Search Results (409)

Background/Objectives: ¹⁸F-PSMA-1007 is one of the more widely used radioligands in prostate cancer imaging with PET/CT. Its major advantage lies in the low urinary tracer activity due to primarily hepatobiliary clearance, but unexpectedly high tracer accumulation in the bladder can occur, potentially hindering assessment of lesions near the prostate bed. This study assesses the impact of furosemide on ¹⁸F-PSMA-1007 tracer accumulation in the bladder. Methods: In this single-center, retrospective, intra-individual comparative analysis, 18 patients undergoing two consecutive ¹⁸F-PSMA-1007 PET/CT scans for biochemical relapse (BCR) or persistence (BCP)—one with and one without prior furosemide administration—were included. Images were acquired 60 min post-injection of 250 MBq of tracer activity. Standardized Uptake Values (SUVmax, SUVpeak, SUVmean) were measured in the bladder and in tissues with physiological uptake by three readers. Differences were analyzed using Wilcoxon signed-rank tests. The inter-reader agreement was assessed using intraclass correlation coefficient. Results: Furosemide significantly decreased bladder SUVmax, SUVpeak, and SUVmean (all p < 0.001). Mean bladder SUVmax decreased from 13.20 ± 10.40 to 3.92 ± 3.47, SUVpeak from 10.94 ± 8.02 to 3.47 ± 3.13, and SUVmean from 8.74 ± 6.66 to 2.81 ± 2.56, representing a large effect size (r ≈ 0.55). Physiological tracer uptake in most organs was not significantly influenced by furosemide (all p > 0.05). Conclusions: Despite the predominantly hepatobiliary clearance of ¹⁸F-PSMA-1007, furosemide-induced forced diuresis leads to a significant reduction in tracer activity in the bladder, which in clinical practice could help in early detection of tumor recurrence. Full article

Targeted radioligand therapy (RLT) is an emerging field in anticancer therapeutics with great potential across tumor types and stages of disease. While much progress has focused on agents targeting somatostatin receptors and prostate-specific membrane antigen (PSMA), the same advanced radioconjugation methods and molecular targeting have spurred the development of numerous theranostic combinations for other targets. A number of the most promising agents have progressed to clinical trials and are poised to change the landscape of positron emission tomography (PET) imaging. Here, we present recent data on some of the most important emerging molecular targeted agents with their exemplar clinical images, including agents targeting fibroblast activation protein (FAP), hypoxia markers, gastrin-releasing peptide receptors (GRPrs), and integrins. These radiopharmaceuticals share the promising characteristic of being able to image multiple types of cancer. Early clinical trials have already demonstrated superiority to ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) for some, suggesting the potential to supplant this longstanding PET radiotracer. Here, we provide a primer for practicing radiologists, particularly nuclear medicine clinicians, to understand novel PET imaging agents and their clinical applications, as well as the availability of companion targeted radiotherapeutics, the status of their regulatory approval, the potential challenges associated with their use, and the future opportunities and perspectives. Full article

Following lung cancer, prostate cancer is the leading cause of cancer death in men. High-risk localized tumor burden or metastatic disease often progresses, refractory to initial treatment regimens. There is ongoing development of technology to appropriately identify high-risk patients, stage them correctly, and offer appropriate treatments to obtain the best clinical outcomes. Prostate cancer-specific membrane antigen (PSMA) is a transmembrane glutamate carboxypeptidase, which helps regulate folate absorption, and its overexpression is pathologically directly proportional and associated with prostate cancer. Increased PSMA expression is a known independent risk factor for poorer survival, and most metastatic lesions in CRPC are PSMA positive. Over the last decade, several PSMA-based PET radiopharmaceuticals have demonstrated superior sensitivities and specificities compared to traditional imaging methods. These outcomes have been demonstrated by several large clinical trials. As the data emerges, these diagnostics are being integrated into standard of care protocol to facilitate nuanced identification of malignant lesions. PSMA is also being targeted through several therapeutics, including radioligands and immunotherapies such as CAR-T, BiTEs, and ADCs. This review will discuss the landscape of PSMA-based theranostics in the context of prostate cancer. Full article

