Annals of Nuclear Medicine最新文献

{"title":"Integrating functional and volumetric assessments in ⁹⁰Y radioembolization: added value of [⁹⁹ᵐTc]Mebrofenin scintigraphy.","authors":"Ali Kibar, Sertac Asa, Mohammad Abuqbeitah, Fuad Aghazada, Haluk Burcak Sayman","doi":"10.1007/s12149-026-02265-2","DOIUrl":"https://doi.org/10.1007/s12149-026-02265-2","url":null,"abstract":"<p><strong>Objectives: </strong>In this study, we aimed to evaluate the association between liver clearance values obtained from pre-treatment [⁹⁹ᵐTc]mebrofenin hepatobiliary scintigraphy and conventional liver function scores and biochemical parameters, and to perform an exploratory prognostic assessment of whether baseline clearance is associated with post-treatment outcomes, including overall survival, prior to ⁹⁰Y radioembolization. We also compared the functional assessment of the treatment region (based on mebrofenin uptake) with its anatomical CT volume (derived from [⁹⁹ᵐTc]macroaggregated albumin SPECT/CT) to determine the concordance between functional and volumetric data.</p><p><strong>Methods: </strong>Pre-treatment [⁹⁹ᵐTc]mebrofenin and [⁹⁹ᵐTc]MAA scintigraphies were performed in 19 patients scheduled to receive Yttrium-90 (⁹⁰Y) microsphere therapy. Mebrofenin clearance was calculated, and its association with biochemical parameters and overall survival was examined. The functional definition of the planned treatment territory was estimated based on mebrofenin uptake, and this was compared with the anatomical volume of the same region on MAA SPECT/CT.</p><p><strong>Results: </strong>Mebrofenin liver clearance showed significant (p < 0.05) negative correlations with pre- and post-treatment total and direct bilirubin levels and a positive correlation with post-treatment albumin. Clearance also demonstrated a strong inverse correlation with ALBI score (p < 0.05). Among biochemical changes, only the post-treatment change in direct bilirubin was significantly associated with clearance (p < 0.05). Functional and volumetric definitions of the treatment area showed strong correlation (ρ = 0.837, p < 0.001). In five patients with target ratio greater than 50% of liver volume, functional definition was not concordant with volumetric estimates. The difference in clearance values between patients surviving ≤ 6 months and > 6 months did not reach statistical significance. Among liver function scores, Child-Pugh exhibited the strongest, though non-significant, correlation with survival (ρ = - 0.407, p = 0.084).</p><p><strong>Conclusion: </strong>[⁹⁹ᵐTc]mebrofenin scintigraphy correlated with both pre- and post-treatment biochemical liver function parameters. The functional definition of the treatment region assessed by scintigraphy and volumetric definition derived from SPECT/CT were also well concordant. The difference in clearance values between patients surviving ≤ 6 months and > 6 months did not reach statistical significance. Discrepancies between volumetric and functional definitions were observed in patients with extensive target volume (> 50% of liver volume). These preliminary findings suggest that [⁹⁹ᵐTc]mebrofenin scintigraphy may complement anatomical volumetry in the pretreatment assessment of functional liver reserve, but its potential role in individualized dosimetry requires confirmation in larger prospective studies.</p>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148590298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and validation of a machine learning-based hierarchical classification model for predicting the early therapeutic response to initial 131I therapy in papillary thyroid carcinoma","authors":"Zhiyue Tang,&nbsp;Zhengjie Wang,&nbsp;Hua Pang","doi":"10.1007/s12149-026-02258-1","DOIUrl":"10.1007/s12149-026-02258-1","url":null,"abstract":"<div><h3>Objective</h3><p>Personalized tools for accurately predicting papillary thyroid carcinoma (PTC) patients’ response to initial ¹³¹I therapy are lacking. This study aimed to develop a machine learning (ML) model for prediction of 6–12 month therapeutic response after therapy.</p><h3>Methods</h3><p>This study retrospectively enrolled 702 PTC patients undergoing initial ¹³¹I therapy. A hierarchical classification framework was designed: the first layer distinguished excellent response from non-excellent response (Non-ER), while the second layer further categorized Non-ER into indeterminate response, biochemical incomplete response, and structural incomplete response. Seven ML algorithms were utilized per layer. Feature selection was performed using recursive feature elimination. Model development employed nested five-fold cross-validation within the training set, with performance further evaluated on an independent testing set. The final model was benchmarked against the American Thyroid Association risk stratification system, interpreted via Shapley Additive exPlanations, and deployed as an interactive web tool.