Pathological fractures occurred in 30 ( 7 % ) of 425 patients assigned to 8 Gy and 20 ( 5 % ) of 425 assigned to 20 Gy ( odds ratio [ OR ] 154 , 95 % CI 085-275 ; p = 015 ) , and spinal cord or cauda equina compressions were reported in seven ( 2 % ) of 425 versus two ( < 1 % ) of 425 , respectively ( OR 354 , 95 % CI 073-1715 ; p = 0094 ) .