Question: Hi how do you know there is near to know oxygen in tumours

Isabel Pires answered on 10 Mar 2015:

Doctors and scientists such as myself have several ways in which they can find out how much oxygen is in a tumour:
Doctors can use special probes (or measuring devices) for oxygen, and stick them in a tumour to measure the oxygen concentration directly. As you can imagine, this can be uncomfortable so there are less drastic ways.
Doctors can also take a small sample of the tumour (also called a biopsy), and scientists in the lab can analyse it to look for specific protein or genes which are only activated or only appear when oxygen is low or absent.
Finally, there is a lot of new research being developed in labs all over the world to use chemicals that can accumulate in regions of low oxygen as a way to detect these areas. The advantage of using these is that doctors would be able to do imaging of the patient (a bit like taking an X-ray, but more sophisticated) without having to take a sample of the tumour, which is much better for the patient.