Garchinger Maier-Leibnitz-Kolloquium: New prospects in Proton Therapy: Minibeam, Ionoacoustics and more

by Prof. Günther Dollinger (Universität der Bundeswehr, München)

Thursday 29 Jun 2023, 16:15 → 17:15 Europe/Berlin

Lecture Hall, ground floor (west) (LMU building, Am Coulombwall 1, campus Garching)

Protons or heavier ions offer advantages over conventional x-ray irradiation in tumor therapy. These advantages are reflected in a higher dose conformity to the tumor volume and the associated sparing of normal tissue. In contrast to X-ray photons, protons have a finite range in the body, which means that the tissue behind the tumor can ideally be completely spared from the dose. Due to their characteristic dose distribution (Bragg curve) with a pronounced maximum (Bragg peak), the dose in the tissue in front of the tumor is also substantially reduced.
However, even when using proton therapy, side effects limit the outcome in terms of tumor control and harm to the patient. We have tackled several options for improvements:
1) When applying submillimeter proton “minibeams”, healthy tissue can be spared by spatial fractionation effects where healthy tissue irradiated in channels of high dose is more easily repaired from  close by areas obtaining nearly no dose. Tumor control may be improved by enhancing mean dose and by optimized heterogeneous dose distribution. We have demonstrated the sparing effects for the healthy tissue in experiments in a mouse ear model.
2) A second problem of todays proton therapy lies in the correct adjustment of the Bragg peak in the tumor. We have demonstrated that the use of an acoustic signal emitted by pulsed proton beams allows to measure the longitudinal position of the Bragg peak to better than 1 mm accuracy and to mark its position in an ultrasound image. This accuracy will allow to target the tumor better avoiding save margins to be irradiated around the tumor tissue.     

3) We have demonstrated that 3D-printing of resonator structures will reduce the high costs of manufacturing proton accelerators that are the main hindrance for an even more widespread use of proton therapy.

Hybrid access via ZOOM:
https://lmu-munich.zoom.us/j/98457332925?pwd=TWc3V1JkSHpyOTBPQVlMelhuNnZ1dz09
Meeting ID: 984 5733 2925
Passcode: 979953

kolloquium-29-06-23.pdf