Belmonte Beitia, Juan. Fernández Calvo, Gabriel. 

Purpose: Radiotherapy retreatment (radical or palliative) is useful in selected patients. Two recent publications provided methods for estimating changes in spinal radio-tolerance with time between initial radiotherapy and retreatment, but with important limitations. Conclusions: The new model allows re-treatment dose estimation within the time window of 70 days to three years after the initial course, and can be adapted for hadrontherapy. It should be used cautiously in clinical practice by choosing doses lower than predicted.