Heavy Ion Therapy 重粒子放射治療

Heavy Particle Therapy is a type of cancer treatment that uses high-energy particles such as carbon or helium ions to target tumors. Compared to protons, these particles have greater mass and charge, resulting in an increased Relative Biological Effectiveness (RBE). Due to this enhanced biological effect, heavy particle therapy can deliver up to three times the biological damage (RBE ≈ 3) to cancer cells compared to photons or protons, even at the same physical dose.

Advantages

Heavy particles have a higher RBE, making them especially effective against certain radioresistant cancers. In addition, they exhibit a more pronounced Bragg peak than other forms of radiation, allowing for more precise dose delivery with minimal damage to surrounding healthy tissue when accurately targeted.

Conditions benefiting from heavy particle therapy:

1. Radioresistant tumors:
   Examples include sarcomas, malignant melanoma, and adenoid cystic carcinoma. These tumors tend to respond poorly to photon therapy, but due to the higher biological effectiveness of heavy particles, treatment outcomes may be significantly improved.

2. Tumors near the skull base or spinal cord:
   Such as chordoma and chondrosarcoma. Given their proximity to critical organs, heavy particle therapy—like proton therapy—can deliver higher doses safely, potentially offering better tumor control than photon therapy.

3. Gastrointestinal and genitourinary cancers:
   Research from Japan has shown promising results for heavy particle therapy in treating cancers such as liver cancer, pancreatic cancer, rectal cancer, and kidney cancer, particularly in the gastrointestinal and genitourinary systems.

重粒子治療（Heavy particle therapy）是利用碳或氦等高能粒子來 治療腫瘤的一種治療方法。這些粒子相對於質子具有較大的質量和 電荷，因此能夠增強生物效應（Relative Biological Effectiveness, RBE）。透過增強的生物效應，重粒子治療在給予相同劑量的情況 下，能夠產生接近光子或質子三倍的破壞（RBE=3），對癌細胞造成更大的治療效果。 

優勢

重粒子具有較高的生物效應（RBE），尤其對於部分對放射具有抗 性的癌症特別有效。同時，重粒子的布拉格尖峰現象更為明顯，若 能精準對位，獨特的物理特性使得劑量分布更加集中，減少對周圍組織的損害。 

適合重粒子治療的可能適用於以下情況： 

1. 具放射抗性之腫瘤：例如惡性肉瘤（sarcoma）、黑色素瘤 （malignant melanoma）及腺樣囊狀癌（adenoid cystic carcinoma）等。這些腫瘤對於光子的反應較差，然而重粒子因為具有較高的生物效應，對於這類腫瘤可能有較高的治療效益。 
2. 顱底部和脊髓腫瘤：例如脊索瘤（chordoma）和軟骨肉瘤 （chondrosarcoma）。因貼近重要器官，等同質子治療，重粒子有機會給予較高劑量，達到比光子治療更好的控制效果。 
3. 消化道及泌尿道腫瘤：根據日本的研究成果顯示，重粒子治療在肝癌、胰臟癌、直腸癌、腎臟癌等消化道及泌尿道方面的癌症治療上，有相當不錯的成效。