.77%, and 100%, respectively.

CONCLUSIONS

The combination of US with SPECT/CT is the best choice for the comprehensive preoperative localization of glands in refractory SHPT. CEUS can elevate the accuracy of US in differential diagnosis via the interpretation of dynamic microvascular features.

Effect of Botulinum Toxin-A Injected to Muscle Tissue on Perfusion and Survival of Fasciocutaneous Single Perforator-pedicled Propeller Flap in Rats

Background:

In plastic surgery practice, fasciocutaneous single-perforator-pedicled propeller flap is a preferred procedure; however, its survival rate is below than expected, especially in flaps with a big rotation arc. When botulinum toxin-A is injected into the muscle tissue that the perforator pedicle is arisen, the tonus of pertinent muscle can reduce and the blood flow of its perforator pedicle can increase. Therefore this procedure can improve the survival rate of single-perforator-pedicled propeller flap.

Aims:

To evaluate the effect of botulinum toxin-A injected with ultrasonographic guidance into the muscle tissue that the perforator pedicle is arisen from one month ago on the perfusion of flap scintigraphically and the survival rate of single-perforator-pedicled propeller flap in a rat model.

Study Design:

Animal experiment.

Methods:

Three study groups were receiving botulinum toxin-A (16 IU-0.4 mL), normal saline (0.4 mL), and no study drug one month ago before flap surgery. Injections were performed under ultrasonography guidance. Flaps were elevated fasciocutaneously over the right 2nd perforator pedicle, under the corneous, with a surgical loupe and microsurgery tool and were rotated clockwise 180°. Then the scintigraphic measurements were obtained after flap elevations in the study groups, including the whole-body and flap perfusions in the study rats. The involvement rate presents the ratio of flap perfusion to whole-body perfusion. Flaps were sutured back to the abdominal wall at the latest twisting angles. With standard photographs taken in all the groups on day 8 after the operation, whole and necrotic flap areas were calculated.

Results:

Scintigraphically the involvement rate (the ratio of flap perfusion to whole-body perfusion) of the flaps in the botulinum toxin-A group were found significantly higher than those in the other groups (p<0.05). The area of a flap in the botulinum toxin-A group on day 8 post flap suturing was found to be significantly higher than those in the other groups (p<0.05). The area of a necrosis and the percentage of necrosis on day 8 post flap suturing in the botulinum toxin-A group was found significantly lower than those of the sham and null groups (p<0.05).

Conclusion:

In a rat model, if with the ultrasonographic guidance, botulinum toxin-A is injected to the muscle which perforator of the prospective single-perforator-pedicled propeller flap originated and flap surgery is performed one month later after this injection, the perfusion of single-perforator-pedicled propeller flap increases scintigraphically and this improves flap survival and reduces its necrosis.

Two Different Causes of Paediatric Hypercalcaemia

Paediatric hypercalcaemia is a rare condition which can be easily overlooked or misdiagnosed. We report two paediatric patients who presented to the Department of Paediatrics, Pardubice Hospital, Pardubice, Czech Republic, in 2009 and 2010, respectively. Each patient was diagnosed with hypercalcaemia due to a different cause. The first case involved a seven-month-old infant who presented with failure to thrive, vomiting and psychomotor retardation. Fluorescent in situ hybridisation revealed Williams-Beuren syndrome. The second patient was a 16-year-old girl with abdominal pain and renal colic due to hypercalcaemia-induced urolithiasis. High parathyroid hormone serum levels suggested primary hyperparathyroidism. An adenoma of the left upper parathyroid gland was diagnosed via technetium-99m-labelled methoxyisobutyl isonitrile single photon emission computed tomography and removed surgically. Hypercalcaemia should be considered in the differential diagnosis of various disease states, particularly among infants who fail to thrive or children with abdominal pain.

Ectopic Undescended Parathyroid Adenoma-SPECT/CT Avoids False-Negative Interpretation on 99mTc-MIBI Dual-Phase Scintigraphy

Undescended parathyroid adenomas are rare, and they are easily missed during neck exploration surgery in patients with hyperparathyroidism. Few reports have described ectopic parathyroid adenomas along the carotid arteries at or near the carotid bifurcation. These may be missed on planar Tc-MIBI dual-phase scintigraphy because of overlapping submandibular gland activity. Our case demonstrates the potential advantage of SPECT/CT in parathyroid scintigraphy to overcome this limitation.