Boron Neutron Capture Therapy (BNCT)

BNCT is biochemically targeted radiation therapy. Boron-10 (10B) atoms are selectively delivered to the tumor, followed by irradiation with epithermal neutrons (nth). A nuclear reaction occurs, when a 10B atom captures a neutron. The short range of the reaction products restricts most of the radiation dose to the boron-loaded cells.

Neutron Capture Reaction

The stable boron isotope 10B has a large neutron capture radius. Thus 10B is more likely to capture neutrons than many other elements that are present in biological environments (e.g. nitrogen and hydrogen). A fission reaction occurs upon neutron capture, and a lithium ion and an alpha particle are produced. These particles have high kinetic energies, but their range is only about 10 microns. This leads to very efficient cancer cell killing precisely at the site of boron accumulation.


Benefits of BNCT

Has been in previous studies curative for 15-20% of terminal phase patients, despite using sub-optimal boron carrier
Can be used to treat many kinds of solid tumors that can be boron loaded
Affects healthy tissues less than conventional radiation therapy
Can be used in combination with other treatments

Low number of treatment sessions
Short hospital period – outpatient in many cases

Can be repeated

Improving the boron carrier is one of the greatest challenges of BNCT

  • The boron concentration gradient between tumor and surrounding healthy tissue should be significantly increased
  • The boron concentration in the tumor cells should be significantly increased
  • The targeting of the boron carrier to the tumor cells (carrier cell surface affinity and/or cell internalisation) should be significantly improved
  • The kinetics of the boron carrier should allow for a long time period within the tumor cells

Tenboron’s boron carrier
has a high number of boron
atoms and an antibody
targeting unit that directs
the carrier specifically to
cancerous cells


Tenboron’s boron carrier is administered directly into the tumor, followed by neutron irradiation

Boron Neutron Capture reaction leads to intense local irradiation precisely at the site of boron accumulation, which leads to tumor necrosis


  • Founded 2010, commenced operation in 2011
    Inspired by the successful trials conducted at the Helsinki University Central Hospital and the VTT nuclear reactor facility FiR-1
  • Privately held SME
  • Financial support from Tekes (Finninsh Funding Agency for Innovation)


  • A number of different molecular designs has been evaluated, and the most promising one selected
  • Efficacy tests in small animals have been carried out
    Results are far superior to anything achieved with current boron carriers
  • A robust synthesis route has been designed
  • A contract manufacturer has been selected for the investigational product, and successful pre-GMP production test runs have been performed
  • Preclinical toxicology studies have been carried out successfully