ESTRO 2024 - Abstract Book

S1972

Clinical - Mixed sites, palliation

ESTRO 2024

reported outcome is seldom described. The goal of this study was to score the result of the treatment according to the patient and to report the prognostic factors.

Material/Methods:

From September 2015 until June 2023, 120 metastatic patients with soft tissue metastases were treated with palliative radiotherapy. Patient characteristics are listed in table 1. Twenty two patients had the metastases in the head and neck region, 40 in the thorax, 53 in the abdomen and 5 in the extremities. Eighty eight patients were treated with 20 Gy in 5 fractions, 21 with 30 Gy in 10 fractions and 11 patients with 8 Gy in 1 fraction or 16 Gy in 2 fractions. The planning target volume consisted of the CTV + 8 mm. The CTV = GTV + 5 mm. The median follow up was 4.2 months. A telephone consultation 4 and 8 weeks after the treatment was done to determine the treatment outcome. Patients who answered “yes” on the following question: “did you have a benefit from the treatment” were classified as responders. If they answered “no” on this question, then they were non -responders. Median volume of the PTV was 587 cc. The median age of the patients was 68 years.

Results:

The median overall survival of the whole group was 4.3 months. Twenty seven patients died within 2 months and therefore the response could not be scored. Of the remaining 93 patients, 64 responders had a significant better survival compared to 24 non-responders (6.6 vs 3.8 months, p=0.003, figure 1). In 5 patients the answer was unknown. On multivariate analysis, bad prognostic factors were Karnofsky score <70, metastases in 2 or more organs, no systemic treatment options after the radiotherapy, treatment <3 years from diagnosis and synchronous metastases.

Table 1: Patient characteristics

number

%

0-70 <70

77 43 43 17 60 61 59 61 59 18 48 54 33 55 32

64 36 36 14 50 51 49 51 49 15 40 45 27 46 27

Age

lung colorectal other

Primary tumor

80-100 <80

Karnofsky

1-2 >2

Number of organs with metastases

1-3 4-10 >10

Total number of metastases

Time between treatment and diagnose of primary tumor 0-6 6-36

months

months

>36 months

Synchronous metastases

yes

60

50