Pharmacokinetic enhancements of bifunctional chelates and uses thereof

A method of radiation treatment planning or radiation treatment, wherein the method comprises administering to a subject in need thereof an effective amount of a compound having the structure of Formula I:

• A-L1-(L2)n-B Formula I
• wherein A is chelating moiety or a metal complex thereof;
• L1 is optionally substituted C1-C6 alkyl, substituted C1-C6 heteroalkyl, substituted aryl or heteroaryl;
• B is a is a therapeutic moiety, a targeting moiety, or cross-linking group,
• or a pharmaceutically acceptable salt thereof;
• n is 1-5;
• each L2, independently, has the structure:
• (—X1-L3-Z1—) Formula II
• wherein is X1 is C═O(NR1), C═S(NR1), OC═O(NR1), NR1C═O(O), NR1C═O(NR1), —CH2PhC═O(NR1), —CH2Ph(NH)C═S(NR1), O, NR1 and R1 is H or optionally substituted C1-C6 alkyl or optionally substituted C1-C6 heteroalkyl, substituted aryl or heteroaryl;
• L3 is optionally substituted C1-C50 alkyl or optionally substituted C1-C50 heteroalkyl or C5-C20 polyethylene glycol;
• Z1 is CH2, C═O, C═S, OC═O, NR1C═O, NR1;
• and
• R1 is a hydrogen or optionally substituted C1-C6 alkyl, pyrrolidine-2,5-dione.