ESTRO 2024 - Abstract Book

S2206

Clinical - Upper GI

ESTRO 2024

was 9 weeks (2- 21). All pts treated with FLOT regimen underwent surgery while 3 pts treated with CROSS were excluded from surgery (1 died, 1 early progression, 1 worse clinical conditions).

Six pts (12%) reached pCR in CROSS vs 7 pts (10%) in FLOT. Percentages of cell viability are reported in table 1.

Table 1: cell viability; comparison between CROSS and FLOT

% Cell viability 0% (pCR)

=<20%

>20%

21%-50%

51%-100% 4 pts (13%) 38 pts (54%)

CROSS

6 (12%) 7 (10%)

25 pts (48%) 18 pts (26%)

14 pts (32 %) 45 pts (64 %)

10 pts (19%)

FLOT

7 pts (10%)

Post-surgical complication rate was 52% in CROSS vs 49% in FLOT pts. Four pts In FLOT received adjuvant radiotherapy (2: R1 and N3 and 2: N3). At a median Follow up of 14 months, 5 pts (10%) in CROSS group had a local relapse vs 5 pts (7%) treated with FLOT. Distant progression was greater in CROSS pts 23 (47%) vs 20 pts (29%) in FLOT. Median OS was slightly better in FLOT pts, it was 26 months vs 21 months in CROSS pts.

Conclusion:

Neoadjuvant CROSS regimen seems not to be the best strategy to assure better OS in pts with distal or esophageal gastric junction adenocarcinoma even if a trend of major pathological response was reached and a cellular viability is lower adding radiotherapy. Post surgery complications and outcome seem to be a little in favor of FLOT regimen. Some questions are open: Does a neoadjuvant treatment with FLOT followed by chemoradiotherapy improve these results? Can RT dose intensification play a significant role? Can radiomic in non risponders pts help to decide the best strategy?

Keywords: Esophageal adenocarcinoma, FLOT, CROSS

1768

Digital Poster

Optimizing Esophageal Cancer Radiotherapy Plans: A Data-Driven Approach

Ti-Hao Wang 1 , Chih-Yuan Lin 2 , Shih-Ming Hsu 2

1 China Medical University Hospital, Radiotherapy, Taichung, Taiwan. 2 National Yang Ming Chiao Tung University, Biomedical Imaging and Radiological Sciences, Taipei, Taiwan

Purpose/Objective: