恶性骨肿瘤放化疗后疗效的MR监测与微血管变化的相关性实验研究

It has always been difficult to monitor the curative effect and biological status of malignant bone tumor after radiation and chemotherapy. Studies have suggested that micro-vessel plays an important role in the recurrence and growth of tumor. But radiography, CT and MR (including plain scan and conventional enhanced scan) are unable to determine if there are new tumor capillaries within the swelling soft tissue or mass. So far little is known about how to achieve the noninvasive observation of micro-vessel of malignant bone tumor in vivo and hereby get the information of tumor recurrence. The results of our preliminary experiment suggest that the quantity and permeability of micro-vessel correlate obviously with the parameters of MR perfusion, therefore the microvascular condition and biological status of tumor can be judged. To verify this hypothesis, we plan to perform MR perfusion of dynamic enhancement on the rabbit model of VX2 malignant bone tumor after radiation and chemotherapy, and the correlating study between MR perfusion, conventional MR imaging, DWI and pathology will be conducted. The correlation between the parameters of MR perfusion, DWI and micro-vessels will be explored to evaluate the tumor status in different phases after radiation and chemotherapy, and then to reveal the recurrent mechanism of malignant bone tumor and effective treatment mechanism.

恶性骨肿瘤放化疗后疗效及肿瘤生物学状态的监测一直是个难点。已有研究确切表明微血管在肿瘤生长与复发中起重要作用，X线平片、CT和MR常规检查均无法判定治疗后肿瘤组织区是否有肿瘤新生毛细血管。迄今为止对活体无创性观察恶性骨肿瘤微血管变化并据此判定肿瘤有否残留或复发等知之甚少。我们的预实验结果提示肿瘤微血管的数量和通透性与病变区域的MR灌注参数变化有明显相关性，据此可推断病变区肿瘤微血管的状况，从而判定肿瘤的生物学状态。为了验证这一假说，我们拟对放化疗后的兔VX2恶性骨肿瘤模型进行MR动态增强灌注成像并与常规MR成像、弥散成像、病理学进行对照研究，探讨MR灌注量化指标与肿瘤微血管的相关性，揭示骨恶性肿瘤治疗后不同时期的变化规律与复发机制，为实时判断肿瘤状态及治疗效果提供精准的无创性方法。

恶性骨肿瘤放化疗后的疗效和生物学状态一直难以监测。研究表明，微血管在肿瘤的复发和生长中起重要作用。但x线摄影、CT和MR(包括平扫和常规增强扫描)不能确定肿胀软组织或肿块内是否有肿瘤新生血管。如何实现对恶性骨肿瘤微血管的无创性观察，从而获得肿瘤复发的信息，目前尚不清楚。我们的初步实验结果表明，微血管的数量和渗透性与MR灌注参数有明显的相关性，因此可以判断肿瘤的微血管生成状况和生物学状态。为了验证这一假设，我们计划对放化疗后的兔VX2恶性骨肿瘤模型进行MR灌注动态增强，并将其与常规MR成像、弥散加权成像与组织病理学之间进行相关性研究。探讨MR灌注参数、弥散参数、微血管参数之间的相关性，评价放化疗后不同阶段的肿瘤生长状态，进而揭示恶性骨肿瘤的复发机制和有效治疗机制。