[en] There are about 6000 new glioblastoma multiform brain tumours diagnosed each year in the United States of America alone. This cancer is usually fatal within six months of diagnosis even with current standard treatments. Research on boron neutron capture therapy (BNCT) has been considered as a method of potentially curing such cancers. There is a great interest at under-utilised research reactors institutions to identify new medical utilization, attractive to the general public. Neutron capture therapy is a true multidisciplinary topic with a large variety of individuals involved. This publication attempts to provide current information for all those thinking about being involved with NCT, based on the knowledge and experience of those who have pioneered the treatment. It covers the whole range of NCT from designing reactor conversions or new facilities, through to clinical trials and their effectiveness. However, since most work has been done with boron capture therapy for brain tumours using modified thermal research reactors, this tends to be the focus of the report. One of the factors which need to be addressed at the beginning is the timing of the further development of NCT facilities. It should be emphasised that all current work is still at the research stage. Many of those now involved believe that there is little need for many more research facilities until such time as the treatment shows more promising results. For this and other reasons discussed in the report, very serious consideration should be given by research reactor owners and operators before spending large sums of money converting their facilities for NCT

[en] Our concept of Boron Neutron Capture Therapy (BNCT) is to selectively destroy tumour cells using the high LET particles yielded from the 10B(n,α)7Li reactions. The effort of clinical investigators has concentrated on how to escalate the radiation dose at the target point. BNCT in Japan combines thermal neutrons and BSH (Na₂B₁₂H₁₁SH). The radiation dose is determined by the neutron fluence at the target point and the boron concentration in the tumour tissue. According to the recent analysis, the ratio of boron concentration (BSH) in tumour tissue and blood is nearly stable at around 1.2 to 1.69. Escalation of the radiation dose was carried out by means of improving the penetration of the thermal neutron beam. Since 1968, 175 patients with glioblastoma (n=83), anaplastic astrocytoma (n=44), low grade astrocytoma (n=16) or other types of tumour (n=32) were treated by BNCT at 5 reactors (HTR n=13, JRR-3 n=1, MulTR n=98, KUR n=30, JRR-2 n=33). The retrospective analysis revealed that the important factors related to the clinical results and QOL of the patients were minimum tumour volume radiation dose, more than 18Gy of physical dose and maximum vascular radiation dose (less than 15Gy) in the normal cortex. We have planned several trials to escalate the target radiation dose. One trial makes use of a cavity in the cortex following debulking surgery of the tumour tissue to improve neutron penetration. The other trial is introduction of epithermal neutron. KUR and JRR-4 were reconstructed and developed to be able to irradiate using epithermal neutrons. The new combination of surgical procedure and irradiation using epithermal neutrons should remarkably improve the target volume dose compared to the radiation dose treated by thermal neutrons. (author)

[en] The RA-6 is an open pool MTR type reactor with 500 Kw nominal power, using fuel elements enriched to 90%. It was designed and constructed fully in Argentina and is owned and operated by the C.N.E.A. at the Bariloche Atomic Center. In this work the analysis of the different alternatives, depending on the main features of a research reactor (type, power, shielding, etc.), are showed to design a BNCT facility. After that, the different steps followed to produce the epithermal beam at the RA-6 are presented: Because only small modifications were required, the first stage was the arrangement of a thermal beam to test and validate our calculation methods and to gain expertise in the different experimental techniques to design and characterise the epithermal facility. A basic design of the epithermal device was performed, analysing different and relative sizes of the materials conforming the neutron filter to optimise the neutron spectrum and the absolute value of the epithermal flux at the beam port. This design was used also to make preliminary studies regarding the nuclear safety and solve potential licensing problems. A complete design of the internal filter was presented to the Regulatory Authority and after some feedback the filter was constructed and mounted. During this stage a very simple (without any geometry complexity) external port was used to test the free beam facility and to get a complete on phantom dosimetry. Using the previous results the new beam port was designed, built and mounted by November 1998, the final characterisation of the facility is being currently performed. Preliminary results of this job for the free beam are: φ_epithermal = 1.1 E9 n/cm² seg (0.5 eV < E < 10 KeV); D_fast/n_epi = 7.5 cGy cm²/n_epi; D_γ/n_epi 3.0 cGy cm²/n_epi5. The next goal will be to optimise the irradiation room to adequate the facility to irradiate patients. (author)

[en] The neutron irradiation characteristics of the Heavy Water Neutron Irradiation Facility (HWNIF) at the Kyoto University Research Reactor Institute (KIJRRI) for boron neutron capture therapy (BNCT), is described. The present method of dose measurement and its evaluation at the KURRI, is explained. Especially, the special feature and noticeable matters were expounded for the BNCT with craniotomy, which has been applied at present only in Japan. (author)

