Strahlenbelastung der Patienten bei der ureterorenoskopischen Steinentfernung

Impact of Surgical Experience on Radiation Exposure during Retrograde Intrarenal Surgery: A Propensity-Score Matching Analysis

BACKGROUND

The impact of surgical experience on radiation exposure (RE) during endourological procedures has been poorly investigated.

OBJECTIVE

To assess the impact of surgical experience on fluoroscopy time (FT) and RE during retrograde intrarenal surgery (RIRS).

DESIGN, SETTING, AND PARTICIPANTS

The study included 140 patients who underwent RIRS performed either by a senior surgeon (expertise of >100 RIRSs) (group A) or by two junior residents (expertise of <15 RIRSs) (group B) between January 2016 and May 2018.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We tested the hypothesis that surgical experience had a limited impact on RE during RIRS. To adjust for potential baseline confounders, propensity-score matching was performed. Descriptive statistics and linear regression models tested the association between clinical variables and FT and patients' effective doses.

RESULTS AND LIMITATIONS

There was no significant difference between the two groups for baseline, intraoperative, and postoperative characteristics. Overall FT (p=0.97) and effective dose (p=0.79) did not differ between groups. A statistically significant association was found between male sex (all p<0.03), stone burden (all p<0.001), operative time (all p<0.003), and postoperative double-J placement (all p<0.02) with both FT and effective dose. Linear multivariable analysis revealed that body mass index was significantly associated with effective dose (p=0.002). Similarly, longer operative time (all p<0.03) and double-J placement (all p<0.04) were significantly associated with increased FT and effective dose.

CONCLUSIONS

Surgical experience has a limited impact on FT and RE during RIRS. Longer operative time and double-J placement were associated with increased FT and effective dose.

PATIENT SUMMARY

In this study, we assessed whether surgical experience affects fluoroscopy time and patient's effective dose during retrograde intrarenal surgery (RIRS). We found that radiation exposure (RE) was not affected by surgeon's experience and that the standardisation of the surgical technique at the beginning of the learning curve of young surgeons may represent the key factor in reducing RE during RIRS.

Decreased Radiation Exposure and Increased Efficacy in Extracorporeal Lithotripsy Using a New Ultrasound Stone Locking System

PURPOSE

To compare fluoroscopy duration, radiation dose, and efficacy of two ultrasound stone localization systems during extracorporeal shockwave lithotripsy (SWL) treatment.

PATIENTS AND METHODS

Monocentric prospective data were obtained from patients consecutively treated for renal stones using the Sonolith(®) i-sys (EDAP TMS) lithotripter, with fluoroscopy combined with ultrasound localization using an "outline" Automatic Ultrasound Positioning Support (AUPS) (group A), or the "free-line" Visio-Track (VT) (EDAP-TMS) hand-held three-dimensional ultrasound stone locking system (group B). Efficacy rate was defined as the within-groups proportion stone free or with partial stone fragmentation not needing additional procedures. Statistical analysis used Pearson chi-square tests for categoric variables, nonparametric Mann-Whitney tests for continuous variables, and linear regression for operator learning curve with VT. Continuous variables were reported as median (range) values.

RESULTS

Patients in group A (n=73) and group B (n=81) were comparable in baseline characteristics (age, kidney stone size, others) and in SWL application (duration, number of shocks, energy [Joules]). During SWL, the median (range) duration (seconds) of radiation exposure was 159.5 (0-690) in group A and 3.5 (0-478) in group B (P<0.001) and irradiation dose (mGy.cm(2)), 10598 (0-54843) in group A and 163 (0-13926) in group B (P<0.001). Fluoroscopy time significantly decreased with operator experience using VT. The efficacy rate was 54.5% in group A and 79.5% in group B (P=0.001).

CONCLUSION

VT significantly reduced fluoroscopy use during SWL and the duration and dose of patient exposure to ionizing radiation. Stone treatment efficacy was significantly greater with VT mainly because of a better real-time monitoring of the stone.

[Eye lens radiation exposure during ureteroscopy with and without a face protection shield: Investigations on a phantom model]

BACKGROUND AND OBJECTIVES

Eye lens radiation exposure during radiologically-guided endoscopic procedures may result in radiation-induced cataracts; therefore, we investigated the ocular radiation exposure during ureteroscopy on a phantom model.

MATERIALS AND METHODS

Using an Alderson phantom model and eye lens dosimeters, we measured the ocular radiation exposure depending on the number of X-ray images and on the duration of fluoroscopic imaging. The measurements were done with and without using a face protection shield.

RESULTS

We could demonstrate that a significant ocular radiation exposure can occur, depending on the number of X-ray images and on the duration time of fluoroscopy. Eye lens doses up to 0.025 mSv were recorded even using modern digital X-ray systems. Using face protection shields this ocular radiation exposure can be reduced to a minimum.

CONCLUSION

The International Commission on Radiological Protection (ICRP) recommendations of a mean eye lens dosage of 20 mSv/year may be exceeded during repeated ureteroscopy by a high volume surgeon. Using a face protection shield, the eye lens dose during ureteroscopy could be reduced to a minimum in a phantom model. Further investigations will show whether these results can be transferred to real life ureteroscopic procedures.

Evaluating Parameters Affecting Fluoroscopy Time During Percutaneous Nephrolithotomy: Focus on the Predictive Role of Guy's, S.T.O.N.E., and CROES Scoring Systems

OBJECTIVE

To identify parameters predicting prolonged fluoroscopy time (FT) during percutaneous nephrolithotomy (PCNL) and to evaluate the predictive ability of Guy's stone score, S.T.O.N.E. nephrolithometry, and CROES nomogram.

PATIENTS AND METHODS

We evaluated 153 consecutive patients who underwent a PCNL by a single experienced surgeon. Several preoperative, intraoperative, and postoperative parameters, including the three scoring systems, were assessed for their ability to predict FT.

RESULTS

FT was significantly associated with stone burden, stone location, number of stones, number of punctures, and number of tracts. It was also significantly associated with all scoring systems. Fluoroscopy use was significantly higher in patients who were effectively treated in these with longer hospitalization, probably reflecting case complexity. No association was found with postoperative complications.

CONCLUSIONS

FT during PCNL can be affected by several parameters. Identifying the ones that can affect FT can lead to fluoroscopy and radiation exposure decrease. Guy's stone score, S.T.O.N.E. nephrolithometry, and CROES nomogram can all predict complexed cases and the need for increased FT.

Extracorporeal shock waves lithotripsy versus retrograde ureteroscopy: is radiation exposure a criterion when we choose which modern treatment to apply for ureteric stones?

The aim of this study is to compare two major urological procedures in terms of patient exposure to radiation. We evaluated 175 patients, that were subjected to retrograde ureteroscopy (URS) and extracorporeal shock waves lithotripsy (ESWL) for lumbar or pelvic ureteral lithiasis, at two urological departments. The C-arm Siemens (produced in 2010 by Siemens AG, Germany) was used for ureteroscopy. The radiological devices of the lithotripters used in this study in the two clinical centers had similar characteristics. We evaluated patient exposure to ionizing radiation by using a relevant parameter, the air kerma-area product (PKA; all values in cGy cm(2)), calculated from the radiation dose values recorded by the fluoroscopy device. PKA depends on technical parameters that change due to anatomical characteristics of each case examined, such as body mass index (BMI), waist circumference, and stone location. For the patients subjected to ESWL for lumbar ureteral lithiasis the mean of PKA (cGy cm(2)) was 509 (SD=180), while for those treated for pelvic ureteral lithiasis the mean of PKA was 342 (SD=201). In the URS group for lumbar ureteral lithiasis, the mean of PKA (cGy cm(2)) was 892 (SD=436), while for patients with pelvic ureteral lithiasis, the mean of PKA was 601 (SD=429). The patients treated by URS had higher exposure to ionizing radiation dose than patients treated by ESWL. The risk factors of higher radiation doses were obesity, exposure time, and localization of the stones.