Skip to content
DraconiticResearch
Search Sources API
203,234 studies31 sourcesUpdated 58 min ago
Peer-reviewedCC BY 4.0European Journal of Nuclear Medicine and Molecular Imaging

Organ and tumor dosimetry of [161Tb]Tb-PSMA-617 radioligand therapy in patients with mCRPC

  • Andrea Schaefer-Schuler1
  • Arne Blickle1
  • Sebastian Ganz1
  • Sven Petto1
  • Caroline Burgard1
  • Tilman Speicher1
  • Moritz B. Bastian1
  • Stephan Maus1
  • Mark Bartholomä1
  • Samer Ezziddin1
  • Florian Rosar1,2
  1. 1Department of Nuclear Medicine, Saarland University - Medical Center, Kirrberger Str. 100, Geb. 50, D-66421 Homburg, Germany
  2. 2Department of Nuclear Medicine, Friedrich-Alexander-Universität Erlangen Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany
Read full textPDFDOICite

Abstract

Purpose: Terbium-161 (161Tb) has emerged as a promising radionuclide for radioligand therapy (RLT) due to its emission of Auger and conversion electrons, which may support therapeutic efficacy through increased local energy deposition. Despite growing research efforts aimed at the clinical potential of 161Tb, dosimetric data, particularly for tumor lesions, remain scarce. To address this gap, we assessed tumor and organ dosimetry in mCRPC patients treated with [161Tb]Tb-PSMA-617.

Methods: The study involved n = 15 patients with metastasized castration-resistant prostate cancer (mCRPC) participating in a registry (NCT04833517) and receiving [161Tb]Tb-PSMA-617. All patients received a median of 2 (range: 1–3) cycles with mean administered activity of 6.0 ± 1.3 GBq and mean cumulative activity of 12.3 ± 4.6 GBq [161Tb]Tb-PSMA-617. Hybrid dosimetry of organs at risk, including the salivary glands, the kidneys, the liver, and tumor lesions was performed analyzing whole-body planar and SPECT/CT images. Absorbed doses were estimated using OLINDA/EXM for 161Tb. Tumor-to-organ ratios (TR) of mean tumor-absorbed doses over relevant organs at risk were calculated.

Results: Mean absorbed dose to kidneys, parotid glands, submandibular glands and liver was 0.70 ± 0.41 Gy/GBq, 0.40 ± 0.20 Gy/GBq, 0.36 ± 0.14 Gy/GBq and 0.13 ± 0.08 Gy/GBq, respectively. Tumor kinetics in 43 lesions demonstrated stable activity over time (mean half-life of all lesions: 44.07 h ± 15.88 h) delivering a mean overall absorbed tumor dose of 5.95 ± 3.60 Gy/GBq, the resulting TR over kidney and parotid gland were 10.55 ± 8.32 and 16.15 ± 11.85, respectively.

Conclusion: [161Tb]Tb-PSMA-617 delivers high tumor-absorbed doses with tolerable doses to relevant organs at risk, translating into favorable tumor-to-normal-organ ratios. Dosimetry results confirm 161Tb as a promising radionuclide for PSMA-targeted radioligand therapy in mCRPC.

Supplementary Information: The online version contains supplementary material available at https://doi.org/10.1007/s00259-026-08171-z.

Related

  1. Prognostic Value of Baseline High-Uptake PSMA Tumor Volume Fraction in Metastatic Castration-Resistant Prostate Cancer Patients Treated with [177Lu]Lu-PSMA Radioligand Therapy
    Marco Cuzzocrea, Giovanna Pecoraro, Cesare Michele Iacovitti +5
    CancersPeer-reviewedCC BY 4.0Full textMedical imaging & radiologyCrossrefEurope PMC
  2. Impact of Realistic 3D Tumor Microarchitecture on Cellular Dosimetry and Radiobiological Response in Targeted Radionuclide Therapy
    T. A. Peirispulle, R. Ware, S. Korevaar +3
    bioRxivPreprintCC BYFull textOncologybioRxiv
  3. Is Eligibility Enough? Pretreatment Prediction of Failure to Reach a Second Cycle of [177Lu]Lu-PSMA Radioligand Therapy
    Halim Özçevik, Enes Mustafa Kaya, Burcu Esen Akkaş +6
    Diagnostics (Basel, Switzerland)Peer-reviewedCC BYFull textGeneral medicineEurope PMC
  4. Targeted radioligand therapy in oncology: clinical development across targets and platforms
    Jiaxin An, Xiaolei Meng, Lara Hathout +5
    Frontiers in OncologyPeer-reviewedCC BY 4.0Full textMedical imaging & radiologyCrossref
  5. Treatment Sequencing in ARPI-Pre-Exposed Metastatic Castration-Resistant Prostate Cancer: Radioligand Therapy, PARP Inhibitors, and Antibody-Drug Conjugates.
    Baha Sharaf, Mohammad Al-Rwashdeh, Osama El Khatib +6
    CancersPeer-reviewedCC BYFull textOncologyEurope PMC

