Pub Date : 2023-10-01Epub Date: 2023-07-06DOI: 10.2967/jnumed.123.265556
Jan J Duin, Hilda A de Barros, Maarten L Donswijk, Eva E Schaake, Tim M van der Sluis, Esther M K Wit, Fijs W B van Leeuwen, Pim J van Leeuwen, Henk G van der Poel
Our objective was to assess the diagnostic value of the sentinel node (SN) procedure for lymph node staging in primary intermediate- and high-risk prostate cancer patients with node-negative results on prostate-specific membrane antigen PET/CT (miN0). Methods: From 2016 to 2022, 154 patients with primary, miN0 PCa were retrospectively included. All patients had a Briganti nomogram-assessed nodal risk of more than 5% and underwent a robot-assisted SN procedure for nodal staging. The prevalence of nodal metastases at histopathology and the occurrence of surgical complications according to the Clavien-Dindo classification were evaluated. Results: The SN procedure yielded 84 (14%) tumor-positive lymph nodes with a median metastasis size of 3 mm (interquartile range, 1-4 mm). In total, 55 patients (36%) were reclassified as pN1. A complication of Clavien-Dindo grade 3 or higher occured in 1 patient (0.6%). Conclusion: The SN procedure classified 36% of patients with miN0 prostate cancer with an elevated risk of nodal metastases as pN1.
{"title":"The Diagnostic Value of the Sentinel Node Procedure to Detect Occult Lymph Node Metastases in PSMA PET/CT Node-Negative Prostate Cancer Patients.","authors":"Jan J Duin, Hilda A de Barros, Maarten L Donswijk, Eva E Schaake, Tim M van der Sluis, Esther M K Wit, Fijs W B van Leeuwen, Pim J van Leeuwen, Henk G van der Poel","doi":"10.2967/jnumed.123.265556","DOIUrl":"10.2967/jnumed.123.265556","url":null,"abstract":"<p><p>Our objective was to assess the diagnostic value of the sentinel node (SN) procedure for lymph node staging in primary intermediate- and high-risk prostate cancer patients with node-negative results on prostate-specific membrane antigen PET/CT (miN0). <b>Methods:</b> From 2016 to 2022, 154 patients with primary, miN0 PCa were retrospectively included. All patients had a Briganti nomogram-assessed nodal risk of more than 5% and underwent a robot-assisted SN procedure for nodal staging. The prevalence of nodal metastases at histopathology and the occurrence of surgical complications according to the Clavien-Dindo classification were evaluated. <b>Results:</b> The SN procedure yielded 84 (14%) tumor-positive lymph nodes with a median metastasis size of 3 mm (interquartile range, 1-4 mm). In total, 55 patients (36%) were reclassified as pN1. A complication of Clavien-Dindo grade 3 or higher occured in 1 patient (0.6%). <b>Conclusion:</b> The SN procedure classified 36% of patients with miN0 prostate cancer with an elevated risk of nodal metastases as pN1.</p>","PeriodicalId":16758,"journal":{"name":"Journal of Nuclear Medicine","volume":null,"pages":null},"PeriodicalIF":9.1,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9758673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.2967/jnumed.123.265557
Holger Palmedo, Hojjat Ahmadzadehfar, Susanne Eschmann, Andreas Niesen, Johann Schönberger, Vahé Barsegian, Knut Liepe, Felix M Mottaghy, Rongjin Guan, Joerg Pinkert, Per Sandström, Ken Herrmann
223Ra, a targeted α-therapy, is approved for the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC) who have bone metastases. In the phase 3 ALSYMPCA study, 223Ra prolonged survival and improved quality of life versus placebo. Our real-world study, PARABO, investigated pain and bone pain-related quality of life in patients with mCRPC and symptomatic bone metastases receiving 223Ra in clinical practice. Methods: PARABO was a prospective, observational, noninterventional single-arm study conducted in nuclear medicine centers across Germany (NCT02398526). The primary endpoint was a clinically meaningful pain response (≥2-point improvement from baseline for the worst-pain item score in the Brief Pain Inventory-Short Form). Results: The analysis included 354 patients, who received a median of 6 223Ra injections (range, 1-6). Sixty-seven percent (236/354) received 5-6 injections, and 33% (118/354) received 1-4 injections. Of 216 patients with a baseline worst-pain score of more than 1, 59% (128) had a clinically meaningful pain response during treatment. Corresponding rates were 67% (range, 98/146) with 5-6 223Ra injections versus 43% (range, 30/70) with 1-4 injections, 60% (range, 60/100) in patients with no more than 20 lesions versus 59% (range, 65/111) in those with more than 20 lesions, and 65% (range, 69/106) in patients without prior or concomitant opioid use versus 54% (range, 59/110) in those with prior or concomitant opioid use. Mean subscale scores (pain severity and pain interference) on the Brief Pain Inventory-Short Form improved during treatment. Conclusion:223Ra reduced pain in patients with mCRPC and symptomatic bone metastases, particularly in patients who received 5-6 injections. The extent of metastatic disease did not impact pain response.
