University of Michigan, Ann Arbor, Michigan.
University of Michigan, Ann Arbor, Michigan.
Int J Radiat Oncol Biol Phys. 2014 Dec 1;90(5):1010-6. doi: 10.1016/j.ijrobp.2014.09.027.
Given evidence from randomized trials that have established the non-inferiority of more convenient and less costly courses of hypofractionated radiotherapy to the whole breast in selected breast cancer patients who receive lumpectomy, we sought to investigate the use of hypofractionated radiation therapy and factors associated with its use in a consortium of radiation oncology practices in Michigan. We sought to determine the extent to which variation in use occurs at the physician or practice level versus the extent to which use reflects individualization based on potentially relevant patient characteristics (such as habitus, age, chemotherapy receipt, or laterality).
We evaluated associations between receipt of hypofractionated radiation therapy and various patient, provider, and practice characteristics in a multilevel model.
Of 1477 patients who received lumpectomy and whole-breast radiation therapy and were registered by the Michigan Radiation Oncology Quality Consortium (MROQC) from October 2011 to December 2013, 913 had T1-2, N0 breast cancer. Of these 913, 283 (31%) received hypofractionated radiation therapy. Among the 13 practices, hypofractionated radiation therapy use ranged from 2% to 80%. On multilevel analysis, 51% of the variation in the rate of hypofractionation was attributable to the practice level, 21% to the provider level, and 28% to the patient level. On multivariable analysis, hypofractionation was more likely in patients who were older (odds ratio [OR] 2.16 for age ≥50 years, P=.007), less likely in those with larger body habitus (OR 0.52 if separation between tangent entry and exit ≥25 cm, P=.002), and more likely without chemotherapy receipt (OR 3.82, P<.001). Hypofractionation use was not higher in the last 6 months analyzed: 79 of 252 (31%) from June 2013 to December 2013 and 204 of 661 (31%) from October 2011 to May 2013 (P=.9).
Hypofractionated regimens of whole-breast radiation therapy have been variably administered in the adjuvant setting in Michigan after the publication of long-term trial results and consensus guidelines. Most of this variability is explained at the practice and provider level rather than by patient-level features, although care is being individualized to some degree.
鉴于随机试验已经证明，对于接受保乳切除术的特定乳腺癌患者，更方便且更经济的少分割放射治疗整个乳房的疗程并不逊于标准疗程，我们试图在密歇根州的放射肿瘤学实践联合体中调查少分割放射治疗的应用情况以及与该治疗应用相关的因素。我们试图确定在医生或实践层面上使用的差异程度，以及在多大程度上反映了基于潜在相关患者特征（如体型、年龄、化疗接受情况或侧别）的个体化治疗。
我们在多水平模型中评估了接受少分割放射治疗与各种患者、提供者和实践特征之间的关联。
在 2011 年 10 月至 2013 年 12 月期间，密歇根放射肿瘤学质量联合会（MROQC）登记的 1477 例接受保乳切除术和全乳放射治疗的患者中，有 913 例为 T1-2、N0 乳腺癌。在这 913 例患者中，有 283 例（31%）接受了少分割放射治疗。在 13 个实践中，少分割放射治疗的使用率从 2%到 80%不等。在多水平分析中，51%的少分割率差异归因于实践水平，21%归因于提供者水平，28%归因于患者水平。在多变量分析中，年龄较大的患者（年龄≥50 岁的比值比[OR]为 2.16，P=.007）更有可能接受少分割治疗，体型较大的患者（如果切线入口和出口之间的距离≥25cm，则 OR 为 0.52，P=.002）不太可能接受少分割治疗，未接受化疗的患者（OR 为 3.82，P<.001）更有可能接受少分割治疗。在分析的最后 6 个月（2013 年 6 月至 12 月）中，252 例患者中有 79 例（31%）接受了少分割治疗，2011 年 10 月至 2013 年 5 月的 661 例患者中有 204 例（31%）接受了少分割治疗（P=.9）。
在公布长期试验结果和共识指南后，在密歇根州，少分割方案的全乳放射治疗在辅助治疗中已得到不同程度的应用。这种差异主要是由于实践和提供者层面的原因，而不是由于患者层面的特征，但治疗已经在一定程度上个体化。