</p><h3>Results</h3><p>For the first-layer classification, the Random Forest model optimally identified Non-ER. For the second-layer classification, the Logistic Regression + Extreme Gradient Boosting fusion model excelled. The final model, built on 17 features, achieved a hierarchical F1 score of 0.849 and an overall accuracy of 69.7%. Both the model’s superior predictive accuracy over the benchmark model and its strong association with progression-free survival confirmed the value of this hierarchical model.</p><h3>Conclusions</h3><p>This study developed an ML-based hierarchical model capable of forecasting early response to initial ¹³¹I therapy in PTC, offering a practical web-based tool for personalized clinical decision-making.</p></div>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":"40 11","pages":"1415 - 1424"},"PeriodicalIF":2.4,"publicationDate":"2026-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148576622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase I/IIa clinical trial of ⁶⁸Ga-PSMA-11 synthesized by a newly developed automated module using cyclotron-generated ⁶⁸Ga.","authors":"Shigeyasu Sugawara, Shozo Okamoto, Noriko Kanno, Naoyuki Ukon, Taiki Joho, Kazuhiro Takahashi, Seiji Hoshi, Yoshiyuki Kojima, Yuko Hashimoto, Yoichi M Ito, Kazuhiko Hanada, Masao Kobayakawa, Noboru Oriuchi, Tohru Shiga","doi":"10.1007/s12149-026-02262-5","DOIUrl":"https://doi.org/10.1007/s12149-026-02262-5","url":null,"abstract":"<p><strong>Objective: </strong>This Phase I/IIa study evaluated the safety, pharmacokinetics, internal radiation dosimetry, and image quality of cyclotron-produced ⁶⁸Ga-PSMA-11 synthesized using an automated module in a Japanese population.</p><p><strong>Methods: </strong>In this single-center trial, nine Japanese men (3 healthy volunteers, 6 prostate cancer patients) received a single intravenous injection of ⁶⁸Ga-PSMA-11 (4.0 MBq/kg). Safety, pharmacokinetics (blood/urine), and internal radiation dosimetry (serial PET/CT) were assessed. Diagnostic performance was evaluated by lesion detection rates and image quality by quantitative metrics, including noise-equivalent count (NEC), to optimize the protocol.</p><p><strong>Results: </strong>No adverse events were observed. The automated synthesis process consistently yielded high-quality ⁶⁸Ga-PSMA-11, with a decay-corrected radiochemical yield of 2841 ± 584 MBq and a radiochemical purity > 99%. The kidneys received the highest absorbed dose, with an effective dose comparable to that reported in published data. The agent demonstrated rapid clearance, primarily via renal excretion (58.99% ± 11.34% in 6 h), with a biological half-life of approximately 3.8 h in whole blood. All histopathology-confirmed primary lesions were detected. Quantitative analysis indicated that high image quality was maintained even with substantially reduced acquisition times.</p><p><strong>Conclusions: </strong>Cyclotron-produced ⁶⁸Ga-PSMA-11 is safe and exhibits favorable pharmacokinetics and dosimetry in a Japanese population. This exploratory Phase I/IIa trial suggests that the production method appears feasible.</p><p><strong>Trial registration: </strong>jRCT2022230014.</p>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148576630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clinical significance of suspicious incidental FDG uptake: a comparison between digital PET/CT and conventional PET/CT.","authors":"Takuya Kitamura, Naoto Kawaguchi, Marika Matsuoka, Kotaro Matsumoto, Hiroki Yakata, Tomohisa Okada, Masao Miyagawa, Teruhito Kido","doi":"10.1007/s12149-026-02264-3","DOIUrl":"https://doi.org/10.1007/s12149-026-02264-3","url":null,"abstract":"<p><strong>Objective: </strong>To compare the clinical significance of incidental ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) uptake detected on silicon photomultiplier-based digital positron emission tomography/computed tomography (dPET) versus conventional positron emission tomography/computed tomography (cPET), focus on suspicious incidental lesions and incidental malignancies.