Journal of Cancer Clinical Research

Boron Neutron Capture Therapy

Neutron capture therapy (NCT) is a nonsurgical therapeutic modality for treating locally invasive malignant tumors such as primary brain tumors, recurrent head and neck cancer, and cutaneous and extracutaneous melanomas. It is a two-step procedure: first, the patient is injected with a tumor-localizing drug containing the non-radioactive isotope boron-10 (10B), which has a high propensity to capture thermal neutrons.[1] The cross section of the 10B (3,837 barns) is many times greater than that of the other elements present in tissues such as hydrogen, oxygen, and nitrogen. In the second step, the patient is radiated with epithermal neutrons, the source of which is either a nuclear reactor or an accelerator. After losing energy as they penetrate tissue, the neutrons are captured by the 10B, which subsequently emits high-energy alpha particles that kill adjacent cells that have taken up sufficient quantities of 10B. All of the clinical experience to date with NCT is with the non-radioactive isotope boron-10, and this is known as boron neutron capture therapy (BNCT).[2] The use of other non-radioactive isotopes, such as gadolinium, has been limited to experimental studies and has not been used clinically. BNCT has been evaluated clinically as an alternative to conventional radiation therapy for the treatment of high-grade gliomas, meningiomas, and recurrent, locally advanced cancers of the head and neck region and superficial cutaneous and extracutaneous melanomas