Search Results (24)

Background and objectives: The identification and preservation of the parathyroid glands (PGs) are of paramount importance in thyroid surgery. Permanent hypoparathyroidism represents a significant post-operative complication that may result from the surgeon’s failure to accurately identify the PGs or their associated blood supply. Post-operative hypocalcemia (POH) represents the most common surgical complication following thyroid surgery and is the primary factor influencing the post-operative course, causing the requirement of frequent electrolyte monitoring and of supportive therapies, precluding the possibility of early discharge, and resulting also in significant healthcare costs. Near-infrared autofluorescence (NIRAF) employs the intrinsic capacity of PGs to emit fluorescent light when exposed to light within the NIR spectrum. In the context of thyroid surgery, NIRAF represents a safe method with no documented risks to the patient. Materials and Methods: A retrospective analysis was conducted on 383 patients who underwent thyroid surgery at our Institution, either with (n = 27) or without (n = 356) intraoperative NIRAF, focusing on its efficacy in reducing the incidence of POH. Conclusions: Our results suggest that the systematic integration of NIRAF within non-high-capacity centres for cervical surgery, owing to its usefulness in identifying PGs intraoperatively, may strongly contribute to a reduction in the incidence of POH (45.8% without vs. 18.5% with NIRAF; p = 0.0078). This, in turn, has the potential to contribute to a decrease in overall healthcare expenditure. Full article

Introduction: Primary hyperparathyroidism (pHPT) is an endocrine disorder characterized by excessive parathyroid hormone production, typically due to adenomas, hyperplasia, or carcinoma. Preoperative imaging plays a critical role in guiding surgical planning, particularly in selecting patients for minimally invasive procedures. While first-line imaging techniques, such as ultrasound and 99mTc-sestamibi scintigraphy, are standard, advanced second-line imaging modalities like 18F-fluorocholine PET/CT (FCH-PET) and four-dimensional computed tomography (4D-CT) have emerged as valuable tools when initial diagnostics are inconclusive. Methods: This article provides an updated review and recommendations of the role of these advanced imaging techniques in localizing parathyroid adenomas. Results: FCH-PET has shown exceptional sensitivity (94% per patient, 96% per lesion) and is particularly useful in detecting small or ectopic adenomas. Despite its higher sensitivity, it can yield false positives, particularly in the presence of thyroid disease. On the other hand, 4D-CT offers detailed anatomical imaging, aiding in the identification of parathyroids in challenging cases, including recurrent disease and ectopic glands. Studies suggest that FCH-PET and 4D-CT exhibit similar diagnostic performance and could be complementary in preoperative planning of most difficult situations. Conclusions: This article also emphasizes a multimodal approach, where initial imaging is followed by advanced techniques only in cases of uncertainty. Although 18F-fluorocholine PET/CT is favored as a second-line option, 4D-CT remains invaluable for its high spatial resolution and ability to guide surgery in complex cases. Despite limitations in evidence, these imaging modalities significantly enhance the accuracy of parathyroid localization, contributing to more targeted and minimally invasive surgery. Full article

Primary hyperparathyroidism is commonly caused by parathyroid adenomas, hyperplasia, or, rarely, carcinoma. In up to 20% of cases, parathyroid tissue may be ectopic, often located in the mediastinum due to aberrant embryologic migration. Ectopic parathyroid glands pose a diagnostic and therapeutic challenge, and an accurate preoperative localization is essential for an effective and safe resection. Imaging modalities such as CT scan, TC-sestamibi scintigraphy, PET/CT, ultrasonography and MRI are routinely employed, whereas combined techniques offer improved diagnostic accuracy. Emerging approaches, however, including PET/CT with choline tracers, have shown promise in enhancing sensitivity in complex or recurrent cases. When ectopic glands are in the mediastinum, thoracic surgical intervention is required. Traditional open approaches, such as sternotomy or thoracotomy, are associated with significant morbidity. The development and evolution of minimally invasive surgery (MIS) has become the preferred approach in selected cases. When MIS is performed, intraoperative assessment and parathyroid identification are crucial to ensure complete gland removal. Intraoperative parathyroid hormone (ioPTH) monitoring provides real-time confirmation of surgical success. The integration of advanced imaging, intraoperative monitoring, and minimally invasive techniques significantly improves surgical outcomes while minimizing complications and accelerating patient recovery. Ultimately, the effective treatment of ectopic parathyroid glands relies on a personalized approach, adapting both diagnostic and surgical strategies to the unique anatomical and clinical context of each patient. Integration of advanced imaging, intraoperative monitoring, and minimally invasive techniques, combined with a multidisciplinary team involving endocrinologists, radiologists, and thoracic surgeons, is key to optimizing outcomes and reducing patient morbidity. Full article

