Newly diagnosed high-risk localized prostate cancer after multiple [177Lu]Lu-PSMA radioligand therapy in the context of metastatic parotid carcinoma: a case report.

Prostate-specific membrane antigen-direct radioligand therapy (PSMA RLT) is primarily used to treat castration-resistant metastatic prostate cancer (PCa) after prior treatment options have been exhausted. Occasionally, other tumor entities, such as parotid carcinoma in this case, also express prostate-specific membrane antigen (PSMA) on their cell surface.

We present the case of a white 67-year-old patient newly diagnosed with locally advanced PCa despite multiple cycles of Lutetium-177-labeled prostate-specific membrane antigen radioligand therapy ([177Lu]Lu-PSMA-RLT), which he had received for metastatic parotid carcinoma. Interestingly, no regressive histopathological changes were found in the prostate biopsy specimen, despite given PSMA-expression in the prostate.

The potential selection of high-grade disease, which appears to have occurred in this patient, underscores the need for further large-scale histopathological examination and thorough follow-up of the current investigational approaches using [177Lu]Lu-PSMA-RLT in high-risk prostate cancer (PCa).

Journal of medical case reports. 2026 Jul 06*** epublish ***

Christopher Orf, Analena Elisa Handke, Joachim Noldus, Florian Roghmann, Martina Dellino, Karl H Tully

Department of Urology and Neurourology, Ruhr-University Bochum, Marien Hospital Herne, Hölkeskampring 40, 44625, Herne, Germany. ., Department of Urology and Neurourology, Ruhr-University Bochum, Marien Hospital Herne, Hölkeskampring 40, 44625, Herne, Germany.