Docetaxel-based chemotherapy, as the first-line treatment for metastatic castration-resistant prostate cancer (mCRPC), has succeeded in helping quite a number of patients to improve quality of life and prolong survival time. However, almost half of mCRPC patients are not sensitive to docetaxel chemotherapy initially. This study aimed to establish models to predict sensitivity to docetaxel chemotherapy in patients with mCRPC by using serum surface-enhanced Raman spectroscopy (SERS). A total of 32 mCPRC patients who underwent docetaxel chemotherapy at our center from July 2016 to March 2018 were included in this study. Patients were dichotomized in prostate-specific antigen (PSA) response group (n = 17) versus PSA failure group (n = 15) according to the response to docetaxel. In total 64 matched spectra from 32 mCRPC patients were obtained by using SERS of serum at baseline (q0) and after 1 cycle of docetaxel chemotherapy (q1). Comparing Raman peaks of serum samples at baseline (q0) between two groups, significant differences revealed at the peaks of 638, 810, 890 (p < 0.05) and 1136 cm1 (p < 0.01). The prediction models of peak 1363 cm^-1 and principal component analysis and linear discriminant analysis (PCA–LDA) based on Raman data were established, respectively. The sensitivity and specificity of the prediction models were 71%, 80% and 69%, 78% through the way of leave-one-out cross-validation. According to the results of five-cross-validation, the PCA–LDA model revealed an accuracy of 0.73 and AUC of 0.83.

Photoacoustic imaging (PAI), also known as optoacoustic imaging, is a rapidly growing imaging modality with potential in medical diagnosis and therapy monitoring. This paper focuses on the techniques of prostate PAI and its potential applications in prostate cancer detection. Transurethral light delivery combined with transrectal ultrasound detection overcomes light scattering in the surrounding tissue and provides optimal photoacoustic signals while minimizing invasiveness. While label-free PAI based on endogenous contrast has promising potential for prostate cancer detection, exogenous contrast agents can further enhance the sensitivity and specificity of prostate cancer PAI. Further in vivo studies are required in order to achieve the translation of prostate PAI to clinical implementation. The minimal invasiveness, relatively low cost, high specificity and sensitivity, and real-time imaging capability are valuable advantages of PAI that may improve the current prostate cancer management in clinic.

光声成像技术近年来已成为一种极具前景的前列腺癌成像技术。由于光声成像范围与光能量的吸收分布直接相关，为了优化经尿道光辐照的前列腺光声成像系统的光源参数，必须了解前列腺组织的光吸收分布。根据前列腺组织的形态特征构建了一个嵌有球状肿瘤的三维前列腺光学模型，利用光学分子影像仿真平台(MOSE) 比较研究了柱状和球状两种弥散光源经尿道辐照时组织内光吸收分布特性。考查了激光能量和肿瘤处光学吸收系数对肿瘤光吸收的影响。模拟结果表明经尿道照明有利于前列腺组织内部光吸收，特别是深处位置。另外，相比于球状弥散光源，柱状弥散光源侧向光吸收分布较均匀，适合于三维扫描光声成像和信源分析。研究结果表明增大输入的激光能量或者肿瘤光学吸收系数可以明显提高肿瘤处光能量吸收，这与组织光学中的有关理论一致。有关结论有助于前列腺光声成像系统的光源优化设计和成像深度的改善。

Metastasis is a very complicated multi-step process and accounts for the low survival rate of the cancerous patients. To metastasize, the malignant cells must detach from the primary tumor and migrate to secondary sites in the body through either blood or lymph circulation. Macrophages appear to be directly involved in tumor progression and metastasis. However, the role of macrophages in affecting cancer metastasis has not been fully elucidated. Here, we have utilized an emerging technique, namely in vivo flow cytometry (IVFC) to study the depletion kinetics of circulating prostate cancer cells in mice and determine how depletion of macrophages by the liposome-encapsulated clodronate affects the depletion kinetics. Our results show different depletion kinetics of PC-3 cells between the macrophage-deficient group and the control group. The number of circulating tumor cells (CTCs) in the macrophage-deficient group decreases in a slower manner compared to the control mice group. The differences in depletion kinetics indicate that the absence of macrophages facilitates the stay of prostate cancer cells in circulation. In addition, our imaging data suggest that macrophages might be able to arrest, phagocytose and digest PC-3 cells. Therefore, phagocytosis may mainly contribute to the depletion kinetic differences. The developed methods elaborated here would be useful to study the relationship between macrophages and tumor metastasis in small animal cancer models.

Ultrasound-guided biopsy procedure for prostate cancer diagnosis, which is the current gold standard, involves quasi-random sampling of prostate tissue without any functional guidance. In this study, we discuss the possibility to augment the detection of prostate cancer using a dual-modality optical approach, which can be coupled with the current needle biopsy setup. Two techniques are light reflectance spectroscopy (LRS) that uses a broadband light source and a CCD array spectrometer, and auto-fluorescence lifetime measurement (AFLM) that uses a custom- designed, time-correlated single photon counting (TCSPC) system. Both LRS and AFLM were employed sequentially in this study to measure cancer tissue along with control tissue on a rat prostate tumor model. At an excitation wavelength of 447 nm, we investigated auto-fluorescence decay curves at the emission wavelengths of 532, 562, 632 and 684 nm for in vivo and ex vivo AFLM. These results show that auto-fluorescence lifetimes at all measured emission wavelengths differ between control and cancerous tissues with 100% specificity and sensitivity. Moreover, absolute values of hemoglobin derivatives and scattering coefficient were quantified using in vivo LRS. This part of study also demonstrates that light scattering and absorption are significantly different between the control and cancerous tissue. Overall, the study demonstrates that both LRS and AFLM may provide several intrinsic biomarkers for in vivo detection of prostate cancer.