Exploring near-infrared autofluorescence properties in parathyroid tissue: an analysis of fresh and paraffin-embedded thyroidectomy specimens.

Significance: Near-infrared autofluorescence (NIRAF) utilizes the natural autofluorescence of parathyroid glands (PGs) to improve their identification during thyroid surgeries, reducing the risk of inadvertent removal and subsequent complications such as hypoparathyroidism. This study evaluates NIRAF's effectiveness in real-world surgical settings, highlighting its potential to enhance surgical outcomes and patient safety. Aim: We evaluate the effectiveness of NIRAF in detecting PGs during thyroidectomy and central neck dissection and investigate autofluorescence characteristics in both fresh and paraffin-embedded tissues. Approach: We included 101 patients diagnosed with papillary thyroid cancer who underwent surgeries in 2022 and 2023. We assessed NIRAF's ability to locate PGs, confirmed via parathyroid hormone assays, and involved both junior and senior surgeons. We measured the accuracy, speed, and agreement levels of each method and analyzed autofluorescence persistence and variation over 10 years, alongside the expression of calcium-sensing receptor (CaSR) and vitamin D. Results: NIRAF demonstrated a sensitivity of 89.5% and a negative predictive value of 89.1%. However, its specificity and positive predictive value (PPV) were 61.2% and 62.3%, respectively, which are considered lower. The kappa statistic indicated moderate to substantial agreement (kappa = 0.478; P < 0.001 ). Senior surgeons achieved high specificity (86.2%) and PPV (85.3%), with substantial agreement (kappa = 0.847; P < 0.001 ). In contrast, junior surgeons displayed the lowest kappa statistic among the groups, indicating minimal agreement (kappa = 0.381; P < 0.001 ). Common errors in NIRAF included interference from brown fat and eschar. In addition, paraffin-embedded samples retained stable autofluorescence over 10 years, showing no significant correlation with CaSR and vitamin D levels. Conclusions: NIRAF is useful for PG identification in thyroid and neck surgeries, enhancing efficiency and reducing inadvertent PG removals. The stability of autofluorescence in paraffin samples suggests its long-term viability, with false positives providing insights for further improvements in NIRAF technology.

[Endoscopic assisted parathyroid surgery via a subclavian approach].

Objective:To explore the safety and efficacy of airless endoscopic surgery in the treatment of parathyroid diseases. Methods:By retrospective comparison, clinical treatment of 26 patients with primary hyperparathyroidism admitted to the Department of Otolaryngology and Head and Neck Surgery of the Hospital, Sun Yat-sen University from January 2018 to January 2023 were collected. They were divided into traditional group（13 cases） and endoscopic group（13 cases） according to the surgical method. The traditional group underwent traditional open parathyroid surgery, and the endoscopic group underwent airless endoscopic surgery through the subclavian approach. The efficacy, postoperative incision pain, incidence of adverse events, and aesthetic effects of the two groups were evaluated. Results:A total of 26 patients were included, including 13 patients in the traditional group and 13 patients in the endoscopic group. There was no significant difference in the incidence of hypocalcemia and transient hypoparathyroidism on the first day after surgery between the two groups（P>0.05）. No patients with incision pain（>3 points） or swallowing pain were found in both groups after the operation, and they were afraid or unwilling to cough and expel phlegm. There were no significant differences in the amount of blood loss, duration of operation, incidence of temporary recurrent laryngeal nerve palsy and transient hypocalcemia, and postoperative pain score between the two groups. The endoscopic group's scar evaluation score and aesthetic effect satisfaction score at 6 months after surgery were higher than those of the traditional group（P<0.01）. Conclusion:Airless Endoscopic parathyroid surgery via the subclavian approach has good effectiveness and safety, which did not significantly increase the risk of surgery. It can safely remove the lesion and leave no surgical scar on the anterior neck, which has the advantage of a good cosmetic effect. It is a safe and feasible endoscopic parathyroid surgery and can be used as a new choice for patients undergoing parathyroid surgery.

Is intraoperative parathyroid monitoring during minimally invasive parathyroidectomy still justified?

