CT findings of chemotherapy-induced toxicity: what radiologists need to know about the clinical and radiologic manifestations of chemotherapy toxicity.

Cancer chemotherapy has evolved from cytotoxic agents and now includes several new agents that target specific molecules responsible for the regulation of cell growth, nutrient supply, and differentiation. These molecularly targeted therapies have a different mechanism of action than do classic cytotoxic agents, which predominantly attack rapidly proliferating cells. Not surprisingly, therefore, the toxicity of targeted and cytotoxic agents may differ in both clinical and radiologic presentation. Many of the toxicities of targeted therapies are not cumulative or dose dependent, some are asymptomatic, and others may first manifest radiologically. It is imperative that radiologists be aware of these toxicities and that they learn to recognize the relevant findings so that they can provide a complete differential diagnosis and thus play an important role in patient care.