Annals of Nuclear Medicine最新文献

{"title":"Comparison and cutoff values of two amyloid PET scaling methods: centiloid scale and amyloid-β load.","authors":"Ryo Yamakuni, Mitsunari Abe, Naoyuki Ukon, Hiroshi Matsuda, Harumasa Takano, Nobukatsu Sawamoto, Atsushi Shima, Yuhei Mori, Hirofumi Sekino, Shiro Ishii, Kenji Fukushima, Toshiki Mizuno, Jin Narumoto, Takashi Hanakawa, Hiroshi Ito","doi":"10.1007/s12149-025-02051-6","DOIUrl":"https://doi.org/10.1007/s12149-025-02051-6","url":null,"abstract":"<p><strong>Objective: </strong>To enhance amyloid-β (Aβ) positron emission tomography (PET) diagnostic accuracy and adjust for tracer differences, the amyloid-β load (Aβ_L) and centiloid (CL) scale were developed. However, the correlation and superiority of these indicators remain unclear. This study aimed to elucidate the correlation and determine cutoff values.</p><p><strong>Methods: </strong>Data from 281 consecutive participants (144 males; mean age, 69.6 years) in the Parkinson's and Alzheimer's Disease Dimensional Neuroimaging Initiative study were analyzed. Initial data, including Aβ PET, structural MRI, and Global Clinical Dementia Rating (G-CDR) scores, were reviewed. CL was calculated using the cerebral cortical and striatum Volume of Interest templates (VOI) and whole cerebellum VOI. Aβ_L was calculated using voxel-wise regression with two canonical images representing non-displaceable and specific binding. Visual estimation was performed by five radiologists, with two independently classify as visual-only Aβ-negative or Aβ-positive. The discrepancies were resolved through majority consensus involving a third observer. Additional visual estimation was performed for cases with CL value under 10 but visual-only Aβ-positive, and those over 30 but Aβ-negative, by two nuclear medicine radiologists. The discrepancies were resolved through discussion and classify as final Aβ diagnosis negative or positive.</p><p><strong>Results: </strong>CL and Aβ_L correlated linearly (CL = Aβ_L × 2.10-9.40, R² = 0.923). In predicting final Aβ diagnosis negative versus positive, both CL (AUC = 0.996) and Aβ_L (AUC = 0.997) were significant, with no significant differences (P = 0.882). The Youden Index was 23.3 for CL and 15.6 for Aβ_L. In predicting cognitively normal participants (G-CDR = 0) from others, both CL (AUC = 0.687) and Aβ_L (AUC = 0.667) were significant, with no significant differences (P = 0.379). The Youden Index was 11.9 for CL and 11.6 for Aβ_L. Using a non-biased Gaussian mixture model, the normal group's mean and SD were -2.5 (SD = 6.5) for CL and 3.7 (SD = 3.0) for Aβ_L, resulting in 95% limits (mean + 2SD) of 10.4 for CL and 9.7 for Aβ_L.</p><p><strong>Conclusions: </strong>This study demonstrated a high correlation and non-inferiority between CL and Aβ_L.</p>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143958021","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":"Multimodal imaging analysis of autosomal recessive Parkinson's disease.","authors":"Başak Soydaş-Turan, Gül Yalçın-Çakmaklı, Eser Lay Ergün, Hacer Dasgin, Kader Karli Oguz, Bulent Elibol, Omer Ugur, Bilge Volkan-Salanci","doi":"10.1007/s12149-025-02053-4","DOIUrl":"https://doi.org/10.1007/s12149-025-02053-4","url":null,"abstract":"<p><strong>Objective: </strong>Pathophysiological backgrounds of idiopathic Parkinson's disease (IPD) and autosomal recessive monogenic Parkinson's disease (AR-PD) have common features that can be assessed through multimodal imaging. In this study, the striatal and myocardial dopaminergic innervation, brain 18F-FDG metabolism, resting-state functional activity of basal ganglia network (BGN) and white-matter (WM) microstructure were evaluated in AR-PD with respect to IPD, to investigate whether AR-PD can be subtyped as \"brain-first\" parkinsonism according to recent etiopathogenetic classification effort.