Patients diagnosed with multiple endocrine neoplasia type-1 (MEN1) often initially present with primary hyperparathyroidism (pHPT), and typically undergo surgical intervention. While laboratory tests are fundamental for diagnosis, imaging is crucial for localizing pathological parathyroids to aid in precise surgical planning. In this pictorial review, we will begin by comprehensively examining key imaging techniques and their established protocols, evaluating their effectiveness in detecting abnormal parathyroid glands. This analysis will emphasize both the advantages and potential limitations within the clinical context of MEN1 patients. Additionally, we will explore integrated imaging approaches that combine multiple modalities to enhance localization accuracy and optimize surgical planning—an essential component of holistic management in MEN1 cases. Various imaging techniques are employed for presurgical localization, including ultrasound (US), multiphase parathyroid computed tomography (CT) scanning (4D CT), magnetic resonance imaging (MRI), and nuclear medicine techniques like single photon emission computed tomography/CT (SPECT/CT) and positron emission tomography/CT (PET/CT). US is non-invasive, readily available, and provides high spatial resolution. However, it is operator-dependent and may have limitations in certain cases, such as intrathyroidal locations, the presence of bulky goiters, thyroid nodules, and previous thyroidectomy. Four-dimensional CT offers dynamic imaging, aiding in the identification of enlarged parathyroid glands, particularly in cases of ectopic or supernumerary glands. Despite concerns about radiation exposure, efforts are underway to optimize protocols and reduce doses, including the use of dual-energy CT. MR imaging offers excellent soft tissue contrast without radiation exposure, potentially providing superior differentiation between parathyroid glands and the surrounding structures. Radionuclide imaging, especially PET/CT using radiopharmaceuticals like [¹⁸F]FCH, shows promising results in localizing parathyroid tumors, particularly in patients with MEN1. [¹⁸F]FCH PET/CT demonstrates high sensitivity and may provide additional information compared to other imaging modalities, especially in cases of recurrent HPT. Full article

Background: Risk of postoperative transient or permanent hypoparathyroidism represents one of the most common complications following total thyroidectomy. This risk increases if a cervical lymphadenectomy procedure must also be performed, as is usually the case in thyroid carcinoma patients. Parathyroid autofluorescence (AF) is a non-invasive method that aids intraoperative identification of parathyroid glands. Methods: In this prospective study, 189 patients with papillary thyroid cancer who underwent total thyroidectomy with central neck dissection were included. Patients were randomly allocated to one of two groups: NAF (no AF, surgery was performed without AF) and the AF group (surgery was performed with AF—Fluobeam LX system, Fluoptics, Grenoble, France). Results: The number of excised lymph nodes was significantly higher in the AF compared to the NAF group, with mean values of 21.3 ± 4.8 and 9.2 ± 4.1, respectively. Furthermore, a significantly higher number of metastatic lymph nodes were observed in the AF group. Transient hypocalcemia recorded significantly lower rates in the AF group with 4.9% compared to 16.8% in the NAF group. Conclusions: AF use during total thyroidectomy with central neck dissection for papillary thyroid carcinoma patients, decreased the rate of iatrogenic parathyroid gland lesions, and increased the rate of lymphatic clearance. Full article

Hypoparathyroidism is the most frequent complication in thyroid surgery. The aim of this study was to evaluate the impact of intraoperative parathyroid gland identification, using autofluorescence imaging, on the rate of post-operative (PO) hypoparathyroidism in thyroid cancer surgery. Patients undergoing total thyroidectomy with central neck dissection from 2018 to 2022 were included. A prospective cohort of 77 patients operated on using near-infrared autofluorescence (NIRAF+) with the Fluobeam^® (Fluoptics, Grenoble, France) system was compared to a retrospective cohort of 94 patients (NIR−). The main outcomes were the rate of PO hypocalcemia, with three cutoffs: corrected calcium (Cac) < 2.10 mmol/L, <2.00 mmol/L and <1.875 mmol/L, and the rate of permanent hypoparathyroidism, at 12 months. The rate of PO Cac < 2.10 mmol/L was statistically lower in the NIRAF+ group, compared to the control group (36% and 60%, p = 0.003, respectively). No statistically significant difference was observed for the other two thresholds. There was a lower rate of permanent hypoparathyroidism in the NIRAF+ group (5% vs. 14% in the control group), although not statistically significant (p = 0.07). NIRAF is a surgically non-invasive adjunct, and can improve patients’ outcomes for thyroid cancer surgery by reducing post-operative temporary hypoparathyroidism. Larger prospective studies are warranted to validate our findings. Full article

