Search Results (38)

The widespread adoption of prostate-specific membrane antigen (PSMA)-targeted PET/CT has profoundly reshaped molecular imaging in prostate cancer and has substantially reduced the routine use of radiolabeled choline tracers. However, the transition from choline to PSMA imaging should not be interpreted simply as the replacement of one radiopharmaceutical by another, but rather as part of a broader evolution from metabolism-based imaging toward receptor-targeted and biology-driven imaging strategies. This narrative review critically reassesses the residual and emerging role of choline PET/CT in the PSMA era, with particular attention to the biological rationale of choline uptake, selected prostate cancer scenarios, and extra-prostatic applications. In prostate cancer, PSMA PET/CT remains the dominant imaging modality because of its superior diagnostic performance, particularly in biochemical recurrence; nevertheless, choline PET/CT may provide complementary metabolic information in highly selected settings, including PSMA-low or heterogeneous disease, aggressive or dedifferentiated variants, neuroendocrine transformation, equivocal PSMA findings, and limited PSMA availability. These prostate cancer applications, however, are supported mainly by biological rationale, indirect evidence, and limited clinical data and should therefore be regarded as exploratory rather than established indications. By contrast, ¹⁸F-fluorocholine PET/CT has emerged as a clinically established imaging modality in primary hyperparathyroidism, particularly after negative or inconclusive conventional imaging, with prospective studies and meta-analyses demonstrating high detection rates and superior performance compared with conventional scintigraphic techniques. Additional applications in hepatocellular carcinoma and selected neuro-oncologic settings remain exploratory and require further validation. Overall, choline PET/CT should not be considered obsolete in the PSMA era, but selectively repositioned within biology-driven and multiparametric imaging strategies, with its strongest evidence currently supporting primary hyperparathyroidism and its other applications requiring cautious interpretation and further prospective validation. Full article

Background: Radiotherapy (RT) combined with androgen deprivation therapy (ADT) is a standard treatment for non-metastatic high-risk (HR) prostate cancer (PC). However, the benefit of elective nodal irradiation (ENI) in clinically node-negative (cN0) patients, although suggested, remains controversial, particularly in the elderly. We report the outcomes of elderly HR PC patients treated with prostate-only RT (PORT) and ADT in a “real-word” setting. Methods: Between 2016 and 2022, 43 consecutive elderly patients (median age 76 years) with HR- or very HR-PC according to NCCN criteria version 1.2026 (cN0, cT3-cT4 and/or ISUP Grade Group 4–5 and/or PSA serum levels at diagnosis ≥ 20 ng/mL) were treated at our institution. All patients were staged with abdominal MRI or CT and bone scan; nineteen patients (44.2%) also underwent 68Ga-PSMA-11 or 18F-fluorocholine PET/CT. All patients received PORT (predominantly moderate hypofractionation, 67.5–70 Gy in 25–28 fractions) and ADT (median duration 24 months). To ensure consistency, all oncological endpoints—Biochemical Failure-Free Survival (BFFS; Phoenix criteria), Disease-Free Survival (DFS), Metastasis-Free Survival (MFS), Prostate Cancer-Specific Survival (PCSS), and Overall Survival (OS)—were calculated from a unified time-zero (initiation of first oncological treatment). DFS was defined as a composite endpoint including biochemical failure, radiological recurrence, or initiation of salvage therapy. Results: at a median follow-up of 60 months, no patient reached the Phoenix threshold, resulting in a 100% 5- and 7-year BFFS. However, 4 patients (9.3%) experienced radiological recurrence detected via PET/CT before reaching the nadir + 2 threshold, yielding an estimated 5-year and 7-year DFS of 94.7% and 71.8%, respectively. The 5- and 7-year MFS was of 97.6% and 88.7%, respectively. Seven deaths occurred, all non-PC related, resulting in a 5-year OS of 86.7% and a Prostate Cancer-Specific Survival of 100%. Gastrointestinal toxicity was notably low (no acute or late G3-G4 events). Conclusions: Our findings suggest that PORT, when combined with long-term ADT and modern staging, provides excellent disease control and a favorable safety profile in elderly HR PC patients. Given the high rate of competing mortality in this population, treatment de-escalation via PORT appears to be a clinically reasonable strategy. These results are hypothesis-generating and warrant validation in prospective randomized trials. Full article

