Boron neutron capture therapy pioneered for head and neck cancer treatment
13 March 2011
A new type of radiotherapy, boron neutron capture therapy, has been successfully used to treat patients with advanced head and neck cancer who have not responded to previous treatments and generally have poor prognosis.
Biologically targeted BNCT treatment is based on producing radiation inside a tumour using boron-10 and thermal neutrons.
Boron-10 is introduced into cancer cells with the help of a
special carrier substance (phenylalanine), after which the tumour is
irradiated with lowenergy neutrons. The latter react with the boron
to generate high-LET radiation, which may destroy the cancer cells.
One to two BNCT treatment sessions may be sufficient to destroy a
tumour, while keeping the impact of radiation on surrounding healthy
tissue to a minimum.
A research reactor is currently used as
the neutron source, but a dedicated neutron accelerator is being
designed for BNCT.
Clinical trials to assess the efficacy
and safety of BNCT in the treatment of locally recurrent head and
neck cancer have been carried out at the Department of Oncology at
Helsinki University Central Hospital (HUCH). Apart from palliative
chemotherapy, conventional treatment was no longer considered
possible for the patients treated in the BNCT trials.
A
total of 30 patients referred to HUCH’s Department of Oncology from
hospitals around Finland took part in the trial. 76% of patients
responded well to the treatment and 30% were still alive two years
after treatment; although only one patient has survived 55 months.
The results of the study, conducted by Professor Heikki Joensuu,
have recently been published in the International Journal of
Radiation Oncology, Biology, Physics.
BNCT treatment is
provided by Boneca Corporation, which is based at the main campus of
Helsinki University Central Hospital and is the world’s only
provider of radiation safetyaudited BNCT treatment. Owned by
Clinical Research Institute HUCH Ltd, Sitra, Finnish Innovation
Fund, and VTT Ventures Ltd., Boneca works closely with HUCH’s
Department of Oncology, and treatment-related decisions are taken
jointly with the hospital’s otolaryngology, radiation therapy and
oncology specialists. Boneca is responsible for administering the
treatment, which is given at a special facility adjacent to the
research nuclear reactor used at the VTT Technical Research Centre
of Finland.
“The positive results that we have achieved in
treating head and neck tumours have convinced us of the benefits of
further developing BNCT treatment and the services needed to
administer it,” says the Chairman of Boneca’s Board of Directors,
Seppo Pakkala, MD, PhD.
“As BNCT saves healthy tissue, this
promises to make it a good choice as a first-line therapy for
patients with large head and neck tumours, avoiding the need for
extensive surgery. Additional studies will be needed, however,
before BNCT can be adopted for this use. We would also like to
extend the use of BNCT to treating tumours in other anatomical areas
for which there are no forms of treatment currently available.”
BNCT treatment has been given to over 200 patients to date, the
majority of whom had recurred head and neck cancer or malignant
brain tumour. Approximately 6% of patients have come from abroad as
a result of international interest in BNCT.
“We have
sufficient capacity to treat more patients and are very interested
in collaborating with hospitals outside Finland that would like to
offer the option of BNCT treatment for their patients,” says
Boneca’s CEO, Markku Pohjola.
Reference
Kankaanranta L et al. Boron neutron capture therapy in the treatment of locally recurred head and neck cancer: final analysis of a phase I/II trial. Int. J. Radiation Oncology Biol., Phys.
Kankaanranta L et al. I-Boronophenylalanine-mediated Boron Neutron Capture Therapy for Malignant Glioma Progressing After External Beam Radiation Therapy: A Phase I Study. Int J Radiat Oncol Biol Phys. 2011 Jan 13