the Quarterly Journal of Nuclear Medicine and Molecular Imaging最新文献

Background: The effect of breathing on the [¹⁸F]fluorocholine parathyroid uptake profile has not been yet evaluated. The main objective of our study is to assess the technical feasibility of respiratory-gated [¹⁸F]fluorocholine PET/CT in patients with hyperparathyroidism. Specifically, we aimed to investigate whether respiratory motion correction has a measurable impact on quantitative PET parameters compared to free-breathing PET in a cohort of patients with clearly identifiable hypermetabolic parathyroid lesions.

Methods: Respiratory-gated [¹⁸F]fluorocholine PET/CT was performed using a pressure-sensitive belt placed around the thorax. An elliptic volume of interest was drawn on each hyperfunctioning parathyroid on both respiratory-gated and free-breathing PET scans, and SUVmax and SUVpeak were measured. An image profile was drawn across hypermetabolic targets on the coronal view, and full-width-at-half-maxima (FWHM) of glandular uptake profile was calculated. Wilcoxon signed-rank test and Mann-Whitney U-test were used for intragroup and intergroup comparison, respectively. A P value <0.05 was considered as significant.

Results: A total of 143 hyperfunctioning parathyroid glands (61 superior, 79 inferior, three ectopic) were identified in 110 patients. Respiratory-gated PET showed a statistically significant increase in both SUVmax and SUVpeak compared to ungated PET across all glands (P<0.001). The effect was more pronounced for inferior glands, with a mean SUVmax increment of 10.14%, compared to 7.81% for superior glands, although the difference was not statistically significant for the latter. The mean extent of respiratory parathyroid blurring in the axial direction was 13.7 mm. FWHM analysis revealed a significant reduction in respiratory blurring in respiratory-gated PET (P<0.001).

Conclusions: Respiratory gating improves image quality and visual assessment of hyperfunctioning parathyroid glands by reducing image blurring. Further research is necessary to assess the diagnostic impact of these findings in clinical practice, especially in cases with indeterminate ungated [¹⁸F]Fluorocholine PET examinations.

Positron emission tomography/computed tomography (PET/CT) with 2-[fluorine-18]fluoro-2-deoxy-D-glucose ([18F]-FDG) is a well-established imaging tool in adult oncology and is increasingly utilized also in pediatric oncology due to its ability to combine functional and anatomic information, thereby enhancing diagnostic accuracy and improving patient management. However, [18F]-FDG uptake in children differs physiologically from adults, and this radiotracer is not tumor-specific, with uptake occurring in various benign conditions such as inflammation, infection, and trauma. Accurate interpretation of pediatric [18F]-FDG PET/CT requires comprehensive knowledge of the normal distribution of FDG in children, recognition of physiological variants, and awareness of common benign lesions and PET/CT-related artifacts. Misinterpretation can lead to unnecessary follow-up studies, suboptimal treatment decisions, and/or increased radiation exposure. This review discusses the typical patterns of physiologic [18F]-FDG uptake in children, common benign mimics of malignancy, and potential artifacts and pitfalls encountered in pediatric [18F]-FDG PET/CT imaging, focus especially on head and neck (lymph nodes), brown adipose tissue, bone marrow and thymus. By increasing familiarity with these patterns, this review aims to improve diagnostic confidence, reduce interpretive errors, and promote safer and more effective imaging practices in pediatric oncology.

Pediatric non-Hodgkin lymphoma (NHL) is an aggressive and heterogeneous malignancy with high rates of extranodal involvement. Accurate staging and response assessment are crucial, yet challenging. While [¹⁸F]FDG PET/CT is a cornerstone in adult NHL management, its role in pediatric cases remains under evaluation. A comprehensive review of the literature, international guidelines, and ongoing clinical trials was conducted, focusing on the diagnostic, prognostic, and therapeutic implications of [¹⁸F]FDG PET/CT in pediatric NHL. [¹⁸F]FDG PET/CT improves staging accuracy by detecting extranodal and bone marrow involvement more sensitively than conventional imaging. Its high negative predictive value supports its use in confirming complete metabolic response, potentially avoiding unnecessary biopsies. However, its positive predictive value is limited, cautioning against treatment escalation based solely on positive PET/CT results. Novel metabolic biomarkers such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG) show promise for prognostic stratification but suffer from methodological variability and lack of standardization. Ongoing clinical trials aim to validate PET/CT's role in therapy response evaluation and optimize its clinical application. [¹⁸F]FDG PET/CT is a valuable imaging modality for pediatric NHL, particularly in FDG-avid subtypes. Despite promising results, broader clinical adoption requires standardized imaging protocols and prospective multicenter validation to establish robust diagnostic and prognostic utility.

Introduction: Morphological and molecular imaging are critical for evaluating pediatric lymphoma; image-derived parameters like metabolic tumor volume are highly prognostic. Advanced image analysis methods, such as radiomics and artificial intelligence, can extract relevant parameters and reveal subtle patterns to enhance diagnostic and prognostic evaluations. This systematic review will assess the current evidence of these techniques in PL.

Evidence acquisition: Original, English-language articles published before March 15^th, 2025 and focusing on artificial intelligence or radiomics applications in pediatric lymphoma imaging were reviewed. Papers focused on the analysis of PET, CT, or MRI datasets were considered; from each chosen article, the most representative data, including design, sample size, studies series, and method of analysis, were extracted.

