a in the absorbed dese to bone ser disintegration 2 90 Sr in cortical bone, . oul rads dis, Ss = the absorbed dose . rads dis Se 71 to bone per disintegration 705, in trabecular bone, ', the absorbed dose to bone per disintegration of 70 Y in cortical bone, . ol rads dis , Sy = the absorbed dose to bone per disintegration of 90 Y in trabecular bone, rads dis. EQUATIONS dN. sot OA + KN, + Py, N. 1 = N° P. ath + Kt . — 1 AP = (1) . (lee (Atk) ty (2) i f. vu, £ l oy q, = AN., (3) E, © RNA, (4) cal (pee ATK, . A+K 1 KX = (pee ATK) £) + 2 KX (3) 3 27