Introduction: Primary hyperparathyroidism (PHPT) is the third most common endocrine disease. With parathyroidectomy, a cure rate of over 95% at initial surgery is reported. Localization of the abnormal parathyroid gland is critical for the operation to be successful. The aim of this study is to analyze data of patients with single gland disease (SGD) and positive concordant localization imaging undergoing minimally invasive parathyroidectomy (MIP) and intraoperative parathyroid hormone monitoring (IOPTH) to evaluate if IOPTH is still justified in patients with localized SGD. Methods: A retrospective database analysis of all minimally invasive operations with IOPTH for PHPT and positive concordant localization in ultrasound (US) and 99mTc-sestamibi scintigraphy (MIBI) between 2016-2021. When both US and MIBI were negative, patients underwent either choline or methionine PET-CT. The patients were also analyzed a second time without applying IOPTH. Results: In total, 198 patients were included in the study. The sensitivity of US, MIBI and PET-CT was 96%, 94% and 100%, respectively. Positive predictive value was 88%, 89% and 94% with US, MIBI and PET-CT, respectively. IOPTH was true positive in 185 (93.4%) patients. In 13 (6.6%) patients, no adequate IOPTH decline was observed after localizing and extirpating the assumed enlarged parathyroid gland. Without IOPTH, the cure rate decreased from 195 (98.5%) to 182 (92%) patients and the rate of persisting disease increased from 2 (1.0%) to 15 (7.5%) patients. Conclusion: Discontinuing IOPTH significantly increases the persistence rate by a factor of 7.5 in patients with concordantly localized adenoma. Therefore, IOPTH appears to remain necessary even for this group of patients.

[The role of immunohistochemical examination in the differential diagnosis of atypical tumors and carcinomas of parathyroid glands]. / Rol' immunogistokhimicheskogo analiza v differentsial'noi diagnostike atipicheskikh opukholei i kartsinom okoloshchitovidnykh zhelez.

Differential diagnosis of atypical parathyroid tumors (APT) and parathyroid carcinomas (PC) is important in determining further management and prognosis. Morphologic diagnosis is sometimes difficult, in which case it is supplemented by immunohistochemical (IHC) examination. OBJECTIVE: Studying the role of IHC analysis in the differential diagnosis of APT and PC. MATERIAL AND METHODS: The study included 44 patients with morphologic diagnosis of the APT established after surgical treatment for primary hyperparathyroidism on the basis of Endocrinology Research Centre during 2018-2023. All cases underwent IHC examination with evaluation of CD31/CD34 and parathormone (PTH) expression for identification of vascular invasion, Ki-67, parafibromin. RESULTS: According to the results of IHC analysis in 8/44 patients (18.2%) the diagnosis of APT was revised in favor of the PC: in 7 of them vascular invasion was detected; in 1 patient the additional series of slices in the surrounding fatty tissue revealed foci of tumor growth, confirmed by positive reaction with antibodies to PTH. According to IHC results, the material was divided into 2 groups: APT and PC. There were no differences in clinical and morphological characteristics, Ki-67% level and parafibromin expression between the groups. CONCLUSION: Assessment of clinical and laboratory-instrumental data at the preoperative stage does not allow differentiating APT from PC. In case of APT diagnosis and detection of suspicious morphological features, it is necessary to perform IHC examination to exclude PC.

The role of parathyroid autotransplantation for hypoparathyroidism following total thyroidectomy with bilateral central neck dissection.

Background: Hypoparathyroidism is the most common complication for patients who undergo total thyroidectomy (TT) with bilateral central lymph node dissection (BCLND). The objective of this retrospective study was to investigate the relationship between parathyroid autotransplantation (PA) and postoperative hypoparathyroidism. Materials and Methods: Four hundred and sixty-five patients with papillary thyroid carcinoma (PTC) who underwent TT with BCLND (including prophylactic and therapeutic BCLND) by the same surgeon were enrolled in this retrospective study. They were divided into five groups based on the number of PAs. Group 0 was defined as no PA, while Group 1, 2, 3, and 4 were considered as 1, 2, 3, and 4 PAs during TT with BCLND, respectively. Results: Transient and permanent hypoparathyroidism occurred in 83 (17.8%) and 2 (0.4%) patients who underwent TT and BCLND, respectively. The incidence of transient hypoparathyroidism increased gradually with an increase in the number of PAs. Compared with the previous group, Groups 2 and 3 had significantly more cases of transient hypoparathyroidism (p=0.03 and p=0.04, respectively). All cases of permanent hypoparathyroidism occurred in the patients without PA. Compared with Group 0, there were more removed central lymph nodes (RCLNs) in patients with one PA. Furthermore, Group 2 had more metastatic central lymph nodes(MCLNs) and RCLNs than Group 1.The number of PAs was the only identified risk factor for transient hypoparathyroidism after the multivariate logistic regression analysis. The median parathyroid hormone level recovered to the normal range within 1 month after surgery. Conclusion: With an increasing number of PAs, the possibility of transient hypoparathyroidism also increases in patients with PTC who undergo TT and BCLND. Considering the rapid recovery of transient hypoparathyroidism in 1 month, two PAs during TT and BCLND could be a good choice, leading to an increase in the central lymph node yield and no permanent hypoparathyroidism. However, this conclusion should be validated in future multicenter prospective studies.

