Utilization of Chemical Deposition Technique for Preparation of Miniature 170 Tm Sources and Preliminary Quality Assessment for Potential Use in Brachytherapy.

OBJECTIVE: This article describes the preparation of a 170 Tm source by chemical deposition technique, its encapsulation in a titanium holder, and preliminary quality evaluation for potential utility as a brachytherapy source.

METHODS: The procedure consisted of electrodeposition of Ni on a Cu wire followed by chemical deposition of 170 Tm on it. Influence of feed solution pH, carrier Tm concentration, and reaction time were studied for optimum deposition of 170 Tm on substrate. After sealing the source core in a titanium capsule, quality control tests were performed. Distribution of 170 Tm on substrate was evaluated by autoradiography. Inactive Tm source was characterized by scanning electron microscope (SEM) and energy-dispersive X-ray (EDS) analyses.

RESULTS: Under optimized conditions (pH 5, 10 μg Tm carrier, 5 h), 170 Tm source core could be prepared by deposition of >95% of 170 Tm radioactivity on substrate. Swipe tests and immersion tests on encapsulated sources confirmed that removable radioactivity and radioactivity leakage levels were within stipulated limits. Autoradiography of 170 Tm source confirmed uniformity of radioactivity distribution. While SEM analysis confirmed good adhesion of Tm on substrate, EDS analysis confirmed elemental constituents of the Tm-deposited substrate.

CONCLUSION: The objective of preparing a 170 Tm source by chemical deposition for potential brachytherapy applications could be successfully achieved.