2026 - Can Consistency in Treatment Time and Positioning time Improve the Reproducibility of Intestinal and Bladder Conditions? A Self-Controlled Prospective Non-Randomized Study
Presenter(s)
R. Cai1, L. L. Xu2, L. Yang1, W. X. Yao3, J. Li4, L. Bo5, H. Yang6, L. C. Wei7, L. Zhao8, and F. Bai9; 1Department of Radiotherapy, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China, 2Department of Radiation Oncology, Xijing Hospital, Fourth Military Medical University, xi'an, shaanxi, China, 3Department of Radiation Oncology, Xijing Hospital, Fourth Military Medical University., xi'an, shaanxi, China, 4Department of Radiation Oncology,Xijing Hospital,Air Force Medical University CN, Xi’an, China, 5Department of Radiation Oncology, Xijing Hospital, Fourth Military Medical University. Xi’an, China, Xi'an, Shanxi, China, 6Department of radiation oncology, Xijing Hospital, the Fourth Military Medical University, Xi'an, China, 7Department of Radiation Oncology, First Affiliated Hospital of Air Force Medical University, Xi'an, China, 8StateKey Laboratory of Holisticntegrative Managementof Gastrointestinal Cancersand Department of RadiationOncology,Xijing Hospital,Fourth Military MedicalUniversity, Xi'an, China, 9Department of Radiation Oncology, Xijing Hospital, Fourth Military Medical University, xi'an, Shaanxi, China
Purpose/Objective(s): The toxicity and survival of radiotherapy at different times have been reported in different diseases in clinical practice.However,there are few reports on whether there are differences between intestinal tract and bladder in patients at different times and at the same times.Therefore,our objective was to investigate whether consistency between treatment time and positioning time affects the repeatability of intestinal and bladder conditions in rectal cancer radiotherapy. It provides reference for clinical reasonable arrangement of treatment time.
Materials/Methods: Patients with rectal cancer who received IMRT with linear accelerator in our department from May 2024 to January 2025 were prospectively selected. The dose of radiotherapy was 5× 5 Gy, and capecitabine was given orally at the same time. All patient positioning times were randomly scheduled by the attending physician according to the daily appointment schedule; the first treatment time was randomly scheduled by the professional staff to the daily fixed time (am10:00-11:00,pm15:00-16:00); the subsequent treatment time was randomly scheduled by the therapist according to the daily treatment situation. All patients underwent CBCT location scan before each treatment and matched with positioning CT. Rectal diameter and bladder filling volume were recorded at positioning and at each treatment. SPSS25.0 software was used for data analysis.
Results: A total of 46 patients were included in the analysis between 2023 and 2024, with a median age of 60 years (range: 31-75 years), including 24 males and 22 females. The average bladder filling volume during positioning was 311.34 ml (range: 182.14-544.30 ml), and the average rectal diameter was 3.60 cm (range: 1.63-6.12 cm). Results was found that when the treatment time was consistent with the positioning time, the bladder filling volume was (299.02±109.79 vs. 311.34±85.73) ml, p=0.519; the rectal diameter was (3.52±0.79 vs. 3.60±0.96) cm, p=0.600. When the treatment time was inconsistent with the positioning time, the bladder filling volume was (309.77±102.01 vs. 311.34±85.73) ml, p=0.952; the rectal diameter was (3.56±0.91 vs. 3.60±0.96) cm, p=0.784. When treatment duration was inconsistent, the bladder filling volume was (299.03 ± 109.80 vs 309.77 ± 102.02) ml, p=0.469;the rectal diameter was (3.52 ± 0.80 vs 3.56 ± 0.92) cm, p=0.732.
Conclusion: This study is the first to demonstrate that bladder filling volume and rectal diameter are independent of treatment timing during radiotherapy for rectal cancer. Therefore, the treatment time can be flexibly arranged according to the workload of the treatment room and the actual situation of the patient.