In this case report, we described the pitfalls in the differential diagnosis of a pituitary stalk lesion in a patient affected by Klinefelter Syndrome (KS) that was initially suspected of infundibulo-neuro-hypophysitis (INH). According to the atypical radiological picture for INH, the not-conclusive pathology findings, and the partial response to glucocorticoid treatment, a [18F] fluorocholine ([18F] FCH) positron emission computed tomography (PET-CT) scan was performed and identified a pituitary stalk proliferative lesion that was suggestive for neoplasia. This clinical case emphasizes the prospective and potential diagnostic role of the [18F] FCH PET-CT in pituitary stalk lesions and in the diagnosis of pituitary germinoma. Our article also includes a brief review of the literature, focusing on the differential diagnosis of lesions involving the pituitary stalk, the oncological risk associated with KS, and the role of nuclear imaging in the evaluation of such cases. Full article

Parathyroid carcinoma (PC) is an exceedingly rare endocrine malignancy, accounting for less than 1% of all primary hyperparathyroidism (pHPT) cases. It typically presents with pronounced hypercalcemia and markedly elevated parathyroid hormone (PTH) levels. Accurate imaging plays a pivotal role in diagnosis, staging, surgical planning, and long-term surveillance, although differentiating PC from benign disease on imaging remains a significant challenge. A multimodal imaging strategy combining cervical ultrasonography (US) and nuclear medicine techniques provides high sensitivity for lesion detection. Ultrasonography with advanced detective flow imaging allows detailed anatomical assessment and evaluation of vascular patterns of the primary tumor. [^99mTc]Tc-methoxyisobutylisonitrile ([^99mTc]Tc-MIBI) scintigraphy frequently demonstrates prolonged tracer retention in PC, while [¹⁸F]fluorocholine positron emission tomography/computed tomography (PET/CT) and positron emission tomography/magnetic resonance (PET/MR) imaging have shown superior performance for detecting both primary tumors and metastatic disease due to its higher spatial resolution and higher molecular sensitivity. [¹⁸F]FDG PET serves as an adjunct modality for identifying aggressive, metabolically active lesions. Emerging radiotracers such as [¹⁸F]-fibroblast activation protein inhibitor ([¹⁸F]FAPI) and [⁶⁸Ga]Ga-trivehexin have shown potential in cases where initial imaging is inconclusive. Theranostic strategies that integrate molecular imaging with targeted radioligand therapy may transform PC management by enabling personalized treatment approaches tailored to each tumor’s biological and imaging characteristics. This review aims to evaluate available imaging modalities for PC diagnosis and provide guidance for their clinical application. Full article

Background: Meta-analyses on the prevalence and clinical significance of breast incidental uptake (BIU) at PET/CT are available only for [¹⁸F]FDG, showing that BIU is rare but malignant in a substantial proportion of cases. This study aimed to update the pooled prevalence and malignancy risk of BIU using different PET radiotracers, expanding [¹⁸F]FDG-based evidence. Methods: A comprehensive literature search of studies on BIU was carried out in two bibliographic databases, and the literature was screened up to 25 May 2025. Only original articles reporting BIU were selected. A proportion meta-analysis was conducted on a patient-based analysis using a random-effects model to estimate pooled prevalence, malignancy rate, and histological distribution. Results: In total, 29 studies were included in the systematic review and meta-analysis. PET/CT was performed using [¹⁸F]FDG (n = 25), radiolabeled somatostatin analogues (SSAs) (n = 3), or [¹⁸F]fluorocholine (n = 1). The pooled prevalence of BIU was 0.5% for [¹⁸F]FDG PET/CT, 3.4% for SSA PET/CT, and 2.6% for [¹⁸F]fluorocholine. The pooled malignancy rate among BIUs (female patients) was 33.5% for [¹⁸F]FDG, 86.4% for SSA, and 70% for [¹⁸F]fluorocholine PET/CT. Histological data were mainly available for [¹⁸F]FDG PET/CT, showing ductal carcinoma as the most frequent malignant histotype (pooled value 42.2%) and fibroadenoma (pooled value 14.8%) as the most frequent benign histotype. Conclusions: Similar to the case for [¹⁸F]FDG, BIU using other PET radiopharmaceuticals is uncommon but often malignant. Therefore, BIU should prompt dedicated breast imaging and, when indicated, histopathological confirmation. Further well-designed studies are needed to clarify the clinical impact of BIU detection and the prevalence and clinical significance of BIU using tracers other than [¹⁸F]FDG. Full article

