ESTRO 2024 - Abstract Book

S1892

Clinical - Mixed sites, palliation

ESTRO 2024

metastases in our institution within the last five years. Furthermore, we aim to analyse the impact of cancer diagnosis and age on the RT schedules that were prescribed.

Material/Methods:

The study performs a retrospective analysis of patients treated with palliative RT for bone metastases in our institution in the period from 2018 to 2022.

Inclusion criteria were a known cancer diagnosis at time of referral and information regarding the RT schedule (doses/fractionations).

Patients were grouped according to diagnosis. Only groups with a sample size of more than 40 patients were chosen for analysis. In total 6 diagnostic groups were defined: lung, prostate, breast, myelomatosis, lower GI, and upper GI cancer. The different RT schedules (8Gy/1F, 20Gy/4F, 20Gy/5F, 30Gy/10F and 39Gy/13F) were analysed descriptively in relation to cancer diagnosis, age, and overall survival (OS). OS was calculated as the interval from start of RT until death from any cause. Kaplan-Meier estimates were used for univariate OS, illustrated by survival plots, and the log rank test was used for comparing the survival between groups.

Results:

A total of 1653 palliative RT treatments were registered in our database. Due to small sample sizes, 38 cases (gynaecological and haematological cancer) were excluded. Of the remainder, 1385 cases had information regarding diagnosis and RT schedule available and were included in the study. The main groups were lung (32.2%), prostate (31.6%), and breast (19.8%) cancer (table 1). As shown in table 1, the clinicians prescribed 30Gy/10F in most patients with myelomatosis, whereas 20Gy/4F or 20Gy/5F were the most preferred RT schedules in all other patients. Clinicians were more likely to prescribe a single fraction schedule in patients with upper GI-cancer, compared to all other tumour types.

Figure 1a shows OS for each diagnosis, with median OS ranging from 1.5 (95%CI: 1.1-1.9) months for upper GI cancers to 13.0 (95%CI: 6.3-19.7) months for patients diagnosed with myelomatosis.