Abstract
Purpose Analysis of patient´s X-ray exposure during percutaneous radiologic gastrostomies
(PRG) in a larger population.
Materials and Methods Data of primary successful PRG-procedures, performed between 2004 and 2015 in 146
patients, were analyzed regarding the exposition to X-ray. Dose-area-product (DAP),
dose-length-product (DLP) respectively, and fluoroscopy time (FT) were correlated
with the used x-ray systems (Flatpanel Detector (FD) vs. Image Itensifier (BV)) and
the necessity for periprocedural placement of a nasogastric tube. Additionally, the
effective X-ray dose for PRG placement using fluoroscopy (DL), computed tomography
(CT), and cone beam CT (CBCT) was estimated using a conversion factor.
Results The median DFP of PRG-placements under fluoroscopy was 163 cGy*cm2 (flat panel detector systems: 155 cGy*cm2; X-ray image intensifier: 175 cGy*cm2). The median DLZ was 2.2 min. Intraprocedural placement of a naso- or orogastric
probe (n = 68) resulted in a significant prolongation of the median DLZ to 2.5 min
versus 2 min in patients with an already existing probe. In addition, dose values
were analyzed in smaller samples of patients in which the PRG was placed under CBCT
(n = 7, median DFP = 2635 cGy*cm2), or using CT (n = 4, median DLP = 657 mGy*cm). Estimates of the median DFP and DLP
showed effective doses of 0.3 mSv for DL-assisted placements (flat panel detector
0.3 mSv, X-ray image converter 0.4 mSv), 7.9 mSv using a CBCT – flat detector, and
9.9 mSv using CT. This corresponds to a factor 26 of DL versus CBCT, or a factor 33
of DL versus CT.
Conclusion In order to minimize X-ray exposure during PRG-procedures for patients and staff,
fluoroscopically-guided interventions should employ flat detector systems with short
transmittance sequences in low dose mode and with slow image frequency. Series recordings
can be dispensed with. The intraprocedural placement of a naso- or orogastric probe
significantly extends FT, but has little effect on the overall dose of the intervention.
Due to the significantly higher X-ray exposure, the use of a CBCT as well as PRG-placements
using CT should be limited to clinically absolutely necessary exceptions with strict
indication.
Key Points
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Fluoroscopically-guided PRG placements are interventions with low X-ray exposure.
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X-ray exposure from fluoroscopy is lower using flat panel detector systems as compared
to image intensifier systems.
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The concomitant placement of an oro- or nasogastric probe extends the fluoroscopy
time.
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Gastric probe placement is worthwhile to prevent the premature use of the significantly
radiation-intensive CT.
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The use of the C-arm CT or the CT increases the beam exposure by 26 or 33 times, respectively.
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The PRG placement using C-arm CT and CT should only be performed in exceptional cases.
Citation Format
Key words
radiation exposure - fluoroscopy time - x-ray exposure - gastrostomy - prg - rig