Background: This Phase 2 trial evaluated the efficacy, tolerability, and safety of [¹⁷⁷Lu]Lu-PSMA-617 (¹⁷⁷Lu-PSMA-617) in patients with ≥1 measurable lesion and progressive prostate-specific membrane antigen-positive (PSMA+) metastatic castration-resistant prostate cancer (mCRPC) in Japan. Methods: This study comprises four parts; data from three parts are presented here. Part 1 evaluated safety and tolerability; Parts 2 (post-taxane) and 3 (pre-taxane/taxane-naive) assessed the overall response rate (ORR; primary endpoint), overall survival (OS), radiographic progression-free survival (rPFS), disease control rate (DCR), PFS, and safety; and Part 4 is the expansion part. Patients received 7.4 GBq (±10%) ¹⁷⁷Lu-PSMA-617 Q6W for up to six cycles. Results: Of the 35 patients who underwent a [⁶⁸Ga]Ga-PSMA-11 (⁶⁸Ga-PSMA-11) PET/CT scan, 30 received ¹⁷⁷Lu-PSMA-617 (post-taxane, n = 12; pre-taxane, n = 18). No dose-limiting toxicity was noted in Part 1 (n = 3). Post- and pre-taxane patients had a median of three and five cycles, respectively. The primary endpoint, ORR, met the pre-specified threshold, with the lower limit of the 90% confidence interval (CI) above the threshold of 5% for post-taxane and 12% for pre-taxane. Post- and pre-taxane patients had an ORR of 25.0% (90% CI: 7.2–52.7) and 33.3% (90% CI: 15.6–55.4), respectively. In post- and pre-taxane patients, the DCR was 91.7% and 83.3%, the median rPFS was 3.71 and 12.25 months, and the median PFS was 3.71 and 5.59 months, respectively. The median OS was 14.42 and 12.94 months in post- and pre-taxane patients, respectively. The most common adverse events were constipation, decreased appetite, decreased platelet count, anemia, and nausea. Conclusions: The primary endpoint (ORR) was met. The safety profile of ¹⁷⁷Lu-PSMA-617 was consistent with the VISION and PSMAfore studies, with no new safety signals in the Japanese patients with mCRPC. Full article

Background/Objectives: The aim of this study was to investigate the relationship between the PRIMARY score derived from [⁶⁸Ga]Ga-PSMA PET/CT and key clinical and pathological parameters of prostate cancer aggressiveness, including the PSA level, ISUP Grade Group, and D’Amico risk classification, in patients with biopsy-proven prostate cancer. A secondary aim was to evaluate the interobserver agreement of the PRIMARY score in routine clinical practice. Methods: This retrospective analysis included 51 patients with histopathologically confirmed prostate adenocarcinoma who underwent [⁶⁸Ga]Ga-PSMA PET/CT imaging for staging. PRIMARY scores were determined based on the intraprostatic uptake pattern, intensity, and zonal localization. These scores were compared with PSA levels, ISUP GG, D’Amico risk classification, and histopathological features such as the cribriform pattern, intraductal carcinoma, perineural invasion, extraprostatic extension, and lymphovascular invasion. The PRIMARY scores were independently assigned by a total of three nuclear medicine physicians, and interobserver agreement was calculated using Fleiss’ kappa analysis. Results: Significant associations were found between the PRIMARY scores and the PSA level, ISUP Grade Group, and D’Amico risk classification. The most prevalent score was PRIMARY 5 (54.9%), which was significantly associated with ISUP GG 5 and the high-risk category in D’Amico classification. Among patients with PRIMARY Score 2, a substantial proportion (64.7%) had ISUP GG ≥ 3, and 58.8% were in the high-risk group, highlighting the limitations of binary PRIMARY classification. No statistically significant correlations were found between the PRIMARY scores and specific histopathologic features. Interobserver agreement was excellent (κ = 0.833). Conclusions: The PRIMARY score demonstrates high reproducibility and clinical relevance in stratifying prostate cancer aggressiveness. However, the findings challenge the reliability of binary classifications, particularly for patients with Score 2, who may still harbor high-grade disease. Integrating imaging-based scores with clinical and histopathological data is essential, particularly for accurate staging and decision-making regarding active surveillance. Full article

