Technological advances in radiotherapy for the treatment of localised prostate cancer
Technological advances in radiotherapy for the treatment of localised prostate cancer
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DOI：
10.1016/j.ejca.2004.12.028
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发表时间：
2005-04-01
影响因子：
8.4
通讯作者：
Horwich, A
中科院分区：
文献类型：
--
作者：
Mangar, SA;Huddart, RA;Horwich, A
有充分的证据表明，局部前列腺癌的辐射剂量增加与细胞杀伤增加有关。传统的二维（2D）治疗计划和实施技术受到正常组织毒性的限制，因此外照射放射治疗可以安全地输送到前列腺的剂量为65-70 Gy。过去 20 年的多项技术进步提高了外照射放射治疗 (EBRT) 的精度，并改善了治疗效果。三维适形放射治疗 (3D-CRT) 方法减少了直肠炎的剂量限制性晚期副作用，并使整个前列腺的剂量增加至 78 Gy。最近，调强放射治疗 (IMRT) 是一种先进形式的适形治疗，当使用超过 80 Gy 的剂量时，可以减少直肠毒性。此外，IMRT 还可以将剂量增加到前列腺特定部位，那里存在肿瘤克隆原的耐药亚群，或者可以用于将高剂量区域扩展到盆腔淋巴结。在常规放疗中加入雄激素剥夺会对生存和局部控制产生影响。初始激素治疗会导致前列腺癌细胞减少，从而减少放射治疗量并对细胞杀伤产生累加效应。长期辅助雄激素剥夺已被证明可以提高晚期肿瘤的总体生存率。前列腺近距离放射治疗现已成为低风险疾病患者公认的治疗方法。它实现了与其他治疗方式类似的长期结果。近距离放射治疗可用作局部疾病的单一疗法，或作为局部晚期疾病常规 EBRT 后的加强治疗。新技术可以提高目标定义和治疗验证的精度。这种所谓的图像引导放射治疗将通过实时校正分次间位置变化和分次内前列腺运动来帮助提高剂量输送的准确性，并允许更紧密的肿瘤边缘和避免正常组织，从而提高治疗的安全性。 (c) 2005 Elsevier Ltd. 保留所有权利。
There is good evidence that radiation dose escalation in localised prostate cancer is associated with increased cell kill. The traditional two-dimensional (2D) technique of treatment planning and delivery is limited by normal tissue toxicity, such that the dose that can be safely delivered to the prostate by external beam radiotherapy is 65-70 Gy. Several technological advances over the last 20 years have enhanced the precision of external beam radiotherapy (EBRT), and have resulted in improved outcomes. The three-dimensional conformal radiotherapy (3D-CRT) approach reduces the dose-limiting late side-effect of proctitis and has allowed for dose escalation to the whole prostate to 78 Gy. More recently, intensity modulated radiotherapy (IMRT), an advanced form of conformal therapy, has resulted in reduced rectal toxicity when using doses greater than 80 Gy. In addition, IMRT can potentially escalate the dose to specific parts of the prostate where there are resistant subpopulations of tumour clonogens, or can be used to extend the high-dose region to pelvic lymph nodes. The addition of androgen deprivation to conventional radiotherapy has an impact on survival and local control. Initial hormone therapy causes cytoreduction of the prostate cancer allowing for a reduction in radiotherapy volume as well as an additive effect on cell kill. Long-term adjuvant androgen deprivation has been shown to improve overall survival in more advanced tumours. Prostate brachytherapy is now a recognised treatment for those with low-risk disease. It achieves similar long-term outcome to other treatment modalities. Brachytherapy can be used as monotherapy for localised disease, or as boost treatment following conventional EBRT for locally advanced disease. New techniques are available to improve the precision of both target definition and treatment verification. This so-called image guided radiotherapy will help to enhance the accuracy of dose delivery by correcting both for inter-fraction positional variation and for intra-fraction movement of the prostate in real-time and will allow for tighter tumour margins and avoidance of normal tissues, thereby enhancing the safety of treatment. (c) 2005 Elsevier Ltd. All rights reserved.