Post-treatment Radiation Safety Precautions for Lutetium-177 Vipivotide Tetraxetan

Lutetium-177 vipivotide tetraxetan (Pluvicto) was approved by the US Food and Drug Administration in 2022 for the treatment of adult patients with prostate-specific membrane antigen avidity for metastatic castration-resistant prostate cancer previously treated with androgen receptor blockers and taxane-based systemic therapy.

A team of researchers from the University of Texas MD Anderson Cancer Center compiled optimized methods for administering, imaging, and providing post-treatment radiation precautions for patients receiving Pluvicto.

Patients who are administered Pluvicto receive six 200 mCi (7.4 GBq) therapeutic cycles every 6 weeks. Prior to infusion, patients are hydrated with 250 mL of sterile 0.9% sodium chloride intravenously and are also given an intravenous antiemetic for 20 minutes. After the antiemetic, Pluvicto can be administered via a syringe, the gravity method, or a peristaltic pump.

Researchers tested all 3 methods of Pluvicto administration and found that the use of a peristaltic pump, which allows for a continuous infusion of the radiopharmaceutical while still adhering to the ALARA principle for personnel doses, is the safest option for patients. Infusing the radiopharmaceutical directly from the vial also eliminates unnecessary radiation exposure to staff, eliminates geometry effects when assaying the dose from a vial to a syringe, and reduces residual activity by eliminating additional materials used for the infusion.

After administration, radiation safety information should be given to patients based on specific criteria: the net dose administered, the patient’s living conditions, and a literature-based biexponential fit to the whole-body clearance curve. The length of time patients should sleep alone and avoid children and pregnant women should then be calculated, as well as the length of time until they are able to travel via mass transportation and return to work based on the US Nuclear Regulatory Commission Regulatory Guide 8.39.

Current conservative practice involves dividing the annual dose limits by 6 for each administration so that the combined therapeutic cycles remain under the dose limits.

In conclusion, a peristaltic pump is a safe and reliable method of infusion recommended for Pluvicto administration. Patient release instructions should be based on administered activity and a biexponential whole-body clearance model to stay below the annual dose limits over the course of all 6 cycles of treatment.