Single-cell analysis reveals transcriptional dynamics in healthy primary parathyroid tissue.

Studies on human parathyroids are generally limited to hyperfunctioning glands owing to the difficulty in obtaining normal human tissue. We therefore obtained non-human primate (NHP) parathyroids to provide a suitable alternative for sequencing that would bear a close semblance to human organs. Single-cell RNA expression analysis of parathyroids from four healthy adult M. mulatta reveals a continuous trajectory of epithelial cell states. Pseudotime analysis based on transcriptomic signatures suggests a progression from GCM2 hi progenitors to mature parathyroid hormone (PTH)-expressing epithelial cells with increasing core mitochondrial transcript abundance along pseudotime. We sequenced, as a comparator, four histologically characterized hyperfunctioning human parathyroids with varying oxyphil and chief cell abundance and leveraged advanced computational techniques to highlight similarities and differences from non-human primate parathyroid expression dynamics. Predicted cell-cell communication analysis reveals abundant endothelial cell interactions in the parathyroid cell microenvironment in both human and NHP parathyroid glands. We show abundant RARRES2 transcripts in both human adenoma and normal primate parathyroid cells and use coimmunostaining to reveal high levels of RARRES2 protein (also known as chemerin) in PTH-expressing cells, which could indicate that RARRES2 plays an unrecognized role in parathyroid endocrine function. The data obtained are the first single-cell RNA transcriptome to characterize nondiseased parathyroid cell signatures and to show a transcriptomic progression of cell states within normal parathyroid glands, which can be used to better understand parathyroid cell biology.

Primary hyperparathyroidism caused by a tiny mediastinal parathyroid adenoma with non-localising imaging studies.

Variations in parathyroid gland positions often cause failure in initial parathyroid adenoma surgery, especially when imaging fails to localise the adenoma. This report describes a female patient with primary hyperparathyroidism for which preoperative localisation studies did not determine the position of the hyperfunctioning gland. The initial approach with bilateral cervical exploration and intraoperative parathyroid hormone monitoring was performed unsuccessfully. A mediastinal adenoma was suspected due to meticulous negative neck exploration and repeated negative images for a neck adenoma. Subsequently, a second approach involving mediastinal exploration was performed. After the removal of remnant thymic tissue in the mediastinal space, a significant drop in intraoperative parathyroid hormone levels was achieved. The pathological result confirmed the presence of a tiny pathological parathyroid adenoma within the thymus. At 6 months follow-up, postoperative biochemical assessment was consistent with normal calcium and parathyroid hormone levels.

Parathyroid-on-a-chip simulating parathyroid hormone secretion in response to calcium concentration.

The parathyroid gland is an endocrine organ that plays a crucial role in regulating calcium levels in blood serum through the secretion of parathyroid hormone (PTH). Hypoparathyroidism is a chronic disease that can occur due to parathyroid defects, but due to the difficulty of creating animal models of this disease or obtaining human normal parathyroid cells, the evaluation of parathyroid functionality for drug development is limited. Although parathyroid-like cells that secrete PTH have recently been reported, their functionality may be overestimated using traditional culture methods that lack in vivo similarities, particularly vascularization. To overcome these limitations, we obtained parathyroid organoids from tonsil-derived mesenchymal stem cells (TMSCs) and fabricated a parathyroid-on-a-chip, capable of simulating PTH secretion based on calcium concentration. This chip exhibited differences in PTH secretion according to calcium concentration and secreted PTH within the range of normal serum levels. In addition, branches of organoids, which are difficult to observe in animal models, were observed in this chip. This could serve as a guideline for successful engraftment in implantation therapies in the future.

