ABSTRACT
Combined radiochemotherapy is now firmly established in clinical practice for a wide spectrum of tumours. Randomized trials have shown that, in many cases, this strategy may lead to better local control and survival than radiotherapy alone. The radiobiological basis for radiochemotherapy and its current results are reviewed in Chapter 18. In this present chapter we emphasize that, despite their proven benefit, currently available chemotherapeutic drugs are far from being perfect for combining with radiotherapy (Krause et al., 2006). Tumour cell kill by chemotherapy at clinically achievable doses is minor compared with that caused by radiation. Only in a relatively small proportion of patients is chemotherapy sufficiently effective to destroy subclinical metastatic deposits. Normal tissue toxicity is frequently increased after combined radiochemotherapy, which may limit doses of drugs or radiation. For these reasons it is obvious that more effective and less toxic substances are needed to further improve the results of systemic therapies combined with radiation.
