The Journal of Nuclear Medicine最新文献

{"title":"CXCR4 PET/CT Predicts Left Ventricular Recovery 8 Months After Acute Myocardial Infarction","authors":"Johanna Diekmann, Tobias König, Annika Hess, Carolin Zwadlo, Andreas Schäfer, Tobias L. Ross, James T. Thackeray, Frank M. Bengel, Johann Bauersachs","doi":"10.2967/jnumed.125.270807","DOIUrl":"https://doi.org/10.2967/jnumed.125.270807","url":null,"abstract":"<p>Acute myocardial infarction (AMI) triggers an inflammatory response, which is a determinant of subsequent healing. We speculated that C-X-C motif chemokine receptor 4 (CXCR4) upregulation early after AMI predicts left ventricular (LV) remodeling and cardiac structural functional outcome. <strong>Methods:</strong> In total, 49 patients underwent multimodal cardiac imaging including PET with the specific CXCR4 ligand ⁶⁸Ga-pentixafor, myocardial perfusion imaging, and cardiac MR (CMR) within the first week after AMI. Follow-up CMR was acquired after 8.3 ± 4.2 mo in 40 patients. <strong>Results:</strong> Initial PET-derived CXCR4 expression in the infarct territory was significantly higher than blood pool (SUV_peak, 2.5 ± 0.5 vs. 2.0 ± 0.3; <em>P</em> &lt; 0.001) but had high variance (1.5–4.2) among patients. The calculated area of CXCR4 upregulation (CXCR4 area, median 27.0% of LV; interquartile range [IQR], 11.0%–42.0%) was significantly larger than perfusion defect size (median 18% of LV; IQR, 3.0%–33.5%; <em>P</em> = 0.043) but not larger than the late gadolinium enhancement (LGE) extent in initial CMR (median 23.6% of LV; IQR, 18.2–30.3; <em>P</em> = 0.382). Myocardial CXCR4 area correlated with initial LV ejection fraction (LV-EF) (<em>r</em> = −0.533, <em>P</em> &lt; 0.001), follow-up LV-EF (<em>r</em> = −0.420, <em>P</em> = 0.005), and initial LGE extent reflecting the area of myocardial injury (<em>r</em> = 0.559, <em>P</em> &lt; 0.001). No correlation was found with LGE extent at follow-up. We investigated the association of baseline ⁶⁸Ga-pentixafor uptake with functional outcome derived from follow-up CMR to established markers of myocardial damage. At 8-mo follow-up, a significant improvement in LV-EF (46.5 ± 10.3% vs. 49.1% ± 10.4%, <em>P</em> = 0.049) was noted, and the extent of LGE (% of LV) decreased (median 23.6% vs. 16.9% of LV; <em>P</em> &lt; 0.001). The CXCR4 area emerged as an independent predictor of follow-up LV-EF (<em>P</em> = 0.049), outperforming baseline LGE extent (<em>P</em> = 0.318); however, its prognostic value diminished when accounting for initial perfusion defect, suggesting overlapping pathophysiologic information. <strong>Conclusion:</strong> CXCR4-targeted molecular imaging early after AMI bears potential to predict subsequent ventricular remodeling and may be a useful clinical tool for risk stratification and guidance of antiinflammatory therapies.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"56 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145083698","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":"Fully Automated Image-Based Multiplexing of Serial PET/CT Imaging for Facilitating Comprehensive Disease Phenotyping","authors":"Lalith Kumar Shiyam Sundar, Sebastian Gutschmayer, Manuel Pires, Daria Ferrara, Toni Nguyen, Yasser Gaber Abdelhafez, Benjamin Spencer, Simon R. Cherry, Ramsey D. Badawi, David Kersting, Wolfgang P. Fendler, Moon-Sung Kim, Martin Lyngby Lassen, Philip Hasbak, Fabian Schmidt, Pia Linder, Xingyu Mu, Zewen Jiang, Elisabetta M. Abenavoli, Roberto Sciagrà, Armin Frille, Hubert Wirtz, Swen Hesse, Osama Sabri, Dale Bailey, David Chan, Jason Callahan, Rodney J. Hicks, Thomas Beyer","doi":"10.2967/jnumed.125.269688","DOIUrl":"https://doi.org/10.2967/jnumed.125.269688","url":null,"abstract":"<p>Combined PET/CT