The following CT simulators are most affected
GE Lightpeed RT and Siemens SOMATOM RT series models need X-Line to treat obese patients.
Three radiopaque lines on an adhesive
The lines are spaced 1” apart on a transparent skin adhesive roll with perforations every 2”. Adhere to regions that may fall within the eFOV, orienting the lines along the patient longitudinally. The lines create hyperdense dots in the CT slices; connect-the-dotsTM to contour the body.
Effectively contour obese patients
More than 100,00 obese cancer patients in Canada and the United States1-3 cannot be accurately contoured with most CT simulators.
“X-Line allows for more accurate delineation of the external body contour in the extended field of view (eFOV) by simply connecting the dots on the CT image.”
Dr. Kirpal Kohli, Medical Physicist BC Cancer Agency
Body shaped CT phantom that falls within the eFOV. The X-Line dots show the true contour in purple.
X-Line is applied over regions that are likely to protrude into the eFOV.
X-Line is useful for imaging patients within the eFOV of CT simulators.
Current methods of eFOV body contouring are inaccurate and may be harmful
Guessing the body contour
Guessing the body contour around distortion puts the patient at risk for improper treatment doses. Displacement of 1-5 cm into the eFOV can result in distortions of up to 15% of the CT slice area.
Relying on software
Image reconstruction software makes distorted regions appear clearer, but does not improve the accuracy of the resulting contour.5 Patients are similarly at risk of improper radiation treatment doses.
Fusing multiple CT scans
When multiple scans are used to image distorted regions patients are exposed to unnecessary X-ray radiation. Extremely obese patients can experience up to 70-80 times the effective radiation dose of normal weight patients.