Boron Neutron Capture Therapy

A Paradigm Shift in Cancer Treatment

A paradigm shift in cancer treatment with high-level of selectivity

History of BNCT

Gordon Locher first proposed BNCT in 1936. Clinical investigation and treatments was first introduced in the USA in the 1950s and showed promising results. Historically, neutrons for BNCT were only available from the core of a nuclear reactor, which posed a significant barrier to clinical research and adoption as a practical cancer therapy.

Despite this challenge, approximately 2,000 patients have been treated at research sites worldwide and have shown encouraging results in the treatment of glioblastomas, head and neck2, and other challenging cancers.

Now, a renaissance in BNCT is occurring with the availability of new accelerator-based neutrons sources and boron-10 target drugs, allowing clinical research to expand with the goal to have BNCT available as a new treatment option for patients everywhere.

How it Works

BNCT is a targeted, non-invasive, two-step procedure designed to treat the most difficult and inoperable cancers. A patient is first infused with a non-toxic boron-10 compound, which preferentially accumulates in tumor tissue. After the infusion, the tumor is irradiated with low energy neutrons. The reaction, inside the cells, emits charged particles that destroy the cell while limiting damage to surrounding healthy tissue without boron-10.

Benefits

BNCT Treatment Benefits and Differentiation

The secondary radiation reaction from BNCT, with cellular-level precision, spares more healthy tissue and can potentially treat cancers that otherwise have few treatment options.

CONVENTIONAL RADIOTHERAPY

Low LET
RelativeBiological Effect (RBE) = 1
Indirect effect (free radicals)
Tumor hypoxia and tumor cell cycle-dependent radiation sensitivity
Predominantly single strand breaks, sublethal damage, and significant repair
Fractionation favors normal tissue repair
Multiple fractions
Predominantly geometrical targeting

BNCT

High LET
RBE > 1
Direct effect (Binary treatment)
Sensitivity depends largely on boron uptake and micro-localization. This can also be affected by tumor hypoxia.
Predominantly double strand breaks and lethal damage
Fractionation offers little advantage (except in the case of potential boron re-targeting)
1 to 2 treatment sessions
Predominantly biological targeting (potentially effective to treat infiltrating cells, micrometastases...)

* All BNCT treatments to date have been conducted under clinical investigations.
** Moss, R. L. Critical review, with an optimistic outlook, on Boron Neutron Capture Therapy (BNCT). Applied Radiation and Isotopes 88 (2014), 2–11.Sauvolainen, S., et al. Boron neutron capture therapy (BNCT) in Finland: Technological and physical prospects after 20 years of experiences. Physica Medica (2013) 29, 233-248
** Coderre and Morris (1999) The Radiation Biology of Boron Neutron Capture Therapy. Radiation Research: January 1999, Vol 151, No. 1, pp. 1-18.