I'm currently having proton bean radiation for my meningioma tumor grade 2. After a second opinion and my own research, I decided to go with this option. Can't tell about results as I just have done 3 sessions/30 total and all is going great. I'm a health care provider so have access to the Pubmed library through my work. The more educated you are about this, the better you can make decisions. To address your question, proton beam does not "eradicate" the tumor. The purpose of its to put the tumor in remission for some years, hopefully several. This radiation stops the tumor from growing but it doesn't eliminate it. By disrupting the growth, hopefully patients will enjoy some years with quality of life but still being followed periodically depending on each person's protocol. If is very localized, so the risk of damaging surrounding tissue is likely less than that of conventional radiation, however, more research is being done to see if there is significant difference between proton beam and conventional radiation. What my doctors explained to me, is very in line with what I have read in some studies. Every case and tumor are different, so no one treatment fits all. Treatments are personalized for each patient depending on their condition, grade of tumor, location, age of the patient, general health condition, and availability of this equipment. I found many useful comments in this support group, so I'm absolutely committed to reciprocate as I navigate my own experience. Best of luck in your journey!