Cosset J-M, Haie-Meder C
Département d'oncologie radiothérapie, institut Curie, 26, rue d'Ulm, 75005 Paris, France.
Cancer Radiother. 2005 Dec;9(8):610-9. doi: 10.1016/j.canrad.2005.09.019. Epub 2005 Oct 13.
Low-dose brachytherapy for prostate cancer was actually proposed in the first years of the XXth century. Its modern version (iodin 125 or palladium 103 permanent implants) now benefits from some 15 years of experience in a few pioneer centers, with very satisfactory results in term of efficacy/toxicity ratio. More recently, a high-dose rate (HDR) prostate brachytherapy technique has been introduced. Initially utilized essentially as a "boost" irradiation combined with external radiotherapy, it is now being proposed by some authors as a monotherapy for selected localized prostate cancers. Although sophisticated radiobiological models have been proposed to compare those two dose-rates, they are not considered to be valid and reliable enough to compare such different irradiation schemes (A low-dose rate irradiation lasting several months vs a few high-dose fractions given in a few days). When it comes to the implantation techniques, it seems that most of the technical problems which arose for both schemes have been solved, and that the experience of a given team is now much more important than the technique itself. Clinical results cannot be reliably compared so far, the follow-up of the patients treated by HDR brachytherapy being usually shorter, and the patients treated with HDR usually presenting with more advanced lesions. Radioprotection features are very different, with no accident reported for low-dose rate implants. For HDR no irradiation is given at all to the staff and family during a normal application, but one has to face the threat of manipulating high activity sources, with a few accidents or incidents reported in the literature. Financial studies show that for more than 20-30 patients treated in a year, HDR is more economical, although a decrease in the cost of the seeds could change the picture. In conclusion, for low-risk localized prostate cancer, it does not appear reasonable to give up using a low-dose rate technique, which proved to be both efficient and poorly toxic. This actually corresponds to the recent GEC-ESTRO recommendations. For the other patients, a dose escalation is appealing: this could be performed using brachytherapy (LDR or HDR), with or without hormonotherapy. Several trials are ongoing or will be activated very soon to try and answer.
20世纪初就有人提出了低剂量近距离放射疗法治疗前列腺癌。其现代版本（碘125或钯103永久性植入物）目前在一些先驱中心已有约15年的经验，在疗效/毒性比方面取得了非常令人满意的结果。最近，一种高剂量率（HDR）前列腺近距离放射疗法技术被引入。最初主要用作与外照射放疗联合的“增敏”照射，现在一些作者提议将其作为某些局限性前列腺癌的单一疗法。尽管已经提出了复杂的放射生物学模型来比较这两种剂量率，但它们被认为不够有效和可靠，无法比较如此不同的照射方案（持续数月的低剂量率照射与在几天内给予的少数高剂量分次照射）。就植入技术而言，似乎两种方案出现的大多数技术问题都已得到解决，而且特定团队的经验现在比技术本身更重要。到目前为止，临床结果无法可靠比较，接受HDR近距离放射疗法治疗的患者随访时间通常较短，接受HDR治疗的患者通常病变更晚期。放射防护特征非常不同，低剂量率植入物未报告任何事故。对于HDR，在正常操作期间工作人员和家属根本不会受到照射，但必须面对操作高活度源的威胁，文献中报告了一些事故或事件。财务研究表明，对于一年治疗超过20 - 30名患者，HDR更经济，尽管种子成本的降低可能会改变这种情况。总之，对于低风险局限性前列腺癌患者，放弃使用已证明有效且毒性低的低剂量率技术似乎不合理。这实际上与最近的GEC - ESTRO建议一致。对于其他患者，剂量递增很有吸引力：这可以通过近距离放射疗法（LDR或HDR）进行，可联合或不联合激素疗法。正在进行或很快将启动多项试验以尝试给出答案。