[en] The technology for computational dosimetry and treatment planning for Boron Neutron Capture Therapy (BNCT) has advanced significantly over the past few years. Because of the more complex nature of the problem, the computational methods that work well for treatment planning in photon radiotherapy are not applicable to BNCT. The necessary methods have, however, been developed and have been successfully employed both for research applications as well as human trials. Computational geometry for BNCT applications can be constructed directly from tomographic medical imagery and computed radiation dose distributions can be readily displayed in formats that are familiar to the radiotherapy community. The SERA system represents a significant advance in several areas for treatment planning. However further improvements in speed and results presentation are still needed for routine clinical applications, particularly when optimization of dose pattern is required. (author)

[en] The first clinical trial in Europe of Boron Neutron Capture Therapy (BNCT) for the treatment of glioblastoma was opened in July 1997. The trial is a Phase I study with the principal aim to establish the maximum tolerated radiation dose and the dose limiting toxicity under defined conditions. It is the first time that a clinical application could be realised on a completely multi-national scale. The treatment takes place at the High Flux Reactor (HFR) in Petten, the Netherlands, is operated by an international team of experts under the leadership of a German radiotherapist, and treats patients coming from different European countries. It has therefore been necessary to create a very specialised organisation and contractual structure with the support of administrations from different countries, who had to find and adapt solutions within existing laws that had never foreseen such a situation. Furthermore, the treatment does not take place in an hospital environment and even more so, the facility is at a nuclear research reactor. Hence, special efforts were made on quality assurance, in order that the set-up at the facility and the personnel involved complied, as closely as possible, with similar practices in conventional radiotherapy departments. (author)

[en] A survey on the Indonesian research reactors and its supporting facilities has been done in order to check the possibility to install BNCT facility. Oncologists from several hospitals have been informing about the BNCT treatment for tumours and they give a positive response to support utilisation of the BNCT facility. Several aspects required to support the BNCT treatment have also been identified and related activities on that matter soon will be initiated. The interim result in our survey indicated that utilisation of the 30 MW Multipurpose reactor would not be possible from the technical point of view. Further study will be concentrated on the TRIGA reactor and an epithermal neutron beam facility at the thermal column of this reactor will be designed for further work. (author)

[en] The operation of JRR-2, in which 33 cases of medical irradiation were performed for clinical trials of BNCT using thermal neutron beam for malignant brain tumour patients since 1990, was terminated at the end of 1996. In order to transfer the medical irradiation for BNCT from JRR-2 to JRR-4, a new medical irradiation facility was installed at JRR-4 in June 1998. The new facility provide a suitable neutron beam (thermal or epithermal neutron beam) for each medical irradiation. It was verified that both thermal and epithermal neutron beams had enough intensity for a clinical trail of BNCT and very low contamination of gamma ray and fast neutron. (author)

[en] The University of Tsukuba project for boron neutron capture therapy (BNCT) was initiated at the Japan Atomic Energy Research Institute (JAERI) in 1992. The clinical study for BNCT began at the Japan Research Reactor (JRR)-2 of the JAERI in November 1995. By the end of 1998, a new medical irradiation facility had been installed in JRR-4 of that included a new medical treatment room and patient-monitoring area adjacent to the irradiation room. The medical treatment room was built to reflect a hospital-type operation room that includes an operating table with a carbon head frame, anesthesia apparatus with several cardiopulmonary monitors, etc. Following craniotomy in the treatment room, a patient under anesthesia is transported into the irradiation room for BNCT. The boron concentration in tissue is measured with prompt gamma ray analysis (PGA) and simultaneously by inductively coupled plasma atomic emission spectroscopy (ICP-AES) methods. For the immediate pre- and post-BNCT care, a collaborating neurosurgical department of the University of Tsukuba was prepared in the vicinity of the JAERI. The long term follow-up is done at the University of Tsukuba Hospital. Epithermal neutron beam also became available at the new JRR-4. By changing the thickness and/or the configuration of heavy water, a cadmium plate, and a graphite reflector, the JRR-4 provides a variety of neutron beams, including three typical beams (Epithermal mode and Thermal modes I and II). Intraoperative BNCT using the thermal beam is planned to study at the beginning of the clinical trial. The ongoing development of the JAERI Computational Dosimetry System (JCDS) and radiobiological studies have focused in the application of the epithermal beam for BNCT. After obtaining these basic data, we are planning to use the epithermal beam for intraoperative BNCT. (author)

[en] The BNCT project at LVR-15 reactor of NRI for treatment of human brain gliomas is before start of clinical trials. A survey of present conditions is included, the attention is devoted to BNCT facility with epithermal neutron beam first of all. The different materials for filter composition were studied, the calculational methods have been used for the determination of neutron and gamma rays in the reactor geometry. Some configurations were experimentally verified. The effort for improvement of epithermal neutron beam parameters in configuration 1998 was concentrated to block of filters remodelling, improvement of collimator-shutter geometry, the choice of optimal reactor core edge configuration. Awaited results from experiment in June 1999 are described. (author)