Our objective was to overview the most recent data on primary hyperparathyroidism (PHP) in children and teenagers from a multidisciplinary perspective. Methods: narrative review based on full-length, English-language papers (from PubMed, between January 2020 and July 2023). Results: 48 papers (14 studies of ≥10 subjects/study, and 34 case reports/series of <10 patients/study). Study-sample-based analysis: except for one case–control study, all of the studies were retrospective, representing both multicenter (n = 5) and single-center (n = 7) studies, and cohort sizes varied from small (N = 10 to 19), to medium-sized (N = 23 to 36) and large (N = 63 to 83); in total, the reviewed studies covered 493 individuals with PHP. Case reports/series (n = 34, N = 41): the mean ages studied varied from 10.2 to 14 years in case reports, and the mean age was 17 years in case series. No clear female predominance was identified, unlike that observed in the adult population. Concerning the assessments, there were four major types of endpoints: imaging data collection, such as ultrasound, 99mTc Sestamibi, or dual-phase computed tomography (CT); gene testing/familial syndrome identification; preoperative findings; and exposure to surgical outcome/preoperative drugs, like cinacalcet, over a 2.2-year median (plus two case reports of denosumab used as an off-label calcium-lowering agent). Single-gland cases (representing 85% of sporadic cases and 19% of genetic PHP cases) showed 100% sensitivity for neck ultrasounds, with 98% concordance with 99mTc Sestamibi, as well as a 91% sensitivity for dual-phase CT, with 25% of the lesions being ectopic parathyroids (mostly mediastinal intra-thymic). Case reports included another 9/41 patients with ectopic parathyroid adenomas, 3/41 with parathyroid carcinomas, and 8/41 subjects with brown tumors. Genetic PHP (which has a prevalence of 5–26.9%) mostly involved MEN1, followed by CDC73, CASR, RET, and CDKN1B, as well as one case of VHL. Symptomatic PHP: 70–100% of all cases. Asymptomatic PHP: 60% of genetic PHP cases. Renal involvement: 10.5% of a cohort with genetic PHP, 71% of sporadic PHP cases; 50% (in a cohort with a mean age of 16.7), 29% (in a cohort with a mean age of 15.2); 0% (in infancy) to 50–62% (in teenagers). Bone anomalies: 83% of the children in one study and 62% of those in two other studies. Gastrointestinal issues: 40% of one cohort, but the data are heterogeneous. Cure rate through parathyroidectomy: 97–98%. Recurrent PHP: 2% of sporadic PHP cases and 38% of familial PHP cases. Hungry bone syndrome: maximum rate of 34–40%. Case reports identified another 7/41 subjects with the same post-parathyroidectomy condition; a potential connection with ectopic presentation or brown tumors is suggested, but there are limited data. Minimally invasive thoracoscopic approaches for ectopic tumors seemed safe. The current level of statistical evidence on pediatric PHP qualifies our study- and case-sample-based analysis (n = 48, N = 534) as one of the largest of its kind. Awareness of PHP is the key factor to benefit our young patients. Full article

Background and Objectives: Surgical treatment for primary hyperparathyroidism (PHPT) has evolved from bilateral exploration through a long transcervical incision to focused parathyroidectomy with a minimal incision above the pathologic gland. Recently, endoscopic or robot-assisted parathyroid surgery without direct neck incision has been introduced. The aim of this study was to investigate the effectiveness of indocyanine green (ICG) fluorescence as a new method for the visual identification of abnormal hyperfunctioning parathyroid glands in robot-assisted parathyroidectomy using Firefly^TM technology. We also aimed to conduct a comparative analysis between robot-assisted parathyroidectomy and conventional focused parathyroidectomy in order to identify clinical differences between the two surgical approaches. Materials and Methods: A total of 37 patients with PHPT underwent parathyroidectomy at a single university hospital between September 2018 and December 2022. Thirty-one patients underwent open focused parathyroidectomy (open group), and six patients underwent robot-assisted parathyroidectomy (robot group). Pre-operative localization via parathyroid SPECT-CT and an intraoperative parathyroid hormone (IOPTH) assay were used to successfully remove the pathologic parathyroid in both groups. ICG was administered only in the robot group. Results: Pathologic parathyroid showed a persistent fluorescence pattern under near-infrared vision. After the removal of the fluorescent parathyroid gland, IOPTH was normalized in all six patients in the robot group. However, the open group showed shorter hospital stays (1.8 ± 1.2 vs. 3.0 ± 0.0 days, p < 0.001) and shorter operation times (91.1 ± 69.1 vs. 152.5 ± 23.6 min, p = 0.001) than the robot group. After 6 months of surgery, PTH, calcium, and ionized calcium levels were all normalized without significant differences between the groups. Conclusions: Robot-assisted parathyroidectomy using ICG is helpful for the visual identification of the pathologic parathyroid gland. The advantage of robot parathyroidectomy is a better cosmetic outcome. However, it still does not show better clinical outcomes than conventional open focused parathyroidectomy. Full article