Update in imaging tests used for the localization of parathyroid pathology.

Preoperative localization of parathyroid pathology, generally a parathyroid adenoma, can be difficult in some cases due to the anatomical variants that these glands present. The objective of this review is to analyse the different imaging techniques used for preoperative localization of parathyroid pathology (scintigraphy, ultrasound, CT, MRI and PET). There is great variability between the different tests for the preoperative localization of parathyroid pathology. The importance of knowing the different diagnostic options lies in the need to choose the most suitable test at each moment and for each patient for an adequate management of primary hyperparathyroidism (PHP) with surgical criteria.

Thyroid and parathyroid function disorders induced by short-term exposure of microplastics and nanoplastics: Exploration of toxic mechanisms and early warning biomarkers.

Human exposure to micro- and nano-plastics (MNPs) primarily occurs through respiration and diet in the environment. However, the early effects and warning signs of MNPs exposure on vertebrates are unclear. Here we used intratracheal instillation and intragastric infusion to establish mouse models for MNPs exposure to systematically investigate the toxic mechanisms of MNPs on endocrine organs. Results showed that MNPs induced endocrine disruptions in short-term exposure by both dietary and respiratory pathways. Microplastics (MPs) exposed through dietary route were more toxic to thyroid gland, whereas nanoplastics (NPs) exhibited the highest level of toxicity to parathyroid gland through respiration. The transcriptome and validation of related functional genes revealed that MNPs affected the synthesis of thyroglobulin by interfering with the expressions of PAX8 and CREB. MNPs also impacted the levels of thyroid stimulating hormone, further mediating the secretion of thyroid hormones. Moreover, MNPs modulate the expression of Mafb, thereby exerting regulatory effects on parathyroid hormone (PTH) synthesis and growth development in parathyroid cells. Meanwhile, MNPs interfered with the expression of IP3R in the calcium signaling pathway, indirectly affecting the secretion of PTH. This study reveals the effects and mechanisms of MNPs on thyroid and parathyroid and highlights the significance of early warning of MNPs exposure.

Gallic acid pretreatment mitigates parathyroid ischemia-reperfusion injury through signaling pathway modulation.

Thyroid surgery often results in ischemia-reperfusion injury (IRI) to the parathyroid glands, yet the mechanisms underlying this and how to ameliorate IRI remain incompletely explored. Our study identifies a polyphenolic herbal extract-gallic acid (GA)-with antioxidative properties against IRI. Through flow cytometry and CCK8 assays, we investigate the protective effects of GA pretreatment on a parathyroid IRI model and decode its potential mechanisms via RNA-seq and bioinformatics analysis. Results reveal increased apoptosis, pronounced G1 phase arrest, and significantly reduced cell proliferation in the hypoxia/reoxygenation group compared to the hypoxia group, which GA pretreatment mitigates. RNA-seq and bioinformatics analysis indicate GA's modulation of various signaling pathways, including IL-17, AMPK, MAPK, transient receptor potential channels, cAMP, and Rap1. In summary, GA pretreatment demonstrates potential in protecting parathyroid cells from IRI by influencing various genes and signaling pathways. These findings offer a promising therapeutic strategy for hypoparathyroidism treatment.

Mechanistic Insights into Tanshinone IIA in the Amelioration of Post-Thyroidectomy Hypoparathyroidism.

BACKGROUND: Thyroidectomy causes impaired blood supply to the parathyroid glands, which leads to hypoparathyroidism. Tanshinone IIA (Tan IIA) is helpful in blood activation and cardiovascular protection. Therefore, the efficacy of Tan IIA in improving hypoparathyroidism was explored in this study. METHODS: New Zealand white rabbits were utilized to establish a unilateral parathyroid gland ischemia injury model. The model was created by selectively ligating the main blood supply vessel of one parathyroid gland, and the rabbits were then divided into three groups receiving 1, 5, and 10 mg/kg of Tan IIA. Serum calcium and parathyroid hormone (PTH) levels were measured using specialized assay kits. Immunohistochemistry was used to assess the microvessel density (MVD) in parathyroid glands. Western blotting (WB) was used to analyze protein expression related to the PI3K/AKT signaling pathway and the pathway-associated HIF-1α and VEGF. Moreover, MMP-2 and MMP-9 involved in angiogenesis were detected by WB. RESULTS: Tan IIA treatment effectively restored serum calcium and PTH levels in a dose-dependent manner. Notably, MVD in the parathyroid glands increased significantly, especially at higher doses. The Tan IIA treatment also elevated the p-PI3K/PI3K and p-AKT/AKT ratios, indicating that the PI3K/AKT pathway was reactivated. Moreover, Tan IIA significantly restored the decreased expression levels of VEGF and HIF-1α caused by parathyroid surgery. Additionally, Tan IIA increased MMP-2 and MMP-9 levels. CONCLUSION: Tan IIA activates the PI3K/AKT pathway, promotes angiogenesis by modulating VEGF, HIF-1α, MMP-2, and MMP-9, thereby further enhancing MVD within the parathyroid glands. This study demonstrates that Tan IIA improved post-thyroidectomy hypoparathyroidism.

[Thoracoscopic resection of recurrent atypically located parathyroid adenoma of anterior mediastinum in a patient with hyperparathyroidism undergoing renal replacement therapy]. / Torakoskopicheskoe udalenie retsidivnoi atipichno raspolozhennoi adenomy okoloshchitovidnoi zhelezy perednego sredosteniya u patsientki s giperparatireozom, nakhodyashcheisya na zamestitel'noi pochechnoi terapii.

We present successful surgical treatment of a patient with chronic kidney disease (CKD) and hyperparathyroidism undergoing renal replacement therapy. At baseline, parathyroidectomy via cervical access was performed for parathyroid adenomas. After 6 years, clinical and laboratory relapse of disease required thoracoscopic resection of atypically located anterior mediastinal adenoma. This case demonstrates that this disease is one of the most difficult in modern medicine requiring a special approach in diagnosis and treatment. Patients with CKD and hyperparathyroidism need for follow-up, control of total and ionized serum calcium, inorganic phosphorus and parathormone, osteodensitometry, ultrasound and scintigraphy of thyroid and parathyroid glands, and, if necessary, CT or MRI of the neck and chest organs.

Impact of autofluorescence-guided surgery of parathyroid glands during total thyroidectomy in experienced surgeons: A randomized clinical trial.

INTRODUCTION: Post-surgical hypoparathyroidism often occurs after total thyroidectomy (TT). The aim of this study is to investigate whether the use of near-infrared autofluorescence (NIRAF) of parathyroid glands (PGs) can aid experienced surgeons in identifying more PGs during surgery, potentially reducing unintended resection, and assessing its impact on post-surgical hypoparathyroidism. MATERIALS AND METHODS: All patients undergoing at least a TT by two experienced surgeons, between 2020 and 2021, were enrolled and randomized into two cohorts: NIRAF group (NG) and CONTROL group (CG). Transient hypoparathyroidism was defined by serum concentration of PTH<12 ng/mL at the 1st post-operative day and permanent by the need of calcium-active vitamin D treatment >6 months from the surgery with still undetectable PTH or <12 ng/m. RESULTS: Among 236 patients (111 in NG, 125 in CG), the number of PGs identified was higher in NG (93.9%, 417/444) compared to CG (81.4%, 407/500) (p < 0.001), with a mean of 3.76 ± 0.44 PGs per patient in NG and 3.25 ± 0.79 in CG. The number of unintendedly resected PGs was 14 in NG and 42 in CG (p < 0.0001). Transient hypoparathyroidism was observed in 18 patients (16.2%) in NG and 40 patients (32.0%) in CG (p = 0.004). Permanent hypoparathyroidism affected 1 patient in NG and 7 patients in CG (p = 0.06). The mean operative time was longer in NG (104.3 ± 32.08 min) compared to CG (85.5 ± 40.62 min) (p < 0.001). CONCLUSIONS: NIRAF enhances the identification of PGs, preventing their inadvertent resection and reducing the overall incidence of post-surgical hypoparathyroidism.

Rare genetic disorders that impair parathyroid hormone synthesis, secretion, or bioactivity provide insights into the diagnostic utility of different parathyroid hormone assays.

PURPOSE OF REVIEW: Parathyroid hormone (PTH) is the major peptide hormone regulator of blood calcium homeostasis. Abnormal PTH levels can be observed in patients with various congenital and acquired disorders, including chronic kidney disease (CKD). This review will focus on rare human diseases caused by PTH mutations that have provided insights into the regulation of PTH synthesis and secretion as well as the diagnostic utility of different PTH assays. RECENT FINDINGS: Over the past years, numerous diseases affecting calcium and phosphate homeostasis have been defined at the molecular level that are responsible for reduced or increased serum PTH levels. The underlying genetic mutations impair parathyroid gland development, involve the PTH gene itself, or alter function of the calcium-sensing receptor (CaSR) or its downstream signaling partners that contribute to regulation of PTH synthesis or secretion. Mutations in the pre sequence of the mature PTH peptide can, for instance, impair hormone synthesis or intracellular processing, while amino acid substitutions affecting the secreted PTH(1-84) impair PTH receptor (PTH1R) activation, or cause defective cleavage of the pro-sequence and thus secretion of a pro- PTH with much reduced biological activity. Mutations affecting the secreted hormone can alter detection by different PTH assays, thus requiring detailed knowledge of the utilized diagnostic test. SUMMARY: Rare diseases affecting PTH synthesis and secretion have offered helpful insights into parathyroid biology and the diagnostic utility of commonly used PTH assays, which may have implications for the interpretation of PTH measurements in more common disorders such as CKD.

Tc-99m-MIBI SPECT/CT imaging to diagnose secondary hyperparathyroidism after parathyroid forearm transplantation.

This article report a 40-year-old male patient who underwent total thyroidectomy and forearm auto-transplantation in another hospital for secondary hyperparathyroidism. After 4 years of follow-up, the level of parathyroid hormone continued to increase, and ultrasound showed nodules in the neck and right forearm, which were considered to be of parathyroid origin. Technetium 99m sestamibi single photon emission computed tomography and computed tomography (Tc-99m-MIBI SPECT/CT) imaging showed increased radioactive uptake in the submuscular soft tissue nodule of the right medial forearm, maximum standardized uptake value (SUVmax) is 0.98, which was identified as transplanted functioning parathyroid tissue. No parathyroid imaging activity was found in the neck. The patient then underwent partial removal of ectopic parathyroid tissue from the right forearm. Pathological examination confirmed parathyroid tissue, and removal was followed by a rapid decline in serum parathyroid hormone levels.

Atypical parathyroid adenoma with severe bone manifestations in early adolescence.

This is a case of primary hyperparathyroidism in a female teenager with multiple fractures and severe bone manifestations. The histopathology revealed atypical parathyroid adenoma, an exceedingly rare form of hyperparathyroidism; its main differential diagnosis is parathyroid carcinoma, as it shares both clinical and histological characteristics with it, in addition to its still uncertain malignant potential.

Contribution of CT scan to patient's radiation exposure in parathyroid SPECT/CT scintigraphy.

INTRODUCTION: Dual phase technetium-99mTc-methoxy isobutyl isonitrile (MIBI) single-photon emission computed tomography with computed tomography (SPECT/CT) may be the most accurate conventional imaging approach for localization of enlarged parathyroid gland (EPG). The imaging is based on the radiopharmaceutical (RP) retention in EPG compared to washout from normal thyroid and normal parathyroid glands. This study aimed to estimate and optimize the contribution of computed tomography (CT) scan and scan range to effective dose (ED) in dual-phase MIBI SPECT/CT parathyroid scintigraphy. METHODS: The study included seventy-four patients; thirty-seven with reduced and thirty-seven with extended CT scan range. The ED caused by the CT scan was calculated using Dose Length Product (DLP) data and estimated using the Imaging Performance Assessment of CT scanners (ImPACT) calculator. RESULTS: For all patients, the contribution of CT to the ED in a combined SPECT/CT examination was 2.62 ± 0.29 mSv (48%). The contribution of CT to the total ED was 1.8 ± 0.18 mSv (33%) when using reduced and 3.44 ± 0.23 mSv (64%) when using extended scan range. The DLP and ED were statistically significantly different between the reduced and extended CT scan range (p < 0.001) in the first and second phases. The individual organ dose was reduced from 8% to 94%. CONCLUSION: The hybrid SPECT/CT improves the interpretation of nuclear medicine images and also increases the radiation dose to the patient. An adequately defined CT scan range on SPECT/CT imaging, can significantly reduce a patient's ED. IMPLICATIONS FOR PRACTICE: The research findings showed that knowledge of anatomy, pathology and technology can provide optimising diagnostic procedures and reduce patient ED after SPECT/CT scans.