Carboranylporphyrins for boron neutron capture therapy of cancer.

A major challenge for cancer treatment is the preferential and irreversible killing of tumor cells and minimal damage of normal tissues, both in the site of the malignancy and in the body. The agents used in boron neutron capture therapy (BNCT) are supposed to have the following advantages over many conventional chemotherapeutics: 1) when irradiated with thermal neutrons, an unstable isotope (11)B is formed whose rapid decay yields local and a thermal effect; 2) because the free path of the released particles is close to the cell diameter, the tissues outside the tumor should gain less damage; 3) local radioactivity and heat should be harmful for cells that, in the course of their natural history, acquired the determinants of altered response to many toxic stimuli. However, a higher specificity of damage would be achieved if the drugs accumulate mostly in cancer cells rather than in non-malignant counterparts.