Evidence synthesis: Twelve studies were included; one focused on radiomics, one combined texture analysis with machine learning, and ten explored artificial intelligence applications. Five studies described the use of automatic volume segmentation, demonstrating that artificial intelligence is a reliable and faster alternative to the manual procedure. Four papers evaluated methods for reducing radiation dose, showing that artificial intelligence can reconstruct images of acceptable quality even with a significant decrease in administered radioactivity. Finally, three radiomics/machine learning studies dealt with the differential diagnosis of PL and the stability of the features.

Conclusions: AI and radiomics in PL are still in their early stages but show great promise in automatically extracting important diagnostic parameters, such as the tumor volume, and in delivering sharp diagnostic images with a significant dose reduction to the patient.

Pediatric lymphoma comprises 15-20% of the childhood cancer spectrum and represents the most curable end of the disease spectrum with current cure rates exceeding 90% for Hodgkin Lymphoma (HL) and over 80% for non-Hodgkin lymphoma (NHL). Whilst these cure rates were achieved over a decade ago, there has been a paradigm shift with current management regimens employing risk-stratified, response-adapted strategies, targeted therapies and increasingly immunotherapy. Ongoing efforts are focused on maintaining and further improving the high cure rates but at the same time limiting the price of cure in term of late effects that survivors have faced in the past decades especially for HL. The current review summarizes the recent advances in the management of pediatric lymphomas and the standard-of-care options for these conditions. Increasing use of PET-CT imaging for staging/risk-stratification and response assessment has played a big role in refinement of treatment strategies. Improved supportive care, reduction in indications, doses, and fields for radiation, and refinement of models of delivery have further contributed to limiting both acute and long-term toxicity. For HL, it is expected that chemo-radiotherapy is likely to get reduced and increasingly replaced by antibody-drug conjugates and immune-checkpoint inhibitors. For NHL, chemotherapy is expected to continue to play a major part along with monoclonal antibodies. Future strategies include increasing use of CAR-T cell therapy especially for NHL for relapsed/ refractory disease.

Background: Primary hyperparathyroidism (PHPT) is an endocrine disorder characterized by excessive parathyroid hormone secretion, typically due to a solitary parathyroid adenoma (PA). Accurate preoperative localization is crucial for successful minimal invasive surgical management. Four-dimensional computed tomography (4DCT) is increasingly used as a first-line imaging modality due to its superior sensitivity and specificity compared to ultrasound and [99mTc]Sestamibi SPECT. Recent studies have highlighted the potential role of [18F]Choline PET/CT in PA detection. This study evaluates the feasibility of a combined [18F]Choline PET/4DCT protocol as a 'one-stop shop' imaging solution for PHPT patients.

Methods: A total of 167 patients with 217 imaging modalities were retrospectively included in the database, consisting of 33 SPECT/CT, 44 4DCT, 79 PET/CT and 61 PET/4DCT studies. Radiation dose was evaluated using dose-length-product (DLP) comparing the imaging modalities and different imaging strategies. Evaluation was also performed with the pertinent radiologists/nuclear medicine physicians and endocrine surgeons.

Results: The PET/4DCT protocol did not have a significantly higher DLP compared to the 4DCT protocol, it did have a higher DLP compared to SPECT/CT and PET/CT. The PET/4DCT protocol had a significant lower total DLP compared to most used imaging strategies except for patients with only a PET/CT. Additionally, the combined protocol facilitated improved anatomical visualisation, supporting potential benefits for surgical planning.

Conclusions: This study demonstrates that [18F]Choline PET/4DCT is a promising 'one-stop shop' imaging approach for PA localisation in PHPT patients without a higher radiation dose compared to previously used imaging strategies. It does increase diagnostic accuracy, streamline patient management and optimise surgical treatment.

To review the current and emerging role of advanced cardiovascular imaging modalities for the detection, characterization, and follow-up of cardiotoxicity in pediatric oncology patients, in light of recent cardio-oncology guidelines. This narrative review synthesizes evidence from recent international guidelines - including the 2022 ESC Cardio-Oncology Position Paper and AHA scientific statements - alongside primary literature. The diagnostic roles of echocardiography, cardiac magnetic resonance (CMR), cardiac computed tomography (CCTA), and molecular imaging techniques are critically discussed. While echocardiography remains the first-line modality, its limited sensitivity for subclinical damage prompts the use of more advanced techniques. CMR provides unparalleled tissue characterization, allowing detection of diffuse fibrosis, inflammation, and early systolic dysfunction via T1/T2 mapping, ECV quantification, and myocardial strain. CCTA may detect radiation-induced coronary disease in high-risk survivors. Investigational imaging tools, such as ¹⁸F-FDG PET, ¹²³I-MIBG SPECT, and FAP-targeted PET, show potential in identifying early metabolic and sympathetic abnormalities before structural changes occur. Advanced cardiovascular imaging - particularly CMR - has become central to modern cardio-oncology care in pediatrics. Current recommendations advocate for personalized, risk-adapted imaging strategies, yet most protocols are extrapolated from adult data. Pediatric-specific frameworks are urgently needed to refine long-term surveillance and reduce cardiovascular late effects in childhood cancer survivors.