dr. Mathieu Spaas (MD)

CRIG member

Doctoral Fellow  - Department of Radiation Oncology and Experimental Cancer Research, Ghent University
Radiation Oncology resident - Department of Radiation Oncology and Experimental Cancer Research, University Hospital Ghent
Principal investigator: prof. Piet Ost (MD, PhD)


Research focus

Radiotherapy has earned its place as one of three main pillars in cancer treatment, alongside surgery and systemic agents. Traditionally considered as a means of achieving local tumor control through induction of DNA damage in irradiated tumor cells, radiotherapy is used in routine clinical practice across all disease stages, whether with curative or palliative intent. However, since as early as 1953, reports have been published describing tumor regression outside the radiation fields. This so-called “abscopal effect” has more recently been postulated to be the result of a radiotherapy-induced antitumor immune response.

With the advent of modern immunotherapy, in particular immune checkpoint inhibitors, the potential for immune activation by radiotherapy has become even more relevant. Indeed, mounting preclinical and clinical evidence suggests a potential synergy between both treatment modalities, creating opportunities for combination strategies across many different cancer types.

Our research aims to investigate the safety and efficacy of immunotherapy-radiotherapy combinations in advanced solid tumors. Furthermore, translational research will help to elucidate the complex interactions between both treatment modalities on a molecular level. In turn, this may lead to the identification of novel predictive and prognostic biomarkers.


  • 2019-present: Radiation Oncologist in training, Ghent University
  • 2018-present: PhD on the combination of Radiotherapy with Immunotherapy, Ghent University Hospital
  • 2017-2019: Radiation Oncologist in training, KU Leuven
  • 2017: Master of Science in Medicine, KU Leuven – Magna cum laude

Key publications

  • 'Checkpoint inhibition in combination with an immunoboost of external beam radiotherapy in solid tumors (CHEERS): study protocol for a phase 2, open-label, randomized controlled trial'. BMC Cancer, 2021 (PMID: 33962592)
  • ‘Is the combination of immunotherapy and radiotherapy in non-small cell lung cancer a feasible and effective approach?’. Front Med, 2019. (PMID: 31788476)

Contact & links