Diffuse Reflectance Spectroscopy of Changes in Tumor Microenvironment in Response to Different Doses of Radiation.

Radiation therapy plays an important role in cancer treatment, as it is an established method used as part of the treatment plan for the majority of cancer patients. Real-time monitoring of the effects of radiation on the tumor microenvironment can contribute to the development of better treatment plans. In this study, we use diffuse reflectance spectroscopy, a non-invasive optical fiber-based technique, to determine the effects of different doses of radiation on the tumor microenvironment, as well as to determine the sensitivity of diffuse reflectance spectroscopy to low doses of radiation that are used in the treatment of certain cancers.

Raman spectroscopy reveals phenotype switches in breast cancer metastasis.

The accurate analytical characterization of metastatic phenotype at primary tumor diagnosis and its evolution with time are critical for controlling metastatic progression of cancer. Here, we report a label-free optical strategy using Raman spectroscopy and machine learning to identify distinct metastatic phenotypes observed in tumors formed by isogenic murine breast cancer cell lines of progressively increasing metastatic propensities. We employed the 4T1 isogenic panel of murine breast cancer cells to grow tumors of varying metastatic potential and acquired label-free spectra using a fiber probe-based portable Raman spectroscopy system.

Longitudinal monitoring of tumor response to immune checkpoint inhibitors using noninvasive diffuse reflectance spectroscopy.

Immune checkpoint inhibitors have revolutionized cancer treatment. However, there are currently no methods for noninvasively and nondestructively evaluating tumor response to immune checkpoint inhibitors. We used diffuse reflectance spectroscopy to monitor in vivo tumor microenvironmental changes in response to immune checkpoint inhibitors in a CT26 murine colorectal cancer model.

Mammary tumors in Sprague Dawley rats induced by N-ethyl-N-nitrosourea for evaluating terahertz imaging of breast cancer.

The objective of this study is to quantitatively evaluate terahertz (THz) imaging for differentiating cancerous from non-cancerous tissues in mammary tumors developed in response to injection of N-ethyl-N-nitrosourea (ENU) in Sprague Dawley rats. While previous studies have investigated the biology of mammary tumors of this model, the current work is the first study to employ an imaging modality to visualize these tumors. A pulsed THz imaging system is utilized to experimentally collect the time-domain reflection signals from each pixel of the rat's excised tumor.

Spectroscopic investigation of radiation-induced reoxygenation in radiation-resistant tumors.

Fractionated radiation therapy is believed to reoxygenate and subsequently radiosensitize surviving hypoxic cancer cells. Measuring tumor reoxygenation between radiation fractions could conceivably provide an early biomarker of treatment response. However, the relationship between tumor reoxygenation and local control is not well understood.

Optical spectroscopic sensing of tumor hypoxia.

Tumor hypoxia is a critical indicator of poor clinical outcome in patients with cancers of the breast, cervix, and oral cavity. The ability to noninvasively and reliably monitor tumor oxygenation both prior to and during therapy can aid in identifying poor treatment response earlier than is currently possible and lead to effective changes in treatment regimen. Diffuse reflectance spectroscopy (DRS) has been used in several studies to measure tissue scattering, total hemoglobin content (THb), and vascular oxygenation (sO2) in tissue.