Analysis of Patients’ X-ray Exposure in 146 Percutaneous Radiologic Gastrostomies

Abstract

ABSTR AC TPurpose Analysis of patient´s X-ray exposure during percutaneous radiologic gastrostomies (PRG) in a larger population. Materials and MethodsData of primary successful PRGprocedures, 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. ResultsThe median DFP of PRG-placements under fluoroscopy was 163 cGy*cm 2 (flat panel detector systems: 155 cGy*cm 2 ; X-ray image intensifier: 175 cGy*cm 2 ). 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*cm 2 ), 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 PRGprocedures 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. Ergebnisse Das mediane DFP von PRG-Anlagen unter DL lag bei 163 cGy*cm 2 (FD: 155 cGy*cm 2 ; BV: 175 cGy*cm 2 ). Die mediane DLZ betrug 2,2 min. Dabei führte eine intraprozedurale Anlage einer naso-oder orogastralen Sonde (n = 68) zu einer signifikanten Verlängerung der medianen DLZ auf 2,5 min gegenüber 2 min bei Patienten mit bereits liegender Sonde. Zusätzlich wurden Dosiswerte von kleineren Patientengruppen analysiert, bei denen die PRG CBCT-gestützt (n = 7; medianes DFP = 2635 cGy*cm 2 ), oder CT-gestützt (n = 4, medianes DLP = 657 mGy*cm) angelegt wurde. Durch Abschätzungen aus den medianen DFP bzw. DLP ergaben sich effektive Dosen von 0,3 mSv für DL-gestützte Anlagen (FD 0,3 mSv; BV 0,4 mSv), mittels FD mit CBCT 7,9 mSv, und bei PRG-Anlagen im CT eine effektive Dosis von 9,9 mSv. Das entspricht einem Faktor 26 von DL gegenüber ...