Seminars in nuclear medicine最新文献

PSMA-PET has become a pivotal imaging method for staging and restaging of prostate cancer. Risk stratification of the disease is a crucial for the patients to receive most appropriate treatment, and for the clinicians to follow the patients more precisely. PSMA-PET provides non-invasive biomarkers for the risk assessment of prostate cancer, offering prediction of clinical outcomes. PROMISE criteria have been developed as comprehensive and integrated framework demonstrating association with overall survival. In this review, we aim to provide a brief update of the prognostic value of PSMA-PET for risk assessment in prostate cancer.

Metastatic prostate cancer heterogeneity is a multifactorial spatiotemporally dynamic process that leads to disease progression, emergence of treatment resistance and eventual treatment failure. Understanding of the root causes of tumor heterogeneity is the key to develop strategies for more effective therapies. The intra-patient (inter-tumor), and inter-patient heterogeneity demands combinatorial treatment strategies anchored to patient-specific disease biology that can successfully tackle the complexity of the disease in the hopes of overcoming the biological barriers to cancer control. The aim of this article is to briefly review the elements of metastatic prostate cancer heterogeneity and propose approaches to tackle the ensuing therapeutic challenges to achieve durable clinical efficacy in the context of radiopharmaceutical therapy.

Radium-223 (²²³Ra), an alpha-emitting radiopharmaceutical targets bone and prolongs overall survival (OS) while reducing skeletal-related events (SREs) in metastatic castration-resistant prostate cancer patients (mCRPC). However, assessing ²²³Ra therapeutic response is difficult due to its distinct mechanism of action on bone remodeling and tumor microenvironment. Therefore, a multimodal approach to evaluate response is required, beyond conventional serum tumor biomarkers such as PSA and ALP. This review integrates current and emerging strategies for evaluating ²²³Ra response. We discuss classic serum biomarkers, highlighting their prognostic and monitoring roles. We also examine emerging liquid biopsy tools, such as circulating tumor cells, circulating tumor DNA, bone metabolism markers and exosomes that may reflect the metabolic changes induced by ²²³Ra. We also explore the clinical response patterns and limitations of imaging biomarkers that play a central role in response assessment such as ¹⁸F-fluoride PET/CT, whole-body diffusion-weighted MRI and PSMA PET/CT. We cover RECIST-based assessments and innovative technologies, including radiomics and artificial intelligence, that integrate clinical, molecular, and imaging data to enhance outcome prediction, automate lesion analysis, and reveal patterns related to treatment response, supporting personalized care. In conclusion, a multimodal approach that combines biological and imaging markers with modern analytical methods enhances ²²³Ra therapy response evaluation, leading to improved clinical outcomes in mCRPC.

Head and neck cancers (HNCs) represent a heterogeneous group of malignancies, predominantly composed of squamous cell carcinoma. Radiotherapy (RT), either alone or concurrently with chemotherapy, remains a central component of definitive and adjuvant treatment in HNCs. The success of radiotherapy depends on precise target volume delineation, which relies heavily on advanced imaging techniques. Positron emission tomography with fluorodeoxyglucose (FDG-PET) is well-established in RT planning workflows and endorsed by international guidelines. Recent advances in molecular imaging using fibroblast activation protein inhibitors (FAPI) targeting PET tracers offer improved tumor visualization and target delineation with early studies demonstrating more distinct tumor margins and improved diagnostic performance compared with FDG PET in HNCs. These advantages align with the critical need for highly reliable imaging in a disease site where complex anatomy complicates RT delivery. Early findings suggest a promising role for FAPI PET, in refining gross tumor volume (GTV) delineation and complementing current RT workflows. Despite the promising findings, current evidence is limited to small, primarily single-center cohorts, some with heterogeneous tumor subtypes, and the absence of prospective outcome-based validation. In addition, the utility of FAPI PET in post-RT response assessment and the optimal timing of imaging has yet to be clear defined. Rigorous, methodologically well-designed prospective studies are needed to establish the clinical value, prognostic significance, and impact of FAPI PET on radiotherapy outcomes in HNCs.

The advent of prostate-specific membrane antigen (PSMA) positron emission tomography (PET) imaging has revolutionized the evaluation and management of prostate cancer, enabling superior lesion detection and characterization across various disease stages. In response to the growing need for standardized interpretation, the Prostate Cancer Molecular Imaging Standardized Evaluation (PROMISE) criteria were introduced in 2018, offering a structured approach to staging and risk assessment. As PSMA-targeted imaging becomes more central in response assessment and theranostics, updated PROMISE criteria have been proposed to reflect treatment-related changes and incorporate newer therapies like PSMA radioligand therapy (RLT). This review provides an in-depth overview of the updated PROMISE criteria, highlighting key changes, their rationale, and their application in assessing treatment response. Comparative discussion with other response criteria, including RECIST, PERCIST, and RECIP, is included. We also address practical challenges, potential pitfalls, and future directions for integrating PROMISE with emerging technologies such as artificial intelligence and radiomics. By refining response evaluation in prostate cancer, the updated PROMISE criteria represent a significant step toward precision imaging and personalized therapy.

Introduction: The aim of this review is to provide a comprehensive synthesis of the current literature on the use of PET radiomics for predicting response to immunotherapy in cancer patients, as well as to discuss the main challenges emerging from data analysis and propose potential directions for its broader integration into clinical practice.

Materials and methods: papers regarding the use of radiomics and immunotherapy by using PET/CT were selected. Some criteria were used for the selection, such as five years from the date of publication and 2) inclusion of several patients (more than 100).

