Bladder Filling in Patients Undergoing Prostate Radiotherapy

Background: Radiotherapy is an effective treatment for prostate cancer, with up to 91% of patients experiencing biochemical or clinical failure-free outcomes after five years. However, the Patients undergoing radiation therapy for prostate cancer or after prostate removal (prostate bed) require precise targeting to minimize negative side effects. The accuracy of radiation delivery is greatly influenced by the volume of the bladder and rectum. Objective: We investigated the dosimetric impact of bladder filling in patients treated on the Synergy Linac for prostate cancer. Specifically, we examined the impact of bladder volume, dosage, and other variables on the treatment outcomes bladder volume variations, adherence to the original bladder filling guidance, and their effects on treatment outcomes. Methods: Ten patients undergoing prostate radiotherapy on the linac were included in this study. Before treatment, patients were instructed to drink water to achieve a bladder volume of 200 - 300 cm³. Bladder and bowel contours were re-outlined offline on 140 images, and treatment plans were recalculated. Bladder preparation: Patients are recommended to ensure that their bladders are sufficiently full throughout radiotherapy treatments. When the bladder is distended, it displaces the colon and a segment of the bladder from the treatment region, thereby reducing the radiation dose received by healthy tissues. The evaluation of bladder volume is based on an individual’s urination frequency. Optimal hydration is crucial. It is advisable for patients to eat approximately two litres of fluid daily to keep their bladder comfortably filled. It is recommended to limit the intake of substances that can irritate the bladder, such as tea, coffee, alcohol, and beverages containing caffeine. Rectal Preparation: It is essential to ensure that the rectum is completely empty to provide accurate therapy. Variations in the composition of the intestinal contents can lead to a displacement of the prostate from its usual position. Before the CT planning scan and in the initial days of treatment, patients are directed to self-administer a gentle enema. If the colon seems enlarged during the planning scan due to the presence of gas, patients are advised to release the gas and undergo a subsequent scan. Factors Affecting Bladder Capacity: Urination patterns of individuals. Pharmaceuticals that affect the operation of the bladder and regulate water balance. Patient compliance with the prescribed fluid consumption. Relevance for medical treatment: