Hypofractionated radiotherapy for localised prostate cancer. Review of clinical trials

ABSTRACT

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 (AU)