1 Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
2 Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, The Netherlands.
Technol Cancer Res Treat. 2019 Jan 1;18:1533033819853532. doi: 10.1177/1533033819853532.
Volumetric and density parameters measured from computed tomography scans were investigated for evaluating treatment response of nonspine bone lesions following stereotactic body radiation therapy.
Twenty-three patients treated with stereotactic body radiation therapy to nonspine bone metastases with pre- and post-treatment radiological follow-up with computed tomography imaging were identified in a retrospective review. An expert radiologist classified 26 lesions by type (lytic, sclerotic) and by response. Two independent radiation oncologists created separate contours of the bone and soft tissue lesion volumes. Density and volume were assessed relative to baseline values.
For bone-only lesions, all lesions designated as local control decreased in volume or remained within 20% of baseline volumes. Lytic lesions classified as progressive disease exhibited much larger volume increases. Lytic bone lesions showed indications of remineralization with some exhibiting immediate increases in density (1-6 months) and others decreasing initially then increasing back toward baseline between 7 and 12 months. The majority of sclerotic lesions, all classified as local control, decreased slightly in both volume and density. Lesions with both soft tissue and boney involvement resulted in contradictory results when employing both radiological and size parameters for assessing treatment response. Classification was dominated by changes in soft tissue volume, despite associated volume or density changes in the corresponding boney lesion. In contrast, when soft tissue volume changes were minimal (<20% increase), classification appeared to be related primarily to density changes and not bone volume.
Volume and density changes show promise as quantitative parameters for classifying treatment responses of nonspine osseous lesions. Further work is required for clarifying how these metrics can be applied to lesions with both boney and soft tissue components.
从计算机断层扫描测量的体积和密度参数用于评估立体定向体部放射治疗后非脊柱骨病变的治疗反应。
在回顾性研究中，确定了 23 例接受立体定向体部放射治疗非脊柱骨转移的患者，这些患者在治疗前后均有影像学随访的 CT 成像。一位专家放射科医生根据类型（溶骨性、硬化性）和反应对 26 个病变进行分类。两名独立的放射肿瘤学家分别对骨和软组织病变的体积进行轮廓勾画。根据基线值评估密度和体积。
对于单纯骨病变，所有被指定为局部控制的病变体积减小或保持在基线体积的 20%以内。被归类为进展性疾病的溶骨性病变体积增加更大。溶骨性骨病变显示出再矿化的迹象，一些病变在密度上立即增加（1-6 个月），而另一些病变则在 7-12 个月之间最初降低然后又恢复到基线水平。大多数硬化性病变，全部被归类为局部控制，体积和密度都略有下降。当使用影像学和大小参数评估治疗反应时，同时涉及软组织和骨的病变会产生矛盾的结果。分类主要由软组织体积的变化决定，尽管相应的骨病变的体积或密度发生了变化。相比之下，当软组织体积变化最小（<20%增加）时，分类似乎主要与密度变化有关，而不是骨体积。
体积和密度变化显示出作为分类非脊柱骨病变治疗反应的定量参数的潜力。需要进一步的工作来阐明如何将这些指标应用于既有骨又有软组织成分的病变。
