Breast Displacement and CT Radiation Dose

Not Applicable

Completed

• Conditions: Radiation Dosage; Computed Tomography
• Interventions: Device: Chrysalis breast displacement device

• Registration Number: NCT01261559
• Lead Sponsor: University of Washington

Brief Summary

The primary hypothesis of this study is that breast displacement out of the direct plane of imaging during computed tomography (CT) of the abdomen will reduce effective radiation dose to the female breast. Secondary hypotheses are that image noise and artifacts will also be decreased.

Detailed Description

Computed tomography (CT) is a significant source of medical-related radiation, and radiation-related cancer risk is increasingly recognized in the medical and lay community. One of the groups at greatest risk for radiation-induced malignancies is young females due to the radiosensitivity of female breast tissue. Breast tissue frequently lies within the imaging plane for CT of the abdomen with limited gain in diagnostic information. We propose displacing this breast tissue out of the direct imaging plane will decrease unnecessary radiation exposure and may also indirectly improve image quality.

A device called Chrysalis has been designed and received FDA approval for the purposes of displacing female breast tissue during CT.

Study Timeline

• Study Start: 2010-12
• Study First Submitted: 2010-12-08
• Study First Submitted QC: 2010-12-14
• Study First Posted: 2010-12-16
• Primary Completion: 2012-02
• Study Completion: 2012-02
• Results First Submitted: 2013-06-18
• Results First Submitted QC: 2013-08-30
• Results First Posted: 2013-11-05
• Status Verified: 2018-06
• Last Update Submitted: 2018-06-07
• Last Update Posted: 2018-07-06

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 72

Inclusion Criteria

• scheduled for CT of the abdomen and pelvis at Harborview Medical Center
• able to provide written informed consent

Read More

Exclusion Criteria

• Inability to provide written consent for self (minor, intubated, sedated, mentally incapacitated, in excessive physical distress)
• Chest or breast surgery within the previous 8 weeks
• Breast implants
• Open wounds to the chest wall
• Fractures of the ribs or spine within the previous 3 months
• Patients requiring oxygen therapy
• Mastectomy
• Breast radiation therapy
• Scarring to the breasts which would prevent displacement
• Claustrophobia is not an absolute exclusion criterion, but patient comfort will be a primary concern.

Read More

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Chrysalis CT	Chrysalis breast displacement device	Women assigned to undergo CT using the standard dose reduction methods (including bismuth shielding and tube current modulation) plus application of the Chrysalis device for breast displacement.

Primary Outcome Measures

Name	Time	Method
Skin Entrance Radiation Dose During Computed Tomography (CT)	from time potential subject approached about possible enrollment to time device and TLDs were removed, on average 1 hour	Skin entrance radiation doses will be measured with Thermoluminescent dosimeters (TLDs) affixed to the subject's chest and breast during CT of the abdomen. TLD #1 is at the inframammary fold, serving as internal control for each subject. Three additional TLDs (#2-4) are affixed to the subject's breast at 3 pre-ascribed locations. The same is done for the right and left breasts (8 TLDs total). TLDs will then be submitted to Landaeur for measurement.
Relative Skin Entrance Radiation Dose in % During Computed Tomography (CT)	from time potential subject approached about possible enrollment to time device and TLDs were removed, on average 1 hour	Relative skin entrance dose at the breast (group mean of patient's average skin entrance dose at TLDs 2-4) divided by skin entrance dose at the inframammary TLD (TLD 1) in %. For each patient, doses at TLDs 2-4 were averaged, and then the group mean of this was divided by the group mean at the inframammary TLD, then multiplied by 100 to get % dose. A relative dose of 20% means that the skin entrance dose at the breast was 20% of the skin entrance dose at the inframammary fold.

Secondary Outcome Measures

Name	Time	Method
Number of Participants With Presence of Artifacts Based on CT Image Quality	two months	CT images acquired will be reviewed for the presence of artifacts that might be attributed to the displacement device or to the presence of the breast tissue.; To evaluate for artifacts, the exam will be qualitatively reviewed by a board certified radiologist for imaging artifacts, such as streak artifact. It will be noted on a per participant basis whether any imaging artifacts are identified.
CT Image Noise	two months	To evaluate image noise, mean of the Standard deviation (SD) of the pixel values, measured in Hounsfield units (HU), will be measured in Picture Archiving and Communication System (PACS) using a region of interest (ROI) measuring 90-110 mm\^2 in size drawn over each of these body regions: hepatic dome, spleen, renal cortex, retroperitoneal fat, subcutaneous fat, paraspinal muscles, and if present, breast tissue, avoiding vascular structures in each case. SD for ROI measuring 90-110 mm\^2 in size will also be drawn over the aorta and inferior vena cava (IVC), remote from contrast mixing artifact, and over medullary bone of the spine.; HU is the linear scale by which digital image data are displayed in PACS and reflect relative attenuation compared to distilled water at a standard temperature and pressure (STP) (defined as 0 HU) and of pure air at STP (defined as -1000HU). Within a drawn ROI, the PACS will give the mean attenuation (in HU) and the standard deviation of HU (reflecting

Trial Locations

Locations (1)

Harborview Medical Center; 🇺🇸 Seattle, Washington, United States