Background: Hypophosphatemia is a frequently underestimated metabolic disorder, yet it can be one of the first biochemical findings in primary hyperparathyroidism (PHPT). Current diagnostic and surgical criteria for PHPT do not include serum phosphate, despite its potential value as an early marker. Methods: We report the case of a 79-year-old woman with type 2 diabetes mellitus, hypertension and osteoarthritis, followed since 2015 for persistent hypophosphatemia (0.8 mg/dL) and stress fractures. Results: Initial calcium and vitamin D levels were normal, but PTH was elevated. Bone scintigraphy revealed multiple stress fractures, while ultrasound and sestamibi scan were inconclusive. Despite cholecalciferol and calcitriol supplementation, hypophosphatemia persisted. From 2023, progressive hypercalcemia developed (10.9 mg/dL), with sustained hypophosphatemia (1.7 mg/dL), persistently high PTH (121 pg/mL) and markedly elevated FGF-23 (1694 kRU/L). Renal phosphate wasting was demonstrated, with reduced tubular reabsorption. An 18F-fluorocholine PET-CT performed in 2024 identified two right parathyroid adenomas, establishing the diagnosis of PHPT. The patient was referred for parathyroidectomy. Conclusions: Hypophosphatemia may serve as a complementary biomarker in the diagnostic and therapeutic approach to PHPT, but only after other potential causes of low phosphate levels have been excluded, as illustrated in this case. Its consideration could facilitate the early identification of PHPT and improve clinical decision-making, particularly in patients who do not meet classical surgical indications. Full article

Background/Objectives: This study aims to evaluate the additional value of [¹⁸F]F-fluorocholine ([¹⁸F]F-FCH) PET/CT over contrast-enhanced magnetic resonance imaging (CE-MRI) in detecting the recurrence of brain metastases (BMs) after stereotactic radiosurgery (SRS) in patients with lung cancer brain metastases (LCBMs). Methods: Thirty-one patients with suspected recurrence of BM in LCBM after SRS were enrolled in this retrospective study. They underwent both [¹⁸F]F-FCH PET/CT and CE-MRI within 2 weeks. The tumor imaging parameters and clinical features were analyzed. The results of histopathology or radiographic follow-up served as the reference standard for the final diagnosis. Results: In these 31 patients, there were 54 lesions, of which 27 lesions were proven to be BM recurrence, while 27 lesions were non-recurrence. [¹⁸F]F-FCH PET/CT showed high radiotracer uptake in recurrent lesions of BM and identified 24 positive lesions (88.89% of sensitivity), while CE-MRI indicated 23 positive lesions (85.19% of sensitivity). [¹⁸F]F-FCH PET/CT indicated higher specificity (81.48%) and accuracy (85.19%) in detecting recurrence of BM than CE-MRI (40.74% and 62.96%, both p < 0.05), particularly in frontal lobes and cerebella. For lesion sizes, the accuracy of [¹⁸F]F-FCH PET/CT in detecting recurrent lesions was higher than that of CE-MRI for lesions over 1.0 cm but below 2.0 cm (p = 0.016). The detective performance of [¹⁸F]F-FCH PET/CT combined with CE-MRI was higher than [¹⁸F]F-FCH PET/CT or CE-MRI alone (all p < 0.05). Interestingly, TLC (≥4.11) was significantly correlated with poor intracranial PFS (iPFS), meaning it was a significant prognostic factor for iPFS. Conclusions: This study identified that compared with CE-MRI, [¹⁸F]F-FCH PET/CT demonstrated higher specificity and accuracy in diagnosing recurrence of BM in LCBM after SRS. Combining [¹⁸F]F-FCH PET/CT with CE-MRI has the potential to improve diagnostic performance for recurrence of BM and management of patient treatment. TLC was an independent risk factor for iPFS. 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

