Summary
Background
Basal cell carcinoma (BCC) is the most common skin cancer in the general population. Treatments vary from Mohs surgery to topical therapy, depending on the subtype. Dermoscopy, ...reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) have gained a foothold in daily clinical practice to optimize diagnosis and subtype‐oriented treatment. The new technique of line‐field confocal OCT (LC‐OCT) allows imaging at high resolution and depth, but its use has not yet been investigated in larger studies.
Aim
To evaluate the main LC‐OCT criteria for the diagnosis and subtyping of BCC compared with histopathology, OCT and RCM.
Methods
In total, 52 histopathologically confirmed BCCs were evaluated for imaging criteria. Their frequency, predictive values and ROC curves were calculated. A multinominal regression with stepwise variables selection to distinguish BCC subtypes was performed.
Results
Nodular BCCs were mainly characterized by atypical keratinocytes, altered dermoepidermal junction (DEJ), tumour nests in the dermis, dark clefting, prominent vascularization and white hyper‐reflective stroma. Superficial BCCs showed a thickening of the epidermis due to a series of tumour lobules with clear connection to the DEJ (string of pearls pattern). Infiltrative BCCs were characterized by elongated hyporeflective tumour strands, surrounded by bright collagen (shoal of fish pattern). The overall BCC subtype agreement between LC‐OCT and conventional histology was 90.4% (95% CI 79.0–96.8).
Conclusion
LC‐OCT allows noninvasive, real‐time identification of BCCs and their subtypes in vertical, horizontal and three‐dimension mode compared with histology, RCM and OCT. Further larger studies are needed to better explore the clinical applications of this promising device.
Background
The treatment of keratinocyte cancers (KC) strictly depends on their differentiation and invasiveness. Non‐invasive diagnostic techniques can support the diagnosis in real time, avoiding ...unnecessary biopsies. This study aimed to preliminarily define main imaging criteria and histological correlations of actinic keratosis (AK), Bowen’s disease (BD) and squamous cell carcinoma (SCC) using the novel device line‐field confocal optical coherence tomography (LC‐OCT).
Methods
Dermoscopy and LC‐OCT images of 73 histopathologically confirmed lesions (46 AKs, 11 BD and 16 SCCs) were included in the study. Exemplary lesions (10 AKs, 5 BD and 5 SCCs) were additionally investigated with optical coherence tomography and reflectance confocal microscopy.
Results
Most common LC‐OCT findings of KC in the descriptive statistics were hyperkeratosis/parakeratosis, disruption of stratum corneum, broadened epidermis, basal and suprabasal keratinocyte atypia, dilated vessels/neoangiogenesis and elastosis/collagen alterations. In the univariate multinomial logistic regression, a preserved DEJ was less common in SCC compared with AK and BD, BD displayed marked keratinocyte atypia involving all epidermal layers (bowenoid pattern), while SCC showed ulceration, increased epidermal thickness, keratin plugs, acantholysis, not visible/interrupted DEJ and epidermal bright particles. LC‐OCT increased the diagnostic confidence by 24.7% compared with dermoscopy alone.
Conclusions
Our study describes for the first time specific LC‐OCT features of different stages of KC and their histopathological correlates, focusing on keratinocyte morphology and architecture of the epidermis and DEJ. LC‐OCT may open new scenarios in the bedside diagnosis, treatment planning and follow‐up of KC.
Purpose
To compare the diagnostic imaging ability of three different optical coherence tomography (OCT) devices in non‐melanoma skin cancer (NMSC).
Methods
Thirty actinic keratoses (AKs) and 27 basal ...cell carcinomas (BCCs) of 29 patients were examined with three different OCT devices, VivoSight®, Callisto® and Skintell®.
Results
Complete data sets were available for 16 BCCs and 10 AKs of 18 patients. All OCT devices were able to discriminate BCCs and AKs significantly from perilesional normal skin due to lower signal intensities as well as a thicker stratum corneum and epidermis in AKs. A significant decrease in the signal intensity and thickness of all skin layers was noted with Skintell® in contrast to VivoSight® and Callisto®. OCT comparisons revealed only slight differences between VivoSight® and Callisto®. Regarding BCC tumor thickness VivoSight® and Callisto® correlated well, histology did not correlate with the three OCT devices, whereas Skintell® showed no correlation with VivoSight®, Callisto® or histology.
Conclusion
All tested OCT devices could identify BCCs and AKs objectively through standardized measurement of signal intensity and skin layer thickness. Due to their technical specifications (resolution, penetration depth), each of the OCT systems offers additional and special information on NMSC.
Summary
Background
We previously described the principal results from an observational, prospective, multicentre, clinical trial of the diagnostic value of optical coherence tomography (OCT) for ...basal cell carcinoma (BCC) in a clinical setting. In this trial, much additional useful information was gathered that warranted further analysis, presented here.
Objectives
To investigate the influence of candidate diagnostic criteria, OCT image quality, lesion location, and observer confidence and interobserver variability on the diagnostic performance of OCT, and to assess its potential use for diagnosis of BCC subtypes.
