Current Status of Carbon Ions Radiotherapy in Taiwan

Ching-Sheng Liu^1,2*, Yu-Ming Liu¹, Tung-Sheng Hsien^1,2, Yu-Lin Lee^1,2, Pin-I Huang¹, Keng-Li Lan¹, Ling-Wei Wang¹, Cheng-Ying Shiau¹, Yi Chao¹

¹Department of Oncology (Cancer Center), Taipei Veterans General Hospital, Taipei, Taiwan, Taiwan
²Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taipei, Taiwan, Taiwan

* Presenter:Ching-Sheng Liu, email:liucs@vghtpe.gov.tw

The carbon ion radiotherapy is a relatively new type of radiotherapy and has several physical and biological advantages compared to conventional x-ray radiotherapy used for cancer therapy. Their physical behavior allows precise delivery of high doses to tumors while minimizing irradiation of surrounding normal tissues. Biologically, they reduce OER and increases RBE and the cells irradiated by them show less variation in cell cycle related radio-sensitivity and decreased repair of radiation injury. Their merits lie on the fact that as they travel deeper inside the body, the RBE becomes larger with depth to reach the maximum at the peak, which are known as Bragg Peak.
In 1975 heavy particle radiotherapy was first started at LBNL using neon ions to irradiate tumors which are difficult to be treated by conventional radiotherapy. In 1994 carbon ion radiotherapy was started at NIRS, and subsequently two other facilities started this therapy. Currently, there are about 12 facilities for carbon beam therapy in operation and several other facilities under construction and planning in the world.
Carbon ion therapy has been applied to more than 20,000 patients around the world. It is effective in such tumors of the head and neck, skull base, lung, liver, prostate, bone/soft tissue and post-operative pelvic recurrence of rectal cancer, as well as adenocarcinoma, malignant melanoma and sarcomas. In carbon ion radiotherapy, when compared with photon and proton therapy, a significant reduction of overall treatment time and fractions has been accomplished without enhancing toxicities.
Taipei Veterans General Hospital has planned the heavy ion therapy project for nine years since hospital executives first visited NIRS in 2009. Our goal is to establish one state-of-the-art comprehensive cancer treatment center with heavy ion therapy in the world. The new facility will be the first heavy ion treatment center in Taiwan and will be located in the densely populated city of Taipei. The total number of treatment is estimated to be 1200 patients per year. We urgent to treat endemic cancer, such as lung, liver, and pancreatic cancer, etc.. Two treatment rooms will be equipped with both horizontal and vertical beam lines with 3D scanning technology and real-time imaging gated irradiation system. Taipei VGH Heavy Ion Cancer Therapy Center will start operation in July 2022.

Keywords: Carbon Ion Radiotherapy, Bragg Peak, Relative Biological Effectiveness (RBE), Oxygen Enhancement Ratio (OER)