Individualization of cancer treatment from radiotherapy perspective

Abstract

Radiotherapy is today used in about 50% of all cancer patients, often in multidisciplinary approaches. With major advance in radiotherapy techniques, increasing knowledge on tumor genetics and biology and the continuous introduction of specifically targeted drugs into combined radio-oncological treatment schedules, individualization of radiotherapy is of high priority to further improve treatment outcomes, i.e. to increase long-term tumor cure and/or to reduce chronic treatment toxicity. This review gives an overview on the importance of predictive biomarkers for the field of radiation oncology. The current status of knowledge on potential biomarkers of tumor hypoxia, tumor cell metabolism, DNA repair, cancer stem cells and biomarkers for combining radiotherapy with inhibition of the epidermal growth factor receptor using monoclonal antibodies is described.

Figure 1

Pimonidazole hypoxic volume (±standard deviation) after 2 weeks of fractionated irradiation shows association with radioresistance to therapy with 30 fractions over 6 weeks in 6 different human tumor xenografts: ∆‐UT‐SCC‐15; ♦‐XF354; ○‐UT‐SCC‐14; ●‐FaDu; □‐SAS; ▲‐UT‐SCC‐5. The radioresistance represents dose to cure 50% of tumors (TCD50 with 95% confidence interval) after 30 fractions over 6 weeks. Adapted from (Yaromina et al., 2011).