Jian Lu, Zhongmin Wang, Kemin Chen, Yunfeng Zheng, Gang Huang
Department of Radiology, Shanghai Ruijin Hospital Luwan Branch, Shanghai.
Acta Radiol. 2013 Sep;54(7):800-4. doi: 10.1177/0284185113484017. Epub 2013 Apr 30.
Interstitial brachytherapy (IBT) has been introduced as treatment for unresectable pancreatic cancers to maximize local dose and minimize irradiation of surrounding normal tissue. MicroPET-CT systems provide excellent anatomic and molecular information.
To use 18F-FDG micro-positron emission tomography (PET)/computed tomography (CT) to evaluate the therapeutic effect of (125)I interstitial brachytherapy on transplantation tumor of human pancreatic carcinoma in Balb/c-nu mice.
Xenograft models were created by subcutaneous injection of Swl990 human pancreatic cancer cell suspensions into the immunodeficient Balb/c-nu mice. The study was randomly divided into three groups: control group (n = 6), empty seed implant group (n = 6), and (125)I seed implant group (n = 6), respectively. Before and 1 week after treatment, 18F-FDG microPET-CT scan was performed. In-vivo cell proliferation and apoptosis were monitored by thymidine kinase 1 (TK1) immunostaining and Dutp-biotin nick end labeling (TUNEL) assay.
Our results showed that before treatment the SUVmax and SUVmean values among three groups had no significant statistical difference. One week after treatment the SUVmax and SUVmean in (125)I seed implant group were significantly lower than before, while for the empty seed group and control group there were no significant difference compared with before treatment. Immunohistochemical analysis of tumor tissue revealed significantly less TK1 positive cells in (125)I seed implant group than in empty seed group and control group. The index of apoptosis was slightly higher in (125)I seed implant group than in empty seed group and control group as evaluated by TUNEL assay.
These results suggest that 18F-FDG microPET-CT may be useful as a non-invasive imaging modality to assess early response to (125)I seed brachytherapy in a pancreatic carcinoma Xenograft.
间质近距离放射治疗（IBT）已被引入用于不可切除胰腺癌的治疗，以最大化局部剂量并最小化周围正常组织的辐射。微型正电子发射断层扫描-计算机断层扫描（MicroPET-CT）系统可提供出色的解剖和分子信息。
使用18F-氟代脱氧葡萄糖微型正电子发射断层扫描（PET）/计算机断层扫描（CT）评估125I间质近距离放射治疗对Balb/c-nu小鼠人胰腺癌移植瘤的治疗效果。
通过将Swl990人胰腺癌细胞悬液皮下注射到免疫缺陷的Balb/c-nu小鼠中建立异种移植模型。研究随机分为三组：对照组（n = 6）、空籽源植入组（n = 6）和125I籽源植入组（n = 6）。在治疗前和治疗后1周进行18F-FDG MicroPET-CT扫描。通过胸苷激酶1（TK1）免疫染色和脱氧尿苷三磷酸生物素缺口末端标记（TUNEL）试验监测体内细胞增殖和凋亡。
我们的结果显示，治疗前三组之间的SUVmax和SUVmean值无显著统计学差异。治疗后1周，125I籽源植入组的SUVmax和SUVmean明显低于治疗前，而空籽源组和对照组与治疗前相比无显著差异。肿瘤组织的免疫组织化学分析显示，125I籽源植入组中TK1阳性细胞明显少于空籽源组和对照组。通过TUNEL试验评估，125I籽源植入组的凋亡指数略高于空籽源组和对照组。
这些结果表明，18F-FDG MicroPET-CT可能作为一种非侵入性成像方式，用于评估胰腺癌异种移植中对125I籽源近距离放射治疗的早期反应。
