The Journal of Nuclear Medicine最新文献

{"title":"Histologic Ex Vivo Validation of the [18F]SITATE Somatostatin Receptor PET Tracer","authors":"Nils F. Trautwein, Sven Mattern, Martina Hinterleitner, Gerald Reischl, Ralf Schirrmacher, Volker Steger, Silvio Nadalin, Konstantin Nikolaou, Johannes Schwenck, Stephan Singer, Christian la Fougère","doi":"10.2967/jnumed.125.269619","DOIUrl":"https://doi.org/10.2967/jnumed.125.269619","url":null,"abstract":"<p>Radiolabeled somatostatin analogs (SSAs), such as [⁶⁸Ga]Ga-DOTA SSAs, have transformed imaging and therapeutic strategies. However, their use is constrained by the high cost of generators and their short half-life. In contrast, [¹⁸F]SITATE presents a promising alternative, offering the advantage of a longer half-life than ⁶⁸Ga, along with the cost-effectiveness of cyclotron-based production. This study evaluated the first histologic ex vivo validation of [¹⁸F]SITATE. <strong>Methods:</strong> This study retrospectively included 47 patients (57% male; mean age, 66.9 ± 14.9 y) with histologically confirmed well-differentiated neuroendocrine neoplasms who underwent [¹⁸F]SITATE PET followed by surgery within 4 mo. Lesion uptake was quantified using SUV_mean, SUV_peak, SUV_max, and tumor-to-liver ratio (TLR). Histologic somatostatin receptor (SSTR) type 2 expression was determined using histological scores (H-scores), with thresholds defining SSTR scores 1–3. The accuracy of PET imaging for preoperative metastatic detection was evaluated against surgical histology. <strong>Results:</strong> PET imaging demonstrated a significant correlation between [¹⁸F]SITATE uptake (SUV_mean and TLR) and SSTR type 2 H-scores (<em>r</em> = 0.618 and 0.622, respectively; <em>P</em> &lt; 0.0001). SSTR score 3 correlated with increased SUV_mean and TLR (<em>P</em> &lt; 0.0001). Among 35 patients with primary resection and lymphadenectomy, PET achieved a sensitivity of 73.9% and specificity of 100%. <strong>Conclusion:</strong> [¹⁸F]SITATE PET imaging strongly correlates with histologic SSTR expression, demonstrating utility in staging and guiding therapeutic decisions in neuroendocrine neoplasms. This ¹⁸F-labeled tracer shows specificity comparable to historical [⁶⁸Ga]Ga-DOTA SSA data, whereas an increase in sensitivity for the detection of locoregional metastases appears possible. Further head-to-head comparisons of [¹⁸F]SITATE with traditional [⁶⁸Ga]Ga-DOTA SSA and histologic validation are warranted to optimize its diagnostic accuracy and clinical impact.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[18F]FDG Metabolic Tumor Volume as a Prognostic Marker in Neuroendocrine Neoplasm: A Multicenter Study","authors":"David L. Chan, Aimee Hayes, Ioannis Karfis, Alice Conner, Magdalena Mileva, Elizabeth Bernard, Shaunak Navalkissoor, Gopinath Gnanasekaran, Stephen J. Clarke, Paul J. Roach, Patrick Flamen, Martyn E. Caplin, Nick Pavlakis, Christos Toumpanakis, Dale L. Bailey","doi":"10.2967/jnumed.124.269031","DOIUrl":"https://doi.org/10.2967/jnumed.124.269031","url":null,"abstract":"<p>[¹⁸F]FDG PET/CT avidity predicts higher-grade disease and worse prognosis in patients with metastatic neuroendocrine neoplasm. However, there is less evidence regarding the role of [¹⁸F]FDG-avid tumor volume in predicting prognosis. We planned to determine whether metabolic tumor volume (MTV) on [¹⁸F]FDG PET/CT predicts prognosis in patients with advanced gastroenteropancreatic neuroendocrine neoplasm (GEPNEN). <strong>Methods:</strong> A multicenter retrospective study was performed on patients with advanced GEPNEN who underwent [¹⁸F]FDG PET/CT in a previously established cohort. Images were acquired across 3 centers using harmonized protocols and were contoured and verified at a flat SUV threshold of 4 using a semiautomated software workflow. The primary endpoint was overall survival. Patients were dichotomized into high- and low-MTV groups by the median value, with the overall survival of the 2 resulting cohorts compared by log-rank tests and multivariate analyses. <strong>Results:</strong> In total, 231 patients were included (49% male; median age, 60 y). In 45% of cases the primary was the pancreas, in 42% the small bowel, and in 13% another location. Regarding World Health Organization 2019 grade, 23% were