ESTRO 2024 - Abstract Book

S2008

Clinical - Mixed sites, palliation

ESTRO 2024

prescriptions were retrospectively reviewed and, in case of deviation, the causes for NDI prescription were addressed. Descriptive and analytical statistics using the chi-square test were performed.

Results:

Overall, records from 231 patients were collected: treatments were delivered with robotic-arm linac or VMAT in 140 and 91 cases, respectively. Dose prescriptions are summarized in Figure 1. HDI accounted for 80% of delivered SRT spinal treatments (n=186). NDI accounted for 35/140 (25%) and 10/91 (9%) prescriptions in 2021 and 2022 respectively. Main reasons for NDI prescription included (a) prior SRT to the same field (n=15/45) and (b) risk of major violation of dose constraints to organs at risk (n=24/45). Physician’s preference accounted for 6 cases. Use of NDI significantly declined in 2022 as compared to 2021 (p=0.009).

Conclusion:

The use of HDI regimens for spinal SRT proved feasible in a sizable cohort and in a clinical setting. NDI schedules were mainly applied in cases of previously-irradiated fields or proximity to the organs at risk. Nevertheless, the use of NDI schedules have decreased over time, thus suggesting a benefit in terms of effectiveness in implementing a clinical harmonization protocol.

Keywords: institutional protocol, spine, dose-intensity

References:

1. Sahgal A, Myrehaug SD, Siva S, et al. CCTG SC.24/TROG 17.06: A Randomized Phase II/III Study Comparing 24Gy in 2 Stereotactic Body Radiotherapy (SBRT) Fractions Versus 20Gy in 5 Conventional Palliative Radiotherapy (CRT) Fractions for Patients with Painful Spinal Metastases. Int J Radiat Oncol Biol Phys. 2020;108(5):1397-1398.