Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
Cancer. 2012 May 15;118(10):2632-40. doi: 10.1002/cncr.26586. Epub 2011 Oct 5.
Local failure after definitive chemoradiation therapy for unresectable esophageal cancer remains problematic. Little is known about the failure pattern based on modern-day radiation treatment volumes. We hypothesized that most local failures would be within the gross tumor volume (GTV), where the bulk of the tumor burden resides.
We reviewed treatment volumes for 239 patients who underwent definitive chemoradiation therapy and compared this information with failure patterns on follow-up positron emission tomography (PET). Failures were categorized as within the GTV, the larger clinical target volume (CTV, which encompasses microscopic disease), or the still larger planning target volume (PTV, which encompasses setup variability) or outside the radiation field.
At a median follow-up time of 52.6 months (95% confidence interval, 46.1-56.7 months), 119 patients (50%) had experienced local failure, 114 (48%) had distant failure, and 74 (31%) had no evidence of failure. Of all local failures, 107 (90%) were within the GTV, 27 (23%) were within the CTV, and 14 (12%) were within in the PTV. On multivariate analysis, GTV failure was associated with tumor status (T3/T4 vs T1/T2; odds ratio, 6.35; P = .002), change in standardized uptake value on PET before and after treatment (decrease >52%: odds ratio, 0.368; P = .003), and tumor size (>8 cm, 4.08; P = .009).
Most local failures after definitive chemoradiation for unresectable esophageal cancer occur in the GTV. Future therapeutic strategies should focus on enhancing local control.
不可切除食管癌根治性放化疗后局部失败仍然是个问题。基于现代放射治疗体积，我们对失败模式知之甚少。我们假设大多数局部失败将发生在大体肿瘤体积（GTV）内，那里是肿瘤负荷的主要部位。
我们回顾了 239 例接受根治性放化疗的患者的治疗体积，并将这些信息与随访正电子发射断层扫描（PET）的失败模式进行了比较。失败被分为 GTV 内、较大的临床靶区（CTV，包括显微镜下的疾病）或更大的计划靶区（PTV，包括设置变异性）或放疗野外。
在中位随访时间为 52.6 个月（95%置信区间，46.1-56.7 个月）时，119 例患者（50%）发生了局部失败，114 例（48%）发生了远处失败，74 例（31%）没有失败的证据。所有局部失败中，107 例（90%）位于 GTV 内，27 例（23%）位于 CTV 内，14 例（12%）位于 PTV 内。多因素分析显示，GTV 失败与肿瘤状态（T3/T4 与 T1/T2；优势比，6.35；P =.002）、治疗前后 PET 标准化摄取值的变化（减少>52%：优势比，0.368；P =.003）和肿瘤大小（>8 cm，4.08；P =.009）有关。
不可切除食管癌根治性放化疗后大多数局部失败发生在 GTV 内。未来的治疗策略应侧重于提高局部控制率。
