Nucl Med Mol Imaging.  2010 Dec;44(4):252-260.

Radiation Safety Issues in Y-90 Microsphere Selective Hepatic Radioembolization Therapy: Possible Radiation Exposure from the Patients

• Kim YC
• Kim YH
• Uhm SH
• Seo YS
• Park EK
• Oh SY
• Jeong E
• Lee S
• Choe JG

Abstract

PURPOSE
The purpose of this study was to estimate the possible external radiation dose to other individuals from patients treated with Y-90 resin microspheres for unresectable hepatocellular carcinoma.
METHODS
We designed the study prospectively to estimate the possible radiation dose to other individuals from patients who had been treated with Y-90 microspheres for unresectable hepatocellular carcinoma. We estimated the total effective dose equivalent (TEDE) using two methods: 'theoretical' TEDEs according to the administered activity and 'measured' TEDE based on the 'measured' ambient radiation exposure rate.We compared the results from each method to determine when we can release patients from confinement at the earliest time complying with the patient release criteria.
RESULTS
A total of 20 administrations of Y-90 resin microspheres were done in 18 patients. The average administered activity was 1.2+/-0.77 (0.28-2.97) GBq. The 'theoretical' TEDEs were in the range of 0.8-10 microSv. The 'measured' TEDEs were in the range of 2.31-185 microSv. The measured TEDEs tend to be higher than the theoretical TEDEs. The values of theoretical and measured TEDE were both far less than 1 mSv, the upper limit at which the licensee can release a patient without any written documents.
CONCLUSION
The effective dose equivalent caused by the Y-90 microsphere administered patient is very low. It is safe in terms of radiation safety to the other individuals when Y-90 microsphere radioembolization therapy is done with dose less than 3 GBq. Because the measured TEDE tends to be higher than the theoretical TEDE, it is recommended to use 'measured' TEDE for determining patient release.

Keyword

Radiation safety; Y-90 microsphere; Selective hepatic radio-embolization therapy; Liver tumor; Hepatocellular carcinoma

MeSH Terms

Carcinoma, Hepatocellular
Humans
Licensure
Microspheres
Prospective Studies