Is Hypoxia a Factor Influencing PSMA-Directed Radioligand Therapy?-An In Silico Study on the Role of Chronic Hypoxia in Prostate Cancer.

Birindelli, Gabriele; Drobnjakovic, Milos; Morath, Volker; Steiger, Katja; D'Alessandria, Calogero; Gourni, Eleni; Afshar-Oromieh, Ali; Weber, Wolfgang; Rominger, Axel; Eiber, Matthias; Shi, Kuangyu (2021). Is Hypoxia a Factor Influencing PSMA-Directed Radioligand Therapy?-An In Silico Study on the Role of Chronic Hypoxia in Prostate Cancer. Cancers, 13(14) MDPI AG 10.3390/cancers13143429

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Radioligand therapy (RLT) targeting prostate specific-membrane antigen (PSMA) is an emerging treatment for metastatic castration-resistant prostate cancer (mCRPC). It administrates 225Ac- or 177Lu-labeled ligands for the targeted killing of tumor cells. Differently from X- or γ-ray, for the emitted α or β particles the ionization of the DNA molecule is less dependent on the tissue oxygenation status. Furthermore, the diffusion range of electrons in a tumor is much larger than the volume typically spanned by hypoxic regions. Therefore, hypoxia is less investigated as an influential factor for PSMA-directed RLT, in particular with β emitters. This study proposes an in silico approach to theoretically investigate the influence of tumor hypoxia on the PSMA-directed RLT. Based on mice histology images, the distribution of the radiopharmaceuticals was simulated with an in silico PBPK-based convection-reaction-diffusion model. Three anti-CD31 immunohistochemistry slices were used to simulate the tumor microenvironment. Ten regions of interest with varying hypoxia severity were analyzed. A kernel-based method was developed for dose calculation. The cell survival probability was calculated according to the linear-quadratic model. The statistical analysis performed on all the regions of interest (ROIs) shows more heterogeneous dose distributions obtained with 225Ac compared to 177Lu. The higher homogeneity of 177Lu-PSMA-ligand treatment is due to the larger range covered by the emitted β particles. The dose-to-tissue histogram (DTH) metric shows that in poorly vascularized ROIs only 10% of radiobiological hypoxic tissue receives the target dose using 177Lu-PSMA-ligand treatment. This percentage drops down to 5% using 225Ac. In highly vascularized ROIs, the percentage of hypoxic tissue receiving the target dose increases to more than 85% and 65% for the 177Lu and 225Ac-PSMA-ligands, respectively. The in silico study demonstrated that the reduced vascularization of the tumor strongly influences the dose delivered by PSMA-directed RLT, especially in hypoxic regions and consequently the treatment outcome.

Item Type:

Journal Article (Original Article)


04 Faculty of Medicine > Department of Radiology, Neuroradiology and Nuclear Medicine (DRNN) > Clinic of Nuclear Medicine

UniBE Contributor:

Birindelli, Gabriele; Gourni, Eleni; Afshar Oromieh, Ali; Rominger, Axel Oliver and Shi, Kuangyu


600 Technology > 610 Medicine & health








Daria Vogelsang

Date Deposited:

05 Jan 2022 08:25

Last Modified:

05 Jan 2022 08:25

Publisher DOI:


PubMed ID:


Uncontrolled Keywords:

convection–reaction–diffusion models dosimetry hypoxia radiobiology radioligand therapy tumor microenvironment




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