A new radiation therapy treatment developed for head and neck cancer patients

Most head-and-neck cancers that recur locally after prior full-dose conventional radiation therapy respond to Boron Neutron Capture Therapy (BNCT). These results were obtained in a Phase I/II study at the Helsinki University Hospital, Finland. The scientific director of the research program, professor Heikki Joensuu, University of Helsinki, considers the results clinically significant and very interesting. They open a new field for BNCT, since thus far BNCT has been evaluated only in the treatment of some brain tumours.

The follow-up results of 12 patients diagnosed with cancer of the head-and-neck and treated in a prospective clinical trial were reported in the International Journal of Radiation Oncology, Biology & Physics.

All patients had cancer of the head-and-neck that had recurred locally after surgery and conventional radiation therapy. Ten out of the 12 patients had substantial tumour shrinkage following BNCT, and in 7 cases the tumour disappeared completely. Adverse effects of treatment were moderate and resembled those of conventional radiation therapy.

The study has been expanded, and up to 30 subjects will now be allowed to enter the study protocol.

Boron neutron capture therapy (BNCT) is a form of targeted radiation treatment for cancer. It is still considered experimental. In this method a boron-containing compound (boronophenylalanine) is first infused into a peripheral vein, following which the compound accumulates in cancer tissue. Cancer is subsequently irradiated with neutrons obtained from a nuclear reactor, which causes boron atoms to split within the cancerous tissue as a result from a boron neutron capture reaction. The resulting smaller particles cause a large radiation effect within the tumour tissue, which destroys cancer cells.

The technique allows targeting of a high dosage of radiation to the tumour while allowing sparing of the adjacent normal tissues from the highest doses of radiation. Boron-mediated targeting of radiation allows treatment of patients who can no longer be treated with conventional radiation therapy. BNCT is administered as single one-day treatment that may be repeated.

The study was sponsored by Boneca Corporation, the spinoff company operating on the medical campus of the Helsinki University and the University Central Hospital (www.boneca.fi). The treatments are carried out in collaboration with the Department of Oncology, Helsinki University Central Hospital, at the BNCT facility constructed at the VTT research nuclear reactor site located at Otaniemi, Espoo. The neutron radiation used in the treatment is provided by VTT.

Boneca Corporation’s clinical research program includes also a phase I/II study that evaluates BNCT in the treatment of primary glioblastoma (a highly malignant brain tumour) and another clinical trial that assesses safety and efficacy of BNCT in the treatment of glioblastomas and anaplastic astrocytomas (a type of brain tumour) that have recurred after conventional radiation therapy.