ium ▁from ▁b arium ▁during ▁the ▁extra ction ▁of ▁rad ium ▁from ▁pitch bl ende . ▁The ▁large ▁quantities ▁of ▁material ▁involved ▁( to ▁extract ▁a ▁gram ▁of ▁pure ▁rad ium ▁metal , about ▁ 7 ▁t onnes ▁of ▁pitch ben de ▁is ▁required ) ▁favour ▁this ▁less ▁cost ly ▁( but ▁less ▁efficient ) ▁method ▁over ▁those ▁based ▁on ▁rad ium ▁b rom ide ▁or ▁rad ium ▁chrom ate ▁( used ▁for ▁the ▁later ▁stages ▁of ▁the ▁separation ). ▁ ▁It ▁was ▁also ▁used ▁in ▁medicine ▁to ▁produce ▁rad on ▁gas ▁which ▁in ▁turn ▁was ▁used ▁as ▁a ▁bra chy ther ap ut ic ▁cancer ▁treatment . ▁ ▁Rad ium - 2 2 3 ▁dich lor ide ▁( US P , ▁rad ium ▁ch lor ide ▁Ra ▁ 2 2 3 ), ▁trad ename ▁X of igo ▁( former ly ▁Al ph ar adin ), ▁is ▁an ▁alpha - em itting ▁radi oph arma ce ut ical . ▁Bayer ▁received ▁F DA ▁appro val ▁for ▁this ▁drug ▁to ▁treat ▁pro state ▁cancer ▁o ste ob last ic ▁b one ▁met ast ases ▁in ▁May ▁ 2 0 1 3 . ▁Rad ium - 2 2 3 ▁ch lor ide ▁is ▁one ▁of ▁the ▁most ▁pot ent ▁dru gs ▁known . ▁One ▁do se ▁( 5 0 ▁kB q / kg ) ▁in ▁an ▁adult ▁is ▁about ▁ 6 0 ▁nan og rams ; ▁this ▁amount ▁is ▁ 1 / 1 0 0 0 ▁the ▁weight ▁of ▁an ▁e y el ash ▁(