Terahertz Pulse Imaging of Micro-metastatic Lymph Nodes in Early-stage Cervical Cancer Patients

Abstract

Lymph node metastasis is an important prognostic factor in cervical cancer patients. We report THz imaging for detecting micro-metastatic foci in the lymph nodes of early-stage uterine cervical cancer patients. Five paraffin-embedded metastatic lymph nodes from two cervical cancer patients were imaged using a THz time-domain spectroscopy system in the reflection mode. The size and shape of the tumor regions were compared with those from histopathologic examinations. The metastatic portions of lymph nodes as small as 3 mm were well delineated by THz imaging. The reflected peak amplitudes were lower in metastatic portions than in the normal portions of lymph nodes, and the difference in their peak-to-peak amplitudes was ~5%.

Terahertz imaging of metastatic lymph nodes using spectroscopic integration technique

“…The unsatisfactory performance of current imaging techniques follows because metastatic LNs have very small metastatic foci and yield lowdiscriminability signals. Conventional terahertz (THz) imaging is promising for achieving good imaging quality, as shown using paraffin-embedded LN models [10]. In addition, frozen THz imaging has been shown to successfully detect small signal differences between normal and cancerous oral tissues [11,12].…”

Diffraction-Limited High-Power Single-Cycle Terahertz Pulse Generation in Prism-Cut LiNbO3for Precise Terahertz Applications

“…To optimize the efficiency of THz pulse generation, we chose two magnification factors (     ≈ ) and the diffraction angle (   °) by using the Eqs. (1) and (2), and the grating equation. After passing through a half-wave plate, the vertically-polarized excitation beam was focused on the 1.3-mol% MgO-doped prism-cut stoichiometric LiNbO 3 crystal with a dimension of 9×9×9 mm 3 by a single spherical lens with 150-mm focal length.…”

“…Ultrashort electromagnetic radiation in the frequency region between 0.1 and 10 THz is of great interest for a variety of applications, such as optical spectroscopy, biomedical imaging, communications, and security systems [1][2][3]. In particular, studies on terahertz (THz) nonlinear phenomena in various materials, often require intense ultrashort THz pulses with microjoule-level energy and electric field strength of >100 kV/cm, are currently regarded as an unexplored new research area [4][5][6][7].…”

Frequency Tuning Characteristics of a THz-wave Parametric Oscillator

“…Applications of the THz-wave in spectrum analysis [1,2], biology and medicine [3,4], communications [5], security technologies [6] and quality control [7] have raised much interest in terahertz photonics. Unfortunately, lack of practical terahertz sources restricts the applications of the THz-wave.…”