INTRODUCTION AND OBJECTIVES: Percutaneous neph-
rolithometry (PCNL) may be associated with signi
fi
cant ionizing radia-
tion exposure for patients and operating room personnel. We conducted
a multicenter study to assess the predictors of increased radiation
exposure during PCNL.
METHODS: We performed a multicenter retrospective review of
patients undergoing PCNL. Patient demographics, stone characteristics
and perioperative data including
fl
uoroscopy time were recorded and
analyzed. Preoperative CT images were reviewed and S.T.O.N.E.
score was assigned to each patient.
RESULTS: A total of 1700 patients were included in the anal-
ysis. The mean age and body mass index (BMI) were 63.4
15 and
31.2
7kg/m2 respectively. Mean stone size and mean overall neph-
rolithometry score was 3.7 and 8.3 (SD
¼
2.2) respectively. Overall sin-
gle procedure stone-free rate was 72%. In logistic regression analysis,
stone size (p
<
0.01), number of calyces (p
<
0.01), BMI (p
<
0.01), longer
procedure time (p
<
0.01), skin-to-stone distance (p
<
0.01) and
S.T.O.N.E. score (p
<
0.01) were signi
fi
cantly associated with increased
fl
uoroscopy time. Stone-free patients had statistically signi
fi
cant lower
radiation exposure compared to patients with residual stones (8.7 vs.
16.9 minutes, respectively; P
<
0.001). On average, for each increase in
one unit of S.T.O.N.E score, there was additional 1.5 minutes of
fl
uo-
roscopy time. In risk strati
fi
cation, low-risk patients with 5-7 scores had
7.8 minutes of
fl
uoroscopy time, compared to medium-risk (8-10) and
high-risk patients (11-13) who had 12.8 and 15.8 minutes of
fl
uoroscopy
time, respectively (p
¼
0.001).
CONCLUSIONS: In this multicenter study, patients with greater
stone size, BMI, number of calyces, skin-to-stone distance and
S.T.O.N.E. nephrolithometry were associated with increased radiation
exposure during PCNL. Alternative modi
fi
ed pulsed
fl
uoroscopy tech-
niques or radiation-free imaging modalities such as ultrasound should
be used in order to reduce the amount of ionizing radiation during the
PCNL procedures |
