Summary

This report describes a case of a 54-year-old man who underwent lutetium-177-PSMA therapy in the setting of metastatic castration-resistant prostate cancer (mCRPC) in the University Medical Center Utrecht. Following administration of the second cycle, patient presented with a slowly impairing, bilateral visual loss. This clinical presentation was most likely the result of the high intracranial pressure due to impediment of cerebrospinal fluid circulation, possibly related to obstructive dural thickness, being either caused by dural and/or leptomeningeal metastases of advanced mCRPC or by local radiation effects following lutetium-177-PSMA therapy. Describing this case, we aim to add to the discussion on ¹⁷⁷Lu-PSMA safety, in which prospective research will ultimately offer definite answers.