grade 1, 52% grade 2, 21% grade 3, and 4% an unknown grade. The median follow-up was 27 mo (interquartile range, 11–49 mo), and median overall survival was 38.6 mo. Median overall survival was shorter in the high-MTV cohort than in the low-MTV cohort (cut point, 16.5 cm³; 23.8 mo vs. not reached; hazard ratio, 2.49; 95% CI, 1.69–3.66; <em>P</em> &lt; 0.0001). Median time to treatment failure was also shorter in the high-MTV cohort (11.7 mo vs. 16.9 mo; hazard ratio, 1.52; 95% CI, 1.13–2.06; <em>P</em> = 0.005). Increasing histologic grade was associated with higher MTV (<em>P</em> = 0.0006, 1-way ANOVA). Multivariate analysis incorporating age, grade, sex, SUV_max, and MTV showed that only grade (<em>P</em> = 0.001) and MTV (<em>P</em> &lt; 0.001) were independently prognostic. <strong>Conclusion:</strong> MTV is a prognostic biomarker in advanced GEPNEN. Reports of [¹⁸F]FDG PET in GEPNEN may benefit from comments on MTV in addition to the degree of [¹⁸F]FDG avidity.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"144 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clinical Outcomes of 177Lu-DOTATATE Peptide Receptor Radionuclide Therapy in Patients with Skeletal Metastases from Neuroendocrine Tumors: Insights from Real-World Experience","authors":"Kunal Ramesh Chandekar, Swayamjeet Satapathy, Sanjana Ballal, Madhav Prasad Yadav, Shubha Gadde Ravindra, Sameer Rastogi, Ranjit Kumar Sahoo, Chandrasekhar Bal","doi":"10.2967/jnumed.125.269456","DOIUrl":"https://doi.org/10.2967/jnumed.125.269456","url":null,"abstract":"<p>Skeletal metastases portend a poor prognosis for patients with neuroendocrine tumors (NETs). Literature on peptide receptor radionuclide therapy (PRRT) specific to patients with skeletal metastases from NETs is scarce. This study assessed real-world clinical outcomes of ¹⁷⁷Lu-DOTATATE PRRT in this patient subgroup. <strong>Methods:</strong> Data from consecutive patients with well-differentiated NETs and skeletal metastases treated with ¹⁷⁷Lu-DOTATATE at our center from January 2014 until August 2024 were retrospectively reviewed. Safety, efficacy, progression-free survival (PFS), and overall survival (OS) outcomes were analyzed. <strong>Results:</strong> In total, 288 PRRT cycles were administered to 74 patients. The median number of PRRT cycles was 4 (interquartile range, 2–6), and the median cumulative activity was 21.3 GBq (interquartile range, 11.1–33.3 GBq). The best objective response rates, evaluated using modified M.D. Anderson criteria (bone metastases) and RECIST 1.1 (overall response), were 31% and 23%, respectively, for 62 evaluable patients. The skeletal metastases burden (≤10 vs. &gt;10 sites) did not significantly affect objective response rates. Among the 23 patients with bone pain (31%), 39% reported complete resolution and 52% experienced a partial reduction after treatment. Grade 4 or 5 adverse events occurred in 12% of patients, with anemia, thrombocytopenia, leukopenia, and neutropenia each occurring in fewer than 5% of patients. Skeletal-related events were noted in 20% of patients. The median PFS and OS were 29 mo (95% CI, 18.0–39.9 mo) and 44 mo (95% CI, 32.8–55.2 mo), respectively. Multivariate Cox regression analysis revealed that higher cumulative activity (≥29.6 GBq) was the strongest independent predictor of improved PFS (hazard ratio [HR], 0.15; <em>P</em> &lt; 0.001) and OS (HR, 0.11; <em>P</em> &lt; 0.001), whereas serum alkaline phosphatase elevation (HR, 2.68; <em>P</em> = 0.048) and male sex (HR, 3.48; <em>P</em> = 0.007) were associated with worse OS rates. <strong>Conclusion:</strong> ¹⁷⁷Lu-DOTATATE PRRT is an effective treatment modality for patients with skeletal metastases from NETs (regardless of metastatic burden), with a favorable safety profile and favorable survival outcomes. Serum alkaline phosphatase monitoring is essential in this patient cohort. Achieving an optimal cumulative activity is crucial to maximizing the survival benefit of patients receiving PRRT.