Gladwish Adam, Didiodato Giulio, Conway Jessica, Stevens Christiaan, Follwell Matthew, Tam Tiffany, Mclean Jesse, Hanrahan Renee
Oncology, Royal Victoria Hospital, Barrie, CAN.
Internal Medicine, Royal Victoria Hospital, Barrie, CAN.
Cureus. 2021 Nov 29;13(11):e20003. doi: 10.7759/cureus.20003. eCollection 2021 Nov.
Background Oncoplastic partial mastectomy (OPM) is a technique utilized to improve aesthetic and survivorship outcomes in patients with localized breast cancer. This technique leads to breast tissue rearrangement, which can have an impact on target definition for boost radiotherapy (BRT). The aim of this study was to determine if the choice of surgical technique independently affected the decision to deliver a radiation boost. Materials and methods This was a retrospective study of patients treated between January 2017 and December 2018. We selected consecutive patients based on surgical procedure: 50 undergoing standard breast-conserving surgery and 50 having had an OPM. The primary outcome was average treatment effect (ATE) of surgery type on reception of BRT. Secondary outcomes included ATE of surgery type on the time to reception of radiotherapy and incidence of ipsilateral breast tumor recurrence (IBTR). The ratio of boost clinical target volume (CTV) to pathologic tumor size was also compared between the two groups. Treatment effects regression adjustment and inverse-probability weighted analysis was used to estimate ATEs for both primary and secondary outcomes. Results For the entire cohort, the median age was 64 years (range: 37-88 years). The median tumor size was 1.5 cm (range: 0.1-6.5 cm). The majority of patients were with ≤ stage IIA (78%), invasive ductal subtype (80%), negative lymphovascular space invasion (78%), negative margin (90%), and positive ER/PR (estrogen receptor/progesterone receptor) (69%). Overall, surgical technique was not associated with differences in the proportion of patients receiving BRT (ATE: 6.0% [95% CI: -4.5 to 16.0]). There were no differences in delays to radiation treatment between the two groups (ATE: 32.8 days [95% CI: -22.1 to 87.7]). With a median follow-up time of 419 days (range: 30-793 days), there were only five recurrences, with one case of IBTR in each group. There was no difference in the ratio of CTV volume to tumor size between the two groups (p=0.38). Conclusions OPM did not affect the decision to offer localized BRT following standard whole breast radiotherapy or significantly affect treatment times or radiation volumes. The decision to offer OPM should include a multi-disciplinary approach.
背景 肿瘤整形部分乳房切除术（OPM）是一种用于改善局部乳腺癌患者美学和生存结果的技术。该技术会导致乳腺组织重新排列，这可能会对瘤床加量放疗（BRT）的靶区定义产生影响。本研究的目的是确定手术技术的选择是否独立影响进行瘤床加量放疗的决策。
材料与方法 这是一项对2017年1月至2018年12月期间接受治疗的患者的回顾性研究。我们根据手术方式选择连续的患者：50例行标准保乳手术，50例行OPM。主要结局是手术方式对接受BRT的平均治疗效果（ATE）。次要结局包括手术方式对接受放疗时间的ATE以及同侧乳腺肿瘤复发（IBTR）的发生率。还比较了两组之间瘤床临床靶体积（CTV）与病理肿瘤大小的比值。使用治疗效果回归调整和逆概率加权分析来估计主要和次要结局的ATE。
结果 对于整个队列，中位年龄为64岁（范围：37 - 88岁）。中位肿瘤大小为1.5 cm（范围：0.1 - 6.5 cm）。大多数患者为≤IIA期（78%）、浸润性导管亚型（80%）、阴性淋巴管侵犯（78%）、切缘阴性（90%）以及雌激素受体/孕激素受体（ER/PR）阳性（69%）。总体而言，手术技术与接受BRT的患者比例差异无关（ATE：6.0% [95% CI：-4.5至16.0]）。两组之间放疗延迟无差异（ATE：32.8天 [95% CI：-22.1至87.7]）。中位随访时间为419天（范围：30 - 793天），仅5例复发，每组各1例IBTR。两组之间CTV体积与肿瘤大小的比值无差异（p = 0.38）。
结论 OPM不影响在标准全乳放疗后进行局部瘤床加量放疗的决策，也不显著影响治疗时间或放疗体积。决定采用OPM应包括多学科方法。