Methods
A total of 234 clinically unclear ‘pink lesions’ were evaluated in three steps: after clinical examination, after adding dermoscopy and after adding OCT. In addition to the diagnoses (including lesion subtype), observers recorded which of 15 diagnostic criteria the OCT image contained, their confidence in the diagnoses, the OCT image quality and the anatomical location of the lesion.
Results
Diagnostic performance of OCT did not depend on the lesion's anatomical location. Good OCT image quality was correlated with improved diagnostic performance, but diagnostic performance for lesions with mediocre image quality was still better than by clinical and dermoscopic examination. The main reason for reduced image quality was superficial scales and crusting. Observer confidence in diagnosis was correlated with diagnostic performance. Interobserver diagnostic performance was consistently higher than clinical examination and dermoscopy across all sites. BCC subtype could be determined with moderate accuracy, but further independent image markers are required.
Conclusion
OCT is useful in the diagnosis of BCC.
What's already known about this topic?
Optical coherence tomography (OCT) is an emerging imaging modality that has been shown to have utility in the noninvasive diagnosis of basal cell carcinoma (BCC), and is more sensitive and more specific than clinical or dermoscopic examination alone.
What does this study add?
Lesion location does not affect diagnostic performance with OCT.
Poor OCT image quality is associated with superficial scales and crusting, reducing diagnostic performance, but in these cases diagnosis with OCT is better than by clinical or dermoscopy examination alone.
Observers’ diagnostic confidence increases when using OCT and their performance reflects this.
Diagnostic performance is consistent between trained observers.
BCC subtype can be diagnosed from OCT images with moderate accuracy.
Linked Editorial: Rossi et al. Br J Dermatol 2018; 178:994–996.
Plain language summary available online
Respond to this article
Background
Previous studies have shown that actinic keratoses (AKs) and basal cell carcinomas (BCCs) can be diagnosed by optical coherence tomography (OCT) based on morphological characteristics. ...There is a lack of systematic studies that give standardized information on signal intensity and layer thickness of AKs and BCCs.
Objective
The aim of this study was to find out if AKs and BCCs can be objectively diagnosed through standardized measurement of signal intensity and layer thickness and to use OCT as a non‐invasive objective method for the diagnosis and evaluation of AKs and BCCs. Additionally, tumour and skin layer thickness were investigated in correlation with histology.
Methods
In this experimental study, 301 lesions (188 BCCs and 113 AKs) of 125 patients were clinically as well as dermoscopically diagnosed and investigated with OCT before therapy. Normal perilesional skin served as control.
Results
It is possible to differentiate BCCs and AKs from normal skin in OCT due to the decrease of local signal intensity in affected skin layers in relation to adjacent healthy skin. In AKs, a strong thickness increase of the stratum corneum and epidermis compared to normal skin were observed. For the distinction between AKs and BCCs, a drop of signal intensity in the dermis of AKs towards BCCs and a thicker epidermis of AKs in contrast to BCCs were registered. All results are statistically highly significant (P < 0.0001). Besides, a strong correlation of tumour and skin layer thickness of BCCs and AKs in OCT with histology was found.
Conclusion
Through standardized measurement of signal intensity and layer thickness, BCCs and AKs can be objectively diagnosed and distinguished from each other with OCT. This will further improve the use of OCT as a non‐invasive objective method for the diagnosis and treatment monitoring of these diseases.
The present contribution reviews the principle of RF separation and explains its dependence on different parameters of beam optics and hardware. The first examination of potential showstoppers for ...the RF-separated beam implementation for Phase-2 of the AMBER experiment in the M2 beam line of the North Area is presented. Different beam optics settings have been examined, providing either focused or parallel beams inside the RF cavities. The separation and transmission capability of the different optics settings for realistic characteristics of RF cavities are discussed and the preliminary results of the potential purity and intensity of the RF-separated beam are presented. These show that a trade-off between the overall beam intensity and the share of the required particle type in the overall beam needs to be established. No showstoppers have been identified for achieving the beam parameters required for AMBER’s kaonic Primakoff reactions, kaon spectroscopy, prompt-photon production and kaon charge-radius programs. However, the high beam intensity requirements of the AMBER Drell–Yan programme cannot be satisfied with an RF-separated beam.
After the initial discoveries fifteen years ago, over 200 extrasolar planets have now been detected. Most of them orbit main-sequence stars similar to our Sun, although a few planets orbiting red ...giant stars have been recently found. When the hydrogen in their cores runs out, main-sequence stars undergo an expansion into red-giant stars. This expansion can modify the orbits of planets and can easily reach and engulf the inner planets. The same will happen to the planets of our Solar System in about five billion years and the fate of the Earth is matter of debate. Here we report the discovery of a planetary-mass body (Msini = 3.2MJupiter) orbiting the star V 391 Pegasi at a distance of about 1.7 astronomical units (au), with a period of 3.2 years. This star is on the extreme horizontal branch of the Hertzsprung-Russell diagram, burning helium in its core and pulsating. The maximum radius of the red-giant precursor of V 391 Pegasi may have reached 0.7 au, while the orbital distance of the planet during the stellar main-sequence phase is estimated to be about 1 au. This detection of a planet orbiting a post-red-giant star demonstrates that planets with orbital distances of less than 2 au can survive the red-giant expansion of their parent stars.
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