Macías Víctor, Biete Albert
Radiation Oncology, Hospital Clínico Universitario de Salamanca, Salamanca, Spain.
Clin Transl Oncol. 2009 Jul;11(7):437-45. doi: 10.1007/s12094-009-0382-2.
Over the last 10 years the radiobiology of prostate cancer has been studied both in experimental research and in clinical trials of hypofractionated radiotherapy. Unlike most cancers, the alpha/beta ratio of the prostatic carcinoma is probably lower than that of the healthy organs around the gland, although there is no agreement as to how low this alpha/beta really is. This peculiarity implies that, theoretically, a hypofractionated schedule would increase the therapeutic gain of radiotherapy. Until now, following four published randomised trials, hypofractionated radiotherapy has shown results in terms of acute and chronic toxicity and tumour control similar to those obtained with conventionally fractionated radiotherapy. However, these studies are not conclusive. The two studies that involved significant followup used 2D technique and delivered low total equivalent dose. On the other hand, the two most recent trials, which administered total equivalent doses = or >78 Gy with modern techniques (IMRT, IGRT), involved the disadvantage of small samples and a short follow-up period. The results of ongoing randomised trials are necessary to confirm the advantages of hypofractionation over normofractionated radiotherapy. The impact of hypofractionated radiotherapy on the patient's health-related quality of life, and on transports and health care costs, should also be investigated.
在过去10年里，前列腺癌的放射生物学在实验研究和大分割放疗的临床试验中均有研究。与大多数癌症不同，前列腺癌的α/β比值可能低于腺体周围健康器官的α/β比值，尽管对于该α/β比值究竟有多低尚无定论。这一特性意味着，从理论上讲，大分割放疗方案会提高放射治疗的治疗增益。到目前为止，在四项已发表的随机试验之后，大分割放疗在急性和慢性毒性以及肿瘤控制方面的结果与传统分割放疗所获得的结果相似。然而，这些研究并不具有决定性。两项涉及大量随访的研究采用的是二维技术，且总等效剂量较低。另一方面，最近的两项试验采用现代技术（调强适形放疗、图像引导放疗）给予总等效剂量≥78 Gy，但存在样本量小和随访期短的缺点。正在进行的随机试验结果对于证实大分割放疗相对于常规分割放疗的优势是必要的。还应研究大分割放疗对患者健康相关生活质量以及交通和医疗保健成本的影响。
