EACR Travel Fellowships are co-sponsored by Worldwide Cancer Research and provide funds up to €3,000 to early-career cancer researchers. For more information on how to apply for Travel Fellowships, you can visit the EACR website.


Eelco Lens at the dual-energy CT console
Eelco Lens at the dual-energy CT console

Name: Eelco Lens
Home Institution: Delft University of Technology & Holland Proton Therapy Center, Netherlands
Host Institution: OncoRay, Dresden, Germany
Dates of visit: 28 September – 06 October 2018

Research: Proton therapy allows for a highly concentrated radiation dose deposition to the tumour but is also highly sensitive to small errors in the predicted proton range. Dual-energy computed tomography (DECT) allows for an accurate and patient-specific prediction of the proton range in the patient. By making two consecutive CT scans at different energies and combining the information, the proton stopping power can be precisely calculated for treatment planning. DECT significantly improves the accuracy of proton therapy compared to conventional single-energy computed tomography.


Why did you decide to apply for an EACR Travel Fellowship?

It was the perfect opportunity for me to visit the lab at OncoRay since we were already planning to start a collaboration. The fellowship facilitated the visit financially and together with the team at OncoRay, we made sure we had the most efficient week possible. With the obtained knowledge we aim to improve cancer patient care in the Netherlands.

Why did you choose the host lab?

The hosting lab (OncoRay) is the world-leading institute when it comes to the clinical application of DECT for range prediction in proton therapy. They have performed comprehensive studies on the different calibration steps needed for the calculation of proton stopping power based on DECT scans. In addition, in numerous high-impact studies they showed the clinical benefit of using this technique. Therefore, OncoRay was the perfect place to learn about all aspects and the clinical use of DECT. This knowledge can greatly benefit the Holland Proton Therapy Center, which has recently treated its first patient.

Eelco Lens setting up the phantom
Patrick Wohlfahrt and Eelco Lens setting up the phantom to make dual-energy CT scans.

What were you able to do that you could not have achieved in your home lab?

We were able to acquire time-resolved DECT scans of a thoracic phantom that was also available at OncoRay. With the measured data, we were able to discuss all the image post-processing and analysis steps. This would not be possible at HollandPTC since the DECT infrastructure is not ready yet. Some of the software has been developed in-house at OncoRay or is provided through other collaborations at OncoRay. In addition, I could join the medical team at OncoRay during the acquisition of a DECT scan of a patient within the clinical routine workflow.

Was the host institution very different from your own, or was there anything you particularly liked about the host institution?

The host institution is very different in the sense that they have already been treating patients with proton therapy and imaging them with DECT for more than 3 years. They have a deep knowledge of these techniques and it was great to see such an active clinical facility. All research that is being performed at OncoRay is done to directly benefit the patient and they aim to translate the new techniques into daily practice as soon as possible.

Did you have a personal mentor or anyone who particularly helped you?

During my visit, I had extensive contact with the group leader of the High Precision Radiotherapy Group, Dr. Christian Richter. He made sure that I came into contact with the experts from the clinic and gave me a tour through the facility. He showed me the different parts of their proton-therapy clinic and DECT systems. We also had in-depth discussions on potential future projects and collaborations. Furthermore, I also worked and discussed a lot with Dr. Patrick Wohlfahrt. Patrick recently finished his PhD and was responsible for almost all the studies and analyses using DECT. He introduced me to the systems, software tools and personalised scripts regarding DECT.

Project Team
Project Team (left to right): Eelco Lens, Patrick Wohlfahrt, Nils Peters, Christian Richter, Jonathan Berthold

Does your lab plan to do any future collaboration with the host lab?

Together with the host lab, OncoRay and the group leader Dr. Christian Richter, I applied for a Marie Curie individual fellowship to work as a postdoctoral fellow at OncoRay for a year. Our plan is to set up a new study using time-resolved DECT. This trip provided me with a lot of in-depth knowledge which will be needed for a swift start if the Marie Curie is granted. Through this visit and the planned stay of one year, we hope to start a long-lasting collaboration.

Is there anything else you’d like to mention?

Every day I was at OncoRay I felt more than welcome. There was a full programme set up for me in order to have the most efficient week possible and to make sure that every aspect of the topic was covered. There was also a colloquium set up for me to give a presentation on my work. After the presentation we had some in-depth discussions on the presented topics and they showed me some of the highly innovative techniques they are working on in order to further improve patient care.

Eelco Lens dinner with project team
Dinner with the project team (left to right): Nils Peters, Christian Richter, Eelco Lens, Patrick Wohlfahrt