Stapleford Liza J, Landry Jerome C, Schreibmann Eduard, Waller Anthony, Pan Lin, Kim Sungjin, Chen Zhengjia, Crocker Ian, Fox Timothy H
Department of Radiation Oncology, Emory University School of Medicine and Winship Cancer Institute, Atlanta, GA, USA.
Department of Biostatistics and Bioinformatics, Emory University School of Medicine and Winship Cancer Institute, Atlanta, GA, USA.
J Radiosurg SBRT. 2012;2(1):51-62.
To investigate the utility of quantitative PET analysis for early prediction of local control following stereotactic body radiation therapy (SBRT).
An initial test cohort of fourteen cases and a validation cohort of twenty-three cases were analyzed. All patients had metastatic or recurrent cancer and underwent PET-CTs pre- and post- SBRT to a variety of sites. Local failure was defined as biopsy proven persistent/recurrent disease or progressive disease on radiologic imaging. Using deformable registration, radiation dose was transferred to the PET-CTs. Using the prescription isodose as the volume of interest (VOI), response was assessed by generating metabolic volume histograms (MVH). MVH curves examine metabolic heterogeneity in the VOI. Exploratory analyses of the test cohort evaluated the viability of multiple iso-SUV and iso-volumetric points selected from the MVH curves to serve as novel markers of response. Standard PET response markers (maximum/mean SUV and qualitative analysis) were also assessed.
In the initial cohort, ten of fourteen patients achieved local control at last follow-up, a median of 225 days following post-SBRT PET. Three out of four local failures had an increase in max SUV, while all patients who achieved local control had a reduction in max SUV (p=0.01). Exploratory analyses using multiple iso-SUV and iso-volumetric points did not yield any factors associated with local control (p>0.05). In the validation cohort, lower post- treatment max SUV (p=.03) and reduction in max SUV (p<0.05) were significantly associated with local control.
Reduction in max SUV following SBRT is associated with local control.
探讨定量PET分析在立体定向体部放射治疗（SBRT）后早期预测局部控制情况的效用。
分析了一个由14例患者组成的初始测试队列和一个由23例患者组成的验证队列。所有患者均患有转移性或复发性癌症，并在SBRT前后对多个部位进行了PET-CT检查。局部失败定义为活检证实的持续性/复发性疾病或影像学上的疾病进展。使用可变形配准，将辐射剂量转移到PET-CT上。以处方等剂量线作为感兴趣体积（VOI），通过生成代谢体积直方图（MVH）来评估反应。MVH曲线检查VOI中的代谢异质性。对测试队列的探索性分析评估了从MVH曲线中选择的多个等SUV和等体积点作为新的反应标志物的可行性。还评估了标准PET反应标志物（最大/平均SUV和定性分析）。
在初始队列中，14例患者中有10例在最后一次随访时实现了局部控制，中位时间为SBRT后PET检查225天。4例局部失败患者中有3例最大SUV增加，而所有实现局部控制的患者最大SUV均降低（p=0.01）。使用多个等SUV和等体积点的探索性分析未产生与局部控制相关的任何因素（p>0.05）。在验证队列中，较低的治疗后最大SUV（p=0.03）和最大SUV的降低（p<0.05）与局部控制显著相关。
SBRT后最大SUV的降低与局部控制相关。
