Gel Rolls Increase Percutaneous Nephrolithotomy Radiation Exposure.

Area of Science:

• Urology
• Medical Physics
• Radiology

Background:

• Reducing radiation exposure during endoscopic stone surgery is a growing concern.
• Conflicting evidence exists regarding the impact of patient positioning (prone vs. supine) on radiation doses during percutaneous nephrolithotomy (PCNL).
• Clinical observations suggested increased radiation with intraoperative CT imaging when patients were positioned prone on gel rolls.

Purpose of the Study:

• To investigate whether gel rolls used for patient positioning in percutaneous nephrolithotomy (PCNL) directly increase intraoperative radiation doses.
• To compare radiation doses associated with different positioning materials and techniques.

Main Methods:

• Anthropomorphic experiments simulating PCNL positions were conducted using a robotic multiplanar fluoroscopy system.
• A fluoroscopy phantom was positioned prone on gel rolls, blankets, or directly on the table, and in modified supine positions.
• Dose Area Product (DAP) was measured and compared across various positioning scenarios, including the impact of C-arm direction and saline bag use.

Main Results:

• Positioning prone on gel rolls resulted in a significant increase in measured DAP (146 μGy*m², 287%) compared to positioning on blankets of equal thickness (62.29 μGy*m², 23%).
• Radiation doses varied considerably between experimental groups even when fluoroscopy time was constant.
• The study found that gel rolls directly increase radiation dose, a finding not previously reported.

Conclusions:

• Gel rolls used for patient positioning during PCNL procedures demonstrably increase radiation doses.
• Surgeons should consider using radiolucent materials for patient positioning to minimize radiation exposure.
• This finding has implications for patient safety and radiation management in urological surgery.