Re-irradiation

We propose to evaluate the contribution of a standardized process combining, * a validation of re-irradiation indications by a group of multi-professional experts (radiotherapists and physicists) and, * a collective validation of the accumulation of doses on all the organs of the anatomical region concerned obtained using deformable fusion software (MiM) allowing the accumulation of doses in terms of Equivalent Dose 2 Grays (EQD2). The primary objective of this study is to determine the rate of patients for whom this process has changed the treatment plan.

In the Netherlands, breast cancer patients with locoregional recurrence (LRR) and intermediate- and high-risk factors are treated with surgery with or without postoperative re-irradiation with or without hyperthermia. Retrospective studies showed that 3-year locoregional control after postoperative re-irradiation with hyperthermia was 68-83%, and severe toxicity in up to 40% of LRR patients. Unfortunately, no prospective (randomized) data are available on clinical outcomes. Consequently, variation exists in hyperthermia-treatment and re-irradiation schedules. Prospective real-world data on oncological outcomes, toxicity and quality of life is highly needed for shared decision-making between patients and professionals. These data will be used in the design of a future randomized trial in high-risk LRR patients.