The Bane of Recurring Breast Surgery
“You have breast cancer.” Nearly a quarter million American women receive that terrible diagnosis every year. Most choose to have a lumpectomy, or breast conserving surgery (BCS), to remove a cancerous tumor while preserving as much of their normal breast tissue as possible. One in four of these patients will end up back under the surgeon’s scalpel because a small amount of diseased tissue was left behind. 1
How can that happen? Recent research shows there are several possible reasons, including a surgeon’s training, level of experience, institutional and clinical variations, or just plain oversight. Defining the edges of a cancerous tumor is a tricky business. If a surgeon cannot feel the tumor, a radiologist usually inserts a needlewire in or near the tumor so the surgeon has at least a sense of its location.
Tumors, however, are rarely well defined or symmetrical. Lacking effective intraoperative surgical guidance, surgeons remove what they can see or feel of the tumor, along with a ring of surrounding healthy tissue. In case remedial surgery is required, surgeons also ink the excised tissue with surgical dye to clearly mark its outer edges and orientation. While inking is a standard procedure, the inks that are currently used interfere with current approaches to tissue imaging. That means the only method available to know if all the cancer is gone depends on a pathology report that can sometimes take days to process. If the lab finds no cancer cells near the edges of the excised tissue, the sample is labeled a “clear margin” and the surgery is declared a success. 2
But, what if that clear margin is ill-defined or open to interpretation? Some surgeons like to remove more healthy tissue just to be safe, which results in more breast deformity. Other surgeons who want to preserve breast tissue remove less healthy tissue surrounding the tumor. Doing so reduces the need for major reconstructive surgery, but it also runs the possibly higher risk of leaving cancerous tissue behind.
After reviewing thousands of lumpectomy cases, the American Society for Radiation Oncology (ASTRO) and the Society of Surgical Oncology (SSO) issued new guidelines in 2014 stating that the surgical ink procedure should define clear margins and not the amount of tissue removed. The guidelines also said that wider margins do not lower the risk of recurrence any more than narrower margins. 3
While the debate over clear margins continues, one troubling statistic remains constant: Too many women undergoing lumpectomy require additional surgery, causing them continued discomfort, prolonged anxiety, and the risk of more complications or side effects. 4
Breast Cancer Research Under a New Light
Researchers at the Optics in Medicine Lab at Dartmouth’s Thayer School of Engineering and Norris Cotton Cancer Center, as well as PerkinElmer, a global leader in human health and environmental science, are working together to develop a new approach to image cancerous breast tumors without compromising the traditional tumor inking procedure favored by surgeons.
The prototype technology uses a modified PerkinElmer IVIS® SpectrumCT to capture high-resolution fluorescent and x-ray images of breast tumors following the surgical inking process. How does it work if those surgical inks make clear imaging impossible? In a first step, the researchers change the inks for intraoperative imaging. In this case, FDA-approved food dyes are substituted for the surgical inks that obscured Near-Infrared (NIR) imaging in the past. The second key step draws on Dartmouth’s novel scatter spectroscopic imaging approach.
“This work is a significant step towards making NIR optical methods for intraoperative breast tumor margin assessment clinically feasible by not compromising the current surgical practice of inking resected specimens for margin orientation,” David M. McClatchy III, a PhD candidate and first author of the study, said in a Dartmouth news release.
According to McClatchy, "This is the first breast tumor margin assessment system that is able to interrogate the breast tissue by seeing through dyes or inks used for marking specimen orientation," "It facilitates a key step toward clinical translation of NIR techniques for breast tumor margin assessment, both here at Dartmouth, and in the biomedical community at large." 5
The PerkinElmer Connection
“The Dartmouth team is a leader in biomedical imaging, so when it approached us with the idea of adapting its optical scatter imaging technology to better define tumor margins in breast cancer, we agreed to help,” says Dr. Wael Yared, R&D Leader, Life Science Technologies at PerkinElmer. He says that the company is providing optimized software and its extensive expertise in pre-clinical imaging to the multi-year, NIH-sponsored project.
“This is an innovative prototype that is one of the first comprehensive approaches to volumetric and surface scanning in a single platform,” Yared says. “It is also an outcome of our close collaboration with Dartmouth, which will hopefully lead to more groundbreaking technologies in the future.”
According to the Dartmouth team, the goal of the NIR project is straightforward: Develop an intraoperative imaging system using the IVIS Spectrum that will not only clearly identify breast tumors during surgery, but also help to end the ongoing debate over what can safely be called the “clear margin.” After all, when it comes to cancer surgery, there really is no margin for error.
For research use only. Not for use in diagnostic procedures.
Variability in Reexcision Following Breast Conservation Surgery, Journal of the American Medical Association, Vol 307, No. 5, February 1, 2012.
Society of Surgical Oncology–American Society for Radiation Oncology Consensus Guideline on Margins for Breast-Conserving Surgery With Whole-Breast Irradiation in Stages I and II Invasive Breast Cancer, Radiation Oncology , Volume 88, Issue 3, Pages 553–564, March 1, 2014.
New Guidelines Say Lumpectomy Margins Can Be Small as Long as Tumor Has No Ink on It, Breastcancer.org, accessed October 27, 2015.
Food Dye, Near Infrared Light Can Aid in Breast Resection, Dartmouth-Hitchcock Norris Cotton Cancer Center (May 12, 2015).