[Prediction of tumor treatment response to radiotherapy]

It has been suggested that one of most important parameters for predicting individual tumor treatment response in both radiotherapy and chemotherapy is intrinsic cellular sensitivity of tumor stem cells. The rationale behind the hypothesis and recent progress in the method of the assay were discussed in this review article. Since there have been no clinical data for the usefulness of the radiobiological approaches in predicting the clinical outcomes, multivariate analysis of the factors affecting prognosis seems most important to determine independent prognostic indicators. Addition of the assay data in the clinical testing may significantly improve the accuracy of the prediction if they are independent of known clinical prognosticators. Close cooperation between radiobiologists and therapeutic radiologists is certainly required for this goal.