
Keywords: 169 یب; 169Yb; Sol-gel; Microspheres; Brachytherapy; SEM; EDS; Leachability; BDL; below detection limit; BET theory; Brunauer, Emmette and Teller theory; BJH method; Barrett-Joyner-Halenda method; EDS; energy dispersive spectroscopy; EOB; end of bombardment