We present a case of 46-year-old man who underwent surgery for a right thigh myxoma 20 years ago. Due to a discovery of cervical metastatic squamous cell carcinoma of unknown primary(CMSCCUP), a 18F-FDG-PET/CT examination was taken and it revealed the recurrence of the right thigh intramuscular myxomas and multiple fibrous dysplasia in the right lower extremity bones, ultimately leading to the diagnosis of Mazabraud's syndrome. Due to its whole-body imaging capability, PET/CT can simultaneously detect the characteristic combination of fibrous dysplasia and intramuscular myxoma in Mazabraud's syndrome and effectively rule out malignant possibilities. It serves as an important imaging modality for the diagnosis of this syndrome.
In routine practice, radiopharmaceuticals are administered via a newly placed peripheral intravenous catheter (PIVC). However, many patients referred for nuclear medicine imaging already have a semipermanent venous access device in place, such as a central venous catheter, peripherally inserted central catheter, or subcutaneous implantable venous port. Evidence regarding residual radiopharmaceutical activity within preexisting devices—and its potential consequences for SPECT/PET image quality, diagnostic interpretation, and radiation safety—remains limited. This study aimed to quantify device-related residual radiopharmaceutical activity across commonly used access types and to assess any associated clinical impact during image review. In this observational cohort study at Skåne University Hospital, Sweden, 167 patient administrations during SPECT or PET imaging between June 2023 and January 2026 were included (40
The diagnosis of brain death (BD) is primarily clinical and usually straightforward when both supratentorial and infratentorial structures are irreversibly injured. In contrast, isolated catastrophic posterior fossa lesions—particularly those involving the brainstem—are uncommon and may demonstrate preserved supratentorial perfusion or cortical electrical activity on ancillary testing, even in the absence of brainstem function. This apparent dissociation is typically transient and invariably progresses to global cerebral circulatory arrest and death. Few reports have documented the natural evolution of this phenomenon, highlighting the rarity of such cases and their uniformly poor outcome. A 47-year-old woman with no known history of chronic seizure disorder presented in an obtunded state. On arrival, she experienced continuous seizures and the clinical status rapidly deteriorated. Initial head CT scan without contrast revealed basilar artery thrombosis. She received intravenous tissue plasminogen activator (tPA) and levetiracetam. She underwent mechanical thrombectomy with partial recanalization (TICI 2b). Despite intervention, neurologic examination remained poor with absent spontaneous respiration and brain stem reflexes. Subsequent non contrast head CT scan demonstrated worsening brain stem edema and obstructive hydrocephalus. Due to poor clinical status, a 99mTc-bicisate brain perfusion scan was performed which demonstrated absent posterior fossa perfusion with preserved supratentorial tracer uptake. Due to this preserved supratentorial perfusion, life support was continued. Follow-up head CT scan without contrast revealed progression to diffuse cerebral edema, and massive trans tentorial and tonsillar herniation. The patient was later clinically declared brain dead. Organ donation followed in accordance with her previously expressed wishes. This is a rare case of isolated posterior fossa injury with preserved supratentorial perfusion compatible with “brainstem death”. The case highlights the importance of ancillary testing in uncommon supra/infra tentorial dissociation to differentiate brain death from brainstem death.
Phosphaturic mesenchymal tumor (PMT) is a rare cause of tumor-induced osteomalacia (TIO), often presenting with nonspecific symptoms and small tumor size, leading to diagnostic challenges. We report a case of a 25-year-old male with progressive generalized bone pain, hypophosphatemia, and elevated alkaline phosphatase, initially misdiagnosed as spondyloarthritis and osteoporosis. Whole-body bone scintigraphy suggested metabolic bone disease. 18F-FDG PET/CT revealed a destructive lesion in the mandible with moderate uptake, whereas ⁶⁸Ga-DOTATATE PET/CT showed high somatostatin receptor expression, accurately localizing the PMT. Serum phosphate levels normalized rapidly after surgical resection. This case highlights the superior diagnostic value of ⁶⁸Ga-DOTATATE PET/CT over 18F-FDG PET/CT in localizing PMT, facilitating targeted treatment and avoiding prolonged morbidity.