Objectives: Primary hyperparathyroidism (PHPT) is associated with normal or elevated calcium levels and affects bone mineral density. The proportion of cases predisposed to metabolic bone disease is unknown in patients with PHPT. The aim of this study was to assess bone mineral density and bone quality in patients with normo- or hypercalcemic primary hyperparathyroidism undergoing baseline parathyroid gland assessment with [¹⁸F]fluorocholine PET/CT imaging. Methods: A total of 140 consecutive patients were enrolled in this observational study. All patients with normo- or hypercalcemic primary hyperparathyroidism underwent dual-energy X-ray absorptiometry (DXA) for assessment of bone mineral density (BMD) and trabecular bone score (TBS). [¹⁸F]fluorocholine PET/CT was performed in all patients for the detection and localization of parathyroid adenoma. Hyper- and normocalcemic patients were compared with regard to the proportion of osteoporosis and osteopenia, T-Score, TBS, serum calcium, phosphorus and parathyroid hormone levels, the maximum standardized uptake value (SUVmax) in PET/CT imaging, and laboratory results. Results: The majority of patients was female (88.57%) and had a pathologic bone mineral density (52.86%). Overall, 33 patients had osteoporosis and 41 osteopenia. The mean lumbar T-Score was −1.48 (SD 1.37) and the T-Score of the femoral neck was −1.21 (SD 0.92). Mean TBS was also decreased (−2.13). No difference was found between normo- or hypercalcemic patients regarding bone metabolism and imaging parameters. Conclusions: More than half of patients with normo- or hypercalcemic PHPT showed abnormal BMD. First-line [¹⁸F]fluorocholine PET/CT identified parathyroid adenoma in a high proportion of patients, even in patients with normocalcemic PHPT. The early evaluation of metabolic bone disease seems desirable in clinical management of females with PHPT. Full article

Background: Primary hyperparathyroidism is a common endocrine disorder characterised by excessive parathormone secretion that results in hypercalcemia, primarily caused by parathyroid adenoma. Accurate localisation of hyperfunctioning tissue is essential for curative surgical treatment. Although conventional imaging modalities like ultrasonography and ^99mTc-MIBI scintigraphy (SPECT) along with ¹⁸F-fluorocholine PET/CT are commonly employed, there are cases with false-negative imaging results. Case presentation: This case report presents a patient with primary hyperparathyroidism and a parathyroid adenoma detected solely through ⁶⁸Ga-PSMA-11 PET/CT, typically used for prostate cancer diagnosis. The lesion observed in the PET/CT was confirmed as a parathyroid adenoma through laboratory evaluation, while other imaging techniques failed to detect it. Conclusions: This finding suggests that the PSMA ligands’ particular affinity for neovascularisation in focal changes may facilitate the visualisation of parathyroid adenomas. The utilisation of ⁶⁸Ga-PSMA-11 PET/CT in primary hyperparathyroidism could potentially improve the preoperative localization of parathyroid adenomas when conventional imaging methods are inconclusive. Full article

Purpose: We aimed to develop a nomogram able to predict treatment failure, skeletal events, and overall survival (OS) in patients with castration-resistant prostate cancer with bone metastases (CRPC-BM) treated with Radium-223 dichloride (²²³Ra). Patients and Methods: Patients from the Castilla-La Mancha Spanish region were prospectively included in the ChoPET-Rad multicenter study from January 2015 to December 2022. Patients underwent baseline, interim, and end-of-treatment bone scintigraphy (BS) and ¹⁸F-Fluorocholine PET/CT (FCH PET/CT) scans, obtaining multiple imaging radiomics as well as clinical and biochemical variables during follow-up and studying their association with the previously defined end-points. Survival analysis was performed using the Kaplan–Meier method and Cox regression. Multivariate logistic and Cox regression models were calculated, and these models were depicted by means of nomograms. Results: Median progression-free survival (PFS) and OS were 4 and 14 months (mo), respectively. The variables that showed independent and significant association with therapeutic failure were baseline alkaline phosphatase (AP) levels (p = 0.022) and the characteristics of BM on the CT portion of PET/CT (p = 0.017). In the case of OS, the significant variables were therapeutic failure (p = 0.038), the number of lines received after ²²³Ra (p < 0.001), average SUVmax (p = 0.002), bone marrow infiltration in FCH PET/CT (p = 0.006), and interim FCH PET/CT response (p = 0.048). Final nomograms included these variables, showing good discrimination among the 100 patients included in our study. In the study of skeletal events, only OS showed a significant association in the multivariate analysis, resulting in an inconsistent nomogram design. Conclusions: FCH PET/CT appears to be a good tool for evaluating patients eligible for treatment with ²²³Ra, as well as for their follow-up. Thus, findings derived from it, such as the morphological characteristics of BM in the CT, bone marrow infiltration, or the response to ²²³Ra in the interim study, have proven to be solid and useful variables in the creation of nomograms for predicting therapeutic failure and OS. Full article