{"title":"Pain Outcomes in Patients with Metastatic Castration-Resistant Prostate Cancer Treated with <sup>223</sup>Ra: PARABO, a Prospective, Noninterventional Study.","authors":"Holger Palmedo, Hojjat Ahmadzadehfar, Susanne Eschmann, Andreas Niesen, Johann Schönberger, Vahé Barsegian, Knut Liepe, Felix M Mottaghy, Rongjin Guan, Joerg Pinkert, Per Sandström, Ken Herrmann","doi":"10.2967/jnumed.123.265557","DOIUrl":"https://doi.org/10.2967/jnumed.123.265557","url":null,"abstract":"<p><p><sup>223</sup>Ra, a targeted α-therapy, is approved for the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC) who have bone metastases. In the phase 3 ALSYMPCA study, <sup>223</sup>Ra prolonged survival and improved quality of life versus placebo. Our real-world study, PARABO, investigated pain and bone pain-related quality of life in patients with mCRPC and symptomatic bone metastases receiving <sup>223</sup>Ra in clinical practice. <b>Methods:</b> PARABO was a prospective, observational, noninterventional single-arm study conducted in nuclear medicine centers across Germany (NCT02398526). The primary endpoint was a clinically meaningful pain response (≥2-point improvement from baseline for the worst-pain item score in the Brief Pain Inventory-Short Form). <b>Results:</b> The analysis included 354 patients, who received a median of 6 <sup>223</sup>Ra injections (range, 1-6). Sixty-seven percent (236/354) received 5-6 injections, and 33% (118/354) received 1-4 injections. Of 216 patients with a baseline worst-pain score of more than 1, 59% (128) had a clinically meaningful pain response during treatment. Corresponding rates were 67% (range, 98/146) with 5-6 <sup>223</sup>Ra injections versus 43% (range, 30/70) with 1-4 injections, 60% (range, 60/100) in patients with no more than 20 lesions versus 59% (range, 65/111) in those with more than 20 lesions, and 65% (range, 69/106) in patients without prior or concomitant opioid use versus 54% (range, 59/110) in those with prior or concomitant opioid use. Mean subscale scores (pain severity and pain interference) on the Brief Pain Inventory-Short Form improved during treatment. <b>Conclusion:</b> <sup>223</sup>Ra reduced pain in patients with mCRPC and symptomatic bone metastases, particularly in patients who received 5-6 injections. The extent of metastatic disease did not impact pain response.</p>","PeriodicalId":16758,"journal":{"name":"Journal of Nuclear Medicine","volume":null,"pages":null},"PeriodicalIF":9.3,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10478815/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10176125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.2967/jnumed.123.265484
Jens Hemmingsson, Johanna Svensson, Andreas Hallqvist, Katja Smits, Viktor Johanson, Peter Bernhardt
Bone marrow suppression is a common side effect after [177Lu]Lu-DOTATATE treatment of neuroendocrine neoplasms. Neuroendocrine neoplasms share expression of somatostatin receptor type 2 with CD34-positive hematopoietic progenitor cells, potentially leading to active uptake in the radiosensitive red marrow region where these cells are located. This study aimed to identify and quantify specific red marrow uptake using SPECT/CT images collected after the first treatment cycle. Methods: Seventeen patients diagnosed with neuroendocrine neoplasms were treated with [177Lu]Lu-DOTATATE. Seven of them had confirmed bone metastases. After the first treatment cycle, each patient went through 4 SPECT/CT imaging sessions 4, 24, 48, and 168 h after administration. Monte Carlo-based reconstructions were used to quantify activity concentrations in tumors and multiple skeletal sites presumed to house red marrow: the T9-L5 vertebrae and the ilium portion of the hip bones. The activity concentration from the descending aorta was used as input in a compartment model intended to establish a pure red marrow biodistribution by separating the nonspecific blood-based contribution from the specific activity concentration in red marrow. The biodistributions from the compartment model were used to perform red marrow dosimetry at each skeletal site. Results: Increased uptake of [177Lu]Lu-DOTATATE was observed in the T9-L5 vertebrae and hip bones in all 17 patients compared with activity concentrations in the aorta. The mean specific red marrow uptake was 49% (range, 0%-93%) higher than the nonspecific uptake. The median (±SD) total absorbed dose to the red marrow was 0.056 ± 0.023 Gy/GBq and 0.043 ± 0.022 Gy/GBq for the mean of all vertebrae and hip bones, respectively. The patients with bone metastases had an absorbed dose of 0.085 ± 0.046 Gy/GBq and 0.069 ± 0.033 Gy/GBq for the vertebrae and hip bones, respectively. The red marrow elimination phase was statistically slower in patients with fast tumor elimination, which is in line with transferrin transport of 177Lu back to the red marrow. Conclusion: Our results suggest that specific red marrow uptake of [177Lu]Lu-DOTATATE is in line with observations of somatostatin receptor type 2-expressing hematopoietic progenitor cells within the bone marrow. Blood-based dosimetry methods fail to account for the prolonged elimination of specific uptake and underestimate the absorbed dose to red marrow.
{"title":"Specific Uptake in the Bone Marrow Causes High Absorbed Red Marrow Doses During [<sup>177</sup>Lu]Lu-DOTATATE Treatment.","authors":"Jens Hemmingsson, Johanna Svensson, Andreas Hallqvist, Katja Smits, Viktor Johanson, Peter Bernhardt","doi":"10.2967/jnumed.123.265484","DOIUrl":"https://doi.org/10.2967/jnumed.123.265484","url":null,"abstract":"<p><p>Bone marrow suppression is a common side effect after [<sup>177</sup>Lu]Lu-DOTATATE treatment of neuroendocrine neoplasms. Neuroendocrine neoplasms share expression of somatostatin receptor type 2 with CD34-positive hematopoietic progenitor cells, potentially leading to active uptake in the radiosensitive red marrow region where these cells are located. This study aimed to identify and quantify specific red marrow uptake using SPECT/CT images collected after the first treatment cycle. <b>Methods:</b> Seventeen patients diagnosed with neuroendocrine neoplasms were treated with [<sup>177</sup>Lu]Lu-DOTATATE. Seven of them had confirmed bone metastases. After the first treatment cycle, each patient went through 4 SPECT/CT imaging sessions 4, 24, 48, and 168 h after administration. Monte Carlo-based reconstructions were used to quantify activity concentrations in tumors and multiple skeletal sites presumed to house red marrow: the T9-L5 vertebrae and the ilium portion of the hip bones. The activity concentration from the descending aorta was used as input in a compartment model intended to establish