</p><p><strong>Methods: </strong>Forty patients (17 with Parkin, 3 with DJ-1 mutations and 20 with IPD) were included. Striatal dopaminergic innervation was assessed semi-quantitatively by 18F-DOPA PET, and cardiac 18F-DOPA uptake was also evaluated. Brain 18F-FDG PET images were evaluated visually. Resting-state functional MRI and diffusion tensor imaging (DTI) were used to assess the BGN activity and WM microstructural alterations.</p><p><strong>Results: </strong>AR-PD patients showed significantly decreased 18F-DOPA uptake in caudate corpus compared to both IPD and controls, with a more symmetrical striatal dopaminergic denervation. Myocardial 18F-DOPA uptake in AR-PD was similar to controls, while it was significantly reduced in IPD. There was no significant difference in cortical 18F-FDG metabolism and functional activity of BGN between PD groups. The DTI data revealed more extensive WM microstructural damage in AR-PD compared to IPD.</p><p><strong>Conclusions: </strong>AR-PD group showed additional significant decreased 18F-DOPA uptake in caudate corpus and more symmetrical striatal denervation. Additionally, relatively preserved myocardial innervation, cortical metabolic and WM microstructural changes suggest the possibility of \"brain-first\" type progression in AR-PD. Also, 18F-DOPA PET/CT may be a practical tool for evaluating dopaminergic innervation of striatum and heart together, but further evaluation is needed in this area.</p>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143966691","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":"Comparative voxel-based dosimetry with pre-treatment Tc-99m SPECT/CT and post-treatment Y-90 PET/MRI for radioembolization with Y-90 microspheres.","authors":"Burak Demir, Nuriye Ozlem Kucuk, Cigdem Soydal, Emre Can Celebioglu, Gizem Inal, Ecenur Dursun, Mehmet Sadık Bilgic, Digdem Kuru Oz, Atilla Halil Elhan, Kemal Metin Kir","doi":"10.1007/s12149-025-02052-5","DOIUrl":"https://doi.org/10.1007/s12149-025-02052-5","url":null,"abstract":"<p><strong>Purpose: </strong>The aim of this study was to investigate the differences between voxel-based dosimetry and the mean absorbed doses calculated with pre-treatment Tc-99 m-MAA SPECT/CT and post-treatment Y-90 PET/MR images. We also sought to present a detailed comparison of dose-volume histograms (DVHs) calculated from pre- and post-treatment imaging.</p><p><strong>Methods: </strong>A total of 47 treatments and 41 patients were included in the analysis as six of the treatments were retreatments of the six patients. Multicompartment and voxel-based dosimetry were performed with pre-treatment Tc-99m-MAA SPECT/CT and Y-90 PET/MRI. Correlation coefficients between the two imaging methods for the mean absorbed dose of tumor, whole liver normal tissue, perfused normal tissue, T/N ratio and tumor D10, D50 and D90 values were calculated. Additionally, differences between these values were also evaluated with Bland-Altman plots.</p><p><strong>Results: </strong>Pre-treatment Tc-99m-MAA SPECT/CT accurately predicted the dose values for healthy liver parenchyma calculated with Y-90 PET/MRI but showed lower accuracy in predicting T/N ratio and tumor doses. There were significant variations in tumor-absorbed doses for both glass and resin microspheres. Additionally, D90 values were higher when calculated with SPECT/CT than with PET/MRI, whereas D10 values were higher in PET/MRI compared to SPECT/CT.</p><p><strong>Conclusion: </strong>The findings in our study suggest that Tc-99m-MAA SPECT/CT had higher accuracy in predicting the dose to the healthy liver parenchyma compared to the tumor, maintaining its importance in treatment planning.</p>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143954709","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":"Low-iodine diet: what to eat and avoid before iodine-131 procedures?","authors":"Gabriela O Silva, Fernando G Romeiro, Sonia Marta Moriguchi, Gláucia Maria F S Mazeto, Katia H Koga","doi":"10.1007/s12149-025-02043-6","DOIUrl":"https://doi.org/10.1007/s12149-025-02043-6","url":null,"abstract":"<p><strong>Objective: </strong>The aim of this study was to compile a list of low-iodine foods for use in the Low-Iodine Diet (LID) to optimize the uptake of Iodine-131 by cells, which is used in the diagnosis and treatment of thyroid gland disorders.