Department of Radiotherapy, Istituto di Ricovero e Cura a Carattere Scientifico, Azienda Ospedaliera Universitaria, Istituto Nazionale per la Ricerca sul Cancro, San Martino, Genoa, Italy.
Anticancer Res. 2012 Nov;32(11):4945-50.
Intraoperative radiotherapy (IORT) has been investigated as an exclusive adjuvant treatment option for early-stage breast cancer (BC). We analysed our experience on the technical aspects of this innovative approach in terms of identification of breast volume actually to be treated during IORT.
A total of 315 patients at low risk of breast cancer recurrence underwent IORT as exclusive treatment after breast-conservative surgery. To evaluate the breast volume actually irradiated with IORT, we considered a sample of eight patients, chosen retrospectively as having enough clips to identify the tumour bed and IORT site in computed-tomography (CT). The clinical target volume (CTV) was assessed for each patient with two different methods: the first, cc-IORT, was considered during surgery according to the chosen collimator diameter and glandular thickness, while the second, cc-CT, was evaluated through computed-tomography performed after surgery. The cc-CT CTV was obtained by contouring the cc-IORT on the CT section on the basis of the clips placed by the surgeon on the resection margins.
In our experience, the 5-cm (50%) and the 6-cm (36%) diameter collimators have been the ones, used the most. The diameter of the collimator used did not appear to adversely affect the satisfactory aesthetic result. The comparison between CTVs showed that glandular breast volume contoured with CT (cc-CT) appeared to be three fold larger than the target identified at surgery and included in the area of chosen collimator (cc-IORT).
The actual volume of breast gland irradiated with the IORT procedure appears to be larger than expected. This may be due to the area being prepared for IORT by placing tissue compactly.
术中放疗（IORT）已被研究作为早期乳腺癌（BC）的一种辅助治疗选择。我们分析了我们在这种创新方法的技术方面的经验，包括在 IORT 期间确定要治疗的乳房体积。
共有 315 例低复发风险的乳腺癌患者在保乳手术后接受 IORT 作为唯一治疗方法。为了评估 IORT 实际照射的乳房体积，我们回顾性选择了 8 例患者，这些患者的样本中夹有足够的夹子来识别肿瘤床和 IORT 部位的 CT。每个患者的临床靶区（CTV）都通过两种不同的方法进行评估：第一种方法，cc-IORT，是在手术中根据选择的准直器直径和腺体厚度进行的；第二种方法，cc-CT，是通过手术后进行的 CT 检查来评估的。cc-CT CTV 是通过在 CT 切片上对 cc-IORT 进行轮廓描记来获得的，其基础是外科医生在切除边缘放置的夹子。
在我们的经验中，最常使用的是 5cm（50%）和 6cm（36%）直径的准直器。准直器的直径似乎不会对满意的美容效果产生不利影响。CTV 的比较表明，通过 CT （cc-CT）轮廓化的乳腺腺体积似乎比手术中确定的、包含在所选准直器（cc-IORT）区域内的目标大三倍。
IORT 手术实际照射的乳房腺体体积似乎比预期的要大。这可能是由于为 IORT 准备的区域通过紧密放置组织而导致的。