a pure red marrow biodistribution by separating the nonspecific blood-based contribution from the specific activity concentration in red marrow. The biodistributions from the compartment model were used to perform red marrow dosimetry at each skeletal site. <b>Results:</b> Increased uptake of [<sup>177</sup>Lu]Lu-DOTATATE was observed in the T9-L5 vertebrae and hip bones in all 17 patients compared with activity concentrations in the aorta. The mean specific red marrow uptake was 49% (range, 0%-93%) higher than the nonspecific uptake. The median (±SD) total absorbed dose to the red marrow was 0.056 ± 0.023 Gy/GBq and 0.043 ± 0.022 Gy/GBq for the mean of all vertebrae and hip bones, respectively. The patients with bone metastases had an absorbed dose of 0.085 ± 0.046 Gy/GBq and 0.069 ± 0.033 Gy/GBq for the vertebrae and hip bones, respectively. The red marrow elimination phase was statistically slower in patients with fast tumor elimination, which is in line with transferrin transport of <sup>177</sup>Lu back to the red marrow. <b>Conclusion:</b> Our results suggest that specific red marrow uptake of [<sup>177</sup>Lu]Lu-DOTATATE is in line with observations of somatostatin receptor type 2-expressing hematopoietic progenitor cells within the bone marrow. Blood-based dosimetry methods fail to account for the prolonged elimination of specific uptake and underestimate the absorbed dose to red marrow.</p>","PeriodicalId":16758,"journal":{"name":"Journal of Nuclear Medicine","volume":null,"pages":null},"PeriodicalIF":9.3,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10478826/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10519348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.2967/jnumed.122.264331
Marwa Daghem, Philip D Adamson, Kang-Ling Wang, Mhairi Doris, Rong Bing, Edwin J R van Beek, Laura Forsyth, Michelle C Williams, Evangelos Tzolos, Damini Dey, Piotr J Slomka, Marc R Dweck, David E Newby, Alastair J Moss
Coronary 18F-sodium fluoride (18F-fluoride) uptake is a marker of both atherosclerotic disease activity and disease progression. It is currently unknown whether there are rapid temporal changes in coronary 18F-fluoride uptake and whether these are more marked in those with clinically unstable coronary artery disease. This study aimed to determine the natural history of coronary 18F-fluoride uptake over 12 mo in patients with either advanced chronic coronary artery disease or a recent myocardial infarction. Methods: Patients with established multivessel coronary artery disease and either chronic disease or a recent acute myocardial infarction underwent coronary 18F-fluoride PET and CT angiography, which was repeated at 3, 6, or 12 mo. Coronary 18F-fluoride uptake was assessed in each vessel by measuring the coronary microcalcification activity (CMA). Coronary calcification was quantified by measuring calcium score, mass, and volume. Results: Fifty-nine patients had chronic coronary artery disease (median age, 68 y; 93% male), and 52 patients had a recent myocardial infarction (median age, 65 y; 83% male). Reflecting the greater burden of coronary artery disease, baseline CMA values were higher in those with chronic coronary artery disease. Coronary 18F-fluoride uptake (CMA > 0) was associated with higher baseline calcium scores (294 Agatston units [AU] [interquartile range, 116-483 AU] vs. 72 AU [interquartile range, 8-222 AU]; P < 0.001) and more rapid progression of coronary calcification scores (39 AU [interquartile range, 10-82 AU] vs. 12 AU [interquartile range, 1-36 AU]; P < 0.001) than was the absence of uptake (CMA = 0). Coronary 18F-fluoride uptake did not markedly alter over the course of 3, 6, or 12 mo in patients with either chronic coronary artery disease or a recent myocardial infarction. Conclusion: Coronary 18F-fluoride uptake is associated with the severity and progression of coronary artery disease but does not undergo a rapid dynamic change in patients with chronic or unstable coronary artery disease. This finding suggests that coronary 18F-fluoride uptake is a temporally stable marker of established and progressive disease.
{"title":"Temporal Changes in Coronary <sup>18</sup>F-Fluoride Plaque Uptake in Patients with Coronary Atherosclerosis.","authors":"Marwa Daghem, Philip D Adamson, Kang-Ling Wang, Mhairi Doris, Rong Bing, Edwin J R van Beek, Laura Forsyth, Michelle C Williams, Evangelos Tzolos, Damini Dey, Piotr J Slomka, Marc R Dweck, David E Newby, Alastair J Moss","doi":"10.2967/jnumed.122.264331","DOIUrl":"https://doi.org/10.2967/jnumed.122.264331","url":null,"abstract":"<p><p>Coronary <sup>18</sup>F-sodium fluoride (<sup>18</sup>F-fluoride) uptake is a marker of both atherosclerotic disease activity and disease progression. It is currently unknown whether there are rapid temporal changes in coronary <sup>18</sup>F-fluoride uptake and whether these are more marked in those with clinically unstable coronary artery disease. This study aimed to determine the natural history of coronary <sup>18</sup>F-fluoride uptake over 12 mo in patients with either advanced chronic coronary artery disease or a recent myocardial infarction. <b>Methods:</b> Patients with established multivessel coronary artery disease and either chronic disease or a recent acute myocardial infarction underwent coronary <sup>18</sup>F-fluoride PET and CT angiography, which was repeated at 3, 6, or 12 mo. Coronary <sup>18</sup>F-fluoride uptake was assessed in each vessel by measuring the coronary microcalcification activity (CMA). Coronary calcification was quantified by measuring calcium score, mass, and volume. <b>Results:</b> Fifty-nine patients had chronic coronary artery disease (median age, 68 y; 93% male), and 52 patients had a recent myocardial infarction (median age, 65 y; 83% male). Reflecting the greater burden of coronary artery disease, baseline CMA values were higher in those with chronic coronary artery disease. Coronary <sup>18</sup>F-fluoride uptake (CMA > 0) was associated with higher baseline calcium scores (294 Agatston units [AU] [interquartile range, 116-483 AU] vs. 72 AU [interquartile range, 8-222 AU]; <i>P</i> < 0.001) and more rapid progression of coronary calcification scores (39 AU [interquartile range, 10-82 AU] vs. 12 AU [interquartile range, 1-36 AU]; <i>P</i> < 0.001) than was the absence of uptake (CMA = 0). Coronary <sup>18</sup>F-fluoride uptake did not markedly alter over the course of 3, 6, or 12 mo in patients with either chronic coronary artery disease or a recent myocardial infarction. <b>Conclusion:</b> Coronary <sup>18</sup>F-fluoride uptake is associated with the severity and progression of coronary artery disease but does not undergo a rapid dynamic change in patients with chronic or unstable coronary artery disease. This finding suggests that coronary <sup>18</sup>F-fluoride uptake is a temporally stable marker of established and progressive disease.</p>","PeriodicalId":16758,"journal":{"name":"Journal of Nuclear Medicine","volume":null,"pages":null},"PeriodicalIF":9.3,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10478818/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10521376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.2967/jnumed.123.266395