Parathyroid pathologies are suspected based on the biochemical alterations and clinical manifestations, and the predominant roles of imaging in primary hyperparathyroidism are localisation of tumour within parathyroid glands, surgical planning, and to look for any ectopic parathyroid tissue in the setting of recurrent disease. This article provides a comprehensive review of embryology and anatomical variations of parathyroid glands and their clinical relevance, surgical anatomy of parathyroid glands, differentiation between multiglandular parathyroid disease, solitary adenoma, atypical parathyroid tumour, and parathyroid carcinoma. The roles, advantages and limitations of ultrasound, four-dimensional computed tomography (4DCT), radiolabelled technetium-99 (^99mTc) sestamibi or dual tracer ^99mTc pertechnetate and ^99mTc-sestamibi with or without single photon emission computed tomography (SPECT) or SPECT/CT, dynamic enhanced magnetic resonance imaging (4DMRI), and fluoro-choline positron emission tomography (¹⁸F-FCH PET) or [¹¹C] Methionine (¹¹C -MET) PET in the management of parathyroid lesions have been extensively discussed in this article. The role of fluorodeoxyglucose PET (FDG-PET) has also been elucidated in this article. Management guidelines for parathyroid carcinoma proposed by the American Society of Clinical Oncology (ASCO) have also been described. An algorithm for management of parathyroid lesions has been provided at the end to serve as a quick reference guide for radiologists, clinicians and surgeons. Full article

Here, we describe the case of a 43-year-old male patient with a metastatic parathyroid carcinoma who underwent dual-tracer whole-body positron emission tomography/computed tomography (PET/CT) with [¹⁸F]fluorocholine and fluorodeoxyglucose ([¹⁸F]FDG) for staging. [¹⁸F]FDG PET/CT detected multiple cervical and mediastinal lymph nodal lesions with increased tracer uptake, whereas [¹⁸F]fluorocholine PET/CT detected increased tracer uptake on cervical and mediastinal lymph nodal lesions and bone and lung lesions with a better evaluation of metastatic spread. Due to these imaging findings, the patient underwent systemic treatment with chemotherapy. This case demonstrates the added value of dual-tracer PET/CT in this rare metastatic tumor. Full article

Oligometastatic patients at [¹⁸F]F-Fluorocholine (¹⁸F-choline) PET/CT may be treated with metastasis-directed therapy (MDT). The aim of this study was to combine radiomic parameters extracted from ¹⁸F-choline PET/CT and clinical data to build machine learning (ML) models able to predict MDT efficacy. Methods: Oligorecurrent patients (≤5 lesions) at ¹⁸F-choline PET/CT and treated with MDT were collected. A per-patient and per-lesion analysis was performed, using 2-year biochemical recurrence (BCR) after MDT as the standard of reference. Clinical parameters and radiomic features (RFts) extracted from ¹⁸F-choline PET/CT were used for training five ML Models for both CT and PET images. The performance metrics were calculated (i.e., Area Under the Curve—AUC; Classification Accuracy—CA). Results: A total of 46 metastases were selected and segmented in 29 patients. BCR after MDT occurred in 20 (69%) patients after 2 years of follow-up. In total, 73 and 33 robust RFTs were selected from CT and PET datasets, respectively. PET ML Models showed better performances than CT Models for discriminating BCR after MDT, with Stochastic Gradient Descent (SGD) being the best model (AUC = 0.95; CA = 0.90). Conclusion: ML Models built using clinical parameters and CT and PET RFts extracted via ¹⁸F-choline PET/CT can accurately predict BCR after MDT in oligorecurrent PCa patients. If validated externally, ML Models could improve the selection of oligorecurrent PCa patients for treatment with MDT. Full article

The skeletal muscles account for approximately 40% of the body weight and are crucial in movement, nutrient absorption, and energy metabolism. Muscle loss and decline in function cause a decrease in the quality of life of patients and the elderly, leading to complications that require early diagnosis. Positron emission tomography/computed tomography (PET/CT) offers non-invasive, high-resolution visualization of tissues. It has emerged as a promising alternative to invasive diagnostic methods and is attracting attention as a tool for assessing muscle function and imaging muscle diseases. Effective imaging of muscle function and pathology relies on appropriate radiopharmaceuticals that target key aspects of muscle metabolism, such as glucose uptake, adenosine triphosphate (ATP) production, and the oxidation of fat and carbohydrates. In this review, we describe how [¹⁸F]fluoro-2-deoxy-D-glucose ([¹⁸F]FDG), [¹⁸F]fluorocholine ([¹⁸F]FCH), [¹¹C]acetate, and [¹⁵O]water ([¹⁵O]H₂O) are suitable radiopharmaceuticals for diagnostic imaging of skeletal muscles. Full article