imaging provides critical insights into both anatomic and molecular processes, yet traditional single‐tracer approaches limit multidimensional disease phenotyping; to address this, we developed the PET Unified Multitracer Alignment (PUMA) framework—an open‐source, postprocessing tool that multiplexes serial PET/CT scans for comprehensive voxelwise tissue characterization. <strong>Methods:</strong> PUMA utilizes artificial intelligence–based CT segmentation from multiorgan objective segmentation to generate multilabel maps of 24 body regions, guiding a 2-step registration: affine alignment followed by symmetric diffeomorphic registration. Tracer images are then normalized and assigned to red–green–blue channels for simultaneous visualization of up to 3 tracers. The framework was evaluated on longitudinal PET/CT scans from 114 subjects across multiple centers and vendors. Rigid, affine, and deformable registration methods were compared for optimal coregistration. Performance was assessed using the Dice similarity coefficient for organ alignment and absolute percentage differences in organ intensity and tumor SUV_mean. <strong>Results:</strong> Deformable registration consistently achieved superior alignment, with Dice similarity coefficient values exceeding 0.90 in 60% of organs while maintaining organ intensity differences below 3%; similarly, SUV_mean differences for tumors were minimal at 1.6% ± 0.9%, confirming that PUMA preserves quantitative PET data while enabling robust spatial multiplexing. <strong>Conclusion:</strong> PUMA provides a vendor-independent solution for postacquisition multiplexing of serial PET/CT images, integrating complementary tracer data voxelwise into a composite image without modifying clinical protocols. This enhances multidimensional disease phenotyping and supports better diagnostic and therapeutic decisions using serial multitracer PET/CT imaging.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145083841","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":"Assessment of Breast Tumors Using Multispectral Optoacoustic Tomography in a Surgical Setting","authors":"Lacey R. McNally, Juan Carlos Claros-Sorto, Ryan C. Bynum, William E. Grizzle, Zheng Han, Ronald Squires, Jacob D. Tippetts, Andrew Brannen, Tabitha Garwe, Andrew Cohoon, Barish H. Edil, Jennifer Holter-Chakrabarty, Ajay Jain","doi":"10.2967/jnumed.125.269852","DOIUrl":"https://doi.org/10.2967/jnumed.125.269852","url":null,"abstract":"<p>In breast-conserving surgery, wire or seed localization and ultrasound are limited by lack of margin detection and contrast imaging, respectively. Handheld multispectral optoacoustic tomography (MSOT) allows for contrast imaging using endogenous or exogenous agents. This trial evaluated the safety and performance of MSOT for imaging breast masses intraoperatively. <strong>Methods:</strong> Imaging with MSOT was performed on 45 women preoperatively and postoperatively. The temperature and appearance of the skin were recorded before and after imaging. Levels of deoxyhemoglobin, oxyhemoglobin, total hemoglobin, and microvascular oxygen saturation were recorded for malignant and benign breast tissue using MSOT. In patients undergoing sentinel lymph node biopsy, the ipsilateral axilla was imaged with MSOT. For analysis, patients were categorized by Fitzpatrick skin type. <strong>Results:</strong> All breast masses were successfully imaged as cancers using MSOT. In preoperative and postoperative imaging, patients’ skin temperatures did not exceed 37 °C, and no adverse effects were observed after imaging across all Fitzpatrick skin types. The findings in breast tumor images using deoxyhemoglobin (mean, 0.0782), oxyhemoglobin (mean, 0.0833), and total hemoglobin (mean, 0.161) were each significantly different from those of contralateral breast presurgery (<em>P</em> &lt; 0.0001). Microvascular oxygen saturation did not significantly differ between breast tumors and contralateral breast tissue (<em>P</em> = 0.704). The average imaging time before and after surgery was 3 min. No adverse events were recorded. All 3 positive sentinel lymph nodes identified intraoperatively using isosulfan blue injection were successfully imaged by MSOT preoperatively, and no false-positives were obtained with MSOT. <strong>Conclusion:</strong> MSOT is safe for use in image-guided breast cancer detection and has not been shown to increase patient skin temperature. MSOT can successfully distinguish between cancer and benign tissue using endogenous contrast agents and identify sentinel lymph nodes using isosulfan blue.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"79 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145083695","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":"68Ga-FAPI-46 PET/CT in Primary Sclerosing Cholangitis and Suspected Cholangiocarcinoma","authors":"Desiree Weiberg, Laura M. Wilhelm, Tim Felgenhauer, Tobias Ross, Heiner Wedemeyer, Frank M. Bengel, Thomas C. Wirth","doi":"10.2967/jnumed.125.270434","DOIUrl":"https://doi.org/10.2967/jnumed.125.270434","url":null,"abstract":"<p>Primary sclerosing cholangitis (PSC) is a chronic cholestatic disease marked by fibrosis, strictures, and a high risk for developing cholangiocarcinoma (CCC). Recognition of CCC in PSC remains a diagnostic challenge. PET/CT using fibroblast activation protein inhibitors (FAPI) has emerged as a promising imaging modality in CCC, but its potential in the specific profibrotic setting of PSC has not yet been explored to the best of our knowledge. <strong>Methods:</strong> PET/CT with ⁶⁸Ga-FAPI-46 was performed in 18 patients (<em>n</em> = 9 with PSC, without proven CCC; <em>n</em> = 7 without PSC, with histologically confirmed CCC; 2 with both PSC and CCC). Results were correlated with endoscopic retrograde cholangiopancreatography, laboratory parameters, and fibrosis-4 as well as albumin–bilirubin scores. Five subjects who underwent FAPI PET/CT without hepatic disease or cancer diagnosis served as controls. For PET analysis, physiologic FAPI uptake was defined as mean SUV_peak of all controls plus 2 SD. Nonphysiologic liver uptake patterns were visually classified, and a fibroblast activation protein (FAP) liver volume above physiologic uptake (FAP-livo) was calculated. <strong>Results:</strong> The physiologic liver FAP signal was low and homogeneous in controls (SUV, 1.5 + 0.2). In CCC and PSC, the liver FAP signal was elevated with a FAP-livo of 1,362 ± 1,302 mL (CCC) and 1,286 ± 835 mL (PSC). Lesion SUV_peak did not differ between PSC and CCC (median, 8.8 [interquartile range, 6.3] vs. 15.0 [interquartile range, 9.2]; <em>P</em> = 0.72). Lesions were reliably detected in all patients with CCC and combined PSC/CCC. In PSC, 2 distinct patterns of the FAP signal existed, either along bile ducts or with field-shaped enhancement. FAP-livo was generally associated with decreased liver function (albumin–bilirubin score; <em>r</em> = 0.70, <em>P</em> = 0.04) and fibrosis-4 (<em>r</em> = 0.63, <em>P</em> = 0.08), and clinical parameters showed specific differences in the 2 distinct imaging pattern subsets of PSC. Because of the nononcological FAP signal elevation in active PSC regions, additional detection of focal lesions typical for CCC was not feasible. <strong>Conclusion:</strong> Active PSC is associated with elevated FAP expression, up to the level of CCC. Although this complicates the detection of PSC-associated CCC, FAPI PET/CT may be used for the assessment of PSC activity. This provides a rationale for future studies using FAPI PET/CT as a measure of fibrotic disease progression risk or response to antiinflammatory and antifibrotic therapy in PSC.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"68 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145083697","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":"Toward Imaging of the GABA Transporter Type 1 In Vivo: Quantitative Evaluation of 4 Novel PET Radiotracers in Nonhuman Primates","authors":"Paul Gravel, Jiwei Gu, Chao Wang, Tommaso Volpi, Jean-Dominique Gallezot, Daniel Holden, Krista Fowles, Ming-Qiang Zheng, Li Zhang, Edilio Borroni, Michael Honer, Luca Gobbi, Gilles Tamagnan, Yiyun Huang, Richard E. Carson","doi":"10.2967/jnumed.125.270332","DOIUrl":"https://doi.org/10.2967/jnumed.125.270332","url":null,"abstract":"<sec><st>Visual Abstract</st><p><fig loc=\"float\"><link locator=\"jnumed.125.270332absf1\"></fig></p></sec>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144996014","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":"Lesion Analysis of 18F-Metafluorobenzylguanidine PET Imaging in Neuroblastoma","authors":"Neeta Pandit-Taskar, Ellen Basu, Ali Pirasteh, Gerald Behr, Audrey Mauguen, Jazmin Schwartz, Serge Lyashchenko, Scott Vietri, Eva Burnazi, Anita P. Price, Shakeel Modak","doi":"10.2967/jnumed.125.269833","DOIUrl":"https://doi.org/10.2967/jnumed.125.269833","url":null,"abstract":"<p>A PET analog of metaiodobenzylguanidine (MIBG)—¹⁸F-metafluorobenzylguanidine (¹⁸F-MFBG)—allows for rapid same-day imaging. We previously reported on the safety and feasibility of ¹⁸F-MFBG PET imaging in patients with neuroendocrine tumors. We now report a comprehensive analysis of lesion detection with ¹⁸F-MFBG imaging in patients with neuroblastoma compared with ¹²³I-MIBG imaging. <strong>Methods:</strong> We analyzed concurrent ¹⁸F-MFBG and ¹²³I-MIBG scans in 37 patients (40 paired scans). Patients with relapsed or refractory neuroblastoma were included. Patients received 74.11–465.83 MBq (2.0–12.6 mCi) of ¹⁸F-MFBG intravenously, followed by imaging 60 min after injection. All patients had an ¹²³I-MIBG scan within 4 wk of ¹⁸F-MFBG imaging without any intervening therapy. ¹²³I-MIBG scans included whole-body planar and SPECT/CT of the chest, abdomen, and pelvis. All detected lesions were noted for each modality. ¹²³I-MIBG and ¹⁸F-MFBG findings were evaluated for concordance and discordance. Modified Curie scores were assigned to both ¹²³I-MIBG scans, equivalent scores were ascertained for ¹⁸F-MFBG imaging, and scores were then compared. <strong>Results:</strong> All patients with a positive ¹²³I-MIBG scan had positive ¹⁸F-MFBG imaging. In 2 patients, both ¹²³I-MIBG and ¹⁸F-MFBG scans were negative. In 1 patient, the ¹⁸F-MFBG scan was positive, whereas the ¹²³I-MIBG scan was negative. In 30 of 40 scans, ¹⁸F-MFBG showed more sites than did ¹²³I-MIBG. Overall, more lesions were noted on the ¹⁸F-MFBG scans (mean, 18; range 0–61) compared with the ¹²³I-MIBG scans (mean, 12; range, 0–44), and 455 lesions were concordant. The Curie score for ¹⁸F-MFBG was higher, with an average of 11 (range, 0–25) compared with 8 for ¹²³I-MIBG (range, 0–22). Of the 273 ¹⁸F-MFBG–positive/¹²³I-MIBG–negative lesions, follow-up clinical and imaging assessment was available for 234 lesions in 30 patients, and 100% of these were confirmed true-positive. <strong>Conclusion:</strong> ¹⁸F-MFBG PET offers faster imaging and superior detection compared with ¹²³I-MIBG imaging. ¹⁸F-MFBG had high concordance with ¹²³I-MIBG at the patient level and showed more lesions in most patients. ¹⁸F-MFBG is an attractive alternative to ¹²³I-MIBG.