New method could lower radiotherapy doses for some cancer patients
A special type of MRI scan where patients inhale 100% oxygen could result in lower radiotherapy doses for some cancer patients.
The study led by scientists at The University of Manchester and the Institute of Cancer Research in London, could potentially benefit patients by using a technique called Oxygen-enhanced magnetic resonance imaging (OE-MRI).
Using the non-invasive technique, the scientists were able to map parts of tumours that had oxygen deficiency- known as hypoxia – in patients with head and neck cancer. Patients with hypoxia in their tumours respond less well to treatment.
This will enable future work to use the MRI technique to target and fine tune treatment more precisely, reducing damage to healthy tissue in some patients.
All cancers can be destroyed by radiation and chemotherapy, but the problem is healthy tissues and organs can destroyed as well. So our aim is to destroy the tumour while preserving healthy tissue thus reducing toxicity. Using Oxygen-enhanced magnetic resonance imaging to map hypoxia in patients’ tumours before therapy, may improve the accuracy of their treatment. Now we have proved the principle, we hope to move on to clinical trials so it can be validated on greater numbers of patients.
Dr Michael Dubec
clinical scientist at The University of Manchester and The Christie NHS Foundation Trust
Funded by Medical Research Council, Cancer Research UK, The National Institute for Health and Care Research, the study is published in Clinical Cancer Research on the 15th August 2024. The study was supported by the NIHR Manchester Biomedical Research Centre (BRC) and the NIHR BRC at The Royal Marsden and The Institute of Cancer Research.
Though the study was performed on patients with head and neck cancer, it raises the prospect that OE-MRI could be useful in patients with other cancers.
The oxygen enhanced imaging provides detail similar to an expensive PET scan, but can be performed on standard – and much cheaper – MRI systems.
The researchers enrolled 27 patients who were given OE-MRI scans of their primary and nodal tumours before they began their standard chemotherapy or radiotherapy treatments. Additional scans were then performed during their treatment.
Using sophisticated mathematical modelling, the method was found to have the potential to help patients whose tumours had reduced levels of hypoxia by the second week.
Few studies have compared the hypoxia modification observed in both primary tumour and nodal metastases following treatment, or the timing of these changes. So our findings amount to a potentially important way to determine optimum radiotherapy planning for patients with locally advanced disease.
Professor James O’Connor
Institute of Cancer Research and The University of Manchester and study lead.
The study “Oxygen-enhanced MRI detects incidence, onset and heterogeneity of radiation-induced hypoxia modification in HPV-associated oropharyngeal cancer” is published in Clinical Cancer Research.
