Surgery is one of the oldest and most effective cancer treatments. Even with chemo, radiation, and novel treatments like cancer-killing microbes, tumours are often removed surgically.
The goal is to remove all malignant tissue while conserving good tissue. Because it might be difficult to distinguish between malignant and benign tissues, surgeons routinely remove healthy tissue to be safe.
This is especially problematic for patients with bone cancer because bones are hard and heal back slowly compared to other tissues.
Caltech researchers have invented a new diagnostic imaging system that allows surgeons to perform 10 times more precise cuts, preserving 1,000 times more healthy tissue and speeding patient recoveries.
Traditional procedures are time-consuming for detecting cancer in bone. The bone fragment is delivered to a lab where its hard calcium matrix is slowly destroyed, leaving just living cells. Slice and picture remaining material. Because the process can take one to seven days, surgeons cannot rely on it during surgery to establish the quality of bone around a tumour, so they remove more than would be necessary—and more than they would in softer tissues that can be promptly biopsied.
UV-PAM is supposed to replace the existing way of diagnosing malignant bone tissue. Because it takes minutes, a surgeon can distinguish between healthy and malignant bone while operating.
H&E-stained malignant tissue. MIT
UV-PAM uses laser light to make biological tissue molecules vibrate, like other Wang technologies. These ultrasonic vibrations can be utilised to visualise tissues and organs like a foetus.
UV-PAM employs laser light to vibrate DNA and RNA. Because cancer cells are formed differently, packed more densely, and contain more DNA than healthy cells, diseased tissue absorbs more UV light and provides a stronger ultrasonic signal than healthy tissue, allowing the surgeon to easily identify bone that has to be removed.
The method gives clinicians with scanned bone images that appear like standard biopsy images.
The technology is only seen in a lab. Wang aims to use it on patients, but first he’ll make improvements.
Rui Cao et al, Label-free intraoperative histology of bone tissue via deep-learning-assisted ultraviolet photoacoustic microscopy, Nature Biomedical Engineering (2022). DOI: 10.1038/s41551-022-00940-z