Takayesu Jamie S K, Baglien Brigit, Edwards Donna, Marsh Robin, Shah Jennifer, Pierce Lori, Speers Corey, Momoh Adeyiza
Department of Radiation Oncology, University of Michigan, Ann Arbor, MI, USA.
Section of Plastic and Reconstructive Surgery, Department of Surgery, University of Michigan Health Systems, Ann Arbor, MI, USA.
Ann Surg Oncol. 2025 May;32(5):3705-3712. doi: 10.1245/s10434-024-16836-y. Epub 2025 Jan 14.
The placement of breast implants in a prepectoral plane has become increasingly popular in breast reconstruction, although data on how this affects radiation delivery in women with breast cancer are limited. This study aimed to assess the dosimetric differences in radiation plans for immediate breast reconstruction between prepectoral and subpectoral implants.
In this study, a retrospective review and dosimetric analysis of patients with breast cancer who underwent immediate implant-based reconstruction and postmastectomy radiation therapy (PMRT) were performed. Patients with pre- or subpectoral implants were matched 1:1 by use of boost and radiation field. Demographics and complications were compared using the Mann-Whitney U test for continuous variables and the chi-square test for categorical variables. Dosimetric data were analyzed to compare doses to the target, heart, lungs, and pectoralis major using a Mann-Whitney U test.
The study identified 42 patients who met the inclusion criteria. Planning target volume (PTV) coverage was better in the prepectoral group (PTV D95%, 45.61 vs. 43.38 Gy; p = 0.04). The heart and lung doses did not differ. The patients with subpectoral implants had a lower absolute volume of pectoralis major receiving 20 to 45 Gy.
This assessment of radiation dosimetry for patients undergoing immediate breast reconstruction found that the primary dosimetric difference between prepectoral and subpectoral implants was the dose to the pectoralis major. Otherwise, no significant difference in target coverage was found. These data suggest that implant placement can be selected to optimize reconstructive outcomes, with less concern for compromise to the oncologic quality of PMRT.
在乳房重建中，将乳房植入物置于胸肌前平面越来越普遍，尽管关于其对乳腺癌女性放疗剂量传递影响的数据有限。本研究旨在评估胸肌前和胸肌下植入物在即刻乳房重建放疗计划中的剂量差异。
本研究对接受即刻植入物乳房重建及乳房切除术后放疗（PMRT）的乳腺癌患者进行了回顾性分析和剂量学分析。根据增量放疗和照射野，将胸肌前或胸肌下植入物的患者按1:1进行匹配。连续变量采用曼-惠特尼U检验，分类变量采用卡方检验比较人口统计学和并发症情况。使用曼-惠特尼U检验分析剂量学数据，比较靶区、心脏、肺和胸大肌的剂量。
该研究确定了42例符合纳入标准的患者。胸肌前组的计划靶体积（PTV）覆盖更好（PTV D95%，45.61 Gy对43.38 Gy；p = 0.04）。心脏和肺的剂量无差异。胸肌下植入物的患者接受20至45 Gy照射的胸大肌绝对体积较小。
对接受即刻乳房重建患者的放疗剂量学评估发现，胸肌前和胸肌下植入物之间的主要剂量差异在于胸大肌的剂量。否则，在靶区覆盖方面未发现显著差异。这些数据表明，可以选择植入物放置方式以优化重建效果，而较少担心会影响PMRT的肿瘤学质量。