Ebrahim S Delpassand, Eric M Rohren, Wolfgang A Weber, Johannes Czernin
{"title":"Toward Integrated Independence: Johannes Czernin Discusses the Future of Theranostics with Ebrahim Delpassand, Eric Rohren, and Wolfgang Weber.","authors":"Ebrahim S Delpassand, Eric M Rohren, Wolfgang A Weber, Johannes Czernin","doi":"10.2967/jnumed.123.266395","DOIUrl":"https://doi.org/10.2967/jnumed.123.266395","url":null,"abstract":"","PeriodicalId":16758,"journal":{"name":"Journal of Nuclear Medicine","volume":null,"pages":null},"PeriodicalIF":9.3,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10192101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.2967/jnumed.123.265759
Shejil Kumar, Megan Crumbaker, Christopher Harvey, Sarennya Pathmanandavel, Nikieth John, Mina M Swiha, Michelle M McDonald, Roderick Clifton-Bligh, Adrian Lee, Patricia Bastick, William Counter, Andrew Nguyen, Louise Emmett
177Lu-prostate-specific membrane antigen (PSMA) is an effective treatment for metastatic castration-resistant prostate cancer. Rarer treatment-related adverse events have not yet been described. Methods: We present case reviews of 2 men with a marked hypocalcemic osteosclerotic response to 177Lu-PSMA-I&T therapy. A clinical dataset of 177Lu-PSMA-I&T therapy was evaluated to estimate the incidence and clinical association with hypocalcemia. Results: Forty-one of the 127 men (32%) had a serum calcium drop, and 6 (5%) developed clinical hypocalcemia during 177Lu-PSMA therapy. The baseline total tumor volume was significantly higher in those who developed hypocalcemia (median, 3,249 cm3 [interquartile range, 1,856-3,852] vs. 465 [interquartile range 135-1,172]; P = 0.002). The mean prostate-specific antigen response in those with hypocalcemia was 78% (SD, 24%). Conclusion: Hypocalcemia may occur in response to 177Lu-PSMA-I&T, particularly with both high-volume bone metastases and a significant prostate-specific antigen response, and may be severe, requiring corticosteroids. Further evaluation of 177Lu-PSMA-induced hypocalcemia is required to better understand mechanisms, optimal treatments, and repercussions from any subsequent osteosclerotic response.
{"title":"The Tyr Phenomenon: A Hypocalcemic Response in High-Volume Treatment Responders to <sup>177</sup>Lu-Prostate-Specific Membrane Antigen Therapy.","authors":"Shejil Kumar, Megan Crumbaker, Christopher Harvey, Sarennya Pathmanandavel, Nikieth John, Mina M Swiha, Michelle M McDonald, Roderick Clifton-Bligh, Adrian Lee, Patricia Bastick, William Counter, Andrew Nguyen, Louise Emmett","doi":"10.2967/jnumed.123.265759","DOIUrl":"https://doi.org/10.2967/jnumed.123.265759","url":null,"abstract":"<p><p><sup>177</sup>Lu-prostate-specific membrane antigen (PSMA) is an effective treatment for metastatic castration-resistant prostate cancer. Rarer treatment-related adverse events have not yet been described. <b>Methods:</b> We present case reviews of 2 men with a marked hypocalcemic osteosclerotic response to <sup>177</sup>Lu-PSMA-I&T therapy. A clinical dataset of <sup>177</sup>Lu-PSMA-I&T therapy was evaluated to estimate the incidence and clinical association with hypocalcemia. <b>Results:</b> Forty-one of the 127 men (32%) had a serum calcium drop, and 6 (5%) developed clinical hypocalcemia during <sup>177</sup>Lu-PSMA therapy. The baseline total tumor volume was significantly higher in those who developed hypocalcemia (median, 3,249 cm<sup>3</sup> [interquartile range, 1,856-3,852] vs. 465 [interquartile range 135-1,172]; <i>P</i> = 0.002). The mean prostate-specific antigen response in those with hypocalcemia was 78% (SD, 24%). <b>Conclusion:</b> Hypocalcemia may occur in response to <sup>177</sup>Lu-PSMA-I&T, particularly with both high-volume bone metastases and a significant prostate-specific antigen response, and may be severe, requiring corticosteroids. Further evaluation of <sup>177</sup>Lu-PSMA-induced hypocalcemia is required to better understand mechanisms, optimal treatments, and repercussions from any subsequent osteosclerotic response.</p>","PeriodicalId":16758,"journal":{"name":"Journal of Nuclear Medicine","volume":null,"pages":null},"PeriodicalIF":9.3,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10221855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.2967/jnumed.123.265691
Jiangyu Ma, Qiao Yang, Li Huo, Jiawen Dai, Na Niu, Xinxin Cao
Erdheim-Chester disease (ECD) involves multiple organs and tissues and has diverse manifestations, which makes it difficult to distinguish lesions caused by ECD from those caused by other diseases. Variable degrees of fibrosis are present in ECD. Therefore, we conducted a prospective cohort study to explore the ability of 68Ga fibroblast activation protein inhibitor (68Ga-FAPI) PET/CT to detect lesions in ECD patients. Methods: Fourteen patients diagnosed with ECD, as confirmed by histology, were included in this study. For every patient, 68Ga-FAPI PET/CT and 18F-FDG PET/CT were conducted within 1 wk. The positive rate and SUVmax of the lesions in the involved organs were compared between the examinations. Results: The most commonly involved organs were bone (100%), heart (57.1%), lung (57.1%), kidney (42.9%), and peritoneum or omentum (35.7%); other common manifestations were intracranial infiltration (50%) and cutaneous infiltration (35.7%). 68Ga-FAPI PET/CT detected 64 of 67 lesions in 14 patients, whereas 18F-FDG PET/CT detected 51 of 67 lesions (P = 0.004). The SUVmax for 68Ga-FAPI PET/CT was significantly higher than the SUVmax for 18F-FDG PET/CT of the heart (4.9 ± 2.4 vs. 2.8 ± 1.2, respectively; P = 0.050), lung or pleura (6.8 ± 4.9 vs. 3.1 ± 1.3, respectively; P = 0.025), peritoneum or omentum (5.7 ± 3.6 vs. 2.8 ± 1.7, respectively; P = 0.032), and kidney or perinephric infiltration (4.9 ± 1.2 vs. 2.9 ± 1.1, respectively; P = 0.009). Conclusion: The detectivity of 68Ga-FAPI PET/CT is superior to that of 18F-FDG PET/CT. Moreover, 68Ga-FAPI PET/CT has a better image contrast and higher SUVmax for lesions in multiple organs including the heart, lungs, peritoneum, and kidneys. 68Ga-FAPI PET/CT is a promising tool to assess pathologic features and disease extent in ECD patients.
