New MRI technique detects lung cancer better that PET-CT
10 October 2011
A new type of diagnostic imaging, diffusion-weighted
MRI, can better differentiate benign lung lesions from those which are
cancerous, and could be used to prevent unnecessary surgery by enabling
more accurate diagnosis of the disease.
A study by Belgian researchers, presented at the European
Respiratory Society’s Annual Congress in Amsterdam last month, found
that the new technique can more accurately determine whether people
have the disease when compared with the current method of PET-CT
PET-CT scans are currently used by a doctor to determine what
stage the cancer is at and whether the detected lung lesions are
cancerous. This test involves a CT scan taking pictures from around
your body and a PET scan which uses a small amount of an injected
radioactive drug to show uptake within structures in your body.
Whilst this is the current gold-standard for treatment, this new
research has shown that a type of MRI scan, known as
diffusion-weighted MRI, is more accurate. This technique measures
water movement in the tissue of the lungs and can detect the
structural changes that lung cancer causes, even in the early stages
of the disease.
The new technique also has the advantage of being non-invasive
and does not require any radiation exposure.
The research analysed 50 people who were due to be operated on
and had been diagnosed with lung cancer or suspected lung cancer
assessed by PET-CT scan. One day before their operation, the same
group also underwent a diffusion-weighted MRI scan.
The results showed that with PET-CT scans, 33 patients were
diagnosed correctly, 7 incorrectly and 10 were undetermined. With
diffusion-weighted MRI scans, 45 patients were diagnosed correctly
and 5 incorrectly. The 10 undetermined cases with PET-CT were
correctly diagnosed using diffusion-weighted MRI scan.
Dr Johan Coolen, from University Hospitals Leuven in Belgium,
said: “Our study has shown that diffusion-weighted MRI scans could
become an appropriate diagnostic instrument for preoperative lung
cancer patients in the near future because they have a high accuracy
for differentiating benign from malignant lung lesions.
“PET/CT scans can wrongly diagnose cancer as they can
misinterpret inflammation in the lungs as a malignant lesion.
Especially in these inflammatory lesions, diffusion weighted MR is
more accurate which could help avoid unnecessary surgical procedures
for those people without malignant disease. In addition, it could
help to classify patients with lung cancer to enable doctors to
provide the most effective therapeutic procedures.”
Professor Marc Decramer, President of the European Respiratory
Society, said: “It is crucial that we continue to evaluate new
diagnostic technologies and look at incorporating these into our
management of lung cancer. A key recommendation of the European
Respiratory Roadmap, which has been launched this week to steer the
future of respiratory medicine, is to focus on effective screening
processes. In a bid to improve patient care, the roadmap also
suggests that personalised targeted medicine will improve a
patient’s quality of life. With the development and evaluation of
new technologies such as the diffusion-weighted MRI scan, we can
work towards achieving these goals.”