ESTRO 2024 - Abstract Book

S1942

Clinical - Mixed sites, palliation

ESTRO 2024

From the group of patients with OMD, treatment was targeted to metastatic lymph nodes 13 (32%), bone metastases 17 (41.5%), liver metastases 8 (19.5%), adrenal gland 2 (5%) and pancreas 1 (2%). The median time from the simulation to the beginning of the treatment was 7 days (range 1, 19 days). For every fraction, online adaptive re-planning was applied using only the ATS workflow in 66 patients (83.5%) of the cases, and combination of ATS/ATP in 22 (16.5%). The median dose was 36.25 Gy (range 8, 78.4Gy) in 5 fractions (range 1, 28). Fifty-four patients (65%) underwent SBRT, while 26 (31%) received hypofractionation treatment. One patient (1%) was treated with normofractionation scheme and 2 (3%) underwent palliative treatment. The median duration for delivering radiation treatment was 38 minutes (range 20, 56 minutes). Following the completion of treatment, none of the patients reported toxicity higher than grade 2; 46 patients (57.5%) reported grade 1 acute toxicity and 3 (4%) grade 2 toxicity, figure 2. None of the patients reported grade 3 toxicity.

Conclusion:

Online adaptive radiation treatment using the MR-Linac system is generally well tolerated. This advanced MR guided treatment technology offers exceptional anatomical resolution, enhancing the visualization of tumor motion and enabling precise dose adjustments. As a result, it is associated with a low incidence of grade 2 acute toxicity and no cases of grade 3 toxicity.

Keywords: Adaptative radiotherapy, magnetic resonance