Abstract

Three-dimensional conformal radiotherapy (3D-CRT) can improve local control of non-small cell lung cancer [1]. During the period of radiotherapy, tumor appears different degrees of shrinkage. It has been demonstrated that a clear dose-response relationship exists for radiotherapy, i.e. higher doses of radiation lead to increased local tumor control. According to tumor regression degree, adjusting the field shape and radiation strength, improve the tumor tissue irradiation dose, decrease peripheral normal tissue affected by radiation, improve local tumor control and prolong the survival time.