Treatment related mortality was : 2.9 % ( exact 95 % confidence interval [ CI ] 0.36-10 .2 % ) and 1.7 % ( exact 95 % CI 0.043-9 .1 % ) for the Concurrent and Sequential group respectively ; relative risk ( RR ) 1.25 ; ( 95 % CI 0.55 , 2.84 ) .