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transarterial Radioembolization in the TACOME Trial: Dosimetric Analysis and Clinical Features in Predicting Response and Overall Survival","authors":"Cigdem Soydal, Mine Araz, Burak Demir, Tunc Ones, Kerim Sonmezoglu, Nalan Alan Selcuk, Tugsan Balli, Emine Goknur Isık, Bilge Volkan Salancı, Erkan Derebek, Selin Kesim, Onur Erdem Sahin, Ferhat Can Piskin, Emre Can Celebioglu, Mehmet Sadik Bilgic, Nuriye Ozlem Kucuk","doi":"10.2967/jnumed.125.269519","DOIUrl":"https://doi.org/10.2967/jnumed.125.269519","url":null,"abstract":"<p>In this multicenter retrospective study, we aimed to analyze the dose–response and survival relationships and estimate the tumor absorbed radiation dose required to achieve response in colorectal cancer liver metastases treated with ⁹⁰Y glass microspheres. <strong>Methods:</strong> Patients with metastatic colorectal cancer treated with ⁹⁰Y glass microspheres were included in this retrospective study. Mean perfused volume, mean estimated perfused volume absorbed dose, mean estimated tumor absorbed dose (ETAD), mean estimated perfused normal liver absorbed dose, and mean estimated whole liver absorbed dose were calculated using [^99mTc]-macroaggregated albumin SPECT images. Treatment to response was evaluated by [¹⁸F]-FDG PET images. <strong>Results:</strong> In total, 176 patients (112 men and 64 women) were included in the analysis. A strong correlation was found between mean ETAD and response to treatment (<em>P</em> = 0.001). The cutoff values to predict a response were calculated as 109 Gy (sensitivity, 68%; specificity, 73%; area under the curve, 0.728; <em>P</em> = 0.001) for mean estimated perfused volume absorbed dose and 152 Gy (sensitivity, 93%; specificity, 89%; area under the curve, 0.945; <em>P</em> = 0.001) for mean ETAD. The median overall survival (OS) of patients with a mean ETAD higher than 152 Gy was significantly longer than that of the remaining patients, at 18.1 mo (95% CI, 15.7–20.4 mo) versus 12.8 mo (95% CI, 10.6–15.0 mo; <em>P</em> = 0.030). Further analysis using maximally selected rank statistics to better predict OS showed that patients with a minimum mean ETAD of 203 Gy had OS 6.4 mo longer than the OS of those with a lower mean ETAD (<em>P</em> = 0.022). <strong>Conclusion:</strong> A mean radiation dose to the tumor of at least 152 Gy may predict a metabolic response. Although a threshold of 152 Gy predicted longer OS, a mean ETAD of 203 Gy, when achievable, predicted even longer OS than found for those with a mean ETAD of less than 203 Gy.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Retreatment of Metastatic Castration-Resistant Prostate Cancer Patients with 223Ra Therapy in Daily Practice","authors":"Joost H.H.M. van Riel, Maarten L. Donswijk, Christel Brouwer, Winald R. Gerritsen, T.T. Ha Tan-Phan, Paul W.L. Thimister, Walter Noordzij, Erik T. Te Beek, Laurence J.C. van Warmerdam, Andries M. Bergman, Inge M. van Oort, Dirk N.J. Wyndaele, Maarten J. van der Doelen","doi":"10.2967/jnumed.125.269746","DOIUrl":"https://doi.org/10.2967/jnumed.125.269746","url":null,"abstract":"<p>²²³Ra-dichloride (²²³Ra) is an approved therapeutic option for patients with metastatic castration-resistant prostate cancer (mCRPC) who have symptomatic bone metastases. After an initial course of 6 ²²³Ra injections, treatment may be repeated. The purpose of this study was to evaluate the safety and efficacy of ²²³Ra retreatment of mCRPC in a real-world population. <strong>Methods:</strong> This multicenter, retrospective cohort study included patients who had mCRPC and bone metastases who previously received 6 consecutive injections of ²²³Ra and received at least 1 ²²³Ra retreatment injection between 2014 and 2024. The primary endpoint was safety, measured as hematologic and nonhematologic adverse events (AEs), including skeletal-related events. Secondary endpoints included the number of injections administered, overall survival, and biochemical response rates. Exploratory analyses intended to identify variables associated with alkaline phosphatase response during retreatment, completion of ²²³Ra retreatment, and overall survival. <strong>Results:</strong> Sixty-one patients were evaluated. Median age was 75 y, 44% of patients received prior chemotherapy, and 87% of patients previously received at least 1 androgen receptor pathway inhibitor. The median number of prior systemic therapies was 3. In total, 56 patients (95%) experienced at least 1 hematologic AE, including 14% with grade 3 hematologic AEs. Forty-four