We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us

Download Mobile App


ATTENTION: Due to the COVID-19 PANDEMIC, many events are being rescheduled for a later date, converted into virtual venues, or altogether cancelled. Please check with the event organizer or website prior to planning for any forthcoming event.
09 Dec 2022 - 11 Dec 2022

Delayed Fluorescence Imaging Method Could Enable Effective Surgical Tumor Removal

By HospiMedica International staff writers
Posted on 12 Oct 2022
Print article
Image: Researchers have proposed a new approach to identify cancerous tissue for surgical removal (Photo courtesy of Petusseau et al)
Image: Researchers have proposed a new approach to identify cancerous tissue for surgical removal (Photo courtesy of Petusseau et al)

In the surgical treatment of cancer, distinguishing between tumors and healthy tissues is critical. Fluorescent markers can help to do this, by enhancing the contrast of tumors during surgery. Some markers show a phenomenon called “delayed fluorescence” (DF) which relies on detecting “hypoxia” (or low oxygen concentration), a condition often presented by tumors. The real-time imaging of hypoxia can provide a high contrast between tumors and healthy cells. This can allow surgeons to remove the tumor effectively. However, real-time hypoxia imaging for surgical guidance has not yet been achieved. In a new study, researchers have proposed an optical imaging system that enables real-time imaging of tissue oxygen concentration for tumors presenting chronic or transient hypoxia. The team achieved this by making use of an endogenous molecule called protoporphyrin IX (PpIX), which exhibits DF in the red to near-infrared region.

The technical challenge in detecting DF is due to its low intensity; background noise makes it difficult to detect without a single photon detector. The team of researchers at Dartmouth College (Hanover, NH, USA) overcame this problem using a highly sensitive time-gated imaging system, which allows signal detection within a specified time window only. This greatly reduces the background noise and enables a wide-field direct mapping of oxygen partial pressure (pO2) changes with the acquired DF signal. The result is real-time metabolic information, a useful map for surgical guidance.

The team demonstrated the efficacy of the technique using mice models of pancreatic cancer, which exhibited hypoxic tumors. The DF signal obtained from the cancerous cells was over five times stronger than that from surrounding healthy oxygenated tissues. The signal contrast was further enhanced when the tissues were palpated before imaging to further enhance transient hypoxia. The imaging of pO2 in tissues could also enable control of tissue metabolism. This, in turn, would help us better understand the biochemistry involved in oxygen supply and consumption.

“This is a truly unique reporter of the local oxygen partial pressure in tissues. PpIX is endogenously synthesized by mitochondria in most tissues, and the particular property of DF emission is directly related to low microenvironmental oxygen concentration,” explained Brian Pogue, Chair of Medical Physics at University of Wisconsin-Madison, Adjunct Professor of Engineering Sciences at Dartmouth College, and senior author of the study. “Healthy cells will show little to no DF, because it is quenched in the presence of molecular oxygen.”

“Acquiring both prompt and delayed fluorescence in a rapid sequential cycle allowed for imaging oxygen levels in a way that was independent of the PpIX concentration,” said Lead author Arthur Petusseau, a doctoral candidate in Engineering Sciences at Dartmouth College.

“The results reported by Petusseau’s team suggest hypoxia imaging as an efficient approach to identifying tumors in cancer treatment,” said Frédéric Leblond, Professor of Engineering Physics at Polytechnique Montréal and JBO Associate Editor. “PpIX DF detection uses a known clinical dye and an already-approved in-human marker, with great potential for surgical guidance, and more.”

Related Links:
Dartmouth College 

BMP Whole Blood Analyzer: GEM Premier ChemSTAT
Gold Supplier
Influenza Type A & B Test
Influenza A+B DUO
M. Tuberculosis Indirect Test
D-Dimer Test
Epithod 616 D-Dimer Kit

Print article



view channel
Image: AI transforms smartwatch ECG signals into a diagnostic tool for heart failure (Photo courtesy of Pexels)

AI-Based Smartwatch Accurately Detects Heart Failure Using ECG Signals

People with a weak heart pump might not have symptoms, but this common form of heart disease affects about 2% of the population and 9% of people over 60. When the heart cannot pump enough oxygen-rich blood,... Read more

Critical Care

view channel
Image: Quantra Hemostasis Analyzer (Photo courtesy of HemoSonics)

Next-Gen POC Whole Blood Hemostasis System Recognizes Specific Needs of EDs and ORs

Current hemostatic tests provide only a subset of needed information, or take too long to be useful in critical bleeding situations, forcing clinicians to use iterative transfusion protocols that do not... Read more

Patient Care

view channel
Image: Automated cleaning system allows endoscopes to be cleaned direct from clinic (Photo courtesy of Aston University)

World’s First Automated Endoscope Cleaner Fights Antimicrobial Resistance

Endoscopes are long, thin tubes with a light and camera at one end. Due to the sensitivity of the materials and electronics they cannot be sterilized in an autoclave (a machine that uses steam under pressure),... Read more

Health IT

view channel
Image: Using digital data can improve health outcomes (Photo courtesy of Unsplash)

Electronic Health Records May Be Key to Improving Patient Care, Study Finds

When a patient gets transferred from a hospital to a nearby specialist or rehabilitation facility, it is often difficult for personnel at the new facility to access the patient’s electronic health records... Read more


view channel
Image: The global multiparameter patient monitoring systems market is expected to surpass USD 15 billion by 2028 (Photo courtesy of Unsplash)

Global Multiparameter Patient Monitoring Systems Market Driven by Rising Chronic Illnesses

Multi-parameter patient monitoring equipment is used to assess the vital signs of patients who are suffering from a serious illness. These devices are meant to give the number of data sets on one screen... Read more
Copyright © 2000-2022 Globetech Media. All rights reserved.