ESTRO 2024 - Abstract Book

S5040

Physics - Radiomics, functional and biological imaging and outcome prediction

ESTRO 2024

For grade≥2 frequency, PRSi-modulated VBA (after BH correction) identifies a caudal-posterior region (also including the trigone) with a lateral extension covering 30% of the bladder wall and a cranio-caudal extension of 54%. HRs for the dose in this region are ∼ 1.01-1.12 (per 1Gy), and p-values range=10E-8-0.05 (Figure-2). We found no specific area (after BH correction) without the inclusion of the modulation from the PRSi, and we had an increase in the slope of the dose-response relationship, with HRs up to 0.06 higher (per 1Gy, PRSi-modulated vs no modulation).

For grade≥1 haematuria, PRSi-modulated VBA detects a large region covering the whole extension of the bladder wall, except for two small areas located centrally in the cranio-caudal direction, one in the anterior part and the other in the posterior position. HRs for the dose are ∼ 1.01-1.07 (per 1Gy) and p=0.0002-0.05. The extension of the region exhibiting statistically significant differences increased by 11% compared to VBA without PRSi-modulation, and HRs increased up to 0.03 (per 1Gy).

Conclusion:

We proposed a new method to include the single-patient genetic risk at a patient level in VBA and showed the benefit through an application on a large cohort of prostate cancer patients with long-term follow-up.

The method created PRSi-modulated dose maps and can be naturally translated and extended into the inclusion of modulation from other patient-specific risk factors, even considering multiple features together.

In the present analysis, we identified specific bladder subregions associated with late haematuria and urinary frequency. Modulation by the PRSi increases the areas classified as significantly different and re-gains steepness for the dose-response curve at a voxel level.

These results suggest the value of clarifying patient-specific risk factors to synergistically clarify dose-response relationships and the identification of heterogeneity in the radiobiology across tissues.

Keywords: Voxel-based analysis, polygenic risk scores, Cox