The ESTRO/ESNM course on Molecular Imaging in Radiation Oncology given in Madrid, 22-25 February 2015 aimed at providing the participants with the knowledge and skills to deal with the new opportunities and challenges of the use of functional imaging in the field(s) of radiation oncology. My current PhD project is concerned with the impact of tumour oxygenation on the outcome of stereotactic body radiotherapy, and has so far been focused on computer simulations. The natural continuation of my project would be to include functional imaging data from animals and/or patients in order to assess the prevalence and extent of hypoxia in lung tumours and with the end goal to find a correlation between tumour oxygenation and clinical outcome.
The interpretation of functional images such as PET is far from trivial; as such images only display the relative uptake of a tracer, which is in turn connected to a biochemical process. Hypoxia could be imaged in PET and hypoxic sub-volumes could in theory be delineated and prescribed a higher dose due to the expected increase in radioresistance in these regions. However, it is the level of hypoxia that determines the radioresistance, and in order to prescribe a suitable dose this quantitative information thus has to be extracted from the qualitative PET image. Although there are several tracers available for hypoxia imaging such as 18F-FMISO, 18F-FAZA and 18F-EF5 to name a few, no standardized method of including information of tumour hypoxia into the treatment planning process currently exists. The ESTRO course on the use of molecular imaging in radiation oncology thus seemed very interesting and of high relevance to me, as I am currently thinking about how to handle functional imaging of hypoxia in a quantitative way as is necessary for my project.
I had high expectations of the course in terms of covering current clinical practice as well as presenting the state-of-the-art. However, this course sadly fell short of every expectation that I had. Most of the participants were radiation oncologists, radiologists or nuclear medicine physicians while six out of forty participants were physicists and the lectures were given by professionals from the same fields. While the lectures concerning physical aspects of e.g. MRI and PET contained several errors, I also found other presentations given by physicians to be rather biased and including a lot of the faculty’s own work which I doubt is entirely representative of the current practice. The main message of the course was that the inclusion of several imaging modalities into target volume delineation reduces the inter-observer variability, which appears to be rather obvious in my view.
In conclusion, I did not acquire the new knowledge that I had been hoping for but attending the course did increase my motivation concerning my PhD project. It has, once again, made me realize that the clinical application of my work might still be quite far into the future given the apparent general attitude towards functional imaging in general and hypoxia in particular as a natural part of radiotherapy treatment planning. I feel that the research that I am involved in thus plays an important role in terms of driving the development forward, and I will if nothing else benefit from this experience in that it will help me adapt the communication of my work in the proper way.