Hypoxia in Rectal Cancer Clinical Trial
Official title:
RHYTHM-I: Modulation of Radiotherapy According to HYpoxia: Exploiting Changes in the Tumour Microenvironment to Improve Outcome in Rectal Cancer.
A low level of oxygen in cancer cells makes them less likely to respond to chemotherapy and
radiotherapy treatments. There is interest in using new drugs that improve the level of
oxygen in tumours. Another approach would be to increase the radiotherapy dose to tumours
with low oxygen levels.
Before we can do this for patients with rectal cancer, we need to develop a reliable way of
identifying areas of low oxygen within the rectal tumour. This will make us able to tell
which patients may be suitable for such a change in their treatment.
Traditionally, the level of oxygen in tumours is measured by inserting a needle into the
tumour and measuring it directly. This is not possible in rectal cancer. This study has been
designed to identify the best alternative method. We would like to do a blood test, take
samples of cancer tissue and some detailed scans (18F-fluoromisonidazole (F-MISO) positron
emission tomography, perfusion computed tomography, functional magnetic resonance imaging).
The results of these tests will be compared to decide which gives us the most comprehensive
and reliable information.
Patients in Group A go straight to surgery. By looking for markers of low oxygen levels on
the tumour that has been removed, we will be able to find out which of the study tests
performed before the tumour was removed is the best. By repeating the scans we will be able
to see how reliable they are and how much they change on a day to day basis. We think that
tumours that still have low levels of oxygen after 8 to 10 doses of radiotherapy are the
least likely to respond to treatment.
Group B will have scans before radiotherapy treatment and after 8 to 10 doses of
radiotherapy to see if we can identify the patients that have persistent low levels of
oxygen.
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