patients (72%) experienced at least 1 nonhematologic AE during ²²³Ra retreatment. No grade 4 or 5 AEs occurred. Patients received a median of 6 ²²³Ra retreatment injections. Overall survival was 16.9 mo (95% CI, 11.9–21.9 mo), and 56% of patients had an alkaline phosphatase response of at least 30%. High baseline hemoglobin levels, no prior chemotherapy, and a prostate-specific antigen response of at least 30% during the initial ²²³Ra course were predictors for completion of 6 ²²³Ra retreatment injections. A prior skeletal-related event, baseline performance status, and baseline hemoglobin level were prognostic for survival in this population. <strong>Conclusion:</strong> ²²³Ra retreatment was well tolerated and is therefore deemed safe in selected patients with mCRPC. In addition, the high number of administered injections and the high alkaline phosphatase response rate suggest that retreatment is beneficial to patients with advanced mCRPC. Patients with high hemoglobin levels, good performance status, and prior prostate-specific antigen response to ²²³Ra therapy may be the best candidates for ²²³Ra retreatment.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"177Lu-PSMA-617 Consolidation Therapy After Docetaxel in Patients with Synchronous High-Volume Metastatic Hormone-Sensitive Prostate Cancer: A Randomized, Phase 2 Trial","authors":"Swayamjeet Satapathy, Chandan K. Das, Shikha Goyal, Ashwani Sood, Kannan Periasamy, Piyush Aggarwal, Komal Preet, Shrawan K. Singh, Ravimohan S. Mavuduru, Girdhar S. Bora, Aditya P. Sharma, Gaurav Prakash, Rajender Kumar, Harmandeep Singh, Bhagwant R. Mittal","doi":"10.2967/jnumed.125.269913","DOIUrl":"https://doi.org/10.2967/jnumed.125.269913","url":null,"abstract":"<p>¹⁷⁷Lu-prostate-specific membrane antigen-617 (¹⁷⁷Lu-PSMA-617) has shown positive survival outcomes in metastatic castration-resistant prostate cancer. However, there are limited data in the hormone-sensitive setting. Here, in the CONSOLIDATE trial (¹⁷⁷Lu-PSMA-617 Consolidation Therapy After Docetaxel in Patients with Synchronous High-Volume Metastatic Hormone-Sensitive Prostate Cancer), we intended to evaluate the role of ¹⁷⁷Lu-PSMA-617 as consolidation therapy for residual disease after chemohormonal treatment in patients with synchronous high-volume metastatic hormone-sensitive prostate cancer (mHSPC). <strong>Methods:</strong> This was an investigator-initiated randomized, parallel-group, open-label phase 2 trial. Synchronous high-volume mHSPC patients treated with androgen-deprivation therapy plus docetaxel and having residual nonprogressive disease after docetaxel completion (defined as prostate-specific antigen [PSA] &gt; 0.2 ng/mL with PSMA-positive disease on ⁶⁸Ga-PSMA-11 PET/CT) were randomized in a 1:1 ratio to the experimental arm (¹⁷⁷Lu-PSMA-617, 7.4 GBq/cycle × 2, 6 wk apart with protocol-permitted standard of care) or control arm (protocol-permitted standard of care alone). The primary endpoint was the proportion of patients achieving a PSA level of 0.2 ng/mL or less at 6 mo from randomization. Secondary endpoints included objective radiographic response rate, radiographic progression-free survival (PFS), PSA PFS, and toxicities. <strong>Results:</strong> The trial was terminated early because of poor accrual after the coronavirus disease pandemic and a change in treatment guidelines for mHSPC. Thirty high-volume mHSPC patients were randomized between January 2021 and June 2024. The primary endpoint was achieved in 9 of 15 (60%; 95% CI, 35%–85%) patients in the experimental arm versus 2 of 15 (13%; 95% CI, 0%–30%) in the control arm (risk ratio, 4.5; 95% CI, 1.2–17.4; <em>P</em> = 0.008). The objective radiographic response rates were 8 of 15 (53%; 95% CI, 28%–78%) and 1 of 15 (7%; 95% CI, 0%–19%) in the experimental and control arms, respectively (<em>P</em> = 0.014). The estimated median radiographic PFS and PSA PFS were 18 mo (95% CI, 9–27 mo) and 15 mo (95% CI, 12–18 mo), respectively, in the experimental arm versus 9 mo (95% CI, 4–14 mo) and 9 mo (95% CI, 1–17 mo), respectively, in the control arm. No grade 3 or 4 toxicity was noted with the addition of ¹⁷⁷Lu-PSMA-617 in the experimental arm. <strong>Conclusion:</strong> In synchronous high-volume mHSPC patients having residual disease after chemohormonal treatment, ¹⁷⁷Lu-PSMA-617 consolidation therapy demonstrated promising efficacy and safety outcomes. Larger phase 3 trials are warranted to definitively establish its survival benefit.