{"title":"A New Approach to Synthesize Carbon-11-PBR28 and its Clinical Validation in ALS Patients.","authors":"Pardeep Kumar, Aishwarya Kumar, Muddasu Keerthipriya, Chandrika H, Atchayaram Nalini, Seena Vengalil, Kirti Sitani, Chandana Nagaraj, Saikat Dey, Monojit Debnath, Vijayalakshmi K, Talakad N Sathyaprabha","doi":"10.2174/0118744710341203250220042349","DOIUrl":null,"url":null,"abstract":"<p><strong>Introduction: </strong>Many studies have reported translocator protein (TSPO) overexpression in various neurological disorders. Carbon-11[<sup>11</sup>C]PBR28 is a widely used TSPO Positron Emission Tomography (PET) radiopharmaceutical. We compared HPLC-based purification with cartridge-based purification and performed PET-MR imaging in ALS patients.</p><p><strong>Methods: </strong>[<sup>11</sup>C]PBR28 was synthesized using both an HPLC-based and cartridge-based purification technique on the FX2C chemistry module. We injected 350 ± 20 MBq of the [<sup>11</sup>C]PBR28 intravenously into the patients diagnosed with amyotrophic lateral syndrome (ALS) limb onset (n =3) and bulbar (n =3). Simultaneous PET-MR dynamic imaging was then performed.</p><p><strong>Results: </strong>The radiochemical purity exceeded 95% with both methods. Using the HPLC-based method, the radiochemical yield was 11.8 ± 3.3%, molar activity was 253 ± 20.9 GBq/μmol, and the total synthesis time of 25 ± 2 minutes. In contrast, the cartridge-based method yielded a radiochemical yield of 53.0 ± 3.6%, a molar activity of 885 ± 17.7 GBq/μmol, and a total synthesis time of 12 ± 2 minutes. In imaging results, higher activity was observed in the precentral gyrus and cerebellum at 2.5 ± 0.5 minutes in bulbar-onset ALS cases, with a standardized uptake value (SUV) of 2.3 ± 0.3. In contrast, limb-onset ALS cases showed the highest uptake at 0.5 ± 0.2 minutes, with an SUV of 1.5 ± 0.2.</p><p><strong>Discussion: </strong>The difference in SUV in bulbar and limb onset may be due to pathological changes.</p><p><strong>Conclusion: </strong>The cartridge-based purification method provided higher radiochemical yield and molar activity as compared to the HPLC purification method.</p>","PeriodicalId":10991,"journal":{"name":"Current radiopharmaceuticals","volume":" ","pages":"216-223"},"PeriodicalIF":1.2000,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Current radiopharmaceuticals","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.2174/0118744710341203250220042349","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"PHARMACOLOGY & PHARMACY","Score":null,"Total":0}
引用次数: 0
Abstract
Introduction: Many studies have reported translocator protein (TSPO) overexpression in various neurological disorders. Carbon-11[11C]PBR28 is a widely used TSPO Positron Emission Tomography (PET) radiopharmaceutical. We compared HPLC-based purification with cartridge-based purification and performed PET-MR imaging in ALS patients.
Methods: [11C]PBR28 was synthesized using both an HPLC-based and cartridge-based purification technique on the FX2C chemistry module. We injected 350 ± 20 MBq of the [11C]PBR28 intravenously into the patients diagnosed with amyotrophic lateral syndrome (ALS) limb onset (n =3) and bulbar (n =3). Simultaneous PET-MR dynamic imaging was then performed.
Results: The radiochemical purity exceeded 95% with both methods. Using the HPLC-based method, the radiochemical yield was 11.8 ± 3.3%, molar activity was 253 ± 20.9 GBq/μmol, and the total synthesis time of 25 ± 2 minutes. In contrast, the cartridge-based method yielded a radiochemical yield of 53.0 ± 3.6%, a molar activity of 885 ± 17.7 GBq/μmol, and a total synthesis time of 12 ± 2 minutes. In imaging results, higher activity was observed in the precentral gyrus and cerebellum at 2.5 ± 0.5 minutes in bulbar-onset ALS cases, with a standardized uptake value (SUV) of 2.3 ± 0.3. In contrast, limb-onset ALS cases showed the highest uptake at 0.5 ± 0.2 minutes, with an SUV of 1.5 ± 0.2.
Discussion: The difference in SUV in bulbar and limb onset may be due to pathological changes.
Conclusion: The cartridge-based purification method provided higher radiochemical yield and molar activity as compared to the HPLC purification method.