Radiation dose to patients in transarterial chemoembolization (TACE) and percutaneous transhepatic biliary drainage (PTBD) from interventional radiology

The patient dosimetry in Transarterial Chemoembolization (TACE) and Percutaneous Transhepatic Biliary Drainage (PTBD) procedures was determined by Gafchromic film (GF) and Dose Area Product (DAP) methods. Maximum skin dose can be measured by GF and the average dose calculated from the DAP meter. The study was conducted at unit of interventional radiology, King Chulalongkorn Memorial Hospital in 65 patients who underwent TACE and PTBD procedures. The dose from DAP meter was the accumulated skin dose at different area on the skin of the patient. The study by DAP meter did not show a peak dose that the patient received, and the dose was averaged. Maximum radiation doses to patients from TACE and PTBD procedures were 1.5 and 0.2 Gy, respectively. The patient skin dose in this study depended on many factors, such as kVp, mA, fluoroscopic time, number of frames, patient body mass index (BMI) and number of exposure. Especially numbers of exposure is the most important factor. Correlation between patient skin dose showed that the highest correlation was R² = 0.40, between maximum skin dose from GF and number of exposure and the poorest correlation was R² = 0.04, between maximum skin dose from GF and BMI. Results of measured patient skin doses were analyzed and compared with the standard reference dose. It was found in every procedure that the accumulated entrance skin dose was less than 2 Gy, the threshold dose for skin injury limit. The result indicated that either procedure of TACE or PTBD in interventional radiology was absolutely safe for the patients.