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"137 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Can 177Lu-DOTATATE Kidney Absorbed Doses be Predicted from Pretherapy SSTR PET? Findings from Multicenter Data","authors":"Azadeh Akhavanallaf, Zhonglin Lu, Avery B. Peterson, Johan Blakkisrud, Sara Kurkowska, Surekha Yadav, Chang Wang, Carlos Uribe, Caroline Stokke, Arman Rahmim, Ka Kit Wong, Jean-Mathieu Beauregard, Thomas A. Hope, Katarina Sjögreen Gleisner, Yuni K. Dewaraja","doi":"10.2967/jnumed.124.269098","DOIUrl":"https://doi.org/10.2967/jnumed.124.269098","url":null,"abstract":"<p>Before performing ¹⁷⁷Lu-DOTATATE therapy for neuroendocrine tumors, somatostatin receptor (SSTR) PET imaging is currently used to confirm sufficient tumor SSTR expression, but it also has potential to be used to personalize treatment by predicting absorbed doses to critical organs. This study aims to validate the predictive capability of SSTR PET in anticipating renal absorbed dose in the first cycle of ¹⁷⁷Lu-DOTATATE using a multicenter dataset to analyze and derive insights from a broader patient population. <strong>Methods:</strong> Retrospective data from 5 centers were included in this study: 1 in Canada (<em>n</em> = 25), 1 in Norway (<em>n</em> = 75), 1 in Sweden (<em>n</em> = 18), and 2 in the United States (<em>n</em> = 36 and <em>n</em> = 26). At each center, pretherapy SSTR PET/CT imaging and postcycle 1 ¹⁷⁷Lu imaging–based dosimetry were performed according to site-specific protocols. The mixed-effects model treating centers as random effects was developed using baseline SSTR PET renal uptake values to predict renal absorbed dose from ¹⁷⁷Lu-DOTATATE. Additionally, leave-one-center-out cross-validation and leave-one-sample-out cross-validation were implemented for external and internal validation, respectively, measuring mean absolute error and mean relative absolute error. <strong>Results:</strong> Across all participating centers, the median cycle 1 renal absorbed dose was 0.56 Gy/GBq (range, 0.14–1.27 Gy/GBq), whereas the median pretherapy SSTR PET renal uptake was 110.7 Bq/mL/MBq (range, 28.6–287.7 Bq/mL/MBq). The differences among center means were statistically significant for both absorbed dose and PET uptake (<em>P</em> &lt; 0.0001 from 1-way ANOVA). A significant (<em>P</em> &lt; 0.05) correlation was observed between kidney SSTR PET uptake and ¹⁷⁷Lu-DOTATATE absorbed dose for each center (center-specific coefficient of determination ranged from 0.14 to 0.53). When data across all centers were aggregated, the mixed-effects model achieved a coefficient of determination of 0.25 (<em>P</em> &lt; 0.01), resulting in an mean absolute error of 0.15 Gy/GBq (SD, 0.11 Gy/GBq) and an mean relative absolute error of 28% (SD, 24%) for external validation and 0.12 Gy/GBq (SD, 0.10 Gy/GBq) and 22% (SD, 20%) for internal validation. <strong>Conclusion:</strong> The correlations observed between SSTR PET renal uptake and ¹⁷⁷Lu-DOTATATE absorbed dose to kidneys across a multicenter population are statistically significant yet modest. The prediction model achieved a mean relative absolute error 28% or less for both external and internal validation of PET-predicted absorbed doses. The intercenter differences suggest the need for standardized imaging protocols and dosimetry workflows.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"137 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rethinking Dosimetry: A European Perspective","authors":"Johannes Tran-Gia, Francesco Cicone, Michel Koole, Francesco Giammarile, Jonathan Gear, Emmanuel Deshayes, Pablo Minguez Gabiña, Marta Cremonesi, Jonathan Wadsley, Peter Bernhardt, Manuel Bardiès, Silvano Gnesin, Mattias Sandström, Ulrike Garske-Román, Mona-Elisabeth R. Revheim, Frederik A. Verburg, Mark Konijnenberg, Bernd Joachim Krause, Michael Lassmann, Caroline Stokke","doi":"10.2967/jnumed.124.269378","DOIUrl":"https://doi.org/10.2967/jnumed.124.269378","url":null,"abstract":"<p>Radiopharmaceutical therapy (RPT) is entering a new era of personalization, driven by advances in molecular