</p><p><strong>Methods: </strong>A bibliographic research was conducted focusing on the most commonly consumed foods in Brazil. Iodine quantification was derived from both national and international food composition tables, with an emphasis on sources indicating the highest concentrations of this microelement. The foods were organized into categories, and their iodine levels were presented in micrograms per 100 grams of food.</p><p><strong>Results: </strong>The compiled list includes foods classified into categories such as cereals, legumes, vegetables, fruits, flours, oils, fats, meats, dairy products, and beverages. Foods with more than 50 μg of iodine per 100 g were identified and classified separately. Based on the findings, marine-derived foods should be avoided, while dairy products and eggs can be consumed, provided substitutions are made.</p><p><strong>Conclusion: </strong>Identifying and quantifying low-iodine foods is essential for guiding the LID, making it more effective and better suited to the population's needs. Legumes, vegetables, and most fruits can be consumed in larger quantities, forming the core of the diet.</p>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143959468","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":"Elapsed time changes of the brain radiopharmaceutical accumulation of the amyloid PET examination using ¹⁸F-flutemetamol.","authors":"Shota Takemoto, Koji Onuki, Keiko Tanimoto, Masaho Taniguchi, Takako Suero, Mio Okamoto, Satoshi Kimura, Monami Osawa, Haruka Takeshige-Amano, Noriko Nishikawa, Shigeki Aoki, Ryohei Kuwatsuru, Nobutaka Hattori, Koji Murakami","doi":"10.1007/s12149-025-02046-3","DOIUrl":"https://doi.org/10.1007/s12149-025-02046-3","url":null,"abstract":"<p><strong>Objective: </strong>The purpose of this study was to examine how the radiopharmaceutical accumulation in the brain changes with the elapsed time between the administration of ¹⁸F-flutemetamol and the start of imaging, and to determine its effect on quantitative indices.</p><p><strong>Methods: </strong>The study population consisted of 25 subjects who agreed to participate in the study. After visual evaluation by the radiologist, 14 subjects tested negative for Aβ accumulation, and 11 subjects tested positive as well. The study population was treated with ¹⁸F-flutemeamol, and list mode acquisition was performed for 50 min starting at 60 min after the time of administration. From the acquired list data, five PET images were extracted at 10-min intervals from the start to the end of acquisition, a PET image corresponding to 20 min of acquisition from 60 min after administration, and a PET image corresponding to 20 min of acquisition from 90 min after administration, respectively. Pixel values were measured for the PET images created and quantitative indices (pixel value, SUVr, Centiloid scale) were calculated and compared.</p><p><strong>Results: </strong>In most of the PET images, pixel values showed a decreasing trend with elapsed time after radiopharmaceutical administration. Accordingly, calculated SUVr and Centiloid Scale also changed.</p><p><strong>Conclusions: </strong>Elapsed time after radiopharmaceutical administration resulted in a washout of the radiopharmaceutical accumulation in the brain. From this, it was suggested that the quantitative indices change.</p>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143956966","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":"Can interactive artificial intelligence be used for patient explanations of nuclear medicine examinations in Japanese?","authors":"Norikazu Matsutomo, Mitsuha Fukami, Tomoaki Yamamoto","doi":"10.1007/s12149-025-02047-2","DOIUrl":"https://doi.org/10.1007/s12149-025-02047-2","url":null,"abstract":"<p><strong>Objective: </strong>This study aimed to evaluate the accuracy and validity of patient explanations about nuclear medicine examinations generated in Japanese using ChatGPT- 3.5 and ChatGPT- 4.