Boron Neutron Capture Therapy (BNCT) 硼中子捕獲治療

Boron Neutron Capture Therapy (BNCT) is a unique form of treatment that utilizes a nuclear reaction between boron-10 and neutrons to selectively destroy tumor cells. The process begins by administering a boron-containing compound to the patient, which preferentially accumulates in tumor cells. The tumor is then irradiated with low-energy neutrons. When the neutrons interact with the boron-10 atoms within the tumor, a nuclear reaction occurs, releasing high-energy particles (lithium-7 and alpha particles) with extremely short penetration ranges, which selectively destroy the tumor cells.

Advantages

The alpha particles and lithium-7 ions generated by BNCT have an extremely short range—only about 5 to 9 micrometers, which is less than the diameter of a typical tumor cell (10 to 20 micrometers). Ideally, this means the damage is confined to the tumor cells, causing minimal harm to surrounding healthy tissue. In addition, alpha particles have a higher Relative Biological Effectiveness (RBE) than photons, making BNCT potentially more effective against radioresistant tumors.

Currently, only a few thousand BNCT treatments have been performed worldwide. BNCT may be suitable for the following cases:

1. Radioresistant malignant tumors:
   Such as malignant gliomas and melanomas. Similar to heavy particle therapy, the alpha particles produced in BNCT have a high RBE, potentially offering greater therapeutic benefits for tumors resistant to conventional radiation.

2. Recurrent tumors:
   Including recurrent malignant brain tumors, head and neck cancers, skin cancers, and pediatric tumors. When traditional treatments have failed, BNCT can sometimes yield remarkably positive results.

硼中子捕獲治療（BNCT）是一種獨特的治療方法。它利用了硼-10 和中子之間的核反應來選擇性地摧毀腫瘤細胞。首先，給予患者含硼的化合物，這些化合物會在腫瘤細胞內積聚，然後用低能量中子照射腫瘤。中子與藥物中的硼-10 相互作用產生核反應，釋放出能量很高但穿透距離很短的粒子（鋰-7 及 α 粒子），選擇性地摧毀腫瘤細胞。 

優勢： BNCT 產生的 α 粒子及鋰-7 粒子的射程非常短，約只有 5-9μM， 不超過一個腫瘤細胞的直徑（約 10-20μM）。理想狀況下破壞的範圍僅限於腫瘤細胞，對周圍正常細胞的傷害較少。此外，產生的 α 粒子的生物效應高於光子，對於具有放射抗性的腫瘤可能有更好的成效。 

目前全球治療案例僅有數千例，BNCT 適用於： 

1. 具有放射抗性的惡性腫瘤，例如顱內惡性膠質瘤（malignant glioma）、黑色素細胞瘤（melanoma）等。類似於重粒子治 療，BNCT 產生的 α 粒子具有較高的生物效應（RBE），對於具有放射抗性的腫瘤可能具有更高的治療效益。 

2. 復發性腫瘤，例如惡性腦瘤、頭頸癌、皮膚癌、兒童腫瘤等。 如果傳統治療已經無效，BNCT 有時可以帶來令人驚艷的治療效果。