Amyloid PET/CT is increasingly used in the diagnostic evaluation of cognitive disorders; however, its real-world impact on patient and caregiver experiences remains insufficiently characterised. This study examined how amyloid PET results influence perceived diagnosis, emotional responses, behavioural adaptations, and daily life organisation. We conducted a retrospective–prospective monocentric mixed-methods study integrating clinical data from the CLEMENS registry, routine amyloid PET interpretations, and a structured telephone survey that included open-ended questions. Adults who underwent amyloid PET between 2015 and 2024 were contacted, and therapeutic representatives were interviewed when patients were unable to participate. Quantitative outcomes were compared between PET-positive and PET-negative individuals using Fisher’s exact and nonparametric tests. Qualitative responses were analysed thematically and integrated with quantitative findings. Twenty-one individuals completed the survey (12 PET-positive and 9 PET-negative individuals). PET-positive individuals were slightly older (72.4 vs. 68.9 years) and had lower MoCA scores (19.4 vs. 22.2) than PET-negative individuals. They exhibited major neurocognitive disorders (5/12 vs. 1/9) and behavioural adaptations (73
Metastatic castration-resistant prostate cancer (mCRPC) is bone-predominant, requiring objective imaging biomarkers to guide Ra-223 therapy. We evaluated overall metabolic bone volume (OMBV) and overall total bone uptake (OTBU) from bone SPECT/CT as prognostic markers in mCRPC patients treated with Ra-223. Thirty mCRPC patients underwent pre-treatment planar and SPECT/CT bone scintigraphy, with OMBV and OTBU derived using GI-BONE software. Overall survival (OS) was the primary endpoint; progression-free survival (PFS) and time to symptomatic skeletal event (TTSE) were secondary. Receiver operating characteristic analysis (Youden index) defined cut-offs for OS and TTSE independently. Treatment response was classified by composite changes in OMBV, OTBU, and bone scan index. OS, OMBV, and OTBU were analyzed by univariate Cox regression as continuous and dichotomized variables. Baseline skeletal burden was substantial (median OMBV 1,191.21 cm3 [IQR 93.80–1,948.01]; median OTBU 9,746.18 [1,280.01– 17,587.11]); 87
Purpose: To evaluate temporal trends in diagnostic testing for cardiac transthyretin amyloidosis (ATTR-CM) across U.S. health systems in the contemporary era. Methods: We conducted a retrospective, descriptive analysis using the TriNetX U.S. Collaborative Network, identifying patients diagnosed with wild-type or hereditary ATTR-CM between January 2017 and November 2025. ATTR-specific ICD-10 codes were combined with evidence of cardiac involvement, and patients with light-chain amyloidosis or plasma cell dyscrasias were excluded. Diagnostic testing, including technetium-99m (Tc-99m) bone scintigraphy, cardiac magnetic resonance imaging (CMR), and biopsy, was assessed within an extended diagnostic ascertainment window spanning 24 months before and 12 months after diagnosis. Results: The number of patients diagnosed with ATTR-CM increased markedly over time. Use of Tc-99m scintigraphy and CMR rose substantially in absolute terms, while biopsy utilization declined steadily. Dual-modality imaging increased modestly, and invasive histologic confirmation became progressively less common, indicating a shift toward imaging-based diagnosis. Conclusion: Between 2017 and 2025, diagnostic evaluation of ATTR-CM shifted decisively toward noninvasive imaging, with declining reliance on biopsy. Although imaging volume increased, proportional adoption did not keep pace with expanding case identification, underscoring the need for broader implementation of guideline-recommended diagnostic pathways.
Abstract Primary hyperparathyroidism during pregnancy is rare but associated with substantial maternal and foetal morbidity, necessitating timely diagnosis and intervention. Intrathyroidal parathyroid adenomas account for as few as 0.7% of parathyroid adenomas, while cystic parathyroid adenomas represent an even smaller subset. The coexistence of both is exceedingly uncommon, with only nine cases reported and none previously described in pregnancy or using [18F]fluorocholine PET/CT for localisation. We describe a 37-year-old pregnant woman with PTH-dependent hypercalcaemia which persisted following initial parathyroidectomy. A left thyroid lesion with mixed cystic and peripheral enhancing components was detected on ultrasound and multiphase IV contrast CT (4D CT) but remained indeterminate. To minimise foetal radiation exposure, an ultra-low dose protocol [18F]fluorocholine PET/CT was performed at 16 weeks’ gestation, demonstrating peripheral tracer uptake consistent with a hyperfunctioning intrathyroidal cystic parathyroid adenoma. Ultrasound-guided sampling confirmed markedly elevated cyst fluid PTH. Definitive management with left hemithyroidectomy at 23 weeks’ gestation resulted in normalisation of biochemistry and an uncomplicated term delivery. This first reported case of intrathyroidal cystic parathyroid adenoma in pregnancy localised with [18F]fluorocholine PET/CT highlights the diagnostic challenges of primary hyperparathyroidism in pregnancy and supports carefully justified, dose-optimised functional imaging when conventional modalities are inconclusive and surgical decision-making depends on accurate localisation.