</p><p><strong>Methods: </strong>ChatGPT was used to generate Japanese language explanations for seven single-photon emission computed tomography examinations (bone scintigraphy, brain perfusion imaging, myocardial perfusion imaging, dopamine transporter scintigraphy [DAT scintigraphy], sentinel lymph node scintigraphy, lung perfusion scintigraphy, and renal function scintigraphy) and ¹⁸F-fluorodeoxyglucose positron emission tomography. Nineteen board-certified nuclear medicine technologists evaluated the accuracy and validity of the responses using a 5-point scale.</p><p><strong>Results: </strong>ChatGPT- 4 demonstrated significantly higher accuracy and validity than ChatGPT- 3.5, with 77.9% of responses rated as above average or excellent for accuracy, in comparison to 36.3% for ChatGPT- 3.5. For validity, 73.1% of ChatGPT- 4's responses were rated as above average or excellent, in comparison to 19.6% for ChatGPT- 3.5. ChatGPT- 4 outperformed ChatGPT- 3.5 in all examinations, with notable improvements in bone scintigraphy, lung perfusion scintigraphy, and DAT scintigraphy.</p><p><strong>Conclusion: </strong>These findings suggest that ChatGPT- 4 can be a valuable tool for providing patient explanations of nuclear medicine examinations. However, its application still requires expert supervision, and further research is needed to address potential risks and security concerns.</p>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143966522","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":"Pre-treatment ¹¹¹In-pentetreotide SPECT/CT vs. baseline ¹⁷⁷Lu-DOTATATE SPECT/CT: are there differences in lesion uptake and detectability?","authors":"Masatoshi Hotta, Daisuke Horikawa, Keiichi Kurihara, Shuhei Ohashi, Kaori Saito, Fuyuki Inagaki","doi":"10.1007/s12149-025-02050-7","DOIUrl":"https://doi.org/10.1007/s12149-025-02050-7","url":null,"abstract":"<p><strong>Background: </strong>¹¹¹In-pentetreotide imaging remains used for pre-treatment screening in peptide receptor radionuclide therapy (PRRT) in regions where somatostatin receptor (SSTR)-PET tracers are clinically unavailable. Post-treatment ¹⁷⁷Lu-DOTATATE imaging at the first PRRT cycle serves as a baseline for response assessment on subsequent post-treatment imaging, paralleling the role of pre-treatment ¹¹¹In-pentetreotide imaging. However, differences between these SSTR scans have not been reported. This study aims to compare ¹¹¹In-pentetreotide and ¹⁷⁷Lu-DOTATATE imaging, focusing on lesion uptake and numbers.</p><p><strong>Methods: </strong>This retrospective, single-center study included patients with neuroendocrine tumors (NETs) who underwent PRRT at our hospital. Planar and SPECT/CT of pre-treatment ¹¹¹In-pentetreotide and post-treatment ¹⁷⁷Lu-DOTATATE imaging at the first PRRT cycle were analyzed. For visual analysis, the number of SSTR-positive (Krenning score ≥ 2) lesions was counted for each tracer. For quantitative analysis, up to three representative SSTR-positive lesions per patient were selected, and the maximum standardized uptake value (SUVmax) and tumor-to-background (T/B) ratio were measured. Wilcoxon signed-rank test was used to compare lesion counts and uptake parameters.</p><p><strong>Results: </strong>A total of 10 patients and 28 lesions were included. The median interval between ¹¹¹In-pentetreotide and ¹⁷⁷Lu-DOTATATE imaging was 43 days. ¹⁷⁷Lu-DOTATATE imaging detected significantly more lesions than ¹¹¹In-pentetreotide on both planar (median 10 vs. 6.5 lesions, p = 0.009) and SPECT/CT (median 13.5 vs. 8 lesions, p = 0.014). Lesion uptake was higher with ¹⁷⁷Lu-DOTATATE, with SUVmax (median 4.5 vs. 2.9, p < 0.001) and T/B ratios (median 13.9 vs. 4.7, p < 0.001). Sub-centimeter lesions accounted for most of the additional detections on ¹⁷⁷Lu-DOTATATE SPECT/CT.</p><p><strong>Conclusion: </strong>Baseline ¹⁷⁷Lu-DOTATATE imaging demonstrated higher lesion uptake and detected more lesions compared to pre-treatment ¹¹¹In-pentetreotide imaging. Careful interpretation of baseline ¹⁷⁷Lu-DOTATATE imaging is essential to avoid misinterpreting the increased number of detected lesions as disease progression. Screening with ¹¹¹In-pentetreotide imaging may underestimate treatable lesions by PRRT, particularly when planar imaging alone is used, highlighting the need for SSTR PET in pre-treatment evaluation.</p>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143956989","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":"Suvmax of the lesion should be considered in the treatment plan for stage I non-small cell lung cancer.","authors":"Gökhan Kocaman, Farrukh Ibrahımov, Yusuf Kahya, Mine Araz, Atilla Halil Elhan, Serkan Enön","doi":"10.1007/s12149-025-02049-0","DOIUrl":"https://doi.org/10.1007/s12149-025-02049-0","url":null,"abstract":"<p><strong>Objectives: </strong>High maximum standardized uptake value (SUVmax) is associated with poorly differentiated tumors and lymph node metastasis. It is still controversial which tumors can be treated with sublobar resection and there are publications stating that SUVmax of the tumor may be important in choosing sublobar resection. Our aim in this study is to examine the prognostic value of tumor SUVmax in stage 1 non-small cell lung cancer and to determine its place in sublobar resection preference.</p><p><strong>Methods: </strong>The study included 314 patients who underwent wedge resection, segmentectomy or lobectomy for pathological stage I NSCLC with tumor size ≤ 3 cm between January 2008 and December 2020. SUVmax of the tumors are dichotomized according to ROC threshold value 5.2 and prognostic factors for recurrence-free and overall survival were analysed.</p><p><strong>Results: </strong>In the multivariate survival analysis, SUVmax (p = 0.012), lymphovascular and/or perineural invasion (p < 0.001) and visceral pleural invasion (p = 0.031) were found to be independent prognostic factors for recurrence-free survival; age (p = 0.027), sex (p = 0.010) and SUVmax (p = 0.036) for overall survival. While there was no difference between lobar or sublobar resection in terms of recurrence-free survival (p = 0.647) in patients with SUVmax ≤ 5.2, lobectomy was found to be advantageous over sublobar resection for recurrence-free survival in patients with SUVmax > 5.2 (76.6% ± 3.9% / 53.4% ± 12.1%, p = 0.006, respectively).</p><p><strong>Conclusions: </strong>High SUVmax (> 5.2) is associated with poor recurrence-free survival and overall survival rates in pathological stage 1 NSCLC patients. In stage 1 patients, sublobar resection should be avoided if the primary tumor has a high SUVmax.</p>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143974781","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":"Factors and predictors affecting late external dose rates and isolation period in patients after lutetium-177-labeled DOTA-Tyr3-octreotate treatment for neuroendocrine tumors.","authors":"Naoto Wakabayashi, Shiro Watanabe, Satoshi Takeuchi, Takahiro Tsuchikawa, Yamato Munakata, Kenji Hirata, Rina Kimura, Junki Takenaka, Hiroshi Ishii, Kohsuke Kudo","doi":"10.1007/s12149-025-02044-5","DOIUrl":"https://doi.org/10.1007/s12149-025-02044-5","url":null,"abstract":"<p><strong>Objective: </strong>In peptide receptor radionuclide therapy (PRRT) using lutetium-177-labeled DOTA-Tyr3-octreotate ([¹⁷⁷Lu] DOTATATE), isolation is required until the external dose rate at 1 m (EDR-1 m) from the body surface falls below the regulatory standards of each country. While it is known that renal function influences EDR-1 m reduction within 180 min post-administration, the factors affecting EDR-1 m on the day following administration (Late EDR-1 m) remain unclear. This study aimed to identify factors influencing Late EDR-1 m after PRRT using [¹⁷⁷Lu] DOTATATE for neuroendocrine tumors and to predict Late EDR-1 m using pretreatment [¹¹¹In] pentetreotide single-photon emission computed tomography/computed tomography (SPECT/CT) data.