Radiation exposure risk from ¹⁷⁷Lu-PSMA-617 in hematuric patients

T he recent Health Canada approval of 177 Lu-PSMA-617 (Pluvicto ® ) represents an important advancement in the treatment of metastatic castration-resistant prostate cancer.This radioligand therapy, which delivers β-particle radiation to prostate-specific membrane antigen (PSMA)expressing cells, has demonstrated improved outcomes in trials such as VISION and PSMAfore.1,2 While primarily managed by medical oncology and nuclear medicine, urologists are increasingly encountering patients receiving this therapy, particularly in inpatient settings, where catheter care may be required.Given the radioactive nature of the compound and its renal clearance, there is a pressing need to evaluate radiation exposure risks to healthcare providers in scenarios involving hematuria and catheter irrigation.Dosimetry data shows that 177 LuPSMA617 delivers modest but meaningful radiation doses to nonmalignant tissues, with implications for both patient safety and exposure to healthcare workers.In a recent systematic review and meta-analysis, Ells et al reported median absorbed doses per GBq of 177 LuPSMA617 as follows: kidneys (0.55 Gy), salivary glands (0.81 Gy), lacrimal glands (2.26 Gy), and bone marrow (0.03 Gy). 3 With the standard Canadian dose of 7.4 GBq per cycle, this translates to organ doses of approximately 4.1 Gy to kidneys, 6.0 Gy to salivary glands, and over 16.7 Gy to lacrimal glands per cycle, explaining common side effects such as xerostomia and dry eyes.These findings underscore the preferential accumulation of radiation in excretory and secretory tissues.