A composition comprising a non-sealed, pharmaceutically acceptable, radioactive composition of the formula Qq-Tt-Aa-Bb-Cc-Rr Formula (I) wherein: Q is a substrate of a different material from the entity Aa-Bb-Cc , in which said substrate has the Aa-Bb-Cc entity deposited or adhered thereto； and is an injectable or implantable substrate that is pharmaceutically acceptable or can be coated to be pharmaceutically acceptable； q is equal to 1 or 0, where 1 means that the entity is present and 0 means that the entity is not present； T is an iron hydroxide, iron oxide, gadolinium hydroxide or non-radioactive gadolinium oxide； t is equal to 1 or 0, where 1 means that the entity is present and 0 means that the entity is not present； A is JvM * w (OH) x (CO3) and (AN) z * nH2O, where: J is a lanthanide metal ion capable of forming hydroxycarbonate compounds； v is greater than or equal to 0； M * is Sm-153, Ho-166, Y-90 or Lu-177 radioactive or mixtures thereof, in which its respective non-radioactive metal of the rare earth type is usually present； w, x and y are each independently greater than 0； AN is a pharmaceutically acceptable anionic structural unit； and z and n are each independently greater than or equal to 0； a is equal to 1 or 0, where 1 means that the entity is present and 0 means that the entity is not present； B is M * w (OH) x (CO3) and * nH2O, where: M * is radioactive Sm-153, Ho-166, Y-90 or Lu-177 or mixtures thereof, in which it is usually present their respective non-radioactive metal of the rare earth type； w, x and y are each independently greater than 0； and n is greater than or equal to 0； b is equal to 1 or 0, where 1 means that the entity is present and 0 means that the entity is not present； C is Sn (L) u- {Mw (OH) x (CO3) and * nH2O} p, where: Sn is radioactive tin (IV) -117m but also contains non-radioactive tin isotopes； L is hydrated oxide, hydroxide or oxyhydroxide such that Sn (L) u is stannic oxide, stannic hydroxide or hydrated stannic oxyhyd