</p><p><strong>Methods: </strong>This study analyzed 111 PRRT cycles administered to 36 patients between September 2021 and August 2024. Late EDR-1 m was set as the dependent variable, whereas total radiopharmaceutical uptake (LUTtotal), dose per body weight, creatinine clearance (CCr), and albumin-bilirubin (ALBI) score were set as the independent variables in the multiple regression analysis. LUTtotal was calculated using SPECT/CT data acquired after the patient left the radiation therapy room, defining the volume of interest (VOI) as the area with SUVmean + 2SD or higher in the skeletal muscle. The VOI volume multiplied by the SUVmean was used to define LUTtotal. In addition, using [¹¹¹In] pentetreotide SPECT/CT data, the total radiopharmaceutical uptake (OCTtotal) was calculated in a manner similar to LUTtotal, and its correlation with LUTtotal was examined. A predictive equation for Late EDR-1 m was developed using the results of the multivariate analysis, and its performance was tested using subsequent cases between August 2024 and January 2025.</p><p><strong>Results: </strong>The median measured Late EDR-1 m was 8.0 (range, 4.0-26.0) μSv/h. LUTtotal and dose per body weight were significantly correlated with Late EDR-1 m, whereas CCr and ALBI scores were not. Based on the results of the multivariate analysis, the predictive equation using the dose per body weight, assuming a dosage of 7400 MBq and OCTtotal, achieved a root mean square error (RMSE) of 2.24 μSv/h. In subsequent test cases, the RMSE was 3.47 μSv/h.</p><p><strong>Conclusions: </strong>Late EDR-1 m is significantly correlated with LUTtotal and dose per body weight. It can be accurately predicted using [¹¹¹In] pentetreotide SPECT/CT data.</p>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143787560","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":"Blood and bone marrow dosimetry for thyroid cancer patients prepared with rhTSH injection.","authors":"Amna Juma Al Jabri, Jennie Cooke, Seán Cournane, Marie-Louise Healy","doi":"10.1007/s12149-025-02042-7","DOIUrl":"https://doi.org/10.1007/s12149-025-02042-7","url":null,"abstract":"<p><strong>Purpose: </strong>Radioiodine (¹³¹I) dosimetry is used to maximise tumour dose while reducing the chances of toxicity. High thyroid-stimulating-hormone (TSH) levels are required for ¹³¹I treatment, achieved through hormone withdrawal or intramuscular injection of recombinant human TSH (rhTSH). Both approaches have shown equivalent results, with the rhTSH approach reported to reduce morbidity and avoid hypothyroidism. There are established differences in ¹³¹I biokinetics using each method. This clinical cohort study investigated if pretherapy iodine biokinetics as measured using a dosimetry protocol without a dose of rhTSH are predictive of post therapy biokinetics in patients prepared with rhTSH injection.</p><p><strong>Methods: </strong>Thirteen patients with differentiated thyroid cancer (DTC) were recruited. An adaptation of the European Association of Nuclear Medicine (EANM) dosimetry protocol was conducted at St James's Hospital, Ireland. The maximum tolerable activity (MTA) was calculated using the EANM, Association of Physics in Medicine (AIFM) and Traino models, after administering ¹³¹I, and subsequent whole-body (WB) dose-rate measurements and blood-sampling were carried out. The MTA estimated from pre-therapeutic (PT) ¹³¹I tracer administration (6.07 ± 2.46 MBq) was compared to during therapy (DT) administration (3.88 ± 0.16 GBq).</p><p><strong>Results: </strong>The PT WB residence-time overestimated the DT with a difference of - 7.72 ± 8.13% (p = 0.007), while no significant difference is reported between the blood residence-time (1.13 ± 6.49%, p = 0.559). The EANM model reported the lowest difference of 1.73 ± 4.83% (p = 0.241) in MTA.</p><p><strong>Conclusion: </strong>This study validated the feasibility of using dosimetry in euthyroid patients to predict therapeutic ¹³¹I biokinetics in DTC patients prepared with rhTSH.</p>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143787508","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}