Researchers Capture First Images of Oxygen in Cancer Tumors during Radiation Therapy

Oxygen in cancer tumors is known to be a major factor that helps radiation therapy be successful. Hypoxia, or starvation of oxygen, in solid tumors is also thought to be an important factor in resistance to therapy. However, it is difficult to monitor tumor oxygenation without invasive sampling of oxygen distributions throughout the tissue, or without averaging across the whole tumor, whereas oxygen is highly heterogenous within a tumor. A research team at Dartmouth's and Dartmouth-Hitchcock's Norris Cotton Cancer Center led by Brian Pogue, PhD, has developed the first non-invasive way to directly monitor oxygen distributions within the tumor right at the time when radiation therapy is happening. With injection of an oxygen probe drug, PtG4, they are able to image the distribution of oxygen from within the tumor. The method measures the luminescence lifetimes of PtG4 while it is excited by the Cherenkov light emitted by the radiation therapy. The drug, PtG4, stays in the tumor for at least a week, and works for imaging repeatedly.

"The imaging is all done without any additional radiation, simply by using a camera to monitor the emissions during radiotherapy treatment," explains Pogue. "Following two tumor lines, one which is known to be responsive to radiation and one which is known to be resistant, we could see differences in the oxygenation of the tumor which are reflective of their differences in response." The team's findings, "Tissue pO2 Distributions in Xenograft Tumors Dynamically Imaged by Cherenkov-Excited Phosphorescence during Fractionated Radiation Therapy," are newly published in Nature Communications, by lead author, Xu Cao.

Pogue's team is able to capture oxygenation imaging through special technology. "We have a unique set of time-gated cameras in our radiation therapy department that were designed for Cherenkov-based radiation dosimetry, but we have used them for this additional purpose of monitoring oxygen in the tumors under treatment," says Pogue. "So access to these specialized Cherenkov cameras made the measurements possible." Pogue's team also collaborated with Professor Sergei Vinogradov and his team at the University of Pennsylvania Perelman School of Medicine, who produced the PtG4 and supported the work with drug characterization and co-supervision of the study.

Pogue hopes to develop this tumor monitoring ability into a useful clinical aid used to track tumor response to radiation therapy, especially tumors that are known to be hypoxic. Having such information available at the time of treatment could be helpful in influencing treatment decisions such as giving a radiation boost where needed. "When a patient gets radiation therapy, the treatment should be designed to directly utilize as much information about the patient's tumor as possible," says Pogue. "Today, we use the shape of the tumor and the tissue around it. But, we need to also think about using measurements of the tumor metabolism because this affects the success of treatment as well. Future radiation therapy treatments should ideally incorporate metabolic features such as oxygenation of the tumor when the treatment is planned or delivered."

The next steps toward this future are already underway. Pogue's team is looking to characterize how small of a region they can track the oxygenation from, and how fast they can take measurements. "Our goal is to produce oxygen images at video rate, with a spatial resolution that allows us to see radiobiologically relevant hypoxia nodules in the tumor of humans," explains Pogue.

Xu Cao, Srinivasa Rao Allu, Shudong Jiang, Mengyu Jia, Jason R Gunn, Cuiping Yao, Ethan P LaRochelle, Jennifer R Shell, Petr Bruza, David J Gladstone, Lesley A Jarvis, Jie Tian, Sergei A Vinogradov, Brian W Pogue.
Tissue pO2 distributions in xenograft tumors dynamically imaged by Cherenkov-excited phosphorescence during fractionated radiation therapy.
Nature Communications volume 11, Article number: 573, 2020. doi: 10.1038/s41467-020-14415-9.

Most Popular Now

New AI Tool Predicts Protein-Protein Int…

Scientists from Cleveland Clinic and Cornell University have designed a publicly-available software and web database to break down barriers to identifying key protein-protein interactions to treat with medication. The computational tool...

AI for Real-Rime, Patient-Focused Insigh…

A picture may be worth a thousand words, but still... they both have a lot of work to do to catch up to BiomedGPT. Covered recently in the prestigious journal Nature...

New Research Shows Promise and Limitatio…

Published in JAMA Network Open, a collaborative team of researchers from the University of Minnesota Medical School, Stanford University, Beth Israel Deaconess Medical Center and the University of Virginia studied...

G-Cloud 14 Makes it Easier for NHS to Bu…

NHS organisations will be able to save valuable time and resource in the procurement of technologies that can make a significant difference to patient experience, in the latest iteration of...

Start-Ups will Once Again Have a Starrin…

11 - 14 November 2024, Düsseldorf, Germany. The finalists in the 16th Healthcare Innovation World Cup and the 13th MEDICA START-UP COMPETITION have advanced from around 550 candidates based in 62...

Hampshire Emergency Departments Digitise…

Emergency departments in three hospitals across Hampshire Hospitals NHS Foundation Trust have deployed Alcidion's Miya Emergency, digitising paper processes, saving clinical teams time, automating tasks, and providing trust-wide visibility of...

MEDICA HEALTH IT FORUM: Success in Maste…

11 - 14 November 2024, Düsseldorf, Germany. How can innovations help to master the great challenges and demands with which healthcare is confronted across international borders? This central question will be...

A "Chemical ChatGPT" for New M…

Researchers from the University of Bonn have trained an AI process to predict potential active ingredients with special properties. Therefore, they derived a chemical language model - a kind of...

Siemens Healthineers co-leads EU Project…

Siemens Healthineers is joining forces with more than 20 industry and public partners, including seven leading stroke hospitals, to improve stroke management for patients all over Europe. With a total...

MEDICA and COMPAMED 2024: Shining a Ligh…

11 - 14 November 2024, Düsseldorf, Germany. Christian Grosser, Director Health & Medical Technologies, is looking forward to events getting under way: "From next Monday to Thursday, we will once again...

In 10 Seconds, an AI Model Detects Cance…

Researchers have developed an AI powered model that - in 10 seconds - can determine during surgery if any part of a cancerous brain tumor that could be removed remains...

Does AI Improve Doctors' Diagnoses?

With hospitals already deploying artificial intelligence to improve patient care, a new study has found that using Chat GPT Plus does not significantly improve the accuracy of doctors' diagnoses when...