ESTRO 2024 - Abstract Book

S5092

Physics - Radiomics, functional and biological imaging and outcome prediction

ESTRO 2024

respectively. The median follow-up time was 31 months from the start of treatment. 14 (34%) patients were classified as non-responders and 27 (66%) as responders. Local relapses were reported after a median time of 19 months, after treatment start. Among the ADC first-order features, at baseline, only lower skewness (cut-off= 0.64; p= 0.043), showed a statistically significant positive impact on the LRFS (Figure2a). Moreover, higher ADC median values after 6 months follow-up (cut-off= 1763 [10-6 mm2/s]; p= 0.048) were positively associated with a better LRFS (Figure 2b).

Figure 2. Local relapse free survival (LRFS) Kaplan-Meier curves for patients stratified based on the baseline ADC skewness median value (0.64) (a), and 6-months follow-up ADC median value (cut-off= 1763 [10-6 mm2/s]) (b).

Conclusion:

Lower pre-treatment skewness and higher median short-term follow-up ADC reported a positive association with local relapse free survival in patients affected by ACC treated with CIRT. Quantitative DW-MRI may represent independent early biomarker in this treatment setting, hence more comprehensive prospective studies, with larger sample size and number of local relapse events, are highly encouraged.

Keywords: Adenoid Cystic Carcinoma, ADC, biomarker

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