Paradigm shift in patients with multiple brain metastases from whole brain radiotherapy to high precision multimodality treatment including stereotactic radiotherapy.

BACKGROUND

Whole brain radiotherapy (WBRT) is increasingly being replaced by high precision multimodality treatment including stereotactic radiotherapy (SRT) in patients with ≥ 4 brain metastases (BMs). The implications of this trend on survival rates are uncertain. Our study examines the time trends for survival rates of patients treated with radiotherapy for brain metastases during this era of shifting treatment paradigms.

METHODS

Patients with newly diagnosed BMs treated with SRT or WBRT between 2010 and 2023 were included, regardless of the number of brain metastases or the primary malignancy. Patients were excluded if they had previously undergone cranial radiotherapy. Differences in survival between treatment years were evaluated using Log-rank tests. A P value of ≤ 0.05 (two-sided) was considered statistically significant.

RESULTS

A total of 1106 patients were included for analysis. Of these, 832 (75%) were treated with SRT, while 274 (25%) were treated with WBRT. The median number of BMs was 2 (IQR 1-5), while 367 (33%) patients had ≥ 4 BMs. The proportion of patients with ≥ 4 BMs who were treated with linear accelerator-based SRT instead of WBRT increased over time: 2010-2014: 9 (11%); 2015-2019: 52 (31%); 2020-2023: 80 (68%). An improvement in survival rates of patients with ≥ 4 BMs was observed over time (median survival 2010-2014: 5 months; 2015-2019: 6 months; 2020-2023: 7 months, P < 0.001).

CONCLUSION

In patients treated for multiple (≥ 4) BMs, survival increased when radiotherapy modality shifted from WBRT to high precision multimodality treatment including SRT, resection, and systemic therapy.