DOS 2016

DOS Kongressen 2016 ·

Organ dose and effective dose with the EOS scanner in

spine deformity surgery. A study on anthropomorphic

phantoms describing patient radiation exposure in full

spine examinations

Peter Heide Pedersen, Søren Peter Eiskjær, Asger Greval Petersen

Orthopedic, Aalborg University hospital; Orthopedic, Aalborg University hospi-

tal; Røntgenfysik, Region North Jutland

Background:

Ionizing radiation potentially leads to tissue damage. It has been

documented in large cohort studies that radiographic imaging during childhood

for spinal deformities eg. scoliosis, increases the lifetime risk of breast cancer.

The EOS biplane x-ray imaging system (EOS Imaging S.A, Paris France) has been

developed to produce high quality images while at the same time reducing ra-

diation dose. At our institution we use the EOS for pre- and postoperative full

spine examinations.

Purpose / Aim of Study:

The purpose of the study is to make first time or-

gan dose and effective dose evaluations with micro-dose settings in full spine

examinations. Our hypothesis is that organ dose and effective dose can be

reduced 5-10 times compared to standard settings, without too high image-

quality trade off, resulting in a theoretical reduction of radiation induced cancer.

Materials and Methods:

Patient dosimetry is performed on anthropomorphic

child phantoms. Thermoluminiscent detectors are used to measure organ dose.

A first time measurement with micro-dose settings in both AP and PA will be

performed in addition to standard settings in AP and PA positions. Effective dose

is calculated using mean organ doses and tissue weighting factors. These find-

ings will be compared to previously reported findings in standard settings and to

conventional digital x-ray(CR)

Findings / Results:

In AP position we found a mean liver organ dose of 0.03mSv

as compared to 0.25mSv with standard dose settings, a significant dose reduc-

tion of 88%. As expected the liver dose was higher in PA position than AP posi-

tion, 0.05mSv vs. 0.03mSv.

Conclusions:

Preliminary results with micro-dose settings show a 88% re-

duction of organ dose and a theoretical reduction of radiation induced cancer.

Previously a 35% effective dose reduction was reported for the EOS in standard

settings compared to CR.

No conflicts of interest reported

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