Ultrastructural studies of epidermis in acute radiation dermatitis. Basal lamina thickening and coated vesicles

Feature-Based vs. Deep-Learning Fusion Methods for the In Vivo Detection of Radiation Dermatitis Using Optical Coherence Tomography, a Feasibility Study

Acute radiation dermatitis (ARD) is a common and distressing issue for cancer patients undergoing radiation therapy, leading to significant morbidity. Despite available treatments, ARD remains a distressing issue, necessitating further research to improve prevention and management strategies. Moreover, the lack of biomarkers for early quantitative assessment of ARD impedes progress in this area. This study aims to investigate the detection of ARD using intensity-based and novel features of Optical Coherence Tomography (OCT) images, combined with machine learning. Imaging sessions were conducted twice weekly on twenty-two patients at six neck locations throughout their radiation treatment, with ARD severity graded by an expert oncologist. We compared a traditional feature-based machine learning technique with a deep learning late-fusion approach to classify normal skin vs. ARD using a dataset of 1487 images. The dataset analysis demonstrates that the deep learning approach outperformed traditional machine learning, achieving an accuracy of 88%. These findings offer a promising foundation for future research aimed at developing a quantitative assessment tool to enhance the management of ARD.

Radiation-induced alterations in multi-layered, in-vitro skin models detected by optical coherence tomography and histological methods

BACKGROUND

Inflammatory skin reactions and skin alterations are still a potential side effect in radiation therapy (RT), which also need attention for patients' health care.

METHOD

In a pre-clinical study we consider alterations in irradiated in-vitro skin models of epidermal and dermal layers. Typical dose regimes in radiation therapy are applied for irradiation. For non-invasive imaging and characterization optical coherence tomography (OCT) is used. Histological staining method is additionally applied for comparison and discussion.

RESULTS

Structural features, such as keratinization, modifications in epidermal cell layer thickness and disorder in the layering-as indications for reactions to ionizing radiation and aging-could be observed by means of OCT and confirmed by histology. We were able to recognize known RT induced changes such as hyper-keratosis, acantholysis, and epidermal hyperplasia as well as disruption and/or demarcation of the dermo-epidermal junction.

CONCLUSION

The results may pave the way for OCT to be considered as a possible adjunctive tool to detect and monitor early skin inflammation and side effects of radiotherapy, thus supporting patient healthcare in the future.

Verrucous carcinoma: a light and electron microscopic, autoradiographic, and immunofluorescence study

Verrucous carcinomas of the rectum, plantar surface of the foot, and oral cavity were studied by means of light and electron microscopy, and autoradiographic and immunofluorescent techniques. Histologic examination showed that each tumor was composed mainly of mature squamous epithelium, and each had foci of slight cellular atypia. The cells in S-phase consistently were situated near the basal layer. Immunofluorescent examination with antibasement membrane antibody showed areas of marked focal thickening and other areas where basement membrane was absent. Ultrastructural examination showed reduplicated as well as normal basal lamina. Numerous interdigitating microvilli and well developed desmosomes characterized the cells above the basal layer. A proliferative basal zone underlying a thick layer of well differentiated nonproliferating keratinocytes and reduplicated basal lamina were seen in all tumors, regardless of location. These consistent findings constitute evidence that verrucous carcinoma is a morphologic and cytokinetic entity that may occur in multiple anatomic sites.

Ultrastructural studies of allergic contact dermatitis in man. Epidermal cell changes at 3, 6, and 12 h after application of DNCB

Early epidermal lesions of allergic contact dermatitis were examined by electron microscopy. Normal human volunteers were sensitized to DNCB, and contact reactions were elicited sequentially. Epidermal cell changes at 3 h included: the occurrence of small vacuoles with or without membrane, focal dilatation of intercellular spaces, and the alteration of tonofilaments into short, aggregated bundles. Non-sensitized skin to which DNCB was applied also showed small vacuoles with or without membrane. Monocytes infiltrated into the intercellular spaces which were not dilated, and the neighboring tonofilaments of keratinocytes remained normal.