Dietary Counselling to Increase Soluble Fibre in Patients with Gynaecological Cancers Undergoing Pelvic Radiotherapy: A Feasibility Study

Background: This study aimed to determine the feasibility of increasing soluble fibre intake via dietary counselling to improve gastrointestinal toxicity and quality of life 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 over the duration of their RT (5-6 weeks) to increase soluble fibre intake incrementally each week. Stakeholder surveys were also completed.

Results: In total, 9 of 14 eligible patients participated (55 years old [SD 13.2], diagnosis: cervical [n = 3], endometrial/uterine [n = 5] and vaginal [n = 1]), with the majority categorised as low fibre consumers at baseline (n = 6). On average, soluble fibre intake increased by 150% throughout treatment. There were no adverse events or major adjustments required for RT delivery. There were improving trends in the functional subset identified. Results may be confounded by the sample size resulting from limited eligibility (n = 14) and a high attrition rate (n = 4).

Conclusions: Most participants successfully increased their soluble fibre intake throughout treatment, without significant adverse events noted for RT delivery accuracy. These results provide preliminary data to calculate the sample size required to produce meaningful effect sizes. However, this study highlighted challenges in participant recruitment and retention, with limited organisational support and perceived compatibility.