{"title":"Performance of <sup>68</sup>Ga-Labeled Fibroblast Activation Protein Inhibitor PET/CT in Evaluation of Erdheim-Chester Disease: A Comparison with <sup>18</sup>F-FDG PET/CT.","authors":"Jiangyu Ma, Qiao Yang, Li Huo, Jiawen Dai, Na Niu, Xinxin Cao","doi":"10.2967/jnumed.123.265691","DOIUrl":"https://doi.org/10.2967/jnumed.123.265691","url":null,"abstract":"<p><p>Erdheim-Chester disease (ECD) involves multiple organs and tissues and has diverse manifestations, which makes it difficult to distinguish lesions caused by ECD from those caused by other diseases. Variable degrees of fibrosis are present in ECD. Therefore, we conducted a prospective cohort study to explore the ability of <sup>68</sup>Ga fibroblast activation protein inhibitor (<sup>68</sup>Ga-FAPI) PET/CT to detect lesions in ECD patients. <b>Methods:</b> Fourteen patients diagnosed with ECD, as confirmed by histology, were included in this study. For every patient, <sup>68</sup>Ga-FAPI PET/CT and <sup>18</sup>F-FDG PET/CT were conducted within 1 wk. The positive rate and SUV<sub>max</sub> of the lesions in the involved organs were compared between the examinations. <b>Results:</b> The most commonly involved organs were bone (100%), heart (57.1%), lung (57.1%), kidney (42.9%), and peritoneum or omentum (35.7%); other common manifestations were intracranial infiltration (50%) and cutaneous infiltration (35.7%). <sup>68</sup>Ga-FAPI PET/CT detected 64 of 67 lesions in 14 patients, whereas <sup>18</sup>F-FDG PET/CT detected 51 of 67 lesions (<i>P</i> = 0.004). The SUV<sub>max</sub> for <sup>68</sup>Ga-FAPI PET/CT was significantly higher than the SUV<sub>max</sub> for <sup>18</sup>F-FDG PET/CT of the heart (4.9 ± 2.4 vs. 2.8 ± 1.2, respectively; <i>P</i> = 0.050), lung or pleura (6.8 ± 4.9 vs. 3.1 ± 1.3, respectively; <i>P</i> = 0.025), peritoneum or omentum (5.7 ± 3.6 vs. 2.8 ± 1.7, respectively; <i>P</i> = 0.032), and kidney or perinephric infiltration (4.9 ± 1.2 vs. 2.9 ± 1.1, respectively; <i>P</i> = 0.009). <b>Conclusion:</b> The detectivity of <sup>68</sup>Ga-FAPI PET/CT is superior to that of <sup>18</sup>F-FDG PET/CT. Moreover, <sup>68</sup>Ga-FAPI PET/CT has a better image contrast and higher SUV<sub>max</sub> for lesions in multiple organs including the heart, lungs, peritoneum, and kidneys. <sup>68</sup>Ga-FAPI PET/CT is a promising tool to assess pathologic features and disease extent in ECD patients.</p>","PeriodicalId":16758,"journal":{"name":"Journal of Nuclear Medicine","volume":null,"pages":null},"PeriodicalIF":9.3,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10125999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.2967/jnumed.122.264972
Françoise Kraeber-Bodéré, Bastien Jamet, Davide Bezzi, Elena Zamagni, Philippe Moreau, Cristina Nanni
Recent innovative strategies have dramatically redefined the therapeutic landscape for treating multiple myeloma patients. In particular, the development and application of immunotherapy and high-dose therapy have demonstrated high response rates and have prolonged remission duration. Over the past decade, new morphologic or hybrid imaging techniques have gradually replaced conventional skeletal surveys. PET/CT using 18F-FDG is a powerful imaging tool for the workup at diagnosis and for therapeutic evaluation allowing medullary and extramedullary assessment. The independent negative prognostic value for progression-free and overall survival derived from baseline PET-derived parameters such as the presence of extramedullary disease or paramedullary disease, as well as the number of focal bone lesions and SUVmax, has been reported in several large prospective studies. During therapeutic evaluation, 18F-FDG PET/CT is considered the reference imaging technique because it can be performed much earlier than MRI, which lacks specificity. Persistence of significant abnormal 18F-FDG uptake after therapy is an independent negative prognostic factor, and 18F-FDG PET/CT and medullary flow cytometry are complementary tools for detecting minimal residual disease before maintenance therapy. The definition of a PET metabolic complete response has recently been standardized and the interpretation criteria harmonized. The development of advanced PET analysis and radiomics using machine learning, as well as hybrid imaging with PET/MRI, offers new perspectives for multiple myeloma imaging. Most recently, innovative radiopharmaceuticals such as C-X-C chemokine receptor type 4-targeted small molecules and anti-CD38 radiolabeled antibodies have shown promising results for tumor phenotype imaging and as potential theranostics.
