Ensuring bladder volume reproducibility and reducing cone-beam computed tomography-related radiation exposure in prostate hypofractionated radiotherapy by a Certified Nurse in Radiation Oncology nursing

The role of the Certified Nurse in Radiation Oncology nursing (CN-RO) has expanded to include support for ensuring treatment reproducibility and minimizing medical radiation exposure through radiation protection measures. In hypofractionated radiotherapy for prostate cancer, in which consistent pretreatment bladder volume is more critical than in conventional fractionation, whether CN-RO intervention contributes to bladder volume reproducibility and reduction of cone-beam computed tomography (CBCT) frequency, lowering radiation exposure, was investigated. Sixty prostate cancer patients undergoing hypofractionated radiotherapy (51.6 Gy in 12 fractions) were retrospectively analyzed. Twenty patients received CN-RO intervention (Current Intervention (CI) group), which involved dehydration risk assessment and bladder volume guidance using a handheld bladder ultrasound scanner from the first session. Forty patients received no such intervention (Previous Intervention (PI) group). Bladder volume reproducibility, calculated as treatment bladder volume divided by planning bladder volume, and the number of CBCT scans were compared between the groups. The target was to achieve ≥70% reproducibility and to initiate treatment with the first CBCT scan in all sessions. There was no significant difference in bladder volume at treatment planning between the groups (P = 0.851). Mean bladder volume reproducibility was significantly higher in the CI group (96.5 ± 12.0%) than in the PI group (86.9 ± 14.2%, P = 0.022). Treatment was initiated after the first CBCT scan in 95.4% of sessions in the CI group (229/240), compared with 80.0% in the PI group (384/480, P < 0.001). These results suggest that CN-RO intervention enhances bladder volume reproducibility and contributes to reduced radiation exposure through fewer CBCT scans.