How it Works
When doses of protons (positively charged parts of an atom) enter the body, they deposit most of their energy at a specific target, destroying cancerous cells and preserving surrounding healthy tissue. This differs from conventional radiation, which uses x-rays that have a higher entrance dose and exit dose before and after the tumor. Reducing damage to surrounding healthy tissue and critical organs results in a lower chance for side effects and secondary cancers.
Our treatment rooms use pencil beam scanning which further increases the precision of proton therapy, allowing the tumor to be directly targeted with aggressive doses of radiation. Pencil Beam Scanning (PBS) allows clinicians to treat or “paint” a tumor using the proton beam at a precisely configured range, and to adjust the intensity of the beam to achieve the appropriate dose. PBS has truly revolutionized proton therapy, offering increased flexibility in dose shaping and improved dose conformality. Therefore, clinicians can treat larger and more complex tumors, while at the same time sparing more healthy tissue. Large and non-contiguous targets benefit especially from pencil beam scanning proton therapy. Clinicians can deliver high doses of proton radiation therapy and sculpt doses to the complex shape of an individual tumor—and therefore can be used for tumors next to critical structures. Pencil beam scanning proton therapy, produces fewer neutrons, further reducing doses to normal, healthy tissue. In the vast majority of cases, pencil beam scanning requires no beam-modifying devices, physical compensator or apertures which allows for rapid, flexible re-planning without the need to fabricate, and manually insert, new beam-shaping devices.
How do I know if it’s for me?
A non-invasive treatment, proton therapy for cancer is best used to treat individuals with a localized tumor, in which the cancer has not spread to other parts of the body and in situations in which tumors cannot be removed surgically or, in some cases, require radiation therapy in addition to surgery. Proton therapy may be combined with other treatment options, depending on the specific details of your case.
This new way of distributing protons to a tumor site has expanded the usefulness and applicability of proton therapy, because it allows a greater deal of customization and precision in cancer treatment.
Pencil beam scanning is a method in which a proton beam spot is moved by magnetic scanning while the beam intensity is adapted simultaneously to allow protons to be delivered to one specific spot, about the size of a dry-erase marker tip, in the patient’s body. Previous methods delivered the dose of radiation to the entire site at one time, making it difficult to accommodate for variations in tumor structure or volume.
Provision offers pencil-beam scanning. The technology has opened the door for a number of additional tumor sites to become candidates for proton therapy including lung, liver, breast esophagus, pelvic, large sarcomas, high risk prostate and mediastinal tumors as well as re-irradiation of recurrent tumors.
Pencil beam scanning reduces the radiation dose by 25 percent compared to existing methods of proton delivery. It has expanded the 20-30 percent of cancers considered good candidates for proton therapy to 80 percent of cancers.