[Therapy by neutron capture of ocular melanoma: dosimetry and microdosimetry]. / Thérapie par capture de neutrons des mélanomes oculaires: approches dosimétrique et microdosimétrique.

Neutron capture therapy (NCT) aims at destroying cancerous cells with the alpha and 7Li particles produced by the neutron capture reaction on 10B. This note reports on the study of the boron distribution in tissues on an animal model (nude mice) xenografted with a human ocular melanoma after an i.p.injection of 2g/kg of 10B-BPA and in cells cultured in the presence of 530 mumol/l of 10B-BPA. A concentration of 64 ppm of 10B in the active part of the tumour with a ratio of concentrations versus the skin of 3.7 are observed. Investigations on cells reveal the presence of boron in the cytoplasm. The biological, dosimetric and microdosimetric consequences of these findings are discussed.

Distribution of lithium in the rat brain after a single administration known to elicit aversive effects.

In order to get insight into the brain areas involved in the initial unpleasant effects resulting from the administration of lithium (Li+), its distribution was mapped in the rat brain using the 6Li(n,alpha)3H nuclear reaction after a single injection of 6Li2SO4 at doses and latencies corresponding to the elicitation of such unpleasant effects. An improved method for visualization and measurement of local Li+ concentrations was used consisting in diffracting light along the tracks left by alpha particles in a dielectric detector. The distribution of Li+ was found less homogeneous than when Li+ was administered chronically. Periaqueductal and periventricular structures were the brain areas containing the highest concentrations of Li+.