EVALUATION OF THE STEREOSCOPIC DOSE DISTRIBUTION IN ENDOSCOPIC RETROGRADE CHOLANGIOPANCREATOGRAPHY ROOM USING N1 PHANTOM AND TLD TECHNIQUE

Abstract

This study envisaged the evaluation of the stereoscopic dose distribution and the corresponding exposure dose for the medical staff in endoscopic retrograde cholangiopancreatography (ERCP) room using the spatial dose distribution method and thermo-luminescent dosimetry (TLD) technique. Feasibility screening and calibration of 135 new TLD-100H chips were performed and sealed into 45 packages with 3 TLDs per pack. Subsequently, the 45 TLD packs were allocated in a matrix form in the ERCP room ([Formula: see text][Formula: see text]cm2) with various heights of 85, 90, 130, 150, and 180[Formula: see text]cm above the ground. In addition, three human-sized dolls with lead vast were located at the position of the medical staff to simulate the ambient exposure dose. The TLDs were held for 2-minute exposure (max, min, average) [Formula: see text] Gy dose as 85[Formula: see text]cm (520.9, 14.9, 31.1), 90[Formula: see text]cm (428.6, 15.7, 28.6), 130[Formula: see text]cm (40.7, NA, 28.0), 150[Formula: see text]cm (1650.3, NA, 1650.3) and 180[Formula: see text]cm (17.6, 15.0, 16.4), respectively. The minimum detectable limit (MDL) of the TLD chips was 6.85[Formula: see text]nC, and the TLD dose calibration curve was revised by using a weighting factor according to lean backward scenario to reach low interception. It was found that the maximal exposure dose of the annual workload (12[Formula: see text]m/d*5[Formula: see text]d/wk*50[Formula: see text]wk/yr=3000[Formula: see text]m) was overestimated as 14.7, 14.5, and 14.1[Formula: see text]mGy, respectively for the medical doctors, radiologists and nurses from the viewpoint of health physics.