Background/Objectives: Red bone marrow irradiation is a major concern for patients with advanced prostate cancer undergoing [¹⁷⁷Lu]Lu-PSMA therapy. However, low uptake in the red bone marrow and the presence of bone lesions complicate image-based red bone marrow dosimetry. This study aimed to investigate the general feasibility of image-based red bone marrow activity estimation for [¹⁷⁷Lu]Lu-PSMA treatment and to develop a fully automated workflow for clinical implementation. Methods: In the first part of the study, 175 virtual patient phantoms with realistic ¹⁷⁷Lu activity distributions were generated based on 639 pre-therapeutic [¹⁸F]F-PSMA-1007 PET/CT scans. The SIMIND Monte Carlo tool was used to simulate the ¹⁷⁷Lu SPECT acquisitions (24 h post-injection (p.i.)), which were used to assess the uncertainty of red bone marrow activity estimation. In the second part, red bone marrow self- and cross-absorbed doses were estimated for four therapy cycles of 20 patients. Results: The simulation study shows a significant overestimation of activity in skeletal sites with bone lesions, with median recovery coefficients (RCs) across all phantoms yielding a median of 225% (range: 106–1015%). In contrast, the median RCs were markedly lower in skeletal sites neighboring or distant to lesion-carrying sites (105% [72–163%] and 107% [77–130%], respectively). The median total absorbed dose to the red bone marrow was 20.8 mGy/GBq (range: 5.6–297.9 mGy/GBq). Median blood levels decreased with an increasing median cumulative total absorbed dose. Conclusions: Reliable estimation of activity concentration in skeletal sites without bone lesion infiltration has been shown to be feasible. Based on this finding, an automated workflow for routine image-based red bone marrow dosimetry was developed. Full article

This study assesses the clinical deployment of SubtlePET™, a commercial AI-based denoising algorithm, across three radiotracers—¹⁸F-FDG, ⁶⁸Ga-PSMA-11, and ¹⁸F-FDOPA—with the goal of improving image quality while reducing injected activity, technologist radiation exposure, and scan time. A retrospective analysis on a digital PET/CT system showed that SubtlePET™ enabled dose reductions exceeding 33% and time savings of over 25%. AI-enhanced images were rated interpretable in 100% of cases versus 65% for standard low-dose reconstructions. Notably, 85% of AI-enhanced scans received the maximum Likert quality score (5/5), indicating excellent diagnostic confidence and noise suppression, compared to only 50% with conventional reconstruction. The quantitative image quality improved significantly across all tracers, with SNR and CNR gains of 50–70%. Radiotracer dose reductions were particularly substantial in low-BMI patients (up to 41% for FDG), and the technologist exposure decreased for high-exposure roles. The daily patient throughput increased by an average of 4.84 cases. These findings support the robust integration of SubtlePET™ into routine clinical PET practice, offering improved efficiency, safety, and image quality without compromising lesion detectability. Full article

Background/Objectives: This study evaluates whether combining ⁶⁸Ga-PSMA-11-PET/CT derived imaging biomarkers with clinical risk factors improves the prediction of early biochemical recurrence (eBCR) or clinical progress in patients with high-risk prostate cancer (PCa) after primary treatment, using machine learning (ML) models. Methods: We analyzed data from 93 high-risk PCa patients who underwent ⁶⁸Ga-PSMA-11 PET/CT and received primary treatment at a single center. Two predictive models were developed: a logistic regression (LR) model and an ML derived probabilistic graphical model (PGM) based on a naïve Bayes framework. Both models were compared against each other and against the CAPRA risk score. The models’ input variables were selected based on statistical analysis and domain expertise including a literature review and expert input. A decision tree was derived from the PGM to translate its probabilistic reasoning into a transparent classifier. Results: The five key input variables were as follows: binarized CAPRA score, maximal intraprostatic PSMA uptake intensity (SUVmax), presence of bone metastases, nodal involvement at common iliac bifurcation, and seminal vesicle infiltration. The PGM achieved superior predictive performance with a balanced accuracy of 0.73, sensitivity of 0.60, and specificity of 0.86, substantially outperforming both the LR (balanced accuracy: 0.50, sensitivity: 0.00, specificity: 1.00) and CAPRA (balanced accuracy: 0.59, sensitivity: 0.20, specificity: 0.99). The decision tree provided an explainable classifier with CAPRA as a primary branch node, followed by SUVmax and specific PET-detected tumor sites. Conclusions: Integrating ⁶⁸Ga-PSMA-11 imaging biomarkers with clinical parameters, such as CAPRA, significantly improves models to predict progression in patients with high-risk PCa undergoing primary treatment. The PGM offers superior balanced accuracy and enables risk stratification that may guide personalized treatment decisions. Full article

