Clip-free Ocular Proton Therapy – PHRT


Clip-free Ocular Proton Therapy

Short Summary

The current procedure for treatment of uveal melanoma with proton therapy involves a pre-treatment surgical intervention. This creates a paradoxical situation, in which the non-invasive tumor treatment via proton therapy requires invasive surgical preparation of patient’s eye. Utilization of modern imaging methods and optical tracking systems opens up a possibility to create completely non-invasive workflow.


The aim of this project is to implement and benchmark the non-invasive workflow based on optical tracking and multi-modality imaging techniques.


Through the novel workflow, one could achieve complete non-invasiveness in ocular proton therapy, thus sparing the patient of the pre-treatment surgical procedure and non-curative radiographic imaging dose, while potentially further improving treatment personalization.


During the pre-treatment surgery, there are small clips sutured on the sclera in the proximity of tumor lesion. The clips serve as a surrogate of a tumor and play a key role in preparation of a patient specific geometric model of the eye and the tumor used for optimization of proton therapy. Clips are further utilized prior to proton therapy, to ensure the accurate alignment of the tumor in relation to the treatment beam (through x-ray imaging of the clips). Modern imaging methods open up a possibility to create a geometrically accurate model representation of an eye and tumor. Optical tracking systems carry a potential to align treated eye to treatment beam without clips and the associated x-ray imaging.

Technology Translation

Dr. Jan Hrbacek

Center for Proton Therapy, Paul Scherrer Institute


  • Prof. Damien C. Weber
  • Dr. Riccardo Via
  • Dr. Alessia Pica
  • Dr. Jürgen Beer
  • Prof. Tony Lomax
  • Prof. Guido Baroni, Politecnico di Milano


In Progress

Funded by