{"title":"New Developments in Myeloma Treatment and Response Assessment.","authors":"Françoise Kraeber-Bodéré, Bastien Jamet, Davide Bezzi, Elena Zamagni, Philippe Moreau, Cristina Nanni","doi":"10.2967/jnumed.122.264972","DOIUrl":"https://doi.org/10.2967/jnumed.122.264972","url":null,"abstract":"<p><p>Recent innovative strategies have dramatically redefined the therapeutic landscape for treating multiple myeloma patients. In particular, the development and application of immunotherapy and high-dose therapy have demonstrated high response rates and have prolonged remission duration. Over the past decade, new morphologic or hybrid imaging techniques have gradually replaced conventional skeletal surveys. PET/CT using <sup>18</sup>F-FDG is a powerful imaging tool for the workup at diagnosis and for therapeutic evaluation allowing medullary and extramedullary assessment. The independent negative prognostic value for progression-free and overall survival derived from baseline PET-derived parameters such as the presence of extramedullary disease or paramedullary disease, as well as the number of focal bone lesions and SUV<sub>max</sub>, has been reported in several large prospective studies. During therapeutic evaluation, <sup>18</sup>F-FDG PET/CT is considered the reference imaging technique because it can be performed much earlier than MRI, which lacks specificity. Persistence of significant abnormal <sup>18</sup>F-FDG uptake after therapy is an independent negative prognostic factor, and <sup>18</sup>F-FDG PET/CT and medullary flow cytometry are complementary tools for detecting minimal residual disease before maintenance therapy. The definition of a PET metabolic complete response has recently been standardized and the interpretation criteria harmonized. The development of advanced PET analysis and radiomics using machine learning, as well as hybrid imaging with PET/MRI, offers new perspectives for multiple myeloma imaging. Most recently, innovative radiopharmaceuticals such as C-X-C chemokine receptor type 4-targeted small molecules and anti-CD38 radiolabeled antibodies have shown promising results for tumor phenotype imaging and as potential theranostics.</p>","PeriodicalId":16758,"journal":{"name":"Journal of Nuclear Medicine","volume":null,"pages":null},"PeriodicalIF":9.3,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10478822/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10521378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Radiolabeled fibroblast activation protein (FAP) inhibitors (FAPIs) have shown promise as cancer diagnostic agents; however, the relatively short tumor retention of FAPIs may limit their application in radioligand therapy. In this paper, we report the design, synthesis, and evaluation of a FAPI tetramer. The aim of the study was to evaluate the tumor-targeting characteristics of radiolabeled FAPI multimers in vitro and in vivo, thereby providing information for the design of FAP-targeted radiopharmaceuticals based on the polyvalency principle. Methods: FAPI tetramers were synthesized on the basis of FAPI-46 and radiolabeled with 68Ga, 64Cu, and 177Lu. In vitro FAP-binding characteristics were identified using a competitive cell-binding experiment. To evaluate their pharmacokinetics, small-animal PET, SPECT, and ex vivo biodistribution analyses were performed on HT-1080-FAP and U87MG tumor-bearing mice. In addition, the 2 tumor xenografts received radioligand therapy with 177Lu-DOTA-4P(FAPI)4, and the antitumor efficacy of the 177Lu-FAPI tetramer was evaluated and compared with that of the 177Lu-FAPI dimer and monomer. Results:68Ga-DOTA-4P(FAPI)4 and 177Lu-DOTA-4P(FAPI)4 were highly stable in phosphate-buffered saline and fetal bovine serum. The FAPI tetramer exhibited high FAP-binding affinity and specificity both in vitro and in vivo. 68Ga-, 64Cu-, and 177Lu-labeled FAPI tetramers exhibited higher tumor uptake, longer tumor retention, and slower clearance than FAPI dimers and FAPI-46 in HT-1080-FAP tumors. The uptake (percentage injected dose per gram) of 177Lu-DOTA-4P(FAPI)4, 177Lu-DOTA-2P(FAPI)2, and 177Lu-FAPI-46 in HT-1080-FAP tumors at 24 h was 21.4 ± 1.7, 17.1 ± 3.9, and 3.4 ± 0.7, respectively. Moreover, 68Ga-DOTA-4P(FAPI)4 uptake in U87MG tumors was approximately 2-fold the uptake of 68Ga-DOTA-2P(FAPI)2 (SUVmean, 0.72 ± 0.02 vs. 0.42 ± 0.03, P < 0.001) and more than 4-fold the uptake of 68Ga-FAPI-46 (0.16 ± 0.01, P < 0.001). In the radioligand therapy study, remarkable tumor suppression was observed with the 177Lu-FAPI tetramer in both HT-1080-FAP and U87MG tumor-bearing mice. Conclusion: The satisfactory FAP-binding affinity and specificity, as well as the favorable in vivo pharmacokinetics of the FAPI tetramer, make it a promising radiopharmaceutical for theranostic applications. Improved tumor uptake and prolonged retention of the 177Lu-FAPI tetramer resulted in excellent characteristics for FAPI imaging and radioligand therapy.
