Update of human spinal cord reirradiation tolerance based on additional data from 38 patients

Conclusions: Based on these updated results, the risk of RM appears small after ≤135.5 Gy2 when the interval is not shorter than 6 months and the dose of each course is ≤98 Gy2. We would recommend limiting the dose to the lowest feasible level. The influence of very steep dose gradients from stereotactic and intensity-modulated approaches (i.e., a more complex volume-effect) requires further evaluation.