Preclinical quantitative in-vivo assessment of skin tissue vascularity in radiation-induced fibrosis with optical coherence tomography

Abstract

Radiation therapy (RT) is widely and effectively used for cancer treatment but can also cause deleterious side effects, such as a late-toxicity complication called radiation-induced fibrosis (RIF). Accurate diagnosis of RIF requires analysis of histological sections to assess extracellular matrix infiltration. This is invasive, prone to sampling limitations, and thus rarely used; instead, current practice relies on subjective clinical surrogates, including visual observation, palpation, and patient symptomatology questionnaires. This preclinical study demonstrates that functional optical coherence tomography (OCT) is a useful tool for objective noninvasive in-vivo assessment and quantification of fibrosis-associated microvascular changes in tissue. Data were collected from murine hind limbs 6 months after 40-Gy single-dose irradiation and compared with nonirradiated contralateral tissues of the same animals. OCT-derived vascular density and average vessel diameter metrics were compared to quantitative vascular analysis of stained histological slides. Results indicate that RIF manifests significant microvascular changes at this time point posttreatment. Abnormal microvascular changes visualized by OCT in this preclinical setting suggest the potential of this label-free high-resolution noninvasive functional imaging methodology for RIF diagnosis and assessment in the context of clinical RT.

Ultra-sound Shear Wave Elastography Tissue Stiffness and Thickness Assessment After Adjuvant Radiotherapy for Breast Cancer Treatment; An Exploratory Study.

“…The irradiated skin was thicker than the control in both neutral and abducted positions. This is consistent with epidermal thickening described post radiation therapy [23] while the thinner subcutaneous adipose tissue nding is consistent with a previous study of post irradiation neck brosis [24] .…”

Quantification metrics for telangiectasia using optical coherence tomography

“…Demidov et al created radiation injuries in mice and imaged the area using SV-OCT. They were able to find significant differences between irradiated tissue and healthy tissue using vessel diameter measured from the SV-OCT images, which conform to the findings from histology-based methods 27 . These metrics have proven important in tracking angiogenesis and tumor progression, and can be applied to HHT lesions throughout a course of treatment; however, there is still a need to develop metrics tailored to progression monitoring of the unique morphology of telangiectases.…”

Analysis of low-scattering regions in optical coherence tomography: applications to neurography and lymphangiography

“…To do this properly in 3D, however, so as to furnish additional helpful visual information will require more research; this will also be pursued in future studies and be reported in a separate publication. For the remainder of this work we thus display the lymphatics/nerves and blood angiograms separately: blood microvasculature depth-encoded in RGB color space as described previously (green-yellow-red-grey shallow to deep color map) [45] and lymphatics/nerves in a grey-scale color map.…”