放射性标记成纤维细胞活化蛋白(FAP)抑制剂(FAPIs)已显示出作为癌症诊断药物的前景;然而,fapi相对较短的肿瘤滞留可能限制其在放射配体治疗中的应用。本文报道了一种FAPI四聚体的设计、合成和评价。本研究旨在评估放射性标记的FAPI多聚体在体外和体内的肿瘤靶向特性,从而为基于多价原理设计靶向fap的放射性药物提供信息。方法:以FAPI-46为基础合成FAPI四聚体,分别用68Ga、64Cu和177Lu进行放射性标记。通过竞争性细胞结合实验鉴定了fap的体外结合特性。为评价其药代动力学,对HT-1080-FAP和U87MG荷瘤小鼠进行了小动物PET、SPECT和体外生物分布分析。此外,对2例肿瘤异种移植物进行177Lu-DOTA-4P(FAPI)4放射配体治疗,评价177Lu-FAPI四聚体的抗肿瘤效果,并与177Lu-FAPI二聚体和单体的抗肿瘤效果进行比较。结果:68Ga-DOTA-4P(FAPI)4和177Lu-DOTA-4P(FAPI)4在磷酸盐缓冲盐水和胎牛血清中高度稳定。FAPI四聚体在体外和体内均表现出高的fap结合亲和力和特异性。在HT-1080-FAP肿瘤中,68Ga-、64Cu-和177lu标记的FAPI四聚体比FAPI二聚体和FAPI-46表现出更高的肿瘤摄取、更长的肿瘤滞留和更慢的清除。177Lu-DOTA-4P(FAPI)4、177Lu-DOTA-2P(FAPI)2和177Lu-FAPI-46在HT-1080-FAP肿瘤中的24 h摄取率(每克注射剂量百分比)分别为21.4±1.7、17.1±3.9和3.4±0.7。此外,U87MG肿瘤中68Ga-DOTA-4P(FAPI)4的摄取约为68Ga-DOTA-2P(FAPI)2的2倍(SUVmean, 0.72±0.02 vs. 0.42±0.03,P < 0.001), 68Ga-FAPI-46的摄取超过4倍(0.16±0.01,P < 0.001)。在放射配体治疗研究中,177Lu-FAPI四聚体对HT-1080-FAP和U87MG荷瘤小鼠均有明显的抑瘤作用。结论:FAPI四聚体具有良好的结合亲和力和特异性,以及良好的体内药代动力学特性,是一种很有前景的放射性药物。改善肿瘤摄取和延长177Lu-FAPI四聚体的保留时间导致FAPI成像和放射配体治疗的优异特征。
{"title":"Development of FAPI Tetramers to Improve Tumor Uptake and Efficacy of FAPI Radioligand Therapy.","authors":"Yizhen Pang, Liang Zhao, Jianyang Fang, Jianhao Chen, Lingxin Meng, Long Sun, Hua Wu, Zhide Guo, Qin Lin, Haojun Chen","doi":"10.2967/jnumed.123.265599","DOIUrl":"https://doi.org/10.2967/jnumed.123.265599","url":null,"abstract":"<p><p>Radiolabeled fibroblast activation protein (FAP) inhibitors (FAPIs) have shown promise as cancer diagnostic agents; however, the relatively short tumor retention of FAPIs may limit their application in radioligand therapy. In this paper, we report the design, synthesis, and evaluation of a FAPI tetramer. The aim of the study was to evaluate the tumor-targeting characteristics of radiolabeled FAPI multimers in vitro and in vivo, thereby providing information for the design of FAP-targeted radiopharmaceuticals based on the polyvalency principle. <b>Methods:</b> FAPI tetramers were synthesized on the basis of FAPI-46 and radiolabeled with <sup>68</sup>Ga, <sup>64</sup>Cu, and <sup>177</sup>Lu. In vitro FAP-binding characteristics were identified using a competitive cell-binding experiment. To evaluate their pharmacokinetics, small-animal PET, SPECT, and ex vivo biodistribution analyses were performed on HT-1080-FAP and U87MG tumor-bearing mice. In addition, the 2 tumor xenografts received radioligand therapy with <sup>177</sup>Lu-DOTA-4P(FAPI)<sub>4</sub>, and the antitumor efficacy of the <sup>177</sup>Lu-FAPI tetramer was evaluated and compared with that of the <sup>177</sup>Lu-FAPI dimer and monomer. <b>Results:</b> <sup>68</sup>Ga-DOTA-4P(FAPI)<sub>4</sub> and <sup>177</sup>Lu-DOTA-4P(FAPI)<sub>4</sub> were highly stable in phosphate-buffered saline and fetal bovine serum. The FAPI tetramer exhibited high FAP-binding affinity and specificity both in vitro and in vivo. <sup>68</sup>Ga-, <sup>64</sup>Cu-, and <sup>177</sup>Lu-labeled FAPI tetramers exhibited higher tumor uptake, longer tumor retention, and slower clearance than FAPI dimers and FAPI-46 in HT-1080-FAP tumors. The uptake (percentage injected dose per gram) of <sup>177</sup>Lu-DOTA-4P(FAPI)<sub>4</sub>, <sup>177</sup>Lu-DOTA-2P(FAPI)<sub>2</sub>, and <sup>177</sup>Lu-FAPI-46 in HT-1080-FAP tumors at 24 h was 21.4 ± 1.7, 17.1 ± 3.9, and 3.4 ± 0.7, respectively. Moreover, <sup>68</sup>Ga-DOTA-4P(FAPI)<sub>4</sub> uptake in U87MG tumors was approximately 2-fold the uptake of <sup>68</sup>Ga-DOTA-2P(FAPI)<sub>2</sub> (SUV<sub>mean</sub>, 0.72 ± 0.02 vs. 0.42 ± 0.03, <i>P</i> < 0.001) and more than 4-fold the uptake of <sup>68</sup>Ga-FAPI-46 (0.16 ± 0.01, <i>P</i> < 0.001). In the radioligand therapy study, remarkable tumor suppression was observed with the <sup>177</sup>Lu-FAPI tetramer in both HT-1080-FAP and U87MG tumor-bearing mice. <b>Conclusion:</b> The satisfactory FAP-binding affinity and specificity, as well as the favorable in vivo pharmacokinetics of the FAPI tetramer, make it a promising radiopharmaceutical for theranostic applications. Improved tumor uptake and prolonged retention of the <sup>177</sup>Lu-FAPI tetramer resulted in excellent characteristics for FAPI imaging and radioligand therapy.</p>","PeriodicalId":16758,"journal":{"name":"Journal of Nuclear Medicine","volume":null,"pages":null},"PeriodicalIF":9.3,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10478824/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10156674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tau PET tracers are expected to be sufficiently sensitive to track the progression of age-related tau pathology in the medial temporal cortex. The tau PET tracer N-(4-[18F]fluoro-5-methylpyridin-2-yl)-7-aminoimidazo[1,2-a]pyridine ([18F]SNFT-1) has been successfully developed by optimizing imidazo[1,2-a]pyridine derivatives. We characterized the binding properties of [18F]SNFT-1 using a head-to-head comparison with other reported 18F-labeled tau tracers. Methods: The binding affinity of SNFT-1 to tau, amyloid, and monoamine oxidase A and B was compared with that of the second-generation tau tracers MK-6240, PM-PBB3, PI-2620, RO6958948, JNJ-64326067, and flortaucipir. In vitro binding properties of 18F-labeled tau tracers were evaluated through the autoradiography of frozen human brain tissues from patients with diverse neurodegenerative disease spectra. Pharmacokinetics, metabolism, and radiation dosimetry were assessed in normal mice after intravenous administration of [18F]SNFT-1. Results: In vitro binding assays demonstrated that [18F]SNFT-1 possesses high selectivity and high affinity for tau aggregates in Alzheimer disease (AD) brains. Autoradiographic analysis of tau deposits in medial temporal brain sections from patients with AD showed a higher signal-to-background ratio for [18F]SNFT-1 than for the other tau PET tracers and no significant binding with non-AD tau, α-synuclein, transactiviation response DNA-binding protein-43, and transmembrane protein 106B aggregates in human brain sections. Furthermore, [18F]SNFT-1 did not bind significantly to various receptors, ion channels, or transporters. [18F]SNFT-1 showed a high initial brain uptake and rapid washout from the brains of normal mice without radiolabeled metabolites. Conclusion: These preclinical data suggest that [18F]SNFT-1 is a promising and selective tau radiotracer candidate that allows the quantitative monitoring of age-related accumulation of tau aggregates in the human brain.
