Prendergast Brendan, Indelicato Daniel J, Grobmyer Stephen R, Saito Anneyuko I, Lightsey Judith L, Snead Felicia E, Morris Christopher G, Copeland Edward M, Mendenhall Nancy P
Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, FL 32610-0385, USA.
Int J Radiat Oncol Biol Phys. 2009 Jul 1;74(3):695-701. doi: 10.1016/j.ijrobp.2008.08.044. Epub 2009 Jan 23.
To characterize the magnitude of volume change in the postoperative tumor bed before and during radiotherapy, and to identify any factors associated with large volumetric change.
Thirty-six consecutive patients with early-stage or preinvasive breast cancer underwent breast-conserving therapy at our institution between June 2006 and October 2007. Computed tomography (CT) scans of the breast were obtained shortly after surgery, before the start of radiotherapy (RT) for treatment planning, and, if applicable, before the tumor bed boost. Postoperative changes, seroma, and surgical clips were used to define the tumor bed through consensus agreement of 3 observers (B.P., D.I., and J.L.). Multiple variables were examined for correlation with volumetric change.
Between the first and last scan obtained (median time, 7.2 weeks), the tumor bed volume decreased at least 20% in 86% of patients (n = 31) and at least 50% in 64% of patients (n = 23). From the postoperative scan to the planning scan (median time, 3 weeks), the tumor bed volume decreased by an average of 49.9%, or approximately 2.1% per postoperative day. From planning scan to boost scan (median interval, 7 weeks), the median tumor bed volume decreased by 44.6%, at an average rate of 0.95% per postoperative day. No single factor was significantly associated with a change in tumor bed volume greater than 20%.
The average postlumpectomy cavity undergoes dramatic volumetric change after surgery and continues this change during RT. The rate of change is inversely proportional to the duration from surgery. In this study no factors studied predicted large volumetric change.
描述放疗前及放疗期间术后瘤床体积变化的幅度，并确定与体积大幅变化相关的任何因素。
2006年6月至2007年10月期间，36例连续的早期或浸润前乳腺癌患者在本机构接受了保乳治疗。术后不久、放疗（RT）开始前用于治疗计划时以及（如适用）瘤床加量前均进行了乳房计算机断层扫描（CT）。术后变化、血清肿和手术夹通过3名观察者（B.P.、D.I.和J.L.）的共识来确定瘤床。检查了多个变量与体积变化的相关性。
在获得的第一次和最后一次扫描之间（中位时间为7.2周），86%的患者（n = 31）瘤床体积至少减少了20%，64%的患者（n = 23）瘤床体积至少减少了50%。从术后扫描到计划扫描（中位时间为3周），瘤床体积平均减少了49.9%，即术后每天约减少2.1%。从计划扫描到加量扫描（中位间隔为7周），瘤床体积中位数减少了44.6%，平均每天减少0.95%。没有单一因素与瘤床体积变化大于20%显著相关。
保乳术后的平均腔隙在手术后经历了显著的体积变化，并且在放疗期间这种变化仍在继续。变化率与手术时间成反比。在本研究中，所研究的因素均未预测到体积的大幅变化。
