Boron neutron capture therapy (bnct) probe

A compound represented by the following General Formula (I) or a salt thereof.

• in the formula,
• X is selected from the group consisting of a fluorine atom, an ester group (—OC(═O)—R′), a carbonate group (—OCO2—R′), a carbamate group (—OCONH—R′), phosphoric acid and an ester group thereof (—OP(═O)(—OR′)(—OR″)), and sulfuric acid and an ester group thereof (—OSO2—OR′),
• where R′ and R″ are each independently selected from a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group;
• Y is —NH—CO-L, —NH-L′, or —OL′,
• where L is a partial structure of an amino acid,
• L′is a saccharide or a partial structure of a saccharide, a saccharide having a self-cleaving linker, or an amino acid or a peptide having a self-cleaving linker;
• R1 and R2 are each independently selected from a hydrogen atom or a monovalent substituent;
• R3 is a hydrogen atom or one to three identical or different monovalent substituents present on a benzene ring;
• Z represents a single bond or a linking group;
• and
• B represents a group containing 10B.