ESTRO 2021 Abstract Book

S108

ESTRO 2021

Conclusion BCI highly determines the development of future cognitive impairment, although the impairment could be sustained (34%), reversible (27%), recurred (31%), or reversed and recurred alternatively (9%).

OC-0177 Quality of life after dose-escalated chemoradiation for locally advanced rectal cancer M. Verweij 1 , S. Hoendervangers 1 , A. Couwenberg 2 , M. Burbach 3 , M. Berbee 4 , J. Buijsen 4 , J. Roodhart 5 , O. Reerink 6 , A. Pronk 7 , E. Consten 8,3 , A. Smits 9 , J. Heikens 10 , H. van Grevenstein 11 , M. Intven 1 , L. Verkooijen 1 1 University Medical Center Utrecht, Radiation-Oncology, Utrecht, The Netherlands; 2 Netherlands Cancer Institute, Radiation-Oncology, Amsterdam, The Netherlands; 3 University Medical Center Groningen, Surgery, Groningen, The Netherlands; 4 Maastricht University Medical Center , Radiation-Oncology, Maastricht, The Netherlands; 5 University Medical Center Utrecht, Medical Oncology, Utrecht, The Netherlands; 6 Isala Cinic, Radiation-Oncology, Zwolle, The Netherlands; 7 Diakonessenhuis, Surgery, Utrecht, The Netherlands; 8 Meander MC, Surgery, Amersfoort, The Netherlands; 9 Antonius Hospital, Surgery, Nieuwegein, The Netherlands; 10 Rivierenland Hospital, Surgery, Tiel, The Netherlands; 11 University Medical Center Utrecht, Surgery, Utrecht, The Netherlands Purpose or Objective Dose-escalated chemoradiation (CRT, preceded by a boost of 5x3Gy) did not result in increased complete response rates in locally advanced rectal cancer (LARC) patients as compared to standard CRT in the randomized RECTAL-BOOST trial (Clinicaltrials.gov NCT01951521). However, dose-escalated CRT initiated significantly more tumor regression (Mandard 1-2), suggesting potential to enable organ preservation in selected patients. This study compared patient reported outcomes (PROs) and disease-free survival (DFS) between patients who received dose-escalated CRT (boost group) or standard CRT (control group) in the first 2 years following randomization. Materials and Methods Patients with LARC (n=128), participating in the RECTAL-BOOST trial, filled out EORTC QLQ-C30 and CR29 questionnaires on general and colorectal cancer specific quality of life (QoL) and symptoms at baseline, and at 3, 6, 12, 18 and 24 months following start of treatment. Between-group differences in functional QoL domains were estimated using a linear mixed effect model and expressed using the effect size (ES). Symptom scores were categorized as no (0), mild (1-49), moderate (50-99) or severe (100) and compared using the Mann-