Objective: Hypoparathyroidism is a known complication of total laryngectomy, although parathyroid preservation and/or reimplantation are not routine. Autofluorescence is a new technique for identifying parathyroid glands intraoperatively. The aim of this study was to evaluate the feasibility of autofluorescence in this context. Materials and Methods: A retrospective study of patients undergoing total laryngectomy/pharyngectomy with concomitant thyroidectomy using the Fluobeam^® (Fluoptics, Grenoble, France) and frozen section of a parathyroid fragment in case of reimplantation. The rates of identification using autofluorescence, reimplantation, and hypoparathyroidism were evaluated. Results: Eighteen patients (16 males, median age 67) underwent total laryngectomy/pharyngectomy with total thyroidectomy (n = 12) or hemithyroidectomy (n = 6). A median of 2 parathyroid glands were identified per patient. Ninety-two percent were identified by autofluorescence before visualisation. All parathyroids were reimplanted due to devascularization. Temporary hypoparathyroidism occurred in nine patients, and was permanent in one patient. After 34 months of median follow-up (range 1–49), no tumor recurrence was observed in the reimplantation sites. Conclusions: To our knowledge, this is the largest study to evaluate autofluorescence during total laryngectomy with thyroidectomy. No tumor recurrence occurred in the sites of parathyroid reimplantation. Full article

Horner’s syndrome (HS), caused by lesions of the 3-neuron oculosympathetic nerve pathway (ONP), includes the triad: blepharoptosis, miosis and anhidrosis (ipsilateral with ONP damage). Thyroid–related HS represents an unusual entity underling thyroid nodules/goiter/cancer–HS (T-HS), and post-thyroidectomy HS (Tx-HS). We aim to overview Tx-HS. This is a narrative review. We revised PubMed published, full-length, English papers from inception to November 2022. Additionally, we introduced data on post-thyroidectomy lymphocele/chylous leakage (Tx-L), and introduced a new pediatric case with both Tx-HS and Tx-L. Tx-HS: the level of statistical evidence varies from isolated case reports, studies analyzing the large panel of post-thyroidectomy complications reporting HS among the rarest side effects (as opposite to hypocalcemia), or different series of patients with HS due to various disorders, including T-HS/Tx-HS. Tx-HS is related to benign or malignant thyroid conditions, regardless the type of surgery. A pre-operatory rate of T-HS of 0.14%; a post-operatory rate of Tx-HS between 0.03% and 5% (mostly, 0.2%) are identified; a possible higher risk on endoscopic rather than open procedure is described. Incomplete HS forms, and pediatric onset are identified, too; the earliest identification is after 2 h since intervention. A progressive remission is expected in most cases within the first 2–6 months to one year. The management is mostly conservative; some used glucocorticoids and neurotrophic agents. One major pitfall is an additional contributor factor like a local compression due to post-operatory collections (hematoma, cysts, fistula, Tx-L) and their correction improves the outcome. The prognostic probably depends on the severity of cervical sympathetic chain (CSC) lesions: indirect, mild injury due to local compressive masses, intra-operatory damage of CSC like ischemia and stretching of CSC by the retractor associate HS recovery, while CSC section is irreversible. Other iatrogenic contributors to HS are: intra-operatory manipulation of parathyroid glands, thyroid microwave/radiofrequency ablation, and high-intensity focused ultrasound, and percutaneous ethanol injection into thyroid nodules. Tx-L, rarely reported (mostly <0.5%, except for a ratio of 8.3% in one study), correlates with extended surgery, especially lateral/central neck dissection, and the presence of congenitally—aberrant lymphatic duct; it is, also, described after endoscopic procedures and chest-breast approach; it starts within days after surgery. Typically low-fat diet (even fasting and parental nutrition) and tube drainage are useful (as part of conservative management); some used octreotide, local sealing solutions like hypertonic glucose, Viscum album extract, n-Butyl-2-cyanoacrylate. Re-intervention is required in severe cases due to the risk of lymphorrhoea and chylothorax. Early identification of Tx-HS and Tx-L improves the outcome. Some iatrogenic complications are inevitable and a multifactorial model of prediction is still required, also taking into consideration standardized operatory procedures, skillful intra-operatory manipulation, and close post-operatory follow-up of the patients, especially during modern era when thyroid surgery registered a massive progress allowing an early discharge of the patients. Full article

The seminal discoveries that parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23) are major endocrine regulators of vitamin D metabolism led to a significant improvement in our understanding of the pivotal roles of peptide hormones and small proteohormones in the crosstalk between different organs, regulating vitamin D metabolism. The interaction of vitamin D, FGF23 and PTH in the kidney is essential for maintaining mineral homeostasis. The proteohormone FGF23 is mainly secreted from osteoblasts and osteoclasts in the bone. FGF23 acts on proximal renal tubules to decrease production of the active form of vitamin D (1,25(OH)₂D) by downregulating transcription of 1α-hydroxylase (CYP27B1), and by activating transcription of the key enzyme responsible for vitamin D degradation, 24-hydroxylase (CYP24A1). Conversely, the peptide hormone PTH stimulates 1,25(OH)₂D renal production by upregulating the expression of 1α-hydroxylase and downregulating that of 24-hydroxylase. The circulating concentration of 1,25(OH)₂D is a positive regulator of FGF23 secretion in the bone, and a negative regulator of PTH secretion from the parathyroid gland, forming feedback loops between kidney and bone, and between kidney and parathyroid gland, respectively. In recent years, it has become clear that vitamin D signaling has important functions beyond mineral metabolism. Observation of seasonal variations in blood pressure and the subsequent identification of vitamin D receptor (VDR) and 1α-hydroxylase in non-renal tissues such as cardiomyocytes, endothelial and smooth muscle cells, suggested that vitamin D may play a role in maintaining cardiovascular health. Indeed, observational studies in humans have found an association between vitamin D deficiency and hypertension, left ventricular hypertrophy and heart failure, and experimental studies provided strong evidence for a role of vitamin D signaling in the regulation of cardiovascular function. One of the proposed mechanisms of action of vitamin D is that it functions as a negative regulator of the renin-angiotensin-aldosterone system (RAAS). This finding established a novel link between vitamin D and RAAS that was unexplored until then. During recent years, major progress has been made towards a more complete understanding of the mechanisms by which FGF23, PTH, and RAAS regulate vitamin D metabolism, especially at the genomic level. However, there are still major gaps in our knowledge that need to be filled by future research. The purpose of this review is to highlight our current understanding of the molecular mechanisms underlying the interaction between vitamin D, FGF23, PTH, and RAAS, and to discuss the role of these mechanisms in physiology and pathophysiology. Full article

Parathyroid scintigraphy with 99mTc-sestamibi (MIBI) is an established technique for localising abnormal parathyroid glands (PGs). However, the identification and localisation of PGs require much attention from medical experts and are time-consuming. Artificial intelligence methods can offer an assisting solution. This retrospective study enrolled 632 patients who underwent parathyroid scintigraphy with double-phase and thyroid subtraction techniques. The study proposes a three-path approach, employing the state-of-the-art convolutional neural network called VGG19. Images input to the model involved a set of three scintigraphic images in each case: MIBI early phase, MIBI late phase, and 99mTcO4 thyroid scan. A medical expert’s diagnosis provided the ground truth for positive/negative results. Moreover, the visualised suggested areas of interest produced by the Grad-CAM algorithm are examined to evaluate the PG-level agreement between the model and the experts. Medical experts identified 545 abnormal glands in 452 patients. On a patient basis, the deep learning (DL) model attained an accuracy of 94.8% (sensitivity 93.8%; specificity 97.2%) in distinguishing normal from abnormal scintigraphic images. On a PG basis and in achieving identical positioning of the findings with the experts, the model correctly identified and localised 453/545 glands (83.1%) and yielded 101 false focal results (false positive rate 18.23%). Concerning surgical findings, the expert’s sensitivity was 89.68% on patients and 77.6% on a PG basis, while that of the model reached 84.5% and 67.6%, respectively. Deep learning in parathyroid scintigraphy can potentially assist medical experts in identifying abnormal findings. Full article

