The History of Proton Therapy

Proton therapy has been used for quite some time. In 1946, Robert Wilson first suggested using protons for medical use. He saw the importance of using localized energy to increase the radiation dose to the tumor while lessening the dose to normal tissues.

Two years later, researchers at the Lawrence Berkeley Laboratory (LBL) did studies on protons and confirmed Wilson’s suggestions. The first treatments on humans consisted of radiation to destroy the pituitary gland in patients with hormone-sensitive metastatic breast cancer. This treatment stopped the pituitary from making the hormones that stimulated the cancer cells to grow. In the 1950s, the treatments were effectively duplicated on patients at a facility in Uppsala, Sweden.

This led to the Harvard Cyclotron Facility treating the pituitary gland and developing specific techniques for treating other conditions such as arteriovenous malformations (AVM). Furthermore, they worked to expand proton treatments to include choroidal melanomas, chondrosarcomas, chordomas, and various cancers located in the brain. However, this early work was limited due to the inability to perform 3-D imaging and being able to work only in facilities primarily dedicated to physics research.

The development of the CT scanner in the 1970s allowed for the treatment of almost any site in the body. The subsequent development of MRI, SPECT, and PET scanning has further improved the ability to define the target, allowing even further benefits to proton therapy.

In the 1980s design and construction began on the first dedicated clinical proton facility at Loma Linda University Medical Center in California. The Proton Therapy Cooperative Group (PTCOG) was also created during the 1980s for scientists to share ideas on the development of proton therapy. This group continues to meet regularly to present both clinical and basic science research to the international proton therapy community.

Facilities are operating all over the world with several more facilities currently under construction or in the planning stages. Proton centers can range a great deal in size and cost. Larger centers can be 100 yards long with the gantries being 3-4 stories high. Smaller, single-room facilities are less expensive and require less space. The single room facilities are becoming more common and will make proton therapy available in more areas.