■灌注加权成像(PWI;磁共振成像[MRI])已显示可在葡萄膜黑色素瘤(UM)中提供有价值的生物学肿瘤信息。临床使用的半定量方法不考虑肿瘤色素沉着和眼球运动。我们假设结合了这些的定量PWI方法,提供了比当前临床方法更准确的肿瘤灌注描述。这项研究的目的是在放疗前后对UM患者进行测试。
■对47例UM患者放疗前后灌注加权3TMRI进行回顾性分析。进行Tofts药代动力学建模以确定血管通透性(Ktrans),细胞外血管外间隙(ve),和反流率(kep)。将这些与半定量临床参数进行比较,包括峰值强度和流出百分比。
■肿瘤色素沉着对峰强度和流出百分比的影响有统计学意义(P<0.01),黑色素瘤和无色素瘤的相对峰强度差异有统计学意义(1.5vs.1.9,P<0.01)。放疗前,中位肿瘤Ktrans为0.63min-1(范围=0.06-1.42min-1),中值ve为0.23(范围=0.09-0.63),中位数kep为2.3min-1(范围=0.6-5.0min-1)。放疗后,85%显示Ktrans和kep降低(P<0.01)。放疗前后肿瘤色素沉着变化小且不显著(T1中位升高33ms,P=0.55)。
■放疗后定量PWI参数显着降低,因此可以作为治疗反应评估的早期生物标志物。然而,由于放疗前后肿瘤色素沉着无明显变化,当前的半定量方法似乎对于检测肿瘤灌注的变化足够灵敏。
UNASSIGNED: Perfusion-weighted imaging (PWI; magnetic resonance imaging [MRI]) has been shown to provide valuable biological tumor information in uveal melanoma (UM). Clinically used semiquantitative methods do not account for tumor pigmentation and eye movement. We hypothesize that a quantitative PWI method that incorporates these, provides a more accurate description of tumor perfusion than the current clinical method. The aim of this study was to test this in patients with UM before and after radiotherapy.
UNASSIGNED: Perfusion-weighted 3T MRIs were retrospectively analyzed in 47 patients with UM before and after radiotherapy. Tofts pharmacokinetic modeling was performed to determine vascular permeability (Ktrans), extracellular extravascular space (ve), and reflux rate (kep). These were compared with semiquantitative clinical parameters including peak intensity and outflow percentage.
UNASSIGNED: The effect of tumor pigmentation on peak intensity and outflow percentage was statistically significant (P < 0.01) and relative peak intensity was significantly different between melanotic and amelanotic tumors (1.5 vs. 1.9, P < 0.01). Before radiotherapy, median tumor Ktrans was 0.63 min-1 (range = 0.06-1.42 min-1), median ve was 0.23 (range = 0.09-0.63), and median kep was 2.3 min-1 (range = 0.6-5.0 min-1). After radiotherapy, 85% showed a decrease in Ktrans and kep (P < 0.01). Changes in tumor pigmentation before and after radiotherapy were small and not significant (median increase in T1 of 33 ms, P = 0.55).
UNASSIGNED: Quantitative PWI parameters decreased significantly after radiotherapy and can therefore can serve as an early biomarker for treatment response assessment. However, due to the nonsignificant changes in tumor pigmentation before and after radiotherapy, the current semiquantitative method appears to be sufficiently sensitive for detection of changes in tumor perfusion.