Hi @buzzliteyear, yes proton therapy is considered SBRT. Here's some info from Mayo Clinic https://www.mayoclinic.org/tests-procedures/sbrt/pyc-20446794#:~:text=Types%20of%20stereotactic%20body%20radiotherapy,that%20are%20near%20vital%20organs.

"Types of stereotactic body radiotherapy:
- Linear accelerator, also known as LINAC. LINAC machines use X-rays, also known as photons, to treat tumors.
- Proton beam, also called charged particle. This newer type of stereotactic radiotherapy uses protons to treat tumors over several sessions. Proton beam radiotherapy might be used to treat tumors in parts of the body that have already had radiation therapy. Or they can treat tumors that are near vital organs."

I'm tagging @jimcinak to make sure he sees your question about his experience with proton beam therapy with 5 treatments.

Buzzliteyear, did you opt for radiation?