</p><p><strong>Methods: </strong>This retrospective single-center study included patients who underwent cPET from April 2019 to March 2020 and dPET from June 2020 to May 2021. Epilepsy PET and cardiac PET examinations requiring prolonged fasting protocols were excluded. Suspicious incidental FDG uptake was defined as a lesion unrelated to the primary indication or previously known disease, showing visually increased uptake and explicitly recommended for further evaluation in the original radiology report because malignancy was considered a concern. Lesions for which only follow-up was advised were excluded. Organ-specific analyses were performed exploratorily. Detection rates, organ distribution, malignant outcomes, and maximum standardized uptake value (SUVmax) were compared between groups.</p><p><strong>Results: </strong>A total of 1,815 cPET examinations and 1,769 dPET examinations were analyzed. Suspicious incidental FDG uptake was identified more often with dPET than with cPET (149/1,769 [8.4%] vs 97/1,815 [5.3%], p < 0.01). Further diagnostic evaluation was performed in 73 cPET lesions and 111 dPET lesions, and confirmed incidental malignancy was identified in 15 and 29 lesions, respectively, corresponding to 0.83% (95% CI: 0.50-1.36%) and 1.64% (95% CI: 1.15-2.35%) of all examinations (p < 0.05). Colorectal cancer was the most common incidental malignancy in both groups. Prostate cancer was the second most frequent incidental malignancy in the dPET/CT group but was not confirmed in the cPET/CT group. Median SUVmax of incidental lesions was higher with dPET than with cPET (6.8 [4.8-9.7] vs 5.5 [4.2-9.0], p < 0.05). However, SUVmax did not significantly distinguish malignant from non-malignant lesions in either group.</p><p><strong>Conclusions: </strong>In routine clinical practice, implementation of dPET was associated with increased detection of suspicious incidental FDG uptake and confirmed incidental malignancy compared with cPET. This difference was most apparent for colorectal and prostatic lesions. However, SUVmax alone had limited value for distinguishing malignant from non-malignant incidental lesions, indicating that organ-specific clinical interpretation remains essential.</p>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148576566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of posture change on patient-specific absorbed dose estimation in nuclear medicine.","authors":"Mei Takahashi, Phornpailin Pairodsantikul, Hiroshi Watabe, Miho Shidahara","doi":"10.1007/s12149-026-02263-4","DOIUrl":"https://doi.org/10.1007/s12149-026-02263-4","url":null,"abstract":"<p><strong>Purpose: </strong>Internal dosimetry in nuclear medicine commonly assumes a fixed upright standing posture of subjects. The use of four recent therapeutic radionuclides with longer half-lives causes long exposure to patients during different daily activities and postures. This study aims to evaluate the effect of posture change on organ absorbed doses for seven radionuclides: diagnostic photon/positron-emitters (⁶⁴Cu, ⁶⁸Ga, ^99mTc) and therapeutic alpha/beta-emitters (¹⁷⁷Lu, ²¹¹At, ²¹²Pb, ²²⁵Ac).</p><p><strong>Method: </strong>Whole body Japanese adult male and female digital human phantoms (National Institute of Information and Communications Technology, Japan) in standing and sitting postures were used in this study. Based on the reference biodistribution of ¹⁷⁷Lu-DOTATATE in kidneys, liver, spleen and remainder of the body, generated 28 time-integrated activity maps (seven radionuclides, two genders, two postures) were used for RT-PHITS Monte Carlo simulations to calculate organ absorbed doses. A comparative analysis of the organ absorbed doses between the two postures was specifically conducted for the liver, kidneys, and spleen.</p><p><strong>Results: </strong>Large differences in organ absorbed doses between the two postures were observed for diagnostic radionuclides, with ⁹⁹ᵐTc exhibiting more than 15% kidney dose differences. In contrast, therapeutic radionuclides showed less than 4% differences, as their energy deposition is dominated by self-dose.</p><p><strong>Conclusion: </strong>Incorporating posture into internal dosimetry may improve the accuracy of absorbed dose estimation and support more personalized applications for diagnostic nuclear medicine.</p>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148560719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Protein expression of glucose metabolism and somatostatin receptor between primary tumor and distant metastasis in differentiated thyroid cancer","authors":"Joon Ho Choi,&nbsp;Jae Kyung Myung,&nbsp;Ji Eun Moon,&nbsp;Joon-Seog Kong,&nbsp;Byung Hyun Byun,&nbsp;Byung Il Kim,&nbsp;Ilhan Lim","doi":"10.1007/s12149-026-02252-7","DOIUrl":"10.1007/s12149-026-02252-7","url":null,"abstract":"<div><h3>Objective</h3><p>This study evaluated differences in the expression of proteins related to glucose metabolism and somatostatin receptors (SSTRs) between primary tumors and distant metastatic lesions in differentiated thyroid cancer (DTC).