Mammary Gland Neoplasms after Fission Neutron Irradiation

Micronucleus Induction inVicia FabaRoots

“…A good correspondence is found between the data obtained for the induction of micronuclei in bean roots and that of lens opacification in mice, determined after irradiation in the same high-energy neutron beam. Furthermore, the present data give an RBE dependence on dose which is very close to that reported in the literature for the induction of chromosome aberrations in Tra.desoantia stamen hairs (Sparrow et al 1972), lens opacification in mice (Bateman et al 1972), induction of mammary tumours in rats (Vogel 1969), chromosome aberrations in human lymphocytes (Biola et al 1971), growth reduction in Vioia faha (Hall et al 1973), and skin damage in humans, rats, and pigs (Field 1969). However, some caution has to be taken when making a comparison with data reported in the literature; in fact in some of the curves shown in figure 6, X-rays have been used as the reference radiation instead of y-rays.…”

“…The data reported in the literature for various biological systems using both plant and animal cells suggest RBE values as high as 100 (Sparrow et al 1972, Bateman and Snead 1970, Vogel 1969, Shellabarger et al 1980. In view of the high values observed in the dose region of particular interest for radiation pro~ection, it is necessary to have more experimental data and careful evaluation of the damage at doses below 10 cGy in order to reduce the extent of extrapolation in the estimate of the shape of the dose-response curve.…”

Biophysical Aspects of Radiation Carcinogenesis

“…A related finding is that the incidence of multiple tumors follows Poisson statistics, supporting the view that the neoplasms arise independently from individual foci. Vogel (1969), as well as Shellabarger etat. (1974), investigated the effectiveness of neutrons for this phenomenon and found it to be high in relation to that of y-rays or X-rays, particularly at low levels of incidence.…”

“…Studies performed by Vogel (1969) and by Shellabarger et al (1973) on the induction of mammary tumors in Sprague-Dawley rats show a logarithmic slope c of the dose-effect curve for neutrons in the range of very small doses which is considerably less than 1. This fact will be further discussed in Section 5 and it will be concluded that in these experiments the observed tumor frequencies in the irradiated animals cannot reflect the action of radiation on individual cells which give rise to the observed tumors without mutual interaction or interference.…”

Nonparametric Determination of Modifying Factors in Radiation Action

“…Another example are studics of tumor incidencc. RBE-dosc relations havc becn investigated (12) for the induction of mammary tumors (18,14) on the basis of total incidences at a given time after irradiation; one can hope to improve these rcsults by basing the analysis on the füll temporal pattern of incidence and not merely on the total incidences at a fixed time after irradiation. Such improvements in Statistical precision are of special importancc in studies which relate to the effectiveness of radiation at small doses.…”