PURPOSE:Despite the approval of 177Lu-PSMA-617 as standard treatment for patients with mCRPC, at least 50% of patients do not respond to the therapy, especially those with visceral disease. This study analyzes real-world outcomes of 177Lu-PSMA-I&T used in heavily pretreated patients in Brazil. METHODS:Retrospective analysis of patients with mCRPC previously treated with at least one androgen receptor pathway inhibitor (ARPI) who underwent 177Lu-PSMA-I&T between 2020 and 2025 in two large oncology centers. Our primary endpoint was prostate-specific antigen (PSA) response rate of 50% or more (PSA50). Secondary endpoints included overall survival (OS) and time to next sequential therapies (TNST). Statistical analyses were performed in JAMOVI and RStudio. RESULTS:Forty-three patients were included, with median age 74 years and median baseline PSA 41 ng/mL. Prior to 177Lu-PSMA-I&T, 86% received more than one ARPI line and 23.3% underwent more than one taxane-based chemotherapy. Visceral disease was present in 41.9%. The overall PSA50 response for all patients was 44.2% and for patients with visceral disease was 33.3%. Median OS was 13.9 months [95% confidence interval (CI) 10.9-19.2] and 12-month survival was 55.5% [95% CI 42.1%-73.3%]. Out of the 24 patients who received subsequent therapies, median TNST was 2.9 months [95% CI 1.6-5.4]. CONCLUSIONS:Our results showed that 177Lu-PSMA-I&T achieved a PSA response comparable to those treated with 177Lu-PSMA-617 in randomized trials, despite our heavily treated patients' characteristics. A significant number of patients had visceral disease with expected lower PSA response, highlighting the need for more active combinations in this subgroup.
Endometriosis can be tough to diagnose accurately, especially when standard imaging misses hidden lesions. We explored whether 68Ga-FAPI-46 PET/CT, a new molecular imaging technique, could spot multifocal endometriosis that conventional methods overlook. A 28-year-old woman with severe menstrual pain underwent transvaginal ultrasound (TVS), pelvic MRI, and 68Ga-FAPI-46 PET/CT. The PET/CT scan was performed 60 minutes after injecting 3 mCi (111 MBq) of 68Ga-FAPI-46, targeting fibroblast activation protein (FAP) in fibrotic tissue. We used Monte Carlo simulations (GATE v9.0) to estimate radiation doses to organs, ensuring safety. TVS and MRI detected a right ovarian endometrioma, but 68Ga-FAPI-46 PET/CT went further, confirming this lesion (SUVmax 9.5) and revealing two additional nodules in the left adnexa (SUVmax 9.6) that MRI missed. Surgical pathology confirmed multifocal endometriosis. Dosimetry showed a low ovarian radiation dose (0.73 × 10− 2 Gy/GBq), proving the procedure’s safety for young women. 68Ga-FAPI-46 PET/CT is a safe and powerful tool for uncovering hidden endometriotic lesions, potentially guiding better surgical planning. While promising, larger studies are needed to confirm its role in routine practice.