imaging, radiopharmaceutical development, and a growing body of clinical evidence linking absorbed dose to treatment outcomes. Although external-beam radiotherapy has long integrated dosimetry into standard practice, RPT historically relied on fixed radiopharmaceutical activities and absorbed dose–effect relationships adapted from external-beam radiotherapy, often without accounting for the unique pharmacokinetics, absorbed dose rate dynamics, and biologic responses of systemically administered radiopharmaceuticals. As RPT expands into earlier disease stages, at which patients have longer life expectancies and better performance status, the role of dosimetry in optimizing treatment is becoming increasingly evident. However, despite growing recognition of its benefits, the implementation of dosimetry in clinical practice remains limited, partly because of a self-reinforcing cycle in which the lack of routine dosimetry limits clinical evidence, which in turn hinders its broader adoption. Breaking this cycle is essential to advancing RPT and ensuring that evaluation of dosimetry is based on clinical merit rather than logistic constraints. This article examines the current landscape of RPT dosimetry, highlighting key challenges and opportunities from a European perspective and aiming to foster a more factual and constructive discussion on the topic. We discuss the fundamental differences between dosimetry-driven treatment planning and posttherapy absorbed dose verification, emphasizing the latter as a practical entry point for clinical adoption. We underscore the need for harmonized standards, improved imaging resolution, and tailored absorbed dose–effect relationships that reflect the heterogeneity of RPT delivery and the complexity of tumor and organ responses. The paper also addresses regulatory, infrastructural, and resource barriers to RPT dosimetry implementation and highlights ongoing European initiatives to strengthen frameworks, enhance stakeholder collaboration, and integrate absorbed dose biomarkers into authorization processes and clinical decision-making. By rethinking dosimetry and promoting standardized, evidence-based approaches, the field can advance beyond fixed-activity protocols toward truly individualized RPT. However, achieving clinically feasible integration of dosimetry into routine practice requires structured efforts to generate high-quality clinical evidence and improve accessibility. Ultimately, reliable, patient-centered dosimetry has the potential to enhance therapeutic efficacy, manage toxicity more effectively, and support the long-term evolution of RPT as a cornerstone of precision oncology.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Establishing In Vitro Dosimetric Models and Dose–Effect Relationships for 177Lu-DOTATATE in Neuroendocrine Tumors","authors":"Giulia Tamborino, Pleun Engbers, Tijmen H. de Wolf, Thom G.A. Reuvers, Rob Verhagen, Mark Konijnenberg, Julie Nonnekens","doi":"10.2967/jnumed.125.269470","DOIUrl":"https://doi.org/10.2967/jnumed.125.269470","url":null,"abstract":"<sec><st>Visual Abstract</st><p><fig loc=\"float\"><link locator=\"jnumed.125.269470absf1\"></fig></p></sec>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Theranostics in Perspective: White Paper","authors":"Marcel P.M. Stokkel, Martin Gotthardt, Ken Herrmann, Gopinath Gnanasegaran","doi":"10.2967/jnumed.125.269776","DOIUrl":"https://doi.org/10.2967/jnumed.125.269776","url":null,"abstract":"<p>Nuclear medicine has evolved from a diagnostic-oriented speciality toward theranostics. Radionuclide therapy has become a booming business with newer radiopharmaceuticals and indications. Although the specialty of nuclear medicine seems scintillating, several challenges might limit sustained and long-term success. Some of the challenges and issues requiring clarification include radiopharmaceutical cost and supply, cost–benefit analysis, reimbursement, training, workforce, collaboration with the radiopharmaceutical industry, national and international nuclear medicine, and applied specialities. This review discusses these challenges and possible solutions to avoid speed breakers in theranostics.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144066510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}