Short Communication: Results of a Consensus Conference on Radiotherapy for Brain and Bone Metastases within the Interreg-Project TreaT

Background/Aim: Differences between radiotherapy for metastases in Northern Germany and Southern Denmark were previously identified, which led to a consensus conference. Patients and Methods: A consensus conference was held between three centers to harmonize radiotherapy regimens for bone and brain metastases. Results: Centers agreed on 1×8 Gy for painful bone metastases in patients with poor or intermediate survival prognoses and 10×3 Gy for favorable-prognosis patients. For complicated bone metastases, 5-6×4 Gy was preferred for poor-prognosis, 10×3 Gy for intermediate-prognosis, and longer-course radiotherapy for favorable-prognosis patients. For ≥5 brain metastases, centers agreed on whole-brain irradiation (WBI) with 5×4 Gy in poor-prognosis and longer-course regimens in other patients. For single brain lesions and patients with 2-4 lesions and intermediate/favorable prognoses, fractionated stereotactic radiotherapy (FSRT) or radiosurgery were recommended. No consensus was reached for 2-4 lesions in poor-prognosis patients; two centers preferred FSRT, one center WBI. Preferred radiotherapy regimens were similar for different age groups including elderly and very elderly patients, but age-specific survival scores were recommended. Conclusion: The consensus conference was successful, since harmonization of radiotherapy regimens was achieved for 32 of 33 possible situations.