P278 - RETROSPECTIVE ASSESSMENT OF A LOW-RESIDUE DIET AS A BOWEL PREPARATION STRATEGY IN PROSTATE RADIOTHERAPY

P278

RETROSPECTIVE ASSESSMENT OF A LOW-RESIDUE DIET AS A BOWEL PREPARATION STRATEGY IN PROSTATE RADIOTHERAPY

A. Majdi^1,2, F. Z. Chraa^2,3, C. ezzouitina^2,3, H. Moubarik^2,3, A. lachgar^2,3, K. Nouni^2,3, H. Elkacemi^1,2, T. kebdani^2,3,*, K. Hassouni^2,3

¹Radiotherapy, Institut National d'Oncologie, ²Medicine, Faculty of medicine and pharmacy mohammed V, ³Radiotherapy, National Institute of Oncology, RABAT, Morocco

Rationale: Prostate radiotherapy (RT) is commonly used for localized prostate cancer, and optimal bowel preparation is crucial for accurate targeting and minimizing toxicity to adjacent organs. A low-residue diet (LRD) has been proposed to reduce bowel content and gas, improving organ stability during RT. However, the effectiveness of a culturally adapted LRD has not been fully explored. This study evaluates the impact of a Moroccan-adapted LRD for patients undergoing prostate RT.

Methods: This retrospective study included 120 prostate cancer patients treated with external beam RT between January 2022 and December 2024. All patients followed a low-residue diet starting one week before radiotherapy and continuing through the treatment. The LRD included lean proteins, refined carbohydrates, cooked vegetables, and low-fiber fruits, while excluding legumes, raw vegetables, whole grains, and fried foods. Tolerability and the quality of pelvic preparation were evaluated, with a focus on prostate positional stability and organ volume reduction (rectum and bladder).

Results: Ninety percent of patients tolerated the LRD well, with mild gastrointestinal symptoms in 22% (bloating), 12% (abdominal pain), and 8% (diarrhea). No severe adverse events were linked to the diet. Adequate bowel preparation was achieved in 80% of patients. Strict adherence to the LRD resulted in significantly better prostate positional stability (mean positional variation: 2.3 mm vs. 4.8 mm) and a reduction in grade ≥2 acute gastrointestinal toxicity: rectal (12% vs. 30%) and bladder (8% vs. 20%).

Conclusion: The adapted LRD was well tolerated and effective in improving bowel preparation, enhancing prostate positional stability, and reducing acute gastrointestinal toxicity during prostate RT. These findings suggest the LRD is a simple, cost-effective strategy for optimizing prostate RT. Further studies are needed to confirm these results.

Disclosure of Interest: None declared