Aim: To determine if increasing soluble fibre intake via dietary counselling is feasible and improves patient outcomes (gastrointestinal toxicity (GI) and quality of life (QOL)) in patients with gynaecological cancers undergoing pelvic radiotherapy without adverse consequences on radiation treatment (RT) delivery accuracy.
Methods: A single-arm, single-centre intervention feasibility trial included patients with gynaecological cancers undergoing pelvic RT ±chemotherapy at a tertiary hospital. Participants were provided weekly dietary counselling to increase soluble fibre intake incrementally each week during treatment. GI toxicity and QOL scores were assessed using the Inflammatory Bowel Disease questionnaire and the European Organisation for Research and Treatment of Cancer Quality of Life questionnaire. Results were analysed using Mann-Whitney U tests.
Results: In total, 9 of 14 eligible patients participated (55 years old (SD 13.2), diagnosis: 3 cervical, 5 endometrial/uterine, 1 vagina), with the majority categorised as low fibre consumers at baseline (n=6). The median soluble fibre baseline intake was 3g (1-6.5g) and on average, increased by 150% throughout treatment. There were no adverse events or major adjustments required for radiation treatment delivery. There were no significant differences between low and moderate/high fibre consumers in fibre change (%) or with fibre intake at the end of RT (g) with GI toxicity (P=0.149) and quality of life (P=0.083), however improving trends in the functional subset were identified. Results may be confounded by the sample size resulting from limited eligibility (n=14) and high attrition rate (n=4).
Conclusion: The majority of participants successfully increased their fibre intake throughout treatment, with no significant adverse events noted for radiation treatment delivery accuracy. This study highlighted challenges in participant recruitment and retention. Further research is required to inform the efficacy of a high fibre diet in this cohort. These results provide preliminary data to calculate the sample size required to produce meaningful effect sizes.