The Benefits of Proton Therapy:
Early Detection Leads to Successful Treatment
The benefits of proton therapy are plentiful. Since most cancers begin as a local lesion that spreads - or metastasizes - to other areas of the body, if the local lesion is eradicated before disease spreads, the cancer can be cured. Because increased awareness and more sensitive screening tools have led to earlier cancer detection, more patients are candidates for treatments like proton therapy.1 What's more, effective systemic treatments can destroy tiny amounts of metastatic cancer, making the role of local therapies more important - even if a cancer has spread.2,3
Two types of local therapy are surgery and radiation. In general, surgery is used for cancers that can be removed without compromising a patient's function or quality of life. In other cases, radiation therapy is used either alone or in conjunction with surgery. Radiation is used in approximately half of all cancer patients at some time during the course of their disease.
The most common source for conventional radiation therapy is X-rays. As X-rays pass through the body, they cause damage to cells and tissues. While the effects of radiation are the same for the cells of tumors and normal tissue, tumor cells divide at a much higher rate and are therefore much more susceptible to radiation-induced damage. The higher the dose of radiation, the greater the cell damage to both normal tissues and tumor cells. In both traditional and proton therapies, dose selection is based on the goal of achieving the greatest benefits with the least risk of exposure of healthy tissue.
Delivering the appropriate dose of radiation can be easier with proton therapy, and a higher dose of radiation can be provided with less risk to healthy tissue.
The main advantage of protons in radiation therapy is that they have a smaller negative impact on the tissue that surrounds a tumor or lesion. Protons deposit a significantly smaller amount of their energy as they travel to the tumor site as compared to X-rays used in traditional therapy. Protons stop at the tumor site, whereas X-rays continue on their path - irradiating healthy cells as they travel through the rest of the body. To see a video explanation of this process, click here. With less concern about potential damage to normal tissues, the tumor dose can be escalated, leading to higher tumor control rates. The promise of protons is two-fold: enhanced tumor control and reduced complications - for a better quality of life for survivors.
1 Eng TY, Thomas CR, Herman TS. Primary radiation therapy for localized prostate cancer. Urol Oncol 2002; 7:239-257.
2 Mehta N, Mauer AM, Hellman S, Haraf DJ, Cohen EE, Vokes EE, Weichselbaum RR. Analysis of further disease progression in metastatic non-small cell lung cancer: implications for locoregional treatment. Int J Oncol 2004; 25:1677-1683.
3 Hellman S. Stopping metastases at their source. N Engl J Med 1997; 337:996-997.
