ESTRO 2024 - Abstract Book

S1871

Clinical - Mixed sites, palliation

ESTRO 2024

independent samples were done with a Log Rank Test. Patients were treated with opposing field in field 3DCRT technique with primarily 6 MV without hippocampus sparing.

Results:

In the period from January 2018 to December 2022, a total of 359 patients received palliative whole brain RT. The patients are listed in table 1 with diagnosis and fractions. The median age of the patient population was 68 (26-90) years. When age was categorized in quartiles, the first quartile included patients aged 26-61 years, while the 2nd, 3rd, and 4th quartile included patients aged 62-67 years, 68-72 years, and 73-90 years respectively. The median OS for the whole patient cohort was 3.1 (95%CI: 2.8-3.6) months. When OS was analysed according to cancer diagnosis, there was an improved OS among patients with breast cancer (median survival 3.4 (95%CI 2.2-4.8) months), compared to all other patients (median survival 3.0 (95%CI 2.6-3.5) months) (p-value = 0.035) (Figure 1a). When OS was analysed according to radiotherapy schedule, median survival was 4.3 (95%CI 3.6-5.0) months for patients treated with 30 Gy in 10 fractions, while OS was only 1.7 (95%CI 1.3-2.2) months and 1.7 (95%CI 1.1-2.3) months for patients treated with 20 Gy in 4 fractions and 20 Gy in 5 fractions, respectively (Figure 1b). Analysis of the impact of age on OS showed a statistically significant lower OS for patients in the eldest quartile with a median OS of 2.3 (95%CI: 1.9-2.7) months, compared to 3.7 (95%CI: 3.0-4.4) months in all other patients grouped together (p-value = 0.006) (Figure 1c). Moreover, 45.3% of the patients in the eldest quartile received fractionated RT with 4-5 fractions, compared to 18.2%, 32.7%, and 28.7% in the first, second, and third quartile of patients.

N (%)

20 Gy/4, N (%)

20 Gy/5F, N (%) 30 Gy/10F, N (%)

Median OS (months)

Breast

83 (23.1)

17 (29.3) 25 (43.1)

7 (13.0)

59 (23.9)

3.5 (2.2-4.8) 3.3 (2.5-3.9)

Lung

198 (55.2)

39 (72.2)

134 (54.3)

GI

16 (4.5) 29 (8.1) 33 (9.2)

5 (8.6)

1 (1.9) 3 (5.5) 4 (7.4)

10 (4.0) 20 (8.1) 24 (9.7)

2.6 (1.1-4.1) 1.9 (1.6-2.3) 3.2 (1.9-4.4) 3.1 (2.8-3.6)

Miscellaneous

6 (10.3)

Unknown

5 (8.6)

N (%)

359 (100) 58 (100)

54 (100)

247 (100)

Table 1: Fractionation schemes for patients treated with whole brain RT for brain metastases between 2018 and 2022 and median OS.