ESTRO 2024 - Abstract Book

S1511

Clinical - Lower GI

ESTRO 2024

Table 1.

Baseline characteristics

60Gy/48Gy/30fractons

3 (1 w/o elective dose)

60.2Gy/50.4Gy/28 fractions

2

50.4Gy/28 fractions

1

30Gy/15 fractions

1

Time since primary radiotherapy, years

Median (range)

4.3 (1.7-12.5)

Recurrence

Size (mm), max diameter (range)

45 (20-70)

Multifocal (n)

3

Intent, re-irradiation

Neo-adjuvant

2

Definitive 5 Concomitant chemotherapy, re-irradiation

Cisplatin/capecitabin

3

Cisplatin monotherapy

2

Capecitabin monotherapy

2

Outcome, 3 month

No response

1

Partial response

3

Complete response

3

The 7 initial patients had reached 3 month follow up and were included. The median follow up was 413 days, (range 126-747). All were female with a median age of 64 years. Two were included in the neo-adjuvant arm, 5 in the definitive arm. Primary radiotherapy was given between 1.7 to 12.5 years prior to reirradiation, and doses ranged from 30 Gy to 60.2 Gy. Recurrences varied in size from 20 to 70 mm (maximal diameter) and three were multifocal (Table 1). One patient had no response at 3-month evaluation, three had complete response and three partial response evaluated by PET-CT and MRI (n=4) or CT (thorax, abdomen, pelvic) and MRI (n=3). The two patients treated with neo-adjuvant intention were not resected at follow up due to response to re-irradiation.

Grade 3 toxicity occurred in two patients, both radiation dermatitis, and one with subsequent grade 3 pain, for most frequent toxicities see figure 1.

Conclusion: