BNCT – Radiotherapy with neutrons for brain tumors

Findings by SBU Alert  

Version: 1

Technology and target group

Boron neutron capture therapy (BNCT) is a new two-part method of radiotherapy for cancer. In the first part of treatment, boron atoms are delivered to the tumor cells being treated. In the second part, the tumor region is irradiated with neutrons that react with the boron atoms. This reaction creates radiation energy that destroys the cells that have been loaded with boron. Consequently, the radiation dose to the tumor is higher than the dose to the surrounding normal tissue. Compared to conventional treatment, radiation doses are lower with BNCT, which means a lower risk for side effects. BNCT requires access to a special type of nuclear reactor. The method is being tested mainly in patients with malignant, rapidly growing brain tumors (malignant glioma). The prevailing treatment for this type of tumor, consisting of surgery followed by conventional radiotherapy, has minor effects on survival and quality of life. BNCT is tested on a smaller scale within the framework of a clinical research project in Studsvik during 2001. The target group in this study includes patients with malignant glioma. Annually, about 500 patients in Sweden are diagnosed with this disease.

Patient benefit

There are no controlled comparative studies that compare BNCT to conventional therapy. To date, only followup studies with small numbers of patients have been performed. One of these studies reports a relapse pattern after BNCT which is similar to that after conventional therapy. Median survival was 13 months, which is also similar to that after conventional radiotherapy. An advantage with BNCT is that treatment time is only about 3 days, compared to 6 weeks for conventional radiotherapy. To date, no serious side effects have been reported after BNCT. However, it should be emphasized that given the limited experience to date, knowledge concerning side effects is insufficient.

Economic aspects

There are no known scientific studies addressing the health economics of BNCT. The estimated cost of a treatment cycle is 130 000 to 150 000 Swedish kronor (SEK), which represents an additional cost of approximately 90 000 SEK compared to traditional radiotherapy.

Scientific evidence

There is poor* scientific documentation showing the medical effects and patient benefits of BNCT. There is no* documentation on the cost-effectiveness of the method.

The apparent advantages of BNCT must be assessed in well-controlled trials in terms of survival and quality of life in treated patients and where the health economic aspects should also be addressed.

* This assessment by SBU Alert uses a 4-point scale to grade the quality and evidence of the scientific documentation. The grades indicate: (1) good, (2) moderate, (3) poor, or (4) no scientific evidence on the subject.

This summary is based on a report prepared at SBU in collaboration with Prof. Roger Henriksson, MD PhD, Norrland University Hospital and has been reviewed by Prof. Lennart Persson, MD PhD, Uppsala University Hospital.

The full report is available only in Swedish.

Alert is a joint effort by the Swedish Council on Technology Assessment in Health Care (SBU), the Medical Products Agency, the National Board of Health and Welfare, and the Federation of Swedish County Councils. 

References

1. Auterinen I, Hiismäki P, Kotiluoto P, Rosenberg R, Salmenhaara S, Seppälä T, et al. The new boron neutron capture therapy facility at the Finnish nuclear research reactor (FiR 1) Medical & Biological Engineering & Computing. Proceedings of the 11th Nordic-Baltic Conference on Biomedical Engineering. Tallinn, ES, 6 - 10 June. 1999;37(1):398-9.
2. Aziz T, Peress NS, Diaz AZ, Capala J, Chanana AD. Postmortem neuropathological features secondary to boron neutron capture therapy for glioblastoma multiforme. J Neuropathol Exp Neuro 2000;59:62-73.
3. Chanana AD, Capala J, Chadha M, Coderre JA, Diaz AZ, Elowitz EH, et al. Boron neutron capture therapy for glioblastoma multiforme: Interim results from the phase I/II dose-escalation studies. Neurosurgery 1999;44:1182-92.
4. Coderre JA, Elowitz EH, Chadha M, Bergland R, Capala J, Joel DD, et al. Boron neutorn capture therapy for glioblastoma multiforme using P-boronophenylalanine and epithermal neutrons: Trial design and early clinical results. J Neurooncol 1997;33:141-52.
5. Coderre JA, Chanana AD, Joel DD, Elowitz EH, Micca PL, Nawrocky MM, et al. Biodistribution of boronophenylalanine in patients with glioblastoma multiforme: Boron concentration correlates with tumour cellularity. Radiat Res 1998;149:163-70.
6. Elowitz EH, Bergland RM, Coderre JA, Joel DD, Chadha M, Chanana AD. Biodistribution of p-boronophenylalanine in patients with glioblastoma multiforme for use in boron neutron capture therapy. Neurosurgery 1998;42:463-69.
7. Hideghety K, Sauerwein W, Haselsberger K, Grochulla F, Fankhauser H, Moss R, et al. Postoperative treatment of glioblastoma with BNCT at the Petten irradiation facility (EORTC protocol 11,961). Strahlenther Onkol 1999;175(2):111-4.
8. Laramore GE, Spence AM. Boron neutron capture therapy (BNCT) for high-grade gliomas of the brain - A cautionary note. Int J Radiat Oncol Biol Phys 1996;36:241-46.
9. Nakagawa Y, Hatanaka H. Boron neutron capture therapy: Clinical brain tumour studies. J Neurooncol 1997;33:105-15.
10. Slatkin DN. A history of boron neutron capture therapy of brain tumours: Postulation of a brain radiation dose tolerance limit. Brain 1991;114:1609-29.
11. Sweet WH. Early history of development of boron neutron capture therapy of tumors. J Neurooncol 1997;33:19-26.