PSMA Uptake in a Subdural Hematoma

Abstract

An 81-year-old man with known metastatic prostate cancer with recent biochemical progression underwent a PSMA PET/CT (18F-piflufolastat) for restaging. Review of the images demonstrated an acute or chronic left cerebral convexity subdural hematoma on CT with corresponding radiotracer activity throughout the collection on PET. Analysis of the patient’s prior imaging showed that this subdural hematoma had significantly increased in size when compared with a head CT obtained 2 months prior. The patient was referred to a nearby emergency department and underwent repeat imaging and subdural drain placement. Unfortunately, the patient died secondary to rapid reaccumulation of subdural blood products after intervention.

Subacute Cerebral Infarct

“…Increased PSMA uptake has been reported in subacute cerebral infarcts, [2][3][4] primary brain tumors such as gliomas and meningiomas and brain metastases of nonprostatic origin, [5][6][7] and intracranial hemorrhage. 8,9 A possible reason is increased endothelial PSMA expression in neovasculature, which would explain the positive uptake on the PSMA PET/CT in this patient, 2 weeks after the onset of neurological symptoms. Careful history and comparison with prior imaging are vital to avoid false-positive diagnosis in such patients.…”

Late Subacute Cerebral Hematoma Mimicking a Metastasis on PSMA PET/CT

“…1 In addition to prostate cancer metastases, PSMA uptake in the brain has been described with primary brain tumors (such as glioblastoma 2 and meningioma 3 ), metastases from other primary malignancies, 4 infections, 5 acute and subacute cerebral infarction, 6,7 and intracranial hematomas. [8][9][10] Caution is therefore recommended before labeling areas of brain uptake as sites of metastatic disease, and MRI should always be obtained for further characterization. Proposed mechanisms for PSMA uptake in cerebral infarction and hemorrhage include radiotracer accumulation due to disruption of the blood-brain barrier and reparative processes involving neovascularization.…”

“…Proposed mechanisms for PSMA uptake in cerebral infarction and hemorrhage include radiotracer accumulation due to disruption of the blood-brain barrier and reparative processes involving neovascularization. 7,11 Our case illustrates the first late subacute intraparenchymal brain hematoma presenting as an area of discrete PSMA uptake in the brain, with all prior reports of PSMA-avid intracranial hematomas corresponding to either acute or early subacute hemorrhages with detectable areas of hyperattenuation on CT. [8][9][10]…”

“…Brain metastases from prostate cancer are rare, with a recent large cohort study of patients undergoing PSMA PET/CT yielding an incidence of 0.18% 1 . In addition to prostate cancer metastases, PSMA uptake in the brain has been described with primary brain tumors (such as glioblastoma 2 and meningioma 3 ), metastases from other primary malignancies, 4 infections, 5 acute and subacute cerebral infarction, 6,7 and intracranial hematomas 8–10 . Caution is therefore recommended before labeling areas of brain uptake as sites of metastatic disease, and MRI should always be obtained for further characterization.…”