Breast Displacement and CT Radiation Dose (Chrysalis)

Effect of Displacement During Computed Tomography on Breast Radiation Dose and Image Quality

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.

Study Overview

• Status: Completed
• Conditions: Computed Tomography; Radiation Dosage
• Intervention / Treatment: Device: Chrysalis breast displacement device

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 Type: Interventional
• Enrollment (Actual): 72
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Washington
    • Seattle, Washington, United States, 98104
      • Harborview Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 60 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

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

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Standard CT; Women assigned to undergo CT using the standard dose reduction methods (including bismuth shielding and tube current modulation) but without the Chrysalis device.
Experimental: Chrysalis CT; 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.	Device: Chrysalis breast displacement device; Chrysalis is a cloth device secured with velcro and buckles around the upper abdomen and chest following manual cephalad breast displacement.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Skin Entrance Radiation Dose During Computed Tomography (CT)	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.	from time potential subject approached about possible enrollment to time device and TLDs were removed, on average 1 hour
Relative Skin Entrance Radiation Dose in % During Computed Tomography (CT)	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.	from time potential subject approached about possible enrollment to time device and TLDs were removed, on average 1 hour

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
CT Image Noise	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	two months
Number of Participants With Presence of Artifacts Based on CT Image Quality	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.	two months

Collaborators and Investigators

• Sponsor: University of Washington
• Investigators: Principal Investigator: Claire K Sandstrom, MD, University of Washington Department of Radiology

Publications and helpful links

General Publications

• Berrington de Gonzalez A, Mahesh M, Kim KP, Bhargavan M, Lewis R, Mettler F, Land C. Projected cancer risks from computed tomographic scans performed in the United States in 2007. Arch Intern Med. 2009 Dec 14;169(22):2071-7. doi: 10.1001/archinternmed.2009.440.
• Kang M, Ragan BG, Park JH. Issues in outcomes research: an overview of randomization techniques for clinical trials. J Athl Train. 2008 Apr-Jun;43(2):215-21. doi: 10.4085/1062-6050-43.2.215.
• Smith-Bindman R, Lipson J, Marcus R, Kim KP, Mahesh M, Gould R, Berrington de Gonzalez A, Miglioretti DL. Radiation dose associated with common computed tomography examinations and the associated lifetime attributable risk of cancer. Arch Intern Med. 2009 Dec 14;169(22):2078-86. doi: 10.1001/archinternmed.2009.427.
• Hurwitz LM, Yoshizumi TT, Reiman RE, Paulson EK, Frush DP, Nguyen GT, Toncheva GI, Goodman PC. Radiation dose to the female breast from 16-MDCT body protocols. AJR Am J Roentgenol. 2006 Jun;186(6):1718-22. doi: 10.2214/AJR.04.1917.
• Parker MS, Hui FK, Camacho MA, Chung JK, Broga DW, Sethi NN. Female breast radiation exposure during CT pulmonary angiography. AJR Am J Roentgenol. 2005 Nov;185(5):1228-33. doi: 10.2214/AJR.04.0770.
• Pajor L, Kalman E, Koszegi T. Cholesteryl hemisuccinate's inductive effect on membrane rigidization regarding both, its remodelling of the cells' surface receptor pattern and its decreasing the natural killer susceptibility of K-562 cells. Acta Biol Hung. 1991;42(4):371-83.
• Yilmaz MH, Albayram S, Yasar D, Ozer H, Adaletli I, Selcuk D, Akman C, Altug A. Female breast radiation exposure during thorax multidetector computed tomography and the effectiveness of bismuth breast shield to reduce breast radiation dose. J Comput Assist Tomogr. 2007 Jan-Feb;31(1):138-42. doi: 10.1097/01.rct.0000235070.50055.e6.

Study record dates

Study Major Dates

• Study Start: December 1, 2010
• Primary Completion (Actual): February 1, 2012
• Study Completion (Actual): February 1, 2012

Study Registration Dates

• First Submitted: December 8, 2010
• First Submitted That Met QC Criteria: December 14, 2010
• First Posted (Estimate): December 16, 2010

Study Record Updates

• Last Update Posted (Actual): July 6, 2018
• Last Update Submitted That Met QC Criteria: June 7, 2018
• Last Verified: June 1, 2018

More Information

Terms related to this study

• Keywords: Computed tomography; Dose reduction; Radiation dose; Image quality; Breast displacement; Chrysalis device
• Other Study ID Numbers: 39071