Introduction to Carbon Ion Therapy
Carbon Ion Radiotherapy (CIRT) is a charged particle radiation treatment used to treat malignant tumors. In many ways, it is similar to proton therapy because they are both positively charged particles; however, CIRT utilizes carbon ion particles instead of protons. These carbon ions are heavier than protons, which leads to higher linear energy transfer and biological effectiveness. Initially discovered in California, CIRT was not adopted for clinical use in the United States. Recently, the MAYO clinic announced the construction of the ﬁrst CIRT center in the western hemisphere — in Jacksonville, FL. In this blog, we will cover the history and development of this treatment.
The advantages of charged particle radiotherapy were discovered by Robert Wilson in 1946. During the 1950s, high-energy accelerators were used for research into clinical treatments for cancer. The ﬁrst human trials began in 1952, by John Lawrence and Cornelius Tobias with helium and deuteron particle beam. These trials lead to an expansion in particle beam research, including the utilization of proton particle therapy in 1954 by the Lawrence Berkeley National Laboratory (LBL). By 1975, LBL installed BEVALAC, a novel particle accelerator, which was instrumental to CIRT research. CIRT was found to be both an effective and safe alternative treatment to traditional photon therapy and proton therapy. Improvements in particle beam delivery, treatment planning, and treatment quality led to the ﬁrst CIRT centers for clinical purposes.
Early Clinical Use
Due to the success at LBL, the Japanese government began construction of the National Institute of Radiological Sciences (NIRS) in 1984. Located in Chiba, Japan, this was the ﬁrst heavy-ion center for clinical use in the world. In 1993, the Heavy Ion Medical Accelerator (HIMAC) was completed, and by 1994 NIRS began treating patients with CIRT.
NIRS was the only CIRT center until the completion of the GSI Carbon-Ion Radiotherapy Facility in 1997. This center was located in Germany and encouraged a large expansion of CIRT centers throughout Asia and Europe.
Expansion of CIRT
Today, there are 13 CIRT centers located throughout Germany, Austria, Italy, Japan and China. Furthermore, there are two centers under construction, including the ﬁrst CIRT center for Korea. Several centers are also in the initial planning phase, including MAYO’s center for Jacksonville. Since the completion of NIRS, over 20,000 patients have been treated using CIRT. The data gathered from these patients is promising and further technological improvements have made the interest in CIRT expand. Despite all the advancements and encouraging research results, CIRT has yet to be widely adopted due to cost. CIRT centers cost $300 million to build, which is more cost-prohibitive than photon and proton therapy centers.
This blog will be one in a series of three covering CIRT. Please stay tuned for next month’s blog that will compare and contrast this treatment against proton therapy. In the meantime, check out the resources below for more information on the development and adoption of CIRT.