Correction Factors for Tumor Dose in the Chest Cavity Due to Diminished Absorption and Scatter in Lung Tissue.

Dose Planning for Irradiation of Thorax with60Co in Fixed-Beam Teletherapy

“…Expressing the dose along the beam axis in water as a function of the depth, gives, as is well known, straight lines in a log-linear diagram for depths greater than 5 cm. This is also the case both in cork (density 0.27 g/cm3) and in sawdust (density 0.25 g/cm3), as has been shown in figures by JACOBSON &KNAUER (1956), andVIKTERLOF (1960), respectively. Measurements have shown that at one and the same field size the quotient of the angular coefficients for the lines in sawdust and in water is approximately 213.…”

Experimental tests of corrections for tissue inhomogeneities in radiotherapy

“…A number of authors have published estimates of average correction factors typical of particular irradiation conditions based upon experimental measurements in either phantoms or patients (Jacobsen and Knauer, 1956;Schumacher and Baerwolff 1956;Haas and Sandberg, 1957;Epp, Lougheed and McKay, 1958;Wootton and Cantril, 1959;Massey 1962). However, assuming the nature of any inhomogeneities in the radiation field can be estimated (this is a separate problem which lies outside the scope of the present paper) it is possible for megavoltage radiation to make simplifying assumptions (not valid at lower energies) which enable corrections to be made at individual points of interest within individual patients.…”