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144996013","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":"Evaluation of a Sensitive Visual Read Algorithm for Assessing 3R/4R Tau PET Images","authors":"Ruben Smith, Valentina Garibotto, Douglas Hägerström, Jonas Jögi, Tomas Ohlsson, Olof Strandberg, Matteo Tonietto, Shorena Janelidze, Sebastian Palmqvist, Erik Stomrud, Gregory Klein, Oskar Hansson","doi":"10.2967/jnumed.125.269685","DOIUrl":"https://doi.org/10.2967/jnumed.125.269685","url":null,"abstract":"<sec><st>Visual Abstract</st><p><fig loc=\"float\"><link locator=\"jnumed.125.269685absf1\"></fig> </p></sec>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144996012","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":"Noninvasive Monitoring of Inflammatory Processes by Myeloid Cell–Directed PET Tracers in an Experimental Severe Acute Respiratory Syndrome Coronavirus 2 Infection Model","authors":"Marieke A. Stammes, Gerrit Koopman, Teresa R. Wagner, Bjoern Traenkle, Philipp D. Kaiser, Petra Mooij, Nicole van der Werff, Roja Fidel Acar, Kinga P. Böszörményi, Simone Blaess, Stefania Pezzana, Gerald Reischl, Andreas Maurer, Jan A.M. Langermans, Ulrich Rothbauer, Manfred Kneilling, Dominik Sonanini","doi":"10.2967/jnumed.125.269721","DOIUrl":"https://doi.org/10.2967/jnumed.125.269721","url":null,"abstract":"<sec><st>Visual Abstract</st><p><fig loc=\"float\"><link locator=\"jnumed.125.269721absf1\"></fig></p></sec>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144916127","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":"Diagnostic Performance of the 68Ga-Labeled Minigastrin Analog DOTA-MGS5 in Patients with Advanced Medullary Thyroid Cancer and Other Neuroendocrine Tumors","authors":"Christian Uprimny, Elisabeth von Guggenberg, Anna Sviridenko, Steffen Bayerschmidt, Lisa Maria Rossetti, Hessamoddin Roustaei, Boris Warwitz, Hanno Ulmer, Angelika Hutter, Gianpaolo di Santo, Irene J. Virgolini","doi":"10.2967/jnumed.125.269863","DOIUrl":"https://doi.org/10.2967/jnumed.125.269863","url":null,"abstract":"<p>A prospective phase 1/2a pilot study (NCT06155994) was performed at our center to compare the diagnostic performance of cholecystokinin-2 receptor (CCK2R) PET/CT imaging with the ⁶⁸Ga-labeled peptide analog DOTA-DGlu-Ala-Tyr-Gly-Trp-(N-Me)Nle-Asp-1-Nal-Phe-NH₂ (⁶⁸Ga-DOTA-MGS5) with that of the reference standard PET/CT. <strong>Methods:</strong> Six patients with advanced medullary thyroid cancer (MTC) and 6 patients with other neuroendocrine tumors (NETs)—4 with gastroenteropancreatic (GEP) NETs and 2 with bronchopulmonary (BP) NETs—were included in the study. All patients had known metastases, documented by ⁶⁸Ga-DOTATOC and ¹⁸F-DOPA PET/CT. Intensity of tracer accumulation (SUV_max/SUV_mean) of normal tissue and lesions judged malignant was compared with standard PET imaging (number of lesions, uptake per lesion). <strong>Results:</strong> When compared with standard imaging, ⁶⁸Ga-DOTA-MGS5 showed significantly increased blood-pool activity (<em>P</em> ≤ 0.009), with improved lesion contrast at 2 h after injection compared with 1 h after injection. Four of 6 patients with MTC had positive lesions on ⁶⁸Ga-DOTA-MGS5 PET/CT. Fifty-one lesions were detected with ¹⁸F-DOPA versus 48 with ⁶⁸Ga-DOTA-MGS5, with a significantly higher mean SUV_max of 7.2 at 1 h and 2 h after injection versus 4.7 with ¹⁸F-DOPA (<em>P</em> &lt; 0.001). In the 2 patients with MTC imaged with ⁶⁸Ga-DOTATOC and ⁶⁸Ga-DOTA-MGS5, the same total number of lesions (<em>n</em> = 14) was detected (mean SUV_max, 24.3 vs. 17.4 and 18.7 at 1 and 2 h after injection, respectively; <em>P</em> &gt; 0.5). In patients with non-MTC NETs, 26 CCK2R-positive lesions were confirmed for 2 patients with BP-NETs compared with 45 lesions visualized with ⁶⁸Ga-DOTATOC. In the 4 patients