中子俘获疗法（NCT）是用于治疗局部侵入性恶性肿瘤如原发性脑肿瘤和复发性头颈部癌的一种非侵入性治疗方法。NCT分两个步骤进行，首先是给病人注射一种含有对慢中子具有俘获倾向性高或吸收截面（ϭ）大的非放射性同位素肿瘤定位药物。该俘获剂的吸收截面比人体组织中的其他元素如氢，氧和氮的吸收截面大许多倍。接着是用超热中子对病人进行照射，超热中子在穿透人体组织后会丧失能量并被俘获剂吸收继而释放出高能带电粒子，引起具有生物杀伤性的核反应（图1）。

迄今为止，所有中子俘获疗法的临床经验均来自于使用非放射性同位素10B，亦被称之为硼中子俘获疗法（BNCT）[2]。目前，使用其他非放射性同位素例如钆受到限制，尚未用于临床。对BNCT的临床评价是一种可替代常规放射治疗恶性脑肿瘤（胶质瘤）的方法，目前亦可用于复发性局部晚期头颈部癌的治疗[3]。

Neutron capture therapy (NCT) is a noninvasive therapeutic modality for treating locally invasive malignant tumors such as primary brain tumors and recurrent head and neck cancer. It is a two step procedure: first, the patient is injected with a tumor localizing drug containing a non-radioactive isotope that has a high propensity or cross section (σ) to capture slow neutrons. The cross section of the capture agent is many times greater than that of the other elements present in tissues such as hydrogen, oxygen, and nitrogen. In the second step, the patient is radiated with epithermal neutrons, which after losing energy as they penetrate tissue, are absorbed by the capture agent, which subsequently emits high-energy charged particles, thereby resulting in a biologically destructive nuclear reaction (Fig.1).