Radiotherapy Unit, University of Florence, Florence, Italy.
Int J Radiat Oncol Biol Phys. 2010 Jun 1;77(2):509-15. doi: 10.1016/j.ijrobp.2009.04.070. Epub 2009 Aug 21.
To evaluate with a randomized clinical trial the possibility of treating the index quadrant with external intensity-modulated radiotherapy (IMRT) in a selected group of patients with early-stage breast cancer and to analyze the acute toxicity.
From September 2005, a randomized Phase III clinical trial has been conducted to compare conventional (tangential field) fractionated whole breast treatment (Arm A) with accelerated partial breast irradiation plus intensity-modulated radiotherapy (Arm B). For intensity-modulated radiotherapy, the clinical target volume was drawn with a uniform 1-cm margin around the surgical clips in three dimensions. The ipsilateral and contralateral breast, ipsilateral and contralateral lung, heart, and spinal cord were contoured as organs at risk. All the regions of interest were contoured according to the International Commission on Radiation Units and Measurements reports 50 and 62 recommendations.
In September 2008, 259 patients were randomized and treated. The mean clinical target volume in Arm B was 44 cm(3) and the mean planning target volume was 123 cm(3). The mean value of the ratio between the planning target volume and the ipsilateral breast volume was 21%. The rate of Grade 1 and Grade 2 acute skin toxicity was 22% and 19% in Arm A (Radiation Therapy Oncology Group scale), respectively. The tolerance in Arm B was excellent with only 5% Grade 1 and 0.8% Grade 2 acute skin toxicity. The planning constraints were fully satisfied in most patients. In a very few cases, this was not possible because of very unfavorable anatomy. Quality assurance procedures were performed according to our internal quality assurance protocol, with excellent results.
In the present preliminary analysis, we have demonstrated that accelerated partial breast irradiation is feasible, with very low acute toxicity.
通过一项随机临床试验评估，在选择的早期乳腺癌患者群体中，采用外部强度调制放射疗法（IMRT）治疗指数象限的可能性，并分析急性毒性。
自 2005 年 9 月起，开展了一项比较常规（切线野）分割全乳治疗（Arm A）与加速部分乳腺照射加强度调制放疗（Arm B）的随机 III 期临床试验。对于强度调制放疗，临床靶区在三个维度上用手术夹周围 1cm 的均匀边界进行描绘。同侧和对侧乳房、同侧和对侧肺、心脏和脊髓被描绘为危及器官。所有感兴趣区域均根据国际辐射单位和测量委员会报告 50 和 62 号建议进行描绘。
2008 年 9 月，259 例患者被随机分组并接受治疗。Arm B 的平均临床靶区体积为 44cm³，平均计划靶区体积为 123cm³。计划靶区与同侧乳房体积比值的平均值为 21%。Arm A（放射治疗肿瘤学组量表）的 1 级和 2 级急性皮肤毒性发生率分别为 22%和 19%。Arm B 的耐受性极好，仅有 5%的 1 级和 0.8%的 2 级急性皮肤毒性。大多数患者的计划限制都得到了充分满足。在极少数情况下，由于非常不利的解剖结构，这是不可能的。质量保证程序按照我们的内部质量保证协议进行，结果非常出色。
在目前的初步分析中，我们已经证明加速部分乳腺照射是可行的，且急性毒性非常低。