</p><h3>Methods</h3><p>We retrospectively analyzed 18 patients with DTC (mean age 56 ± 10 years) who had bone or soft tissue metastasis. Immunohistochemical staining of surgical specimens was performed to assess the expression of glucose transporter 1 (GLUT-1), hexokinase-2 (HK-2), and somatostatin receptor subtype 2 (SSTR-2). Protein expression was classified as negative, weakly positive, or strongly positive. Correlations between primary and metastatic lesions were evaluated using Spearman analysis. FDG SUVmax values were compared according to protein expression using the Mann–Whitney U test, and the association between iodine avidity and SSTR-2 expression was assessed using Fisher’s exact test.</p><h3>Results</h3><p>GLUT-1 expression was more frequent in metastatic lesions than in primary tumors (65% vs. 50%). HK-2 expression was high in both primary and metastatic lesions (94% each). SSTR-2 expression was similar between primary (50%) and metastatic lesions (41%). GLUT-1 expression demonstrated a marginal positive correlation between primary tumors and bone metastasis (<i>r</i> = 0.462, <i>p</i> = 0.062). After excluding primary tumors smaller than 1 cm, significant correlations were observed for both GLUT-1 (<i>r</i> = 0.624, <i>p</i> = 0.023) and HK-2 (<i>r</i> = 0.695, <i>p</i> = 0.008), whereas SSTR-2 showed no significant correlation. Among patients who underwent surgery and ¹⁸F-FDG PET/CT within one year, GLUT-1–positive metastatic lesions demonstrated significantly higher FDG SUVmax values than GLUT-1–negative lesions (<i>p</i> = 0.046). Among a small subset of evaluable iodine-non-avid metastatic lesions, preserved SSTR-2 expression was observed, although the association was not statistically significant.</p><h3>Conclusion</h3><p>GLUT-1 expression showed partial concordance between primary and metastatic DTC lesions and was associated with higher FDG uptake, which may reflect altered glucose metabolic activity. Although SSTR-2 expression was not associated with iodine avidity, its retention in a subset of iodine-refractory metastatic lesions may indicate a possible avenue for future investigation of SSTR-targeted imaging or radionuclide therapy in selected patients with advanced DTC.</p></div>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":"40 11","pages":"1359 - 1369"},"PeriodicalIF":2.4,"publicationDate":"2026-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148547718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of a ¹⁸F-FDG PET/CT-based radiomic risk score as an independent prognostic factor in small cell lung cancer.","authors":"Kerim Şeker, Mukaddes Yılmaz, Eda Erdiş, Zekiye Hasbek","doi":"10.1007/s12149-026-02261-6","DOIUrl":"https://doi.org/10.1007/s12149-026-02261-6","url":null,"abstract":"<p><strong>Objective: </strong>Prognosis in small cell lung cancer (SCLC) remains poorly predicted by conventional staging and metabolic parameters. This study aimed to develop a positron emission tomography/computed tomography (PET/CT) based Radiomic Risk Score (Rad-Score), evaluate its independent prognostic value for overall survival (OS), and assess the clinical utility of an integrated model using Decision Curve Analysis (DCA).</p><p><strong>Materials and methods: </strong>143 SCLC patients (120 male, 23 female) who underwent pre-treatment staging ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET/CT between January 2012 and June 2024 were included. Using LIFEx (v25.06.1), 129 Image Biomarker Standardisation Initiative (IBSI) compliant radiomic features were extracted alongside standard metabolic parameters (SUVmax, SUVmean, MTV, TLG). After eliminating highly correlated features (|r|> 0.90), five key features were selected via tenfold cross-validation LASSO-Cox regression to construct the Rad-Score. Patients were stratified into Low and High Radiomic Risk groups. Independent prognostic factors were identified through Cox regression analyses, and the incremental value of the Rad-Score was assessed by hierarchical C-index comparisons and DCA.</p><p><strong>Results: </strong>Median OS was 10.8 months (95% CI: 8.2-13.3), with a mortality rate of 83.9%. Multivariable analysis identified the Radiomic Risk Group (HR: 2.12; 95% CI: 1.33-3.40; p = 0.002) and Curative CRT (HR: 0.17; 95% CI: 0.06-0.48; p < 0.001) as independent prognostic factors. The C-index improved from 0.657 to 0.688 (p = 0.018) and to 0.701 with Rad-Score integration (p = 0.0017). DCA demonstrated superior net benefit at high threshold probabilities (≥ 65%).