ESTRO 2024 - Abstract Book

S5167

Radiobiology - Immuno-radiobiology

ESTRO 2024

Adverse Events (CTCAE) v5.0. Fourteen patients (36.8%) developed grade 1 acute GU toxicity and 7 (18.4%) grade 2. As regards acute GI toxicity, 26.3% of patients experienced grade 1 and 31.6% of patients grade 2 toxicity. The prevalence of grade 1 and 2 GU late toxicity at last follow up was 34.2% and 15.2% respectively, and for grade 1 and 2 GI toxicity was 31.6% and 15.8% respectively. No grade ≥3 was registered.

Considering the entire group of enrolled patients (38), the circulating concentrations of IFN-α, IL-2 and IFN-β displayed significant variations (p-value < 0.05) during the 5 time points considered (Figure 1). In particular, we found reduction of IFN-α values for all time points, reduction of IL-2 until the FUP 3mo and a slight subsequent increase, IFN-β clear reduction in value at time points FUP 6mo and FUP 12mo. We observed no statistically significant differences of basal cytokines concentration for age or for clinical/pathological T stage groups. As regards the treatment, basal serum concentration of IFN-γ was significantly lower in definitive patients group (median: 12.7 pg/ml; IQR: 12.1-14.3 pg/ml) respect to post-operative one (median: 13.9 pg/ml; IQR: 13.9-18.7 pg/ml) (p-value: 0.039). No correlation between late GI or GU toxicity and the cytokines concentrations at PRE-RT and END-RT time points was found.