Background: PSMA PET/CT imaging has become a cornerstone in the management of prostate cancer, particularly in the setting of biochemical recurrence (BCR). While semi-quantitative parameters such as SUVmean have been evaluated as prognostic biomarkers in metastatic castration-resistant prostate cancer (mCRPC), particularly after the VISION trial, the prognostic role of volumetric measures such as Total Molecular Volume (TMV) remain largely unexplored, especially in earlier stages of the disease such as in biochemical recurrence following primary treatment. Methods: This retrospective monocentric study included 84 patients with BCR who underwent PSMA PET/CT imaging between 2020 and 2021 using either [⁶⁸Ga]Ga-PSMA-11(Ga-PSMA) or [¹⁸F]-PSMA-1007 (F-PSMA) as tracers. Total tumor burden was assessed through manual 3D segmentation to derive whole-body Total Molecular Volume (wb TMV) and Total Lesion PSMA (wb TL-PSMA). Clinical and imaging variables were correlated with overall survival (OS) and progression-free survival (PFS) using Cox regression models. Kaplan–Meier analyses were performed based on wb TMV and thresholds determined by the Youden index. Results: A PSMA PET/CT correlation for BCR was identified in 69% of patients, with comparable detection rates between tracers (Ga-PSMA 67% vs. F-PSMA 63%, p = 0.7). A higher wb TMV was significantly associated with worse OS (HR 2.20, p < 0.001) and PFS (HR 2.01, p < 0.001) in univariable analyses. In multivariable models, log₂(wb TMV) remained an independent prognostic factor for PFS (HR 1.78, p = 0.005). Patients with log₂(wb TMV) > 2.87 exhibited significantly poorer survival outcomes. A PSA at diagnosis > 17 ng/mL also predicted shorter PFS. Conclusions: Tumor segmentation from PSMA PET/CT imaging provides powerful prognostic information in patients with biochemical recurrence of prostate cancer, independently of the tracer used. The wb TMV represents a promising volumetric biomarker for future risk stratification and therapeutic decision-making, particularly in earlier stages of prostate cancer progression, where predictive imaging biomarkers remain largely undefined. Full article

Since its development in 1904, radical prostatectomy (RP) has remained a fundamental surgical option in the management of localised prostate cancer. Over time, continuous advancements in surgical techniques have improved oncological outcomes while reducing functional complications. This narrative review explores the evolution of RP, depicting its progression from the traditional open approach to minimally invasive laparoscopic and robotic-assisted techniques. Key developments in RP techniques, including nerve-sparing, bladder neck-sparing and Retzius-sparing techniques as well as enhanced perioperative management, have contributed to reduced postoperative complications, namely incontinence and erectile dysfunction. Additionally, technological innovations such as augmented reality, utilising indocyanine green for improved visualisation of prostatic boundaries and illuminare-1 to easily identify nerves intraoperatively, artificial intelligence, and novel molecular imaging technologies such as PSMA PETs for improved margin assessment are shaping the future of RPs. Despite these advancements, challenges persist, including a steep learning curve associated with newer techniques, disparities in access due to cost considerations, and a lack of standardised outcome measures across different surgical approaches. This review provides insight into current trends, ongoing challenges, and future directions that may further refine surgical precision, enhance patient safety, and improve long-term treatment success in prostate cancer management. Full article

Positron emission tomography (PET) imaging targeting glypican-3 (GPC3) holds promise for improving the detection and characterization of hepatocellular carcinoma (HCC). Preclinical and early clinical studies have largely utilized high-molecular-weight antibodies radiolabeled with isotopes such as ⁸⁹Zr and ¹²⁴I, demonstrating high affinity and tumor uptake but suffering from prolonged circulation times and suboptimal signal-to-background ratios. To address these limitations, interest has shifted toward low-molecular-weight vectors—synthetic peptides and small antibody fragments—labeled with shorter-lived radionuclides (e.g., ⁶⁸Ga and ¹⁸F) to enable rapid pharmacokinetics and same-day imaging protocols. Emerging platforms such as affibodies and aptamers offer further advantages in target affinity and reduced immunogenicity. However, clinical translation requires rigorous validation: larger, histologically confirmed cohorts, head-to-head comparison with CT/MRI, and correlation with hard clinical endpoints. Moreover, leveraging GPC3 expression as a biomarker could guarantee a deeper knowledge of tumor biology—differentiation grade and vascular invasion risk—and guide theranostic strategies. While β-emitters (⁹⁰Y, ¹⁷⁷Lu) have been explored for GPC3-directed therapy, their efficacy is influenced by oxygenation and cell-cycle status, whereas α-emitters (²²⁵Ac) may overcome these constraints, albeit with challenges in radionuclide selection and daughter nuclide management. Finally, dual-targeting probes combining GPC3 and prostate-specific membrane antigen (PSMA) have demonstrated superior uptake and retention in murine models, suggesting a versatile approach for future clinical diagnostics and therapy planning. Full article

Background/Objectives: Pulmonary lymphangitic carcinomatosis (PLC) is a rare, aggressive manifestation of metastatic cancer characterized by lymphatic infiltration of the lungs, typically indicating advanced disease and poor prognosis. Methods: This comprehensive narrative review evaluates the role of [18F]fluorodeoxyglucose ([18F]FDG) positron emission tomography (PET) imaging in assessing PLC. Results: Current evidence demonstrates that [18F]FDG PET/CT achieves high diagnostic accuracy, with sensitivity and specificity ranging from 86 to 97% and 84 to 100%, respectively, particularly when employing semiquantitative metrics such as peritumoral standardized uptake value (SUVmax) thresholds (e.g., ≥2.1). PET/CT surpasses high-resolution computed tomography (HRCT) in distinguishing PLC from mimics like pulmonary sarcoidosis by identifying distinct metabolic patterns: bronchovascular hypermetabolism in PLC versus subpleural nodular uptake in sarcoidosis. Prognostically, metabolic tumor burden (e.g., SUVmax × involved lobes) and novel cPLC classifications (localized to the ipsilateral or contralateral lung) independently predict progression-free survival. However, challenges persist, including non-specific tracer uptake in inflammatory conditions and variability in SUV measurements due to technical factors. Emerging digital PET/CT systems, with enhanced spatial resolution, may improve the detection of focal PLC and reduce false negatives. While [18F]FDG PET/CT is invaluable for whole-body staging, therapeutic monitoring and biopsy guidance, the standardization of protocols and multicenter validation of prognostic models are critical for clinical integration. Future research should explore novel tracers (e.g., PSMA for prostate cancer-related PLC) and machine learning approaches to refine diagnostic and prognostic accuracy. Conclusions: This review underscores the role and the transformative potential of [18F]FDG PET/CT in PLC management while advocating for rigorous standardization to maximize its clinical utility. Full article

