Orbital and brain metastases on 68Ga-PSMA PET/CT in a patient with prostate carcinoma refractory to 177Lu-PSMA and 225Ac-PSMA therapy

Document Type : Case report


Department of Nuclear Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India


We present a case of metastatic prostate cancer with rare metastases involving the brain and orbit, in addition to liver, skeletal and nodal metastases. The patient had undergone prior hormonal therapy and chemotherapy and had disease progression despite 2 cycles of 177Lu-Prostate specific membrane antigen (177Lu-PSMA) based radioligand therapy. He had a partial response after 2 cycles of 225Ac-PSMA based targeted alpha therapy, as demonstrated on the 68Ga-PSMA PET/CT study. However, the patient had disease progression at the end of 4 cycles of 225Ac-PSMA therapy, evident by rising prostate specific antigen levels and imaging findings. The end of treatment 68Ga-PSMA PET/CT showed additional sites of metastases in the orbit and brain apart from overall disease progression. These are rare sites of distant spread in prostate cancer and require urgent evaluation and local treatment to prevent potential complications. The importance of detection of metastatic sites in closed cavities is because of the requirement for urgent intervention to avoid compression related complications.


1. Perera M, Papa N, Roberts M, Williams M, Udovicich C, Vela I, et al. Gallium-68 Prostatespecific Membrane Antigen Positron Emission Tomography in Advanced Prostate Cancer— Updated Diagnostic Utility, Sensitivity, Specificity, and Distribution of Prostatespecific Membrane Antigen-avid Lesions: ASystematic Review and Meta-. Eur Urol. 2020; 77:403–17 .
2. Rousseau C, Le Thiec M, Ferrer L, Rusu D, Rauscher A, Maucherat B, et al. Preliminary results of a 68Ga-PSMA PET/CT prospective study in prostate cancer patients with occult recurrence: Diagnostic performance and impact on therapeutic decision-making. Prostate. 2019; 79:1514–22 .
3. Parihar AS, Vadi SK, Mittal BR, Kumar R, Bal A, Singh SK. 68Ga-PSMA-HBED-CC-avid synchronous urinary bladder paraganglioma in a patient with metastatic prostate carcinoma. Clin Nucl Med. 2018; 43:e329–30 .
4. Barbosa FG, Queiroz MA, Nunes RF, Viana PCC, Marin JFG, Cerri GG, et al. Revisiting prostate cancer recurrence with PSMA PET: Atlas of typical and atypical patterns of spread. Radiographics. 2019; 39:186–212 .
5. Parihar AS, Mittal BR, Sood A, Basher RK, Singh G. 68Ga-Prostate-Specific Membrane Antigen PET/CT and 18F-FDG PET/CT of Primary Signet Ring Cell Breast Adenocarcinoma. Clin Nucl Med. 2018; 43:e414–6 .
6. Parihar AS, Sood A, Mittal BR, Kumar R, Singh H, Dhatt SS. 68Ga-PSMA-HBED-CC PET/CT and 18F-FDG PET/CT in Ewing Sarcoma. Clin Nucl Med. 2020; 45:E57–8 .
7. Vadi SK, Kumar R, Mittal BR, Parihar AS, Singh SK. Unusual Case of Diffuse Penile Metastasis of Prostate Cancer on 68Ga PSMA PET/CT Imaging and 177Lu PSMA Posttherapy Scintigraphy. Clin Nucl Med. 2018; 43:276–8 .
8. Weiberg D, Radner H, Derlin T, Thon WF. Early Detection of Bilateral Testicular Metastases From Prostatic Adenocarcinoma Using 68Ga-PSMA Ligand PET/CT. Clin Nucl Med. 2017; 42 .
9. Gandaglia G, Abdollah F, Schiffmann J, Trudeau V, Shariat SF, Kim SP, et al. Distribution of metastatic sites in patients with prostate cancer: A population-based analysis. Prostate. 2014; 74:210–6 .
10. Ahmed M, Begum T. Orbital metastasis from prostate cancer. BMJ Case Rep. 2015: bcr2015211447
11. Kratochwil C, Giesel FL, Heussel CP, Kazdal D, Endris V, Nientiedt C, et al. Patients resistant against PSMA-targeting α-radiation therapy often harbor mutations in DNA damagerepair-associated genes. J Nucl Med. 2020; 61:683–8 .
12. Nonnekens J, van Kranenburg M, Beerens CEMT, Suker M, Doukas M, van Eijck CHJ, et al. Potentiation of peptide receptor radionuclide therapy by the PARP inhibitor olaparib. Theranostics. 2016; 6:1821–32 .
13. Ahmad SM, Esmaeli B. Metastatic tumors of the orbit and ocular adnexa. Curr Opin Ophthalmol. 2007; 18:405–13 .
14. Jain TK, Parihar AS, Sood A, Basher RK, Bollampally N, Shekhawat AS, et al. Orbital metastasis: Rare initial presentation of an occult gall bladder carcinoma. Clin Nucl Med. 2018; 43:188–9 .
15. Boldt HC, Nerad JA. Orbital Metastases from Prostate Carcinoma. Arch Ophthalmol. 1988; 106:1403–8 .
16. Wei X, Schlenkhoff C, Schwarz B, Essler M, Ahmadzadehfar H. Combination of 177LuPSMA-617 and external radiotherapy for the treatment of cerebral metastases in patients with castration-resistant metastatic prostate cancer. Clin Nucl Med. 2017; 42:704–6 .
17. Sathekge MM, Bruchertseifer F, Lawal IO, Vorster M, Knoesen O, Lengana T, et al. Treatment of brain metastases of castrationresistant prostate cancer with 225Ac-PSMA- 617. Eur J Nucl Med Mol Imaging. 2019; 46:1756–7 .