Abstract Purpose Patients with liver metastases from gallbladder carcinoma have limited treatment options. This retrospective multicenter study evaluated overall survival, tumor control and safety after transarterial radioembolization in this rare patient group. Materials and methods Patients with histologically confirmed gallbladder carcinoma and liver-dominant metastatic disease treated with yttrium-90 or holmium-166 radioembolization at five tertiary centres were retrospectively identified. Baseline clinical and imaging data, details of the radioembolization procedure and follow-up imaging were collected. Tumor response was assessed locally using RECIST 1.1. Overall survival was analysed descriptively using Kaplan–Meier curves. Results Sixteen patients (9 women, mean age 65.7 ± 5.5 years) were included; 93.8% had received prior systemic chemotherapy and 75.0% had extrahepatic metastases. At approximately 3 months, hepatic disease control was achieved in 81.8% (9/11) of patients with available imaging, whereas global disease control was 36.4% (4/11). Median overall survival was 7.1 months (95% confidence interval 1.7–12.3). The median time to hepatic progression was 115 days and the median time to global progression was 112 days. Procedure-related complications were limited to one coil dislocation, one contrast reaction and one liver abscess. Conclusion Radioembolization was feasible and well tolerated in patients with liver-dominant metastases from gallbladder carcinoma and provided intrahepatic disease control in a heavily pretreated population. Given the small sample size, these exploratory findings require confirmation in prospective studies.
Abstract Background Primary central nervous system lymphoma (PCNSL) can be differentiated from glioblastoma multiforme (GBM) using positron emission tomography (PET) with [18F]fluoro-2-deoxy-D-glucose (FDG). However, differentiation is often difficult with magnetic resonance imaging (MRI) or FDG PET alone. We have used various PET tracers to aid glioma diagnosis; here, we assessed whether multiple PET tracers improve the distinction between GBM and PCNSL. Methods We studied 148 patients with newly diagnosed brain tumors: 96 with GBM and 52 with PCNSL (according to the 2016 World Health Organization classification). Tumor-to-normal tissue ratios (TNRs) were calculated for FDG, L[methyl[11C]]methionine, and 3′deoxy3′[18F]fluorothymidine (FLT). Tumor-to-blood ratio (TBR) was measured for [18F]fluoromisonidazole (FMISO). Results Median FDG TNR was 1.52 (interquartile range [IQR], 1.13–2.13) for GBM and 2.89 (IQR, 1.95–3.85) for PCNSL. MET TNR was 6.38 (IQR, 4.68–7.48) for GBM and 4.01 (IQR, 3.28–7.52) for PCNSL. FLT TNR was 17.35 (IQR, 11.10–22.28) for GBM and 25.61 (IQR, 15.91–55.30) for PCNSL. FMISO TBR was 2.72 (IQR, 2.22–3.62) for GBM and 1.58 (IQR, 1.04–1.93) for PCNSL. Receiver operating characteristic analysis showed areas under the curve of 0.78 (FDG), 0.62 (MET), 0.69 (FLT), and 0.85 (FMISO). FLT TNR had the highest sensitivity of 83.2% while FMISO TBR had the highest specificity of 84.2%. Among the four tracers, FLT showed the highest sensitivity and FMISO showed the highest specificity. Dual‑tracer combinations did not improve overall diagnostic accuracy beyond the best single tracers. Conclusions Among four PET tracers, FMISO was most effective in distinguishing GBM from PCNSL. Diagnostic accuracy was highest when each tracer was used individually.
Abstract Primary aldosteronism (PA) is the most common cause of secondary hypertension, where accurate subtype differentiation between unilateral aldosterone-producing adenoma (APA) and bilateral adrenal hyperplasia (BAH) determines therapeutic strategy. Adrenal venous sampling (AVS) remains the reference standard but is invasive, technically demanding, and not widely available. Recent advances in molecular imaging have introduced CXCR4-targeted positron emission tomography using ⁶⁸Ga-Pentixafor as a promising non-invasive tool for functional characterization and lateralization of aldosterone-producing lesions. CXCR4 is highly expressed in the zona glomerulosa and in aldosterone-producing adenomas, and it closely correlates with CYP11B2 (aldosterone synthase) expression. Across multiple clinical studies, ⁶⁸Ga-Pentixafor PET/CT has demonstrated high diagnostic accuracy, with reported sensitivities ranging from 74% to 98% and specificities from 84% to 100%, showing substantial concordance with AVS findings. In addition, PET-guided adrenalectomy yields biochemical and clinical outcomes comparable to AVS-guided management while avoiding procedural risks. By targeting CXCR4 expression, ⁶⁸Ga-Pentixafor PET/CT offers reliable lateralization with good agreement to AVS and strong clinicopathological correlation. Ongoing studies will further clarify its diagnostic role and integration into routine evaluation of primary aldosteronism.
