It is important to point out that the scientific evidence that suggests that both tridimensional conformal radiotherapy and IMRT can be of benefit to minimize normal tissue structure involvement and to contribute to a lower toxicity, preserving or improving the therapeutic efficacy, is still limited and of poor quality. More prospective, comparative clinical trials which evaluate relevant clinical results (such as mortality, disease-free survival, acute and immediate toxicity) must be carried out to assess its relative efficacy and cost-effectiveness in relation to bidimensional radiotherapy.