Tau PET示踪剂有望足够敏感地追踪内侧颞叶皮层中与年龄相关的Tau病理进展。通过优化咪唑[1,2-a]吡啶衍生物,成功制备了tau PET示踪剂N-(4-[18F]氟-5-甲基吡啶-2-基)-7-氨基咪唑[1,2-a]吡啶([18F]SNFT-1)。我们通过与其他已报道的18F标记的tau示踪剂进行头对头比较来表征[18F]SNFT-1的结合特性。方法:比较SNFT-1与第二代tau示踪剂MK-6240、PM-PBB3、PI-2620、RO6958948、JNJ-64326067和flortaucipir对tau蛋白、淀粉样蛋白和单胺氧化酶A和B的结合亲和力。18f标记的tau示踪剂的体外结合特性通过对不同神经退行性疾病谱患者的冷冻脑组织进行放射自显影评估。静脉给药[18F]SNFT-1后,对正常小鼠进行药代动力学、代谢和辐射剂量测定。结果:体外结合实验表明[18F]SNFT-1对阿尔茨海默病(AD)大脑中tau聚集物具有高选择性和高亲和力。对AD患者内侧颞叶脑切片中tau沉积物的放射自显像分析显示,[18F]SNFT-1的信本比高于其他tau PET示踪剂,并且在人脑切片中与非AD tau、α-突触核蛋白、交易反应dna结合蛋白-43和跨膜蛋白106B聚集体没有明显结合。此外,[18F]SNFT-1不能与多种受体、离子通道或转运体显著结合。[18F]在没有放射性标记代谢物的正常小鼠中,SNFT-1表现出高初始脑摄取和快速冲洗。结论:这些临床前数据表明[18F]SNFT-1是一种有前途的选择性tau放射性示踪剂候选物,可以定量监测人脑中与年龄相关的tau聚集体积累。
{"title":"Preclinical Characterization of the Tau PET Tracer [<sup>18</sup>F]SNFT-1: Comparison of Tau PET Tracers.","authors":"Ryuichi Harada, Pradith Lerdsirisuk, Yuki Shimizu, Yuka Yokoyama, Yiqing Du, Kaede Kudo, Michinori Ezura, Yoichi Ishikawa, Ren Iwata, Miho Shidahara, Aiko Ishiki, Akio Kikuchi, Yuya Hatano, Tomohiko Ishihara, Osamu Onodera, Yasushi Iwasaki, Mari Yoshida, Yasuyuki Taki, Hiroyuki Arai, Yukitsuka Kudo, Kazuhiko Yanai, Shozo Furumoto, Nobuyuki Okamura","doi":"10.2967/jnumed.123.265593","DOIUrl":"https://doi.org/10.2967/jnumed.123.265593","url":null,"abstract":"<p><p>Tau PET tracers are expected to be sufficiently sensitive to track the progression of age-related tau pathology in the medial temporal cortex. The tau PET tracer <i>N</i>-(4-[<sup>18</sup>F]fluoro-5-methylpyridin-2-yl)-7-aminoimidazo[1,2-a]pyridine ([<sup>18</sup>F]SNFT-1) has been successfully developed by optimizing imidazo[1,2-a]pyridine derivatives. We characterized the binding properties of [<sup>18</sup>F]SNFT-1 using a head-to-head comparison with other reported <sup>18</sup>F-labeled tau tracers. <b>Methods:</b> The binding affinity of SNFT-1 to tau, amyloid, and monoamine oxidase A and B was compared with that of the second-generation tau tracers MK-6240, PM-PBB3, PI-2620, RO6958948, JNJ-64326067, and flortaucipir. In vitro binding properties of <sup>18</sup>F-labeled tau tracers were evaluated through the autoradiography of frozen human brain tissues from patients with diverse neurodegenerative disease spectra. Pharmacokinetics, metabolism, and radiation dosimetry were assessed in normal mice after intravenous administration of [<sup>18</sup>F]SNFT-1. <b>Results:</b> In vitro binding assays demonstrated that [<sup>18</sup>F]SNFT-1 possesses high selectivity and high affinity for tau aggregates in Alzheimer disease (AD) brains. Autoradiographic analysis of tau deposits in medial temporal brain sections from patients with AD showed a higher signal-to-background ratio for [<sup>18</sup>F]SNFT-1 than for the other tau PET tracers and no significant binding with non-AD tau, α-synuclein, transactiviation response DNA-binding protein-43, and transmembrane protein 106B aggregates in human brain sections. Furthermore, [<sup>18</sup>F]SNFT-1 did not bind significantly to various receptors, ion channels, or transporters. [<sup>18</sup>F]SNFT-1 showed a high initial brain uptake and rapid washout from the brains of normal mice without radiolabeled metabolites. <b>Conclusion:</b> These preclinical data suggest that [<sup>18</sup>F]SNFT-1 is a promising and selective tau radiotracer candidate that allows the quantitative monitoring of age-related accumulation of tau aggregates in the human brain.</p>","PeriodicalId":16758,"journal":{"name":"Journal of Nuclear Medicine","volume":null,"pages":null},"PeriodicalIF":9.3,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10156678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}