Medullary thyroid carcinoma (MTC) is a neoplasm originating from parafollicular C cells. MTC is a rare disease, but its prognosis is less favorable than that of well-differentiated thyroid cancers. To improve the prognosis of patients with MTC, early diagnosis and prompt therapeutic management are crucial. In the following paper, recent advances in laboratory and imaging diagnostics and also pharmacological and surgical therapies of MTC are discussed. Currently, a thriving direction of development for laboratory diagnostics is immunohistochemistry. The primary imaging modality in the diagnosis of MTC is the ultrasound, but opportunities for development are seen primarily in nuclear medicine techniques. Surgical management is the primary method of treating MTCs. There are numerous publications concerning the stratification of particular lymph node compartments for removal. With the introduction of more effective methods of intraoperative parathyroid identification, the complication rate of surgical treatment may be reduced. The currently used pharmacotherapy is characterized by high toxicity. Moreover, the main limitation of current pharmacotherapy is the development of drug resistance. Currently, there is ongoing research on the use of tyrosine kinase inhibitors (TKIs), highly specific RET inhibitors, radiotherapy and immunotherapy. These new therapies may improve the prognosis of patients with MTCs. Full article

Background: Postoperative hypoparathyroidism is the most common complication after total thyroidectomy. Over the past years, optical imaging techniques, such as parathyroid autofluorescence, indocyanine green (ICG) angiography, and laser speckle contrast imaging (LSCI) have been employed to save parathyroid glands during thyroid surgery. This study provides an overview of the utilized methods of the optical imaging techniques during total thyroidectomy for parathyroid gland identification and preservation. Methods: PUBMED, EMBASE and Web of Science were searched for studies written in the English language utilizing parathyroid autofluorescence, ICG-angiography, or LSCI during total thyroidectomy to support parathyroid gland identification or preservation. Case reports, reviews, meta-analyses, animal studies, and post-mortem studies were excluded after the title and abstract screening. The data of the studies were analyzed qualitatively, with a focus on the methodologies employed. Results: In total, 59 articles were included with a total of 6190 patients. Overall, 38 studies reported using parathyroid autofluorescence, 24 using ICG-angiography, and 2 using LSCI. The heterogeneity between the utilized methodology in the studies was large, and in particular, regarding study protocols, imaging techniques, and the standardization of the imaging protocol. Conclusion: The diverse application of optical imaging techniques and a lack of standardization and quantification leads to heterogeneous conclusions regarding their clinical value. Worldwide consensus on imaging protocols is needed to establish the clinical utility of these techniques for parathyroid gland identification and preservation. Full article

Patients with primary hyperparathyroidism (pHPT) can develop persistent (P-pHPT) or recurrent (R-pHPT) disease after parathyroidectomy. Before recommending reoperation, recurrence must be accurately identified because of the high risk of complications. Our study evaluates ¹⁸F-fluorocholine (¹⁸F-FCH) PET/CT and 4D-CT integrated in PET/4D-CT in patients with P-pHPT/R-pHPT. Patients with P-pHPT/R-pHPT investigated by ¹⁸F-FCH PET/4D-CT between May 2018 and March 2021 were retrospectively included. Forty-two patients were included, 37 of whom underwent 4D-CT. The sensitivity and detection rate (DR%) were 95% and 88% for ¹⁸F-FCH PET/CT and 70% and 63% for 4D-CT, respectively. PET/CT and 4D-CT were concordant in 18/24 glands and concordant and positive in 15/24 (63%) glands. Discordant results were obtained for 6/24 glands. The surgical success rate was 65%. PET/CT showed significantly higher sensitivity than 4D-CT. Dynamic CT allowed the identification of no additional glands missed by PET/CT, and the combination of the 2 techniques did not improve the sensitivity or DR%. ¹⁸F-FCH PET/CT appears to be a valuable technique to accurately detect hyperfunctioning parathyroid tissue in patients with P-pHPT/R-pHPT and is better than 4D-CT. Except for cases with doubtful locations of PET targets that may require 4D-CT for surgical guidance, standard nonenhanced ¹⁸F-FCH PET/CT can be effectively recommended in patients with P-pHPT/R-pHPT before reoperation. Full article