ESTRO 2024 - Abstract Book

S2233

Clinical - Upper GI

ESTRO 2024

We included in the analysis 73 patients, (median age 66 years, range 41 - 83), encompassing 81 treated metastases. Treatments were delivered in oligometastatic (OM) setting and oligoprogressive (OP) setting in 32 and 49 cases respectively. Breast cancer (n= 29/81) and colorectal cancer (n=19/81) were the most represented histotypes.

More than one chemotherapy line was prescribed in 27/81 cases. SBRT was delivered with RRT and VMAT in 25 and 56 cases respectively.

SBRT was delivered in 3 or 5 fractions for a total dose of 30-60 Gy. Median BED was 112.5 Gy (range 59.5 - 180) with 54 lesions treated with BED > 100Gy.

Median OS, LC and PFS were 28 months (95CI 16-37), 30 months (95CI 21-41) and 8 months (95CI 6-10) respectively.

OS, LC and PFS were 79%, 74% and 32% at 1 year and 50%, 57% and 21% at 2 years, respectively.

LC was correlated only to BED >100 Gy (41 vs 21 months, p 0.041, HR 0,47 95CI 0.19 - 1.1) (Fig.1)

At univariate analysis, PFS was associated with BED >100 Gy (p 0.0002, HR 0,4 95CI 0.2-0.75) and administration of a second or further treatment line (p 0.00014 HR 0,4 95CI 0.2-0.75). Both variables proved independently correlated at multivariate analysis (p 0.008 and p 0,0048 respectively). OS was correlated with BED >100 Gy (p 0,001, HR 0,35 95CI 0.16-0.78) (Fig. 2) and administration of a second or further treatment line ( 31 vs 12 months, p 0.0301, HR 2.4 95CI 1.1 -5.9). Both variables proved independent at multivariate analysis (p 0.01 and p 0,037 respectively).

No differences were found in terms of treatment outcome for technique, OP/OM disease, primary histology and age <66 years.

Conclusion: