Presented by: Akin S. Amasyali MD
Loma Linda University Health

Introduction

There has been little study of radiation safety among pregnant healthcare workers, but current occupational recommendations limit fetal dose to 1 mSv. No prior study has investigated surgeon uterine radiation dose during percutaneous nephrolithotomy (PCNL). With the increased gender diversity in urology, understanding uterine radiation exposure is important. The purpose of this study was to determine surgeon uterine radiation dose during PCNL and the efficacy of radiation reduction techniques. 

Materials

A coronally bisected cadaver, with an 8-week sized uterus, was positioned standing at bedside, similar to a surgeon performing PCNL. An ion chamber was placed behind the anterior wall of the uterus to measure radiation dose. A second complete cadaver was positioned prone on the operating table to produce scatter radiation. Three different methods for reducing exposure were studied: pulsed fluoroscopy (1, 4, 8, 15, 30 pps), low dose (LD) fluoroscopy, and surgeon shielding (none, 0.35, 0.50, 0.70 mm lead equivalents). Using an image intensifier C-arm, 20 trials were conducted for each of 40 comparison groups to determine dose/second. For calculations, PCNL exposure time was assumed to be 5 minutes and the case number prior to reaching the 1 mSv limit was determined. Statistical analysis was performed using the Wilcoxon test, and Kruskal Wallis with Dunn’s test

Results

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Decreasing pulse frequency from 30 to 1 pps resulted in a 96% dose reduction (p<0.001). Compared to automatic exposure control (AEC), the low-dose setting decreased dose by 56% (p<0.001). Using continuous fluoroscopy with AEC and without shielding resulted in 0.086 mSv per PCNL to the uterus. Addition of a standard (0.35 mm) lead vest resulted in a 94% dose reduction (p <0.001). Compared to the 0.35 mm lead, the 0.50 and 0.70 mm lead vests further reduced dose by 12% and 47%, respectively. At AEC (30 pps) with no lead and 0.35 mm lead, a surgeon could perform 12 and 189 PCNLs respectively, prior to reaching the 1 mSv limit.  

Conclusion

Pregnant surgeons performing PCNL with conventional fluoroscopy settings and no lead could reach unsafe fetal exposure levels after 12 cases. By employing shielding, low-dose, and pulsed fluoroscopy, pregnant surgeons can safely perform PCNL without exceeding safe uterine exposure levels. Surgeons, especially those considering pregnancy, are strongly encouraged to implement dose reduction strategies. 

Funding

None

Lead Authors

Akin S. Amasyali, MD
Loma Linda University Health

Toby Clark,
Loma Linda University Health

Co-Authors

Kyu Park,
Loma Linda University Health

Nicole Mack,
Loma Linda University Health

Cliff De Guzman,
Loma Linda University Health

Matthew I. Buell, MD
Loma Linda University Health

Rose Leu, MD
Loma Linda University Health

Kanha Shete, DO
Loma Linda University Health

Ala'a Farkouh, MD
Loma Linda University Health

Elizabeth Baldwin,
Loma Linda University Health

Sikai Song, MD
Loma Linda University Health

D. Duane Baldwin, MD
Loma Linda University Health