FP659
IONIZING RADIATION EXPOSURE FROM DIALYSIS CENTRAL VENOUS ACCESS PROCEDURES

INTRODUCTION: Advances in medical imaging and interventional procedures have been associated with increased Ionizing Radiation Exposure (IRE) and, as a consequence, with a not negligible excess cancer risk from IRE. Dialyzed patients are exposed to very high IRE due to the large IRE, because of several comorbidities. While the IRE in the most common radiological imaging and interventional procedures are well known, IRE from fluoroscopically inserted dialysis tunneled central venous catheters (td-CVC) represents a gap in knowledge among nephrologists. The aim of this retrospective study was to quantify the effective dose (ED) and organ dose (OD) to relevant organs in td-CVC. The ED was also compared to the oncologic chest porth procedures.

METHODS: 88 consecutive td-CVC and 46 porth procedures acquired on the Integris 5000 (Philips Healthcare) angiographic system in our Institution were revised in terms of dose area product (DAP) and anatomical district of catheter introduction, right internal jugular vein (RIJV), left internal jugular vein (LIJV), subclavian veins (SVs) and femoral veins (FVs). ED was evaluated from DAP by the conversion coefficients available in the literature, namely 0.14 and 0.25 mSv*Gy-1*cm-2 for chest and abdomen, respectively. For a small subsample of IJV procedures, data of peak-kilovoltage, image width and height, projection angles and focus-to-image distance were also retrieved and input in PCXMC Rotation Dose Calculation 2.0.1.5 software (Stuk, 2012) for OD evaluation.

RESULTS: 88 td-CVC were placed in 42 (48%) male and 46 (52%) female, aged 67±14years; 48 (54%) in RIJV, 31(35%) in LIJV, 5 (6%) in SV and 4 (5%) in FV. The radiological parameters for td-CVC were: DAP=13±22.2 (IQR 3-13.5) Gy*cm2, and ED=1.9±3.3 (IQR 0.42-2.27) mSv, much higher (p=0.02) than the correspondent ones for oncological porth (DAP=4.8±4.1 Gy*cm2, and E=0.7±0.6 mSv). With regard to the anatomical district, DAP for LIJV, SV, FV were similar (19.3± 33.5, 16.4±16.9 and 20.1±15.3 Gy*cm2, p=not significant) but higher than for RIJV (8.4±10.7 Gy*cm2, p=0.07). Effective dose for LIJV, SV and FV are similar (2.5±4.7, 2.3±2.4 and 5.2± 6.3 mSv, respectively, p=not significant) but higher than RIJV (1.2±1.5 mSv, p=0.07). The estimated doses to the relevant organs included in the beam field for IJV procedures were: 4.4+3.6, 3.9+1.4, 6.4+3.0 and 2.2+1.2 mGy for bone marrow, heart, lungs and breast, respectively

CONCLUSIONS: Dt-CVC insertion is associated with “low” dose of IRE but higher than others CVC; in particular, the right internal jugular vein should be preferred, due to the lower exposition. In addition, the estimated doses to relevant organs, although slight, are not negligible.