Investigation in Effect of Fourfold Parameters on Preparation of 166ho Radiopharmaceutical

Radiopharmaceuticals are now increasingly used for therapy of cancer, palliation of pain secondary to bone metastasis and for the treatment of rheumatoid arthritis. 165ho (n,γ) 166ho is currently used for radiotherapy due to its attractive properties which include emission of high energy ß- particles (eß-1=1855 kev (51%), eß-2=1776 kev (48%) and eave =666 kev), an appropriate physical half- life of 26.4 h and decay to stable daughter. in this research holmium oxide (ho2o3, purity > 99.9%) was irradiated in tehran research reactor (trr) and four parameters mass, thermal neutron flux (ф), bombarding time (tb) and cooling time (tc) were investigated. the best conditions for producing of 166ho were achieved (m=2 mg, ф=5.7~1013 n/cm2.s, tb=8 h, tc=40 h, correction factor 92%).