Radiation Exposure - How Do CT Scans for Appendicitis Compare Between a Free Standing Children's Hospital and Non-Dedicated Pediatric Facilities?

Saturday, October 26, 2013: 7:51 AM
Windermere Ballroom W (Hyatt Regency Orlando, formerly the Peabody)
Nicole E. Sharp, MD1, Maneesha U. Raghavan, MD1, Priscilla Thomas, MD1, Susan W. Sharp, PhD2, James C. Brown, MD2, Douglas C. Rivard2, Shawn D St Peter, MD2 and George W. Holcomb III, MD, MBA2, (1)Pediatric Surgery, Children's Mercy Hospital, Kansas City, MO, (2)Pediatric Surgery, Children's Mercy Hospitals and Clinics, Kansas City, MO

Purpose

 Recent appreciation about the risks of radiation exposure from computed tomography (CT) scans have led to heightened awareness about decreasing radiation exposure.  Children can be exposed to excessively high doses of radiation if CT scanner parameters are not adjusted appropriately for the patient's size.  The objective of this study is to compare the amount of radiation children received from CT scans done at non-dedicated pediatric facilities versus those from a children's hospital.

Methods

We performed a retrospective chart review of all children who were transferred to our facility after undergoing a CT scan for appendicitis at a non-dedicated pediatric facility from 1/2011 to 11/2012.  Radiation exposures of outside images were compared to children who underwent CT for appendicitis at our hospital (CMH) during the same time period by matching each outside case to same age and nearest date of scan. This patient matching was blinded as to radiation and scan data.  Radiation measures included dose length product (DLP), computed tomography dose length index (CTDI), and size-specific dose estimate (SSDE) which are all measures of radiation exposure. Methods to calculate patient dose were utilized based on patient age and size.  Accuracy of these scans for appendicitis was also compared.

Results

During the study period, there were 263 children who underwent a CT scan to evaluate for appendicitis at 42 outside non-dedicated pediatric facilities (OSH).  One hundred were excluded due to lack of a CT dose report.  Results are summarized in Table 1.  Average weight was 47.03 ± 22.92 kg at the OSH and 41.79 ± 19.60 kg at CMH (P= 0.003).  Body mass index was similar between the two groups (21.00 ± 6.49 kg/m2, 19.58 ± 5.18 kg/m2, P= 0.07).  CTDI was only recorded in 65 patients.  Subset analysis was performed in Table 2.

Conclusion

Children receive 86% less radiation exposure with CT scans to evaluate for appendicitis when performed at a children's hospital without compromising diagnostic accuracy.  Non-dedicated pediatric facilities should be urged to update their CT standards appropriately or refer to children's hospitals to minimize radiation exposure. 

Table 1: Results

OSH (n=163)

CMH (n=163)

P value

DLP (mGycm)

619.53 ± 540.3

253.78 ± 211.08

<0.001

Positive forAppendicitis

64 (39%)

60 (37%)

0.732

Pathology= appendicitis

52 (81%)

57 (95%)

0.026

Table 2: Subset analysis excluding any CT without recorded CTDI

OSH (n=65)

CMH (n=65)

P value

DLP (mGycm)

586.25 ± 521.59

143.54 ± 41.19

<0.001

CTDI (mGy)

16.98 ± 15.58

4.89 ± 2.64

<0.001

SSDE (mGy)

26.71  ± 23.1

3.81  ± 2.02

<0.001