Neuromelioidosis is a rare but severe manifestation of melioidosis with central nervous system (CNS) involvement, caused by gram negative saprophytic bacteria named Burkholderia pseudo-mallei and is associated with high morbidity and mortality. Early and accurate detection of active disease is crucial for appropriate management. We report a series of three cases of neuromelioidosis evaluated using Gallium-68–labelled fibroblast activation protein inhibitor ([⁶⁸Ga]Ga-FAPI) positron emission tomography/computed tomography (PET/CT). [⁶⁸Ga]Ga-FAPI, a novel molecular imaging tracer targeting activated fibroblasts, has demonstrated utility in imaging infection and inflammation in addition to malignancies. Unlike [¹⁸F]FDG (F-18 Fluorodeoxyglucose), [⁶⁸Ga]Ga-FAPI shows negligible physiological uptake in normal brain parenchyma, allowing superior lesion conspicuity. In the three cases reported, [⁶⁸Ga]Ga-FAPI PET/CT clearly demonstrated active CNS inflammatory lesions better than [¹⁸F]FDG PET-CT, facilitating accurate disease assessment and aiding clinical decision-making. The findings on [⁶⁸Ga]Ga-FAPI PET/CT correlated with the MRI findings and further it was found to be better than MRI for response evaluation in one case. This highlights the potential role of [⁶⁸Ga]Ga-FAPI PET/CT as a promising functional imaging modality in the evaluation of neuromelioidosis and other CNS infections.
To evaluate the diagnostic accuracy of SPECT/CT for localizing parathyroid adenomas and to determine how radiopharmaceutical choice (MIBI vs. Myoview) and quality control (QC) practices affect detection performance and administered dose consistency in clinical practice. This retrospective study included 136 patients who underwent dual-phase parathyroid scintigraphy with SPECT/CT at Al-Hada Armed Forces Hospital. Patients were classified into four groups according to radiopharmaceutical (MIBI or Myoview) and QC status (Regular or Irregular QC). Administered activity, detection accuracy, lesion localization, and concordance with surgical findings were assessed. Diagnostic performance was compared between SPECT/CT and planar imaging. Statistical analyses included ANOVA, χ² tests, and correlation analysis. SPECT/CT demonstrated significantly higher diagnostic accuracy than planar imaging across all groups. Regular QC conditions produced the most consistent administered activities and the highest detection rate (97.1
Glomus tumors (glomangiomas) are rare mesenchymal neoplasms derived from modified smooth muscle cells of the glomus body. Since they most commonly occur in the subungual regions of the extremities, primary involvement of the spine is exceedingly rare, particularly in atypical variants with borderline biological behavior. A 61-year-old man presented with a long-standing history of intermittent back pain that had recently worsened. Magnetic resonance imaging revealed a solid lesion involving the T10–T11 vertebral region with intermediate T1 signal intensity, mildly hypointense T2 signal, intralesional hemorrhagic foci, and marked heterogeneous enhancement causing spinal canal stenosis. 18F-FDG PET/CT demonstrated mild to moderate focal radiotracer uptake (SUVmax 5.6) corresponding to the spinal lesion, without evidence of other FDG-avid lesions suggestive of a primary malignancy or metastatic disease. Surgical resection was primarily indicated based on progressive symptoms and MRI findings; PET/CT findings did not alter the surgical decision but provided additional staging information, and histopathological examination established the diagnosis of an atypical glomus tumor. This case highlights the complementary role of MRI and 18F-FDG PET/CT in the evaluation of rare spinal glomus tumors. 18F-FDG PET/CT may provide supportive metabolic information and help assess the presence of additional FDG-avid lesions in atypical presentations.
Positron emission tomography (PET) of the brain using [18F]fluorodeoxyglucose (FDG) is becoming increasingly important for the diagnosis and differential diagnosis of atypical parkinsonian syndrome such as multiple system atrophy (MSA), which is characterized by hypometabolism of the putamen, pons, and cerebellum. We report on a patient with clinically established MSA based on a rapidly progressive, poorly levodopa-responsive parkinsonian syndrome, multidomain autonomic failure, and imaging findings where hereditary spastic paraplegia was discussed as a differential diagnosis. PET images revealed a well-preserved glucose metabolism in the striatum, specifically in the putamen, while metabolism in the cerebellum was significantly reduced. This pattern of glucose metabolism might indicate a distinct subtype of synucleinopathy as proven by seed-amplification assay and should be taken into account when diagnosing patients with MSA.