Results: Totally 24 papers were selected by using the following criteria. Most studies (N = 18/24; 75%) were related to the utility of radiomics for predicting immunotherapy in patients affected by lung cancer. In this setting, radiomics was able to predict the expression of PDL-1, with an important effect on the invasive procedures. In four studies, radiomics was used for predicting the prediction of response to CAR-T in patients affected by lymphoma. Emerging results are now available in patients with colon-rectal tumors and endometrial cancers, although with still limited evidence.

Conclusions: radiomics holds substantial potential for characterizing the tumor immune microenvironment and predicting response to immunotherapy, especially in lung cancer and lymphoma.

Differentiated thyrοid carcinoma (DTC) is the most common endocrine malignancy, generally associated with excellent long-term survival. Hοwever, a subset of patients develοps advanced disease (aDTC), particularly when refractοry to radioactive iodine (RAIR), which poses significant therapeutic challenges and wοrse outcomes. Accurate, individualized assessment οf treatment respοnse is essential for optimizing patient management. This review summarizes current principles fοr biοmarker- and imaging-based evaluation of aDTC. Serum thyroglobulin (Tg) and anti-thyroglobulin antibodies (TgAb), including their dynamic changes οver time, remain central biomarkers for detecting persistent, recurrent, or metastatic disease. Mοlecular profiling, including BRAF, TERT, and RAS mutatiοns, provides additional prognοstic and predictive information and guides the use of targeted therapies. Imaging modalities, including post-therapy radioiodine whole-body scans (WBS), single-phοton emission computed tomography/computed tomography (SPECT/CT), ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT), and emerging tracers such as ⁶⁸Ga-DOTATATE and PSMA PET/CT, οffer complementary anatomical and functional data for respοnse assessment, particularly in RAIR or metabοlically active disease. Current guidelines recommend integrating biomarker trends with imaging findings within a dynamic risk stratification framework to guide individualized treatment decisiοns. Despite well-established recοmmendations, real-world application remains variable due to patient heterogeneity and center-specific resources. Emerging imaging modalities, quantitative PET metrics, and artificial intelligence (ΑΙ) -assisted approaches hold prοmise for enhancing prognostic accuracy and personalizing fοllow-up and therapy. Cοnclusions: Integrating biomarkers, molecular profiling, and advanced imaging within a dynamic, patient-centered framework is essential for accurate response assessment and optimal management of advanced differentiated thyroid carcinoma.

Congenital abnormalities of the kidney and urinary tract are amongst the most common in children, often requiring nuclear medicine imaging for diagnosis and treatment planning. Efforts to harmonise paediatric renal scintigraphy have gained momentum, notably through unified guidelines published by the Society of Nuclear Medicine and Molecular Imaging (SNNMI) and the European Association of Nuclear Medicine (EANM). However, despite these guidelines, significant variation in clinical practice persists. Advances in imaging technology have also influenced protocols, with some institutions now incorporating single photon emission computed tomography (SPECT) studies when performing cortical scintigraphy. To assess the current practices, the International Atomic Energy Agency (IAEA) conducted a global survey, revealing substantial variability and gaps in the performance and interpretation of renal studies within countries and globally. This underscores the urgent need for standardization and quality improvement across institutions. The IAEA is uniquely positioned to support the global nuclear medicine community through targeted educational and capacity building initiatives.

For certain clinical scenarios accurate and precise GFR measurement is required. In the majority of situations this is calculated from the plasma clearance of an exogenous marker that undergoes glomerular filtration, using the slope-intercept (SI) or single-sample (SS) methods. This paper is intended to complement a previous Seminars paper with a specific focus on practical ways to avoid potential pitfalls and quality control measures that can be implemented to minimize the risk of GFR measurement errors. The underlying causes of GFR errors can be understood in terms of measurement errors or procedural errors. All measurements are accompanied by inherent errors that are related to the finite precision of the measuring instruments used. Kept within an acceptable range, measurement errors make a small contribution to GFR error when compared to expected biological variation. Procedural errors consist of a diverse group of deviations from correct procedure ranging from selection of an inappropriate methodology through to missteps at many points in the investigation procedure. Procedural errors can significantly affect the accuracy of GFR measurements. Errors are primarily avoided by regular equipment quality control and careful adherence to clear standard operating procedures. Quality control parameters integrated into a calculation spreadsheet can play a useful secondary role to flag potential measurement or procedural errors.

Bladder cancer (BC) poses significant diagnostic challenges for molecular imaging, as [¹⁸F]FDG PET/CT demonstrates not only intense urinary excretion that obscures pelvic lesions but also inherently limited diagnostic accuracy in differentiating tumor from inflammation and in detecting small or low-grade lesions. These shortcomings have spurred the development of non-FDG PET tracers aimed at improving lesion detectability and providing more tumor-specific information. Early-generation tracers such as [¹¹C]acetate, [¹¹C]/[¹⁸F]choline, [¹⁸F]fluciclovine, [¹¹C]methionine, as well as PSMA-targeted agents demonstrated feasibility for imaging primary and recurrent disease but offered modest sensitivity for nodal or distant metastases, restricting their clinical impact. In contrast, novel molecularly targeted agents, including fibroblast activation protein (FAP) inhibitors and Nectin-4-directed ligands, have emerged as promising tracers with high tumor-to-background ratios, less urinary clearance, and strong correlation with histopathologic markers. [⁶⁸Ga]FAPI PET has shown superior lesion detection and staging performance compared with [¹⁸F]FDG, while Nectin-4 PET offers potential for precision imaging and theranostic integration with antibody-drug conjugate therapies. Collectively, these advances signal a shift from conventional metabolic imaging toward receptor-targeted, biologically driven PET approaches that enable more accurate, personalized assessment of bladder cancer.