Department of Radiology, Optical Radiology Laboratory, Washington University School of Medicine, 4525 Scott Avenue, Saint Louis, MO 63108, USA.
Transl Res. 2012 Mar;159(3):175-81. doi: 10.1016/j.trsl.2011.09.006. Epub 2011 Oct 21.
The identification of cancer cells in the lymph nodes surrounding a tumor is important in establishing a prognosis. Optical detection techniques such as fluorescence and photoacoustic tomography (PAT) have been reported in preclinical studies for noninvasive sentinel lymph node (SLN) mapping. A method for validation of these techniques is needed for clinical trials. We report the use of a multimodal optical-radionuclear contrast agent as a validation tool for PAT in a preclinical model. Methylene blue (MB) was radiolabeled with (125)I for multimodal SLN mapping and used in conjunction with MB to assess the feasibility of multimodal SLN mapping in a rat model by PAT and single-photon emission computed tomography (SPECT). MB provided sufficient contrast for identifying SLNs noninvasively with a PAT system adapted from a clinical ultrasound imaging system. The signal location was corroborated by SPECT using (125)I labeled MB. The translation of PAT into the clinic can be facilitated by a direct comparison with established imaging methods using a clinically relevant dual SPECT and photoacoustic imaging agent. The new high-resolution PAT is a promising technology for the sensitive and accurate SLN detection in cancer patients.
在确定肿瘤周围淋巴结中的癌细胞方面，这对于建立预后非常重要。在临床前研究中，已经报道了光学检测技术，如荧光和光声断层扫描（PAT），用于非侵入性前哨淋巴结（SLN）测绘。需要一种方法来验证这些技术，以进行临床试验。我们报告了使用多模态光学放射性核对比剂作为临床前模型中 PAT 的验证工具。亚甲蓝（MB）用（125）I 放射性标记，用于多模态 SLN 测绘，并与 MB 一起用于通过 PAT 和单光子发射计算机断层扫描（SPECT）评估在大鼠模型中进行多模态 SLN 测绘的可行性。MB 提供了足够的对比度，可以使用从临床超声成像系统改编的 PAT 系统非侵入性地识别 SLN。使用（125）I 标记的 MB 通过 SPECT 验证了信号位置。通过使用临床相关的双 SPECT 和光声成像剂与已建立的成像方法进行直接比较，可以促进 PAT 向临床的转化。新的高分辨率 PAT 是一种有前途的技术，可用于敏感和准确地检测癌症患者的 SLN。