Cite

BibTeXRIS
BibTeX
@article{schaeferschuler2026organ,
  title = {{Organ and tumor dosimetry of [161Tb]Tb-PSMA-617 radioligand therapy in patients with mCRPC}},
  author = {Andrea Schaefer-Schuler and Arne Blickle and Sebastian Ganz and Sven Petto and Caroline Burgard and Tilman Speicher and Moritz B. Bastian and Stephan Maus and Mark Bartholomä and Samer Ezziddin and Florian Rosar},
  journal = {European Journal of Nuclear Medicine and Molecular Imaging},
  year = {2026},
  month = sep,
  doi = {10.1007/s00259-026-08171-z},
  url = {https://doi.org/10.1007/s00259-026-08171-z},
  note = {CC BY 4.0},
}
RIS
TY  - JOUR
TI  - Organ and tumor dosimetry of [161Tb]Tb-PSMA-617 radioligand therapy in patients with mCRPC
AU  - Andrea Schaefer-Schuler
AU  - Arne Blickle
AU  - Sebastian Ganz
AU  - Sven Petto
AU  - Caroline Burgard
AU  - Tilman Speicher
AU  - Moritz B. Bastian
AU  - Stephan Maus
AU  - Mark Bartholomä
AU  - Samer Ezziddin
AU  - Florian Rosar
PY  - 2026
DA  - 2026/09/08
JO  - European Journal of Nuclear Medicine and Molecular Imaging
DO  - 10.1007/s00259-026-08171-z
UR  - https://doi.org/10.1007/s00259-026-08171-z
AB  - Purpose: Terbium-161 (161Tb) has emerged as a promising radionuclide for radioligand therapy (RLT) due to its emission of Auger and conversion electrons, which may support therapeutic efficacy through increased local energy deposition. Despite growing research efforts aimed at the clinical potential of 161Tb, dosimetric data, particularly for tumor lesions, remain scarce. To address this gap, we assessed tumor and organ dosimetry in mCRPC patients treated with [161Tb]Tb-PSMA-617.  Methods: The study involved n = 15 patients with metastasized castration-resistant prostate cancer (mCRPC) participating in a registry (NCT04833517) and receiving [161Tb]Tb-PSMA-617. All patients received a median of 2 (range: 1–3) cycles with mean administered activity of 6.0 ± 1.3 GBq and mean cumulative activity of 12.3 ± 4.6 GBq [161Tb]Tb-PSMA-617. Hybrid dosimetry of organs at risk, including the salivary glands, the kidneys, the liver, and tumor lesions was performed analyzing whole-body planar and SPECT/CT images. Absorbed doses were estimated using OLINDA/EXM for 161Tb. Tumor-to-organ ratios (TR) of mean tumor-absorbed doses over relevant organs at risk were calculated.  Results: Mean absorbed dose to kidneys, parotid glands, submandibular glands and liver was 0.70 ± 0.41 Gy/GBq, 0.40 ± 0.20 Gy/GBq, 0.36 ± 0.14 Gy/GBq and 0.13 ± 0.08 Gy/GBq, respectively. Tumor kinetics in 43 lesions demonstrated stable activity over time (mean half-life of all lesions: 44.07 h ± 15.88 h) delivering a mean overall absorbed tumor dose of 5.95 ± 3.60 Gy/GBq, the resulting TR over kidney and parotid gland were 10.55 ± 8.32 and 16.15 ± 11.85, respectively.  Conclusion: [161Tb]Tb-PSMA-617 delivers high tumor-absorbed doses with tolerable doses to relevant organs at risk, translating into favorable tumor-to-normal-organ ratios. Dosimetry results confirm 161Tb as a promising radionuclide for PSMA-targeted radioligand therapy in mCRPC.  Supplementary Information: The online version contains supplementary material available at https://doi.org/10.1007/s00259-026-08171-z.
SN  - 1619-7070
SN  - 1619-7089
ER  -