{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"omics_type":["Unknown"],"volume":["14(5)"],"submitter":["Schaefer-Schuler A"],"pubmed_abstract":["<b>Rationale:</b> Evaluation of alternative radionuclides for use in prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT) is currently focusing on <sup>161</sup>Tb, which may provide advantages by emitting additional Auger and conversion electrons. In this pilot study, we present preliminary dosimetry data for [<sup>161</sup>Tb]Tb-PSMA-617 RLT in a direct comparison with [<sup>177</sup>Lu]Lu-PSMA-617. <b>Method:</b> Six patients with metastatic castration-resistant prostate cancer (mCRPC) underwent treatment with [<sup>177</sup>Lu]Lu-PSMA-617 and subsequently - after inadequate response - with [<sup>161</sup>Tb]Tb-PSMA-617. Whole-body planar and SPECT imaging-based dosimetry of organs at risk (kidneys and salivary glands) and tumor lesions were calculated using IDAC for <sup>177</sup>Lu and OLINDA/EXM for <sup>161</sup>Tb. The therapeutic index (TI) of mean tumor-absorbed doses over relevant organs at risk was calculated. <b>Results:</b> Mean absorbed doses to organs at risk of PSMA-RLT were slightly higher for [<sup>161</sup>Tb]Tb-PSMA-617 compared to [<sup>177</sup>Lu]Lu-PSMA-617 (kidneys: 0.643 ± 0.247 vs. 0.545 ± 0.231 Gy/GBq, factor 1.18; parotid gland: 0.367 ± 0.198 vs. 0.329 ± 0.180 Gy/GBq, factor 1.10), but markedly higher regarding tumor lesions (6.10 ± 6.59 vs 2.59 ± 3.30 Gy/GBq, factor 2.40, <i>p</i> < 0.001). Consequently, the mean TI was higher for [<sup>161</sup>Tb]Tb-PSMA-617 compared to [<sup>177</sup>Lu]Lu-PSMA-617 for both, the kidneys (11.54 ± 9.74 vs. 5.28 ± 5.13, <i>p</i> = 0.002) and the parotid gland (16.77 ± 13.10 vs. 12.51 ± 18.09, <i>p</i> = 0.008). <b>Conclusion:</b> In this intra-individual head-to-head pilot study, [<sup>161</sup>Tb]Tb-PSMA-617 delivered higher tumor-absorbed doses and resulted in superior TI compared to [<sup>177</sup>Lu]Lu-PSMA-617. This preliminary data support <sup>161</sup>Tb as a promising radionuclide for PSMA-RLT in mCRPC."],"journal":["Theranostics"],"pagination":["1829-1840"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC10945337"],"repository":["biostudies-literature"],"pubmed_title":["[<sup>161</sup>Tb]Tb-PSMA-617 radioligand therapy in patients with mCRPC: preliminary dosimetry results and intra-individual head-to-head comparison to [<sup>177</sup>Lu]Lu-PSMA-617."],"pmcid":["PMC10945337"],"pubmed_authors":["Ezziddin S","Schaefer-Schuler A","Rosar F","Maus S","Petrescu C","Petto S","Blickle A","Stemler T","Burgard C","Bartholoma M"],"additional_accession":[]},"is_claimable":false,"name":"[<sup>161</sup>Tb]Tb-PSMA-617 radioligand therapy in patients with mCRPC: preliminary dosimetry results and intra-individual head-to-head comparison to [<sup>177</sup>Lu]Lu-PSMA-617.","description":"<b>Rationale:</b> Evaluation of alternative radionuclides for use in prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT) is currently focusing on <sup>161</sup>Tb, which may provide advantages by emitting additional Auger and conversion electrons. In this pilot study, we present preliminary dosimetry data for [<sup>161</sup>Tb]Tb-PSMA-617 RLT in a direct comparison with [<sup>177</sup>Lu]Lu-PSMA-617. <b>Method:</b> Six patients with metastatic castration-resistant prostate cancer (mCRPC) underwent treatment with [<sup>177</sup>Lu]Lu-PSMA-617 and subsequently - after inadequate response - with [<sup>161</sup>Tb]Tb-PSMA-617. Whole-body planar and SPECT imaging-based dosimetry of organs at risk (kidneys and salivary glands) and tumor lesions were calculated using IDAC for <sup>177</sup>Lu and OLINDA/EXM for <sup>161</sup>Tb. The therapeutic index (TI) of mean tumor-absorbed doses over relevant organs at risk was calculated. <b>Results:</b> Mean absorbed doses to organs at risk of PSMA-RLT were slightly higher for [<sup>161</sup>Tb]Tb-PSMA-617 compared to [<sup>177</sup>Lu]Lu-PSMA-617 (kidneys: 0.643 ± 0.247 vs. 0.545 ± 0.231 Gy/GBq, factor 1.18; parotid gland: 0.367 ± 0.198 vs. 0.329 ± 0.180 Gy/GBq, factor 1.10), but markedly higher regarding tumor lesions (6.10 ± 6.59 vs 2.59 ± 3.30 Gy/GBq, factor 2.40, <i>p</i> < 0.001). Consequently, the mean TI was higher for [<sup>161</sup>Tb]Tb-PSMA-617 compared to [<sup>177</sup>Lu]Lu-PSMA-617 for both, the kidneys (11.54 ± 9.74 vs. 5.28 ± 5.13, <i>p</i> = 0.002) and the parotid gland (16.77 ± 13.10 vs. 12.51 ± 18.09, <i>p</i> = 0.008). <b>Conclusion:</b> In this intra-individual head-to-head pilot study, [<sup>161</sup>Tb]Tb-PSMA-617 delivered higher tumor-absorbed doses and resulted in superior TI compared to [<sup>177</sup>Lu]Lu-PSMA-617. This preliminary data support <sup>161</sup>Tb as a promising radionuclide for PSMA-RLT in mCRPC.","dates":{"release":"2024-01-01T00:00:00Z","publication":"2024","modification":"2025-04-26T12:07:11.63Z","creation":"2025-04-06T13:55:48.424Z"},"accession":"S-EPMC10945337","cross_references":{"pubmed":["38505615"],"doi":["10.7150/thno.92273"]}}