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Detecting canine brain lesions on computed tomography (CT) or magnetic resonance (MR) scans can be difficult if the lesions do not enhance well following administration of intravenous contrast material. Changes in the shape and position of the ventricular system can be important in the diagnosis of such lesions. Normal variation within the canine ventricular system has not been documented. MR scans from 62 normal Labrador retriever type dogs were evaluated. Five dogs had symmetric enlargement of the ventricles, while nineteen dogs had mild to severe ventricular asymmetry. The incidence of asymmetry in normal dogs must be considered when using ventricular configuration as an indication of central nervous system abnormality.

Purpose: Normal tissue tolerance of boron neutron capture irradiation using borocaptate sodium (NA 2 B 12 H 11 SH) in an epithermal neutron beam was studied. Methods and Materials: Large retriever-type dogs were used and the irradiations were performed by single dose, 5 × 10 dorsal portal. Fourteen dogs were irradiated with the epithermal neutron beam alone and 35 dogs were irradiated following intravenous administration of borocaptate sodium. Results: Total body irradiation effect could be seen from the decreased leukocytes and platelets following irradiation. Most values returned to normal within 40 days postirradiation. Severe dermal necrosis occurred in animals given 15 Gy epithermal neutrons alone and in animals irradiated to a total peak physical dose greater than 64 Gy in animals following borocaptate sodium infusion. Lethal brain necrosis was seen in animals receiving between 27 and 39 Gy. Lethal brain necrosis occurred at 22–36 weeks postirradiation. A total peak physical dose of approximately 27 Gy and blood-boron concentrations of 25–50 ppm resulted in abnormal magnetic resonance imaging results in 6 months postexamination. Seven of eight of these animals remained normal and the lesions were not detected at the 12-month postirradiation examination. Conclusion: The bimodal therapy presents a complex challenge in attempting to achieve dose response assays. The resultant total radiation dose is a composite of low and high LET components. The short track length of the boron fission fragments and the geometric effect of the vessels causes much of the intravascular dose to miss the presumed critical target of the endothelial cells. The results indicate a large dose-sparing effect from the boron capture reactions within the blood.

An epithermal neutron beam is needed to treat relatively deep seated tumors. The scattering characteristics of neutrons in this energy range dictate that in vivo experiments be conducted in a large animal to prevent unacceptable total body irradiation. The canine species has proven an excellent model to evaluate the various problems of boron neutron capture utilizing an epithermal neutron beam. This paper discusses three major components of our study: I) the pharmacokinetics of borocaptate sodium (NA2B12H11SH or BSH) in dogs with spontaneously occurring brain tumors, II) the radiation tolerance of normal tissues in the dog using an epithermal beam alone and in combination with borocaptate sodium, and III) initial treatment of dogs with spontaneously occurring brain tumors utilizing borocaptate sodium and an epithermal neutron beam.

The Power Burst Facility/Boron Neutron Capture Therapy (PBF/BNCT) Program has been funded since 1988 to evaluate brain treatment using Na2B12H11SH (borocaptate sodium or BSH) and epithermal neutrons. The PBF/BNCT Program pursues this goal as a comprehensive, multidisciplinary, multiorganizational endeavor applying modern program management techniques. The initial focus was to: (1) establish a representative large animal model and (2) develop the generic analytical and measurement capabilities required to control treatment repeatability and determine critical treatment parameters independent of tumor type and body location. This paper will identify the PBF/BNCT Program elements and summarize the status of some of the developed capabilities.

Neutron Capture Therapy (NCT) was suggested in theory as a treatment for malignant tumors some 50 years ago. Since then, considerable data have accumulated on the mechanisms of action and possible application of this technique. This paper outlines a protocol for a controlled study of the use of Boron Neutron Capture Therapy (BNCT) for the treatment of Glioblastoma Multiforme (GM). The protocol is one component of a comprehensive national BNCT research program at the Idaho National Engineering Laboratory (INEL) directed towards validating (or invalidating) NCT as a treatment for human malignancies.

There is evidence showing that there is a significant variation in tumor-boron and blood-boron concentrations for individual patients. There also is a wide variation in the size and location of the tumor. This diversity creates a situation in which treatment must be carefully tailored to the specific needs of each patient. Patient treatment planning will require computer modeling of the various radiation transport and interaction processes expected to occur, coupled with a display of the results in easily interpretable form. Such an analytical evaluation will allow the radiation oncologist to select the beam configuration, specify the irradiation field and positions of local thermal neutron shields, establish the optimum time after boron administration to begin irradiation, and specify the duration of irradiation.

All methods of Boron Neutron Capture Therapy (BNCT) in use or envisioned for treatment of brain tumors have, as an inseparable component, an element of ionizing radiation (incident and induced). This paper reviews data on the effects of ionizing radiation on the blood-brain-barrier (BBB) and the blood-tumor-barrier (BTB) and the potential impact of the effects on the delivery techniques of BNCT. This paper has the following objectives: 1. Review the available technique for BNCT of brain tumors, 2. Review the literature on experimental and human studies regarding the effects of ionizing radiation on the BBB, 3. Discuss the impact of these effects on the fractionization question for BNCT, and 4. Draw conclusions from that information.

Using computed tomography (CT) and magnetic resonance imaging (MRI), we are following a 30-year old, white female and a 64-year old, white male, both with biopsy-proven Glioblastoma Multiforme, from their preoperative through post-operative stages and pre- and post-BNCT treatment. The images visually demonstrate the evolving changes in the tumor and surrounding cortex. These patients were treated by Hiroshi Hatanaka of Teikyo University, at the Musashi Institute of Technology (MIT) reactor in Kawasaki, Japan. The MIT reactor is a 100 kW Triga-II facility that has been used by Hatanaka for many years for BNCT therapy.