Background: Prostate-specific membrane antigen (PSMA)-PET imaging has significantly improved prostate cancer (PCa) staging, yet its interpretation remains challenging, even for experienced specialists. No prior study has assessed urologists’ ability to interpret PSMA-PET. Methods: We conducted a multicenter prospective study involving 63 urologists from eight Italian institutions. Participants evaluated 20 PSMA-PET scans of high-risk PCa cases, with no clinical information provided. Proficiency was defined as correctly identifying at least two of three staging components (T, N, M) in ≥75% of cases. Associations between performance and factors such as hierarchy (resident vs. consultant), institution type, surgical volume, and multidisciplinary team (MDT) presence were analyzed using univariable and multivariable logistic regression. Results: Only one participant achieved full staging proficiency, while 44% reached the ≥75% threshold for partial (almost correct) staging. Urologists from centers with ≥300 PCa diagnoses per year demonstrated better T and M stage identification. Institutions with ≥150 robot-assisted radical prostatectomies (RARPs) per year and those with MDTs showed higher accuracy in M staging. No significant predictors of proficiency emerged in the multivariable analysis, although hierarchy and surgical volume approached significance for nodal metastasis detection. Conclusion: PSMA-PET interpretation is complex for urologists, with particular challenges in T and M staging. High institutional case volumes and MDT involvement may enhance interpretation skills. Structured training programs and increased exposure to multidisciplinary imaging discussions are essential to optimize urologists’ diagnostic proficiency and ultimately improve patient care. Full article

Purpose/Objectives: Salvage radiotherapy (SRT) after a radical prostatectomy is a curative approach for patients with biochemical recurrence (BR). However, outcomes are often less favorable when imaging reveals macroscopic local recurrence. In such cases, dose escalation through stereotactic salvage radiotherapy (SSRT) may offer improved disease control. The STARR trial (NCT05455736) is a prospective, multicenter study evaluating the efficacy and safety of SSRT in patients with macroscopic prostate bed recurrence. This interim analysis reports early findings from the initial patient cohort. Materials and Methods: Patients with BR (PSA > 0.2 ng/mL) post-prostatectomy and PET-confirmed macroscopic recurrence (PSMA or Choline PET, confirmed by MRI) were eligible. Treatment involved CyberKnife^®-based SSRT delivering 35 Gy in five fractions to the visible lesion. Androgen deprivation therapy (ADT) was not permitted. Complete biochemical response (CBR) was defined as PSA < 0.2 ng/mL, and biochemical response (BR) as a ≥50% PSA reduction. Additional outcomes included biochemical, radiological, and ADT-free survival (bPFS, rPFS, aPFS). Results: As of analysis, 51 patients were enrolled, with a median follow-up of 16 months (95% CI: 16–22). CBR and BR were achieved in 45.1% and 80.4% of patients, respectively. Events affecting bPFS, rPFS, and aPFS occurred in 12, 5, and 6 patients, with median values not yet reached. Toxicity was minimal, with two cases each of acute grade 2 GI and GU events, and one late grade 2 GI event. No grade ≥ 3 toxicities were reported. Conclusion: Early data support SSRT as a safe and a promising option for macroscopic local recurrence, with encouraging response rates and minimal toxicity. Full article

Locametz^®/Illuccix^®/Gozellix^TM (Novartis AG (Basel, Switzerland) and Telix Pharmaceuticals, Ltd. (Melbourne, Australia), all three [⁶⁸Ga]Ga-PSMA-11), Pylarify^®/Pylclari^® (Progenics Pharmaceuticals, Inc. (New York, USA) and Curium PET France SA (Paris, France), both [¹⁸F]DCFPyL), Radelumin^® (ABX GmbH (Radeberg, Germany), [¹⁸F]PSMA-1007), and Posluma^® (Blue Earth Diagnostics, Ltd. (Oxford, UK), [¹⁸F]rhPSMA-7.3) are four approved PSMA-PET imaging agents that have significantly advanced the diagnosis and management of prostate cancer. These agents offer a new level of precision and accuracy, enabling clinicians to detect prostate cancer with enhanced sensitivity. As a result, they play a critical role in improving detection, staging, and management, ultimately enhancing clinical outcomes for patients. Their use in routine clinical practice is expected to increase diagnostic precision and provide clearer pathways for personalized therapy. This review offers a comprehensive chemical, pharmaceutical, and medicinal overview, discusses comparative studies, and highlights additional highly relevant candidates for prostate cancer detection. Full article