</p><p><strong>Conclusion: </strong>The ¹⁸F-FDG PET/CT-based Rad-Score independently predicts survival in SCLC beyond conventional staging and metabolic parameters. The integrated model provides meaningful incremental prognostic value; however, multicenter external validation is warranted prior to clinical implementation.</p>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148519788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"18F-flortaucipir PET imaging: Biodistribution in the Japanese population and diagnostic accuracy by Japanese readers","authors":"Etsuko Imabayashi,&nbsp;Amanda Morris,&nbsp;Leonardo Iaccarino,&nbsp;Anupa K. Arora,&nbsp;Eriko Kamiki,&nbsp;Ming Lu","doi":"10.1007/s12149-026-02239-4","DOIUrl":"10.1007/s12149-026-02239-4","url":null,"abstract":"<div><h3>Objective</h3><p>¹⁸F-flortaucipir (Tauvid™) is an ¹⁸F-labeled diagnostic positron emission tomography (PET) radiopharmaceutical, which was developed to detect tau pathology in the brain and to estimate the density and/or distribution of aggregated tau neurofibrillary tangles for patients being evaluated for Alzheimer’s disease (AD). The objective of this article is to report findings from two studies. The primary objective of the first <i>(</i>dose and biodistribution) study was to investigate the consistency of ¹⁸F-flortaucipir PET biodistribution between Japanese and non-Japanese individuals. In the second (reader) study, the comparability of visual reads performed by Japanese and US expert readers who followed the same training program was evaluated.</p><h3>Methods</h3><p>This article reports findings from two separate studies and datasets. In the dose and biodistribution study, whole-body distribution of ¹⁸F-flortaucipir was assessed (<i>N</i> = 9). Standardized uptake value ratios, normalized to the entire cerebellum, were calculated, and whole-body effective dose was calculated using a 73.7 kg bodyweight model. In the reader study (Study A27; I7E-AV-A27), five Japanese physicians visually interpreted 60 PET scans randomly selected from a previous US reader study (Study FR01; NCT03901092). Scan positivity was determined based on increased activity of ¹⁸F-flortaucipir in posterolateral temporal, occipital, or parietal/precuneus regions with or without frontal activity. Each scan was visually interpreted by all Japanese readers, who determined whether scans were consistent with an AD or non-AD pattern. Concordance between Japanese and US readers who underwent the same training on the interpretation of ¹⁸F-flortaucipir PET images was then evaluated (reader study primary endpoint).</p><h3>Results</h3><p>The biodistribution of ¹⁸F-flortaucipir was consistent between Japanese and non-Japanese individuals. When interpreting ¹⁸F-flortaucipir PET images to distinguish between AD versus non-AD patterns, Japanese and US readers who underwent the same training showed 100% agreement on the majority reads, with a Cohen’s Kappa value of 1.</p><h3>Conclusions</h3><p>¹⁸F-flortaucipir whole-body biodistribution for Japanese individuals was consistent with that of non-Japanese individuals. After completing the same training, Japanese readers showed high concordance with US readers on the interpretation of ¹⁸F-flortaucipir PET images to distinguish between AD and non-AD patterns. Data and scans were from previous studies registered with ClinicalTrials.gov (registration numbers: NCT04474405; NCT03901092).</p></div>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":"40 10","pages":"1219 - 1228"},"PeriodicalIF":2.4,"publicationDate":"2026-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s12149-026-02239-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148468487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prospective evaluation of ¹⁸F-PSMA-1007 PET/CT in renal masses paired with PSMA immunohistochemistry.","authors":"André Marcondes Braga Ribeiro, José Augusto Rinck, Stênio de Cássio Zequi","doi":"10.1007/s12149-026-02259-0","DOIUrl":"https://doi.org/10.1007/s12149-026-02259-0","url":null,"abstract":"<p><strong>Background: </strong>Incidental renal masses (RM) are increasingly detected with cross-sectional imaging, and 20-30% of resected small RM are benign, exposing patients to potentially unnecessary surgery. Improved preoperative characterization is needed. Prostate-Specific Membrane Antigen (PSMA) expression in tumor neovasculature enables functional assessment, and ¹⁸F-PSMA-1007 has lower renal elimination than ⁶⁸Ga-PSMA-11, potentially improving lesion conspicuity.</p><p><strong>Methods: </strong>This was a prospective cross-sectional accuracy study including 24 adults with renal masses scheduled for nephrectomy. All underwent ¹⁸F-PSMA-1007 positron emission tomography/computed tomography (PET/CT) approximately 60 min post-injection. PET positivity was defined as uptake greater than splenic standardized uptake value maximum (SUVmax) or unequivocally positive uptake on visual assessment. PSMA immunohistochemistry (IHC) in tumor vasculature was graded as absent, mild, moderate, or marked.