Scholarlink

Background <p>In clinical practice, several radiopharmaceuticals are used for PSMA-PET imaging, each with distinct biodistribution patterns. This may impact treatment decisions and outcomes, as eligibility for PSMA-directed radioligand therapy is usually assessed by comparing tumoral uptake to normal liver uptake as a reference. In this study, we aimed to compare tracer uptake intraindividually in various reference regions including liver, parotid gland and spleen as well as the respective tumor-to-background ratios (TBR) of different <sup>18</sup>F-labeled PSMA ligands to today’s standard radiopharmaceutical <sup>68</sup>Ga-PSMA-11 in a series of patients with biochemical recurrence of prostate cancer who underwent a dual PSMA-PET examination as part of an individualized diagnostic approach.</p> Results <p>Differences in background activity among different PSMA-PET tracers lead to variations in tumor-to-background ratios (TBR). In [<sup>18</sup>F]F-DCFPyL-PET, TBR with the liver as the reference organ (TBR<sub>liver</sub>) was comparable to [<sup>68</sup>Ga]Ga-PSMA-11-PET, while [<sup>18</sup>F]F-PSMA-1007-PET and [<sup>18</sup>F]F-JK-PSMA-7-PET showed significantly lower values. Using the parotid gland as the reference (TBR<sub>parotidgland</sub>), [<sup>18</sup>F]F-DCFPyL-PET exhibited significantly higher values, whereas [<sup>18</sup>F]F-PSMA-1007-PET and [<sup>18</sup>F]F-JK-PSMA-7-PET were comparable. For the spleen (TBR<sub>spleen</sub>), [<sup>18</sup>F]F-JK-PSMA-7-PET was comparable, but [<sup>18</sup>F]F-DCFPyL-PET and [<sup>18</sup>F]F-PSMA-1007-PET showed significantly higher and lower values, respectively. An additional Bland-Altman analyses revealed low bias for [<sup>18</sup>F]F-DCFPyL-PET in TBR<sub>parotidgland</sub>, whereas significant differences in TBR<sub>liver</sub> and TBR<sub>spleen</sub> for the other tracers resulted in higher bias.</p> Conclusion <p>Different PSMA-PET tracers exhibit distinct biodistribution patterns, leading to variations in tumor-to-background ratios (TBR) in reference organs such as the liver, parotid gland, and spleen. Patient selection for PSMA-directed radioligand therapy is currently based on a semiquantitative approach using the liver as a reference region in [<sup>68</sup>Ga]Ga-PSMA-11-PET. Thus, the use of alternative [<sup>18</sup>F]-labeled tracers may result in under- or overestimation of a patient’s suitability for therapy. This highlights the importance of a comprehensive understanding of the differences in tracer-specific uptake behavior for accurate decisions regarding PSMA-expression levels. However, as the patient cohort in this study is at earlier disease stages, the generalizability of these findings to later-stage patients remains unclear and requires further investigation.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Do you know your PSMA-tracer? Variability in the biodistribution of different PSMA ligands and its potential impact on defining PSMA-positivity prior to PSMA-targeted therapy

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年1月10日

查看全文
  • Jan Heilinger,
  • Katrin Sabine Roth,
  • Henning Weis,
  • Antonis Fink,
  • Jasmin Weindler,
  • Felix Dietlein,
  • Philipp Krapf,
  • Klaus Schomäcker,
  • Bernd Neumaier,
  • Markus Dietlein,
  • Alexander Drzezga,
  • Carsten Kobe

摘要

Background

In clinical practice, several radiopharmaceuticals are used for PSMA-PET imaging, each with distinct biodistribution patterns. This may impact treatment decisions and outcomes, as eligibility for PSMA-directed radioligand therapy is usually assessed by comparing tumoral uptake to normal liver uptake as a reference. In this study, we aimed to compare tracer uptake intraindividually in various reference regions including liver, parotid gland and spleen as well as the respective tumor-to-background ratios (TBR) of different 18F-labeled PSMA ligands to today’s standard radiopharmaceutical 68Ga-PSMA-11 in a series of patients with biochemical recurrence of prostate cancer who underwent a dual PSMA-PET examination as part of an individualized diagnostic approach.

Results

Differences in background activity among different PSMA-PET tracers lead to variations in tumor-to-background ratios (TBR). In [18F]F-DCFPyL-PET, TBR with the liver as the reference organ (TBRliver) was comparable to [68Ga]Ga-PSMA-11-PET, while [18F]F-PSMA-1007-PET and [18F]F-JK-PSMA-7-PET showed significantly lower values. Using the parotid gland as the reference (TBRparotidgland), [18F]F-DCFPyL-PET exhibited significantly higher values, whereas [18F]F-PSMA-1007-PET and [18F]F-JK-PSMA-7-PET were comparable. For the spleen (TBRspleen), [18F]F-JK-PSMA-7-PET was comparable, but [18F]F-DCFPyL-PET and [18F]F-PSMA-1007-PET showed significantly higher and lower values, respectively. An additional Bland-Altman analyses revealed low bias for [18F]F-DCFPyL-PET in TBRparotidgland, whereas significant differences in TBRliver and TBRspleen for the other tracers resulted in higher bias.

Conclusion

Different PSMA-PET tracers exhibit distinct biodistribution patterns, leading to variations in tumor-to-background ratios (TBR) in reference organs such as the liver, parotid gland, and spleen. Patient selection for PSMA-directed radioligand therapy is currently based on a semiquantitative approach using the liver as a reference region in [68Ga]Ga-PSMA-11-PET. Thus, the use of alternative [18F]-labeled tracers may result in under- or overestimation of a patient’s suitability for therapy. This highlights the importance of a comprehensive understanding of the differences in tracer-specific uptake behavior for accurate decisions regarding PSMA-expression levels. However, as the patient cohort in this study is at earlier disease stages, the generalizability of these findings to later-stage patients remains unclear and requires further investigation.