Background: In the last decades, cancer treatment has increased in complexity and cost, therefore a careful monitoring of the response to treatment has become increasingly relevant in our clinical practice. Content: In this presentation the discussion will focus on a few clinical examples able to give an overview of the state-of-the art in cancer treatments and of the most relevant issues in the evaluation of the response to treatment, with particular reference to the role of computed tomography (CT). Patient series of different oncologic subspecialties will be also analyzed, highlighting challenges and opportunities in terms of the use of CT for assessing the response to treatment. The materials will be put in a clinical perspective to give practical guidance to the participating physicians. Conclusions: The presentation aims will be achieved if the participating physicians will improve their knowledge of the most relevant issues in the evaluation of the response to oncologic treatments.