Pathologists take note: In one clinical study, diagnostic results produced by a prototype “smart knife” matched postoperative histological diagnosis in 100% of cases
Will a smart knife used in cancer surgery eventually replace the need for a skilled pathologist to diagnose tissue collected during such surgeries?
That’s a question that may be asked in the future if an invention developed at Imperial College London makes it through clinical trials and is accepted for use in patient care. Researchers at Imperial College developed a surgical knife that allows doctors to discern cancer in real-time during surgery—and without consulting with a pathologist.
This invention, dubbed an intelligent knife or iKnife, could be a significant development for clinical laboratory professionals and pathologists if primary research is validated in planned clinical trials.
Pathologists know that when a patient is suspected of having cancer, the current protocols for frozen specimens call for tissue specimens to be sent from the surgical suite to the medical laboratory for analysis. This step may take 20 to 30 minutes.
Meanwhile, the study points out, the patient remains in surgery and under anesthesia. The surgeon waits to learn from the pathologist whether more tissue may need to be removed to ensure that no malignant cells remain in the patient.
iKnife Speeds Up Diagnosis, Reduces Follow-up on Surgeries
The iKnife was developed to reduce the time-to-answer for these surgeries. Diagnosis using the electrosurgical and mass spectrometry-backed iKnife takes up to three seconds. During 81 cancer surgeries, the iKnife results matched postoperative histological diagnosis in 100% of the cases, the study authors wrote in their paper published in Science Translational Medicine.
Researchers believe that the smart knife has the potential to support more effective and accurate surgeries. This would make it possible for doctors to reduce follow-up operations to remove further pieces of cancerous tumors, reported Reuters in its story about the iKnife study.
“We believe using this technology, since there is no waiting time, can significantly reduce the amount of time the patient spends in the operating theater,” noted study co-author Zoltan Takats, Ph.D., in a HealthDay News article. “We also can hopefully decrease the local tumor recurrence rate, which in cases like breast cancer can be as high as 30%,” he added.
Takats is a researcher with Computational and Systems Medicine in the Department of Surgery and Cancer at Imperial College London.
iKnife Smartly Uses Mass Spectrometry and Electrosurgery
So, what is the technology that allows this smart knife to achieve such results? The iKnife blends established electrosurgery with an emerging technique called rapid evaporative ionization mass spectrometry (REIMS).
In its story about the smart knife, National Geographic described the iKnife’s appearance as “an electrosurgical wand” that is hooked up to a rolling mass spectrometry machine.
Essentially, the iKnife, in the hands of the surgeon, works as it sends up molecules in the form of smoke. Then, the molecules are directed to the mass spectrometer for testing and analysis, explained Orthopedics This Week in its coverage of the news.
Smoke and Heat
- In electrosurgery, the surgeon’s knife delivers an electric current heating the targeted tissue and cuts through it.
- Heat from the electric current vaporizes tissue, giving off a smoke.
- Mass spectrometer technology behind REIMS instantly identifies chemicals present in the human tissue by analyzing the smoke.
- The REIMS technology (primed with profiles of healthy and cancerous cells) screens the sample of smoke and informs the surgeon of whether it is from a tumor or healthy tissue.
One expert, who called the iKnife “cool,” also wondered how it will address the all-important tumor margin, which is a boundary between the tumor and healthy tissue.
“The edge of the tumor is more challenging to detect than cancer-versus-healthy-tissue due to a mix of different tissue types, and it is the edge that surgeons want to know about,” said Nimmi Ramanujam, a biomedical engineer of Duke University in a Science Magazine article.
Prior to hands-on use of the iKnife in three Hungarian hospitals, researchers created a collection of 3,000 tissue samples from 302 cancer patients. They showed the iKnife, after touching tissues could distinguish normal and tumor tissues from different organs, such as breast, liver, and brain, Science reported.
Will Providers Buy It?
While the study is intriguing and the results noteworthy, the device itself will not come cheap to providers. Cost to build the iKnife was more than $300,000. But Takats told Reuters that cost will be reduced at time of product launch.
A next step is likely clinical trials with the iKnife “where we are giving real-time feedback to the surgeon and they can make decisions based on that feedback,” Takats told HealthDay News.
Should the iKnife eventually gain clearance for clinical use, it may be the technology that supplants the current practice of having pathologists evaluate frozen tissue sections to guide physicians during surgery. Patients would benefit from surgeries that are much shorter, since the time required for a frozen section would be eliminated at no sacrifice in diagnostic accuracy. Another benefit would be a reduction in follow-on surgical procedures that are performed in circumstances where the surgeons and pathologists did not identify all the malignant tissue during earlier surgeries.
—Donna Marie Pocius