Radiation Oncology Department, ERESA, Hospital General Universitario de Valencia, Avenida Tres Cruces no 2, Valencia, Spain.
Clin Transl Oncol. 2013 Jan;15(1):39-45. doi: 10.1007/s12094-012-0884-1. Epub 2012 Jul 25.
In breast IMRT simultaneous integrated boost (SIB) treatment and accelerated partial breast irradiation (APBI), proper delineation of the tumor bed is necessary. Conservative oncoplastic surgery causes changes in peritumoral breast tissue that complicates locating the site of the tumor. Nevertheless, there are still centers that do not use surgical clips to delineate the site. This study aims to show how the lack of clips affects the techniques of SIB and APBI in terms of dose distribution and safety margins in the tumor bed.
On 30 patients, the defining of the tumor bed obtained from the pre-surgery CT scan to that outlined on the basis of clips on the post-surgery CT was compared. Tumor bed deviation from the original tumor site was quantified. In addition, the margins to the original tumor site necessary to guarantee the coverage of the tumor bed were calculated.
Variations were detected in the distances between geometric centers of the PTV (minimum 0.5-maximum 3 cm). The maximum margin necessary to include the entire tumor bed was 4.5 cm. Lesions located in the upper outer quadrant required the widest margins. If margins are not added, the tumor bed volume defined with clips will be underdosed.
The definition of the tumor bed based on studies before surgery does not have the necessary accuracy. Clips need to be placed in the surgical bed to identify the changes occurring after the restorative mammoplasty. Without clips, SIB and APBI are not safe.
在乳腺癌调强放疗（IMRT）同步整合增敏（SIB）治疗和加速部分乳腺照射（APBI）中，需要对肿瘤床进行准确的描绘。保乳整形手术后，肿瘤周围的乳腺组织发生变化，这使得定位肿瘤部位变得更加复杂。然而，仍有一些中心不使用手术夹来描绘肿瘤床的位置。本研究旨在展示在 SIB 和 APBI 技术中，缺乏手术夹如何影响肿瘤床的剂量分布和安全边界。
对 30 名患者进行研究，将术前 CT 扫描确定的肿瘤床与术后 CT 上基于手术夹勾画的肿瘤床进行比较。测量肿瘤床相对于原始肿瘤部位的偏差。此外，计算了保证肿瘤床覆盖所需的原始肿瘤部位的安全边界。
在 PTV（最小 0.5cm-最大 3cm）的几何中心之间检测到了变化。为了包括整个肿瘤床，最大的安全边界为 4.5cm。位于外上象限的病变需要最宽的安全边界。如果不添加安全边界，使用手术夹定义的肿瘤床体积将剂量不足。
基于术前研究定义肿瘤床的方法不够准确。为了识别保乳整形手术后发生的变化，需要在手术床中放置手术夹。如果没有手术夹，SIB 和 APBI 是不安全的。
