Abstract
The concept of Nominal Standard Dose (NSD) determined from the time dosefractionation relation between acute reaction of skin and normal connective tissue to radiation, was suggested by F. Ellis. Using Ellis' formula, C. G. Orton proposed the time, dose, and fractionation (TDF) factor. The TDF value is generally used to evaluate tolerance of normal connective tissue. However, the TDF is not applicable to other organs such as the spinal cord and lungs.
Cohen, using data from radiation complications, has determined exponents of the Ellis' formula for some organs. From those formulae, we have calculated organ-specific TDFs, based on treatment schedule and dose distribution.
In the case of esophageal cancer, organ-specific TDF distributions of the irradiation technique were compared and evaluated.
