Long-lived gadolinium based tumor targeted imaging and therapy agents

A method for detecting or imaging one or more cancer tumor cells in a biological sample, comprising:

• (a) administering to a biological sample an effective amount of a compound having the formula:
• or a salt thereof, wherein:
• R1 comprises a chelating agent that is chelated to one or more gadolinium (Gd) atoms;
• a is 0 or 1;
• n is an integer from 12 to 30;
• m is 0 or 1;
• Y is selected from the group consisting of —H, —OH, —COOH, —COOX, —OCOX, and —OX, wherein X is an alkyl or an arylalkyl;
• R2 is selected from the group consisting of —N+H3, —N+H2Z, —N+HZ2, and —N+Z3, wherein each Z is independently an alkyl or an arylalkyl;
• and
• b is 1 or 2;
• and
• (b) identifying individual cells or regions within the biological sample that are emitting signals characteristic of gadolinium, whereby one or more cancer tumor cells are detected or imaged.

A method of treating cancer in a subject, comprising:

• (a) administering an effective amount of a compound to a subject having cancer, the compound having the formula:
• or a salt thereof, wherein:
• R1 comprises a chelating agent that is chelated to one or more gadolinium (Gd) atoms;
• a is 0 or 1;
• n is an integer from 12 to 30;
• m is 0 or 1;
• Y is selected from the group consisting of —H, —OH, —COOH, —COOX, —OCOX, and —OX, wherein X is an alkyl or an arylalkyl;
• R2 is selected from the group consisting of —N+H3, —N+H2Z, —N+HZ2, and —N+Z3, wherein each Z is independently an alkyl or an arylalkyl;
• and
• b is 1 or 2;
• (b) identifying individual cells or regions within the subject that are emitting signals characteristic of gadolinium;
• and
• (c) directing an external radiotherapy beam to the identified individual cells or regions within the subject.