ESTRO 2024 - Abstract Book

S1510

Clinical - Lower GI

ESTRO 2024

definitive therapy for anal cancer recurrences. Here we report the first feasibility analysis of acute toxicity and 3 month outcome.

Material/Methods:

Patients fulfilling in- and no exclusion criteria (in brief, squamous cell, anal cancer recurrence, previously treated with radiotherapy and a minimum of 30 Gy overlap, Clinical Trials NCT 05055635) were evaluated at multidisciplinary team conferences as either marginally resectable or non-resectable, and included in the neo adjuvant or definitive radiotherapy arm. The reirradiation consisted of intensity modulated proton therapy, 55Gy(RBE) in 1.25 Gy fractions, twice daily (neo adjuvant) or 57.5-65 Gy(RBE) in 1.25 Gy fractions twice daily (definitive), and concomitant chemotherapy according to Danish national guidelines: cisplatin and capecitabine combined or as monotherapy depending on previous toxicity.

Toxicity was scored prospectively using CTCAE v. 5.0. Here we report baseline, acute (worst toxicity during last week of radiotherapy until 14-day follow-up), and 3-month toxicity.

Results:

Table 1.

Baseline characteristics

Gender, female (n)

7

Age

years, median (range)

64 (56-74)

Primary radiotherapy dose (n)