3D imaging helps surgeons measure size of tumours
26 November/ updated 3 December 2014
Three-dimensional ultrasound imaging and augmented-reality
software allows surgeons to pinpoint a tumour and measure its
volume, including its depth, according to a study presented at the
2014 American College of Surgeons Clinical Congress. See video
Surgical oncologists, or cancer surgeons, usually remove breast
cancers by relying on tactile feedback and radiologic images of the
tumour, such as mammograms and ultrasound images. M. Catherine Lee,
MD, FACS, coauthor of the study and associate professor of surgery
at H. Lee Moffitt Cancer Center, Tampa, Florida, said, “Our goal in
a lumpectomy is to get the lump out with a small rim of normal
tissue around it, but we sometimes find out we did not get all of
Dr Lee’s team developed an imaging guidance system designed to
minimize the need for repeated operations while sparing greater
amounts of healthy breast tissue. Collaborating with St. Thomas
University, Florida, the researchers designed a software algorithm
that works with digital ultrasound technology. Ultrasound images are
converted into 3D images on a computer screen.
In a simulated surgical procedure, the investigators studied the
use of augmented-reality to fuse real-world and virtual 3D images.
These augmented-reality images can then be transmitted to
high-definition 3D glasses or other devices. When the surgeon wears
such glasses, they see a superimposed, reconstructed 3D digital
image over the actual tumour.
“It gives the impression of
X-ray vision. You can see the tumour through the skin,” said lead
author Segundo J. Gonzalez, MD, a surgical oncology fellow at
Moffitt Cancer Center.
He and his co-investigators analyzed
66 ultrasound images of tumours (32 pictures of a single tumour and
34 of multiple tumours) inside a plastic model of a breast to
determine the augmented-reality system’s accuracy of measuring
tumour volume. The closer the 3D ultrasound image overlapped with
the actual tumour, the more accurate the software was.
For detecting a single tumour, the volumetric accuracy was 1.2
cubic mm, which Dr. Gonzalez called “extremely accurate.” Likewise,
accuracy for multitumour detection was 5.4 cubic millimeters, or
0.0003 cubic inches.
The investigators hope to study their
software using a smart phone camera and, eventually, study it in
patients. Dr. Gonzalez is commercializing the new technology through
a start-up company, MedSights Tech Corp., in Tampa.
An animated illustration of the technology