</p><p><strong>Results: </strong>Twenty-five RM were analyzed in 24 patients, all incidentalomas: 14 (56%) renal cell carcinomas (RCC) - 10 clear cell, 3 papillary, and 1 chromophobe - and 11 (44%) benign lesions.¹⁸F-PSMA-1007 PET/CT detected 10/14 RCC (sensitivity 71.4%) with specificity 54.5% for malignant versus benign discrimination; sensitivity was higher in clear cell RCC (80%) than papillary RCC (33.3%). PET uptake correlated with PSMA expression on IHC (p = 0.026). Mass size showed a linear association with PSMA expression; all lesions > 30 mm expressed PSMA on IHC, with marked expression in 54.5% versus 7.7% of lesions ≤ 30 mm. By contrast, SUVmax values overlapped between malignant and benign PET-positive lesions, and no robust SUV-based threshold emerged from this cohort.</p><p><strong>Conclusion: </strong>¹⁸F-PSMA-1007 PET/CT showed concordance with PSMA immunohistochemistry and higher detectability in clear cell RCC, but its ability to distinguish malignant from benign renal masses was limited by modest specificity and overlap with benign oncocytic lesions. These findings support ¹⁸F-PSMA-1007 PET/CT as a complementary, not stand-alone, tool for selected cases of renal mass characterization.</p>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148429685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative SPECT imaging for predicting therapeutic response to lutetium-177 DOTATATE in neuroendocrine tumors","authors":"Yuichiro Furuya,&nbsp;Masakazu Tsujimoto,&nbsp;Tsubasa Asai,&nbsp;Isanori Iwama,&nbsp;Hisashi Hattori,&nbsp;Yoshitaka Inaba","doi":"10.1007/s12149-026-02256-3","DOIUrl":"10.1007/s12149-026-02256-3","url":null,"abstract":"<div><h3>Objective</h3><p>As the incidence of neuroendocrine tumors (NETs) increases, Lutetium-177 (Lu-177) DOTATATE targeted radionuclide therapy (TRT) has become a vital treatment strategy. However, its prolonged course makes early prediction of response challenging, and current predictive methods like dosimetry are complex. Therefore, a simpler, earlier prediction method is needed for timely treatment planning. This study aimed to investigate whether quantitative metrics from a single, initial post-therapy single-photon emission computed tomography / computed tomography (SPECT/CT) image could predict the final treatment response.</p><h3>Methods</h3><p>This retrospective, single-center study included 17 patients (60 tumor lesions) receiving Lu-177 DOTATATE TRT. Patients were classified into G1, G2, and G3/neuroendocrine carcinoma (NEC) groups according to the World Health Organization (WHO) 2019 classification. When multiple lesions with discrepant grades were present, the highest grade was assigned for patient-level classification. Tumor volume and maximum standardized uptake value (SUVmax) were calculated from initial and final post-therapy SPECT images using an adaptive thresholding method. Response was evaluated based on a ≥ 50% reduction in tumor volume. Statistical analyses included one-way analysis of variance (ANOVA) and Pearson’s correlation.</p><h3>Results</h3><p>A higher initial post-therapy SUVmax tended to correlate with a better volumetric response. In an exploratory analysis, all lesions (<i>n</i> = 8) with an initial post-therapy SUVmax exceeding 55 achieved a volumetric response, yielding a positive predictive value of 100% for this subgroup. The overall response rates for tumor volume and SUVmax were 71.7% and 65.0%, respectively. Additionally, G3/NEC tumors showed a significantly greater initial volume reduction than G2 tumors (<i>p</i> = 0.042).</p><h3>Conclusions</h3><p>Our findings suggest that the initial post-therapy SUVmax from a single SPECT/CT acquisition may serve as a promising exploratory predictor of early volumetric response to Lu-177 DOTATATE TRT. While this metric is clinically intriguing, it may reflect treatment-induced necrosis or edema rather than durable tumor control, particularly in high-grade tumors. Therefore, its relationship with long-term clinical endpoints such as progression-free survival remains to be established. This streamlined approach could contribute to personalized medicine, though further validation is required.</p></div>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":"40 11","pages":"1395 - 1404"},"PeriodicalIF":2.4,"publicationDate":"2026-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148417656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}