Yasir Andrabi MD, MPH, Presenter: Nothing to Disclose

Jorge Mario Fuentes MD, Abstract Co-Author: Nothing to Disclose

Koichi Hayano MD, Abstract Co-Author: Nothing to Disclose

Manuel Patino MD, Abstract Co-Author: Nothing to Disclose

Mukta Dilipkumar Agrawal MBBS, MD, Abstract Co-Author: Nothing to Disclose

Dushyant V. Sahani MD, Abstract Co-Author: Research Grant, General Electric Company

Repeat CT exams following image guided catheter placement in the abdomen can result in substantial increase in cumulative radiation dose (CRD) exposure to patients. We have introduced dose modified protocols (DMP) to evaluate the success of IR catheter. We investigated the impact DMP on CRD in patients undergoing repeated catheter F/U exams.

Between December 2012 to December 2013, 130 patients (M:F=68:62, BW=78.5 Kgs, Age= 59 Years) underwent F/U CT exams for image guided catheter placement on 64-slice GE Healthcare scanner (Discover CT750 HD). The scanning parameters for F/U exams included weight based kVp (80/100), low mA(75-350) and NI=30, while for baseline Abd-Pelvis CT exams included kVp=120, mA=(75-450), NI=18-22. Patient demographics, number of repeated exams and CRD were retrieved using an automated dose tracking software (eXposure, Radimetrics).

On an average, 3 F/U CT exams were performed per patient (Range 1-5) while average number of CT exams per patient/year was 6.5 (range: 1-26 exams). The mean CRD was 4888.8 mGy-cm (range: 232-26,200) with a linearity in number of CT exams and CRD (R2 =0.82, P<0.0001). With the increase in the number of CT exams performed per patient, an exponential decrese (R2=0.77) in the impact of DMP CT on CRD was noted (mean dose reduction=13%, Range: 5-80%, p=xx). A substantial impact DMP on CRD was noted for less than four CT exams performed per patient (33% reduction).

Using dose modified protocols in F/U CT exams can serve its intended purpose while lowering the cumulative radiation dose in patients undergoing repeated exams for image guided catheter placement followup. These dose reduction benefits are considerable for <4 repeated CT exams performed per patient.

Repeated CT exams are associated with considerable CRD and significant radiation related side effects. Customizing protocols based on the clinical indication can significantly lower CRD especially in less complicated patients undergoing repeated CT exams for non-cancer indications.

Andrabi, Y, Fuentes, J, Hayano, K, Patino, M, Agrawal, M, Sahani, D, Impact of Low Dose Protocols on Cumulative Radiation Dose in Patients Undergoing Repetitive Follow Up CT Exams for Image Guided Catheter Placement: Impact of Dose Modified Protocols on the Cumulative Radiation Dose in Patients Undergoing Repeat Abdome.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045715.html