with GEP-NETs, only 1 of 21 lesions displaying positive uptake on ⁶⁸Ga-DOTATOC PET/CT was visualized with ⁶⁸Ga-DOTA-MGS5 (an ileal NET), whereas the lesions in the other 3 patients were negative on ⁶⁸Ga-DOTA-MGS5 PET/CT. <strong>Conclusion:</strong> CCK2R PET/CT using ⁶⁸Ga-DOTA-MGS5 showed a high tumor lesion detection rate in patients with MTC, with lesion uptake values comparable to those with ¹⁸F-DOPA and ⁶⁸Ga-DOTATOC. In patients with non-MTC NETs, ⁶⁸Ga-DOTA-MGS5 PET/CT showed possible applicability in patients with BP-NETs, which needs to be verified in a larger patient cohort. In contrast, ⁶⁸Ga-DOTA-MGS5 PET/CT seemed to be of limited value in patients with GEP-NETs.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144916167","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":"Randomized Phase 2 Trial of an Extended and Flexible Dosing Schedule of 177Lu-PSMA Molecular Radiotherapy in Patients with Metastatic Castration-Resistant Prostate Cancer (FLEX-MRT): Study Protocol","authors":"Adrien Holzgreve, Astrid Delker, Zachary Ells, Julia Brosch-Lenz, Lena M. Unterrainer, John Nikitas, Shaojun Zhu, Maria M. Contreras, Hamzah Alam, Rejah M. Nabong, Stephanie Lira, Arseniy Vasilyev, Lillian Chen, Tristan Grogan, David Elashoff, Catherine A. Meyer, Magnus Dahlbom, Johannes Czernin, Jérémie Calais","doi":"10.2967/jnumed.125.269495","DOIUrl":"https://doi.org/10.2967/jnumed.125.269495","url":null,"abstract":"<p>[¹⁷⁷Lu]Lu-PSMA-617 radiopharmaceutical therapy has been approved for the treatment of men with metastatic castration-resistant prostate cancer (mCRPC) using a fixed dosing schedule of once every 6 wk for up to a total of 6 doses. We hypothesized that patients may benefit from a flexible and extended dosing schedule, up to 12 doses with potential \"treatment holiday\" periods. <b>Objective:</b> The objective of this study is to determine the 2-y survival rate of patients with mCRPC treated with an extended and flexible dosing schedule of [¹⁷⁷Lu]Lu-PSMA-617 therapy in comparison to patients treated with the standard fixed dosing schedule of a maximum of 6 treatment cycles once every 6 wk. <b>Study Design:</b> The FLEX-MRT trial is an investigator-initiated prospective phase 2, parallel group, randomized, controlled, open-label, single-center trial in men with mCRPC to determine the efficacy of a flexible and extended dosing schedule of [¹⁷⁷Lu]Lu-PSMA-617 therapy. Key inclusion criteria are patients eligible for Pluvicto (i.e., prior androgen receptor signaling inhibitors, prior chemotherapy, PSMA PET VISION criteria). Key exclusion criteria are prior [¹⁷⁷Lu]Lu-PSMA-617 therapy and less than 6 wk since last myelosuppressive therapy. The trial aims to centrally randomize 90 patients in a 1:1 ratio to 2 treatment arms. In the control arm, patients will be treated with the approved standard dosing schedule (<I>n</I> = 45). In the investigational arm, patients will be treated with up to 12 cycles and with potential treatment holidays depending on response (<I>n</I> = 45). Response assessment is based on SPECT/CT at each cycle and on PSMA PET/CT during treatment holiday periods (every 12 wk). Primary endpoint is the 2-y survival rate. Survival is calculated from the date of the first cycle of [¹⁷⁷Lu]Lu-PSMA-617 therapy. Secondary endpoints include safety by Common Terminology Criteria for Adverse Events and dosimetry and determination of overall and progression-free survival (evidence of progression as defined by radiographic, prostate-specific antigen level, or clinical progression, or death from any cause).</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"106 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144916128","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}