质子束放疗在肿瘤中的研究进展

肿瘤放疗的基本准则是提高肿瘤靶区的放射剂量，同时更好地保护肿瘤周围的正常组织器官。质子束治疗（PBT）是目前全球最先进的放疗技术之一，其能更好地体现这一准则。理论上，质子束以其特有的Bragg峰和优越的相对生物学效应，可给予肿瘤靶区最大剂量，同时降低肿瘤周围正常组织器官的接受剂量，实现对肿瘤靶区的“定向爆破”，提高肿瘤的局部治疗率和控制率，优于传统光子治疗。目前已应用于临床的研究包括黑色素瘤、肺癌、食管癌、乳腺癌、肝癌、前列腺癌和儿童恶性肿瘤等多种病变，但多为回顾性研究，而且建立和维护质子设备的成本巨大，因此用PBT治疗恶性肿瘤尚存争议。PBT面临的挑战是缺乏足够的临床证据和不明确的生物学效应等，克服这些不足可能会更好地促进PBT的快速发展。笔者详细论述了PBT的物理、生物学特性及其在肿瘤治疗中的研究和应用进展。

Overview of proton beam therapy in cancer treatment

Tumor radiotherapy increases radiation dose in a tumor target area and improves protection for normal tissues and organs around tumors. Proton beam therapy (PBT) is the most advanced radiotherapy technology worldwide. In theory, the unique Bragg peak and superior relative biological effect of proton beam can deliver a maximum dose to tumor target areas, reduce the dose received by normal tissues and organs around tumors, achieve the "directional blasting" of a tumor target area, and improve the local treatment and control rates of tumors. This method has better features than traditional photon therapy. Currently, existing clinical studies focus on melanoma; lung, esophageal, breast, liver, and prostate cancers; childhood malignant tumor; and other diseases. However, most of these studies are retrospective clinical studies, and the cost of establishing and maintaining a proton equipment is immense. Thus, proton therapy for malignant tumors remains controversial. Future studies must address the insufficient clinical evidence of PBT, and biological effects are still under investigation. Overcoming these deficiencies is associated with the rapid development of PBT. This review discusses the physical and biological characteristics of PBT, and its application in cancer therapy.