| 1. |
- Annala, Leevi, et al.
(författare)
-
Generating Hyperspectral Skin Cancer Imagery using Generative Adversarial Neural Network.
- 2020
-
Ingår i: Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference. - 2694-0604. ; 2020, s. 1600-1603
-
Tidskriftsartikel (refereegranskat)abstract
- In this study we develop a proof of concept of using generative adversarial neural networks in hyperspectral skin cancer imagery production. Generative adversarial neural network is a neural network, where two neural networks compete. The generator tries to produce data that is similar to the measured data, and the discriminator tries to correctly classify the data as fake or real. This is a reinforcement learning model, where both models get reinforcement based on their performance. In the training of the discriminator we use data measured from skin cancer patients. The aim for the study is to develop a generator for augmenting hyperspectral skin cancer imagery.
|
|
| 2. |
- Bieliauskiene, Giedre, et al.
(författare)
-
Incidence of Kaposi Sarcoma in Sweden is Decreasing.
- 2020
-
Ingår i: Acta dermato-venereologica. - : Medical Journals Sweden AB. - 1651-2057. ; 100:17
-
Tidskriftsartikel (refereegranskat)abstract
- Kaposi sarcoma is a rare skin cancer, and epidemiological research into Kaposi sarcoma is therefore scarce. The current epidemiological situation for Kaposi sarcoma in Sweden is unknown. The authors hypothesized that the incidence of Kaposi sarcoma should have decreased after the introduction of antiretroviral therapy in 1996. Using data from the Swedish Cancer Registry, this study aimed to determine the incidence rates and survival for Kaposi sarcoma in Sweden from 1993 to 2016. The results showed that a total of 657 patients (74.0% men, 26.0% women) were diagnosed with Kaposi sarcoma in Sweden during 1993 to 2016. The overall incidence per 100,000, age-standardized to the world population, decreased from 0.40 to 0.10 (p=0.003) for both sexes combined, from 0.76 to 0.14 (p=0.003) for men, and from 0.07 to 0.06 (p=0.86) for women. The 10-year overall survival rate was significantly lower for the study population (30%) compared with the age- and sex-matched Swedish population (56%) (p<0.00001). Over the study period, incidence rates of Kaposi sarcoma decreased significantly in men, especially during the late 1990s.
|
|
| 3. |
- Fougelberg, Julia, et al.
(författare)
-
Dermoscopic Findings in Intraepidermal Carcinoma: an Interobserver Agreement Study
- 2023
-
Ingår i: Dermatology Practical & Conceptual. - : Mattioli1885. - 2160-9381. ; 13:1
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: A wide range of descriptive terms have been used for dermoscopic findings in intraepidermal carcinoma (IEC) and the clinical diagnostic accuracy of IEC can be challenging. Furthermore, dermoscopic findings in IEC have only rarely been evaluated in fair-skinned populations.Objectives: To measure the interobserver agreement between dermatologists for dermoscopic findings in IEC. Furthermore, to describe the frequency of these findings in a predominantly fair-skinned population. Methods: One hundred dermoscopic images of histopathologically verified IECs were collected. The 11 most common dermoscopic findings described in previous studies were re-defined in a new terminology in a pre-study consensus meeting. Images were assessed by eight experienced international dermoscopists. The frequency of findings and the interobserver agreement was analyzed.Results: Scales (83%), dotted/glomerular vessels (77%), pinkish-white areas (73%) and hemorrhage (46%) were the most commonly present dermoscopic findings. Pigmented structures were found in 32% and shiny white structures (follicular or stromal) in 54% of the IEC. Vascular structures (vessels and/or hemorrhage) could be seen in 89% of the lesions. Overall, the interobserver agreement for the respective dermoscopic findings was poor to moderate, with the highest kappa values noted for scales (0.55) and hemorrhage (0.54) and the lowest for pinkish-white areas (0.015).Conclusion: Our results confirm those of previous studies on dermoscopy in IEC, including the frequency of pigmented structures despite the fair-skinned population. The interobserver agreement was relatively low. The proposed new terminology and our findings can hopefully serve as a guideline for researchers, teachers and students on how to identify IEC.
|
|
| 4. |
- Gillstedt, Martin, 1977, et al.
(författare)
-
Evaluation of Melanoma Thickness with Clinical Close-up and Dermoscopic Images Using a Convolutional Neural Network
- 2022
-
Ingår i: Acta dermato-venereologica. - : Medical Journals Sweden AB. - 0001-5555 .- 1651-2057. ; 102
-
Tidskriftsartikel (refereegranskat)abstract
- Convolutional neural networks (CNNs) have shown promise in discriminating between invasive and in situ melanomas. The aim of this study was to analyse how a CNN model, integrating both clinical close-up and dermoscopic images, performed compared with 6 in-dependent dermatologists. The secondary aim was to address which clinical and dermoscopic features derma-tologists found to be suggestive of invasive and in situ melanomas, respectively. A retrospective investigation was conducted including 1,578 cases of paired images of invasive (n = 728, 46.1%) and in situ melanomas (n = 850, 53.9%). All images were obtained from the Department of Dermatology and Venereology at Sahl-grenska University Hospital and were randomized to a training set (n = 1,078), a validation set (n = 200) and a test set (n = 300). The area under the receiver operating characteristics curve (AUC) among the der-matologists ranged from 0.75 (95% confidence in-terval 0.70-0.81) to 0.80 (95% confidence interval 0.75-0.85). The combined dermatologists' AUC was 0.80 (95% confidence interval 0.77-0.86), which was significantly higher than the CNN model (0.73, 95% confidence interval 0.67-0.78, p = 0.001). Three of the dermatologists significantly outperformed the CNN. Shiny white lines, atypical blue-white structures and polymorphous vessels displayed a moderate interob-server agreement, and these features also correlated with invasive melanoma. Prospective trials are needed to address the clinical usefulness of CNN models in this setting.
|
|
| 5. |
- Mirzaei, Nushin, et al.
(författare)
-
Sentinel lymph node localization and staging with a low-dose of superparamagnetic iron oxide (SPIO) enhanced MRI and magnetometer in patients with cutaneous melanoma of the extremity - The MAGMEN feasibility study
- 2022
-
Ingår i: European Journal of Surgical Oncology. - : Elsevier BV. - 0748-7983. ; 48:2, s. 326-332
-
Tidskriftsartikel (refereegranskat)abstract
- Background: In patients with melanoma, sentinel lymph node (SLN) status is pivotal for treatment decisions. Current routine for SLN detection combines Technetium99m (Tc99) lymphoscintigraphy and blue dye (BD). The primary aim of this study was to examine the feasibility of using a low dose of superparamagnetic iron oxide (SPIO) injected intracutaneously to detect and identify the SLN, and the secondary aim was to investigate if a low dose of SPIO would enable a preoperative MRI-evaluation of SLN status. Methods: Patients with melanoma of the extremities were eligible. Before surgery, a baseline MRI of the nodal basin was followed by an injection of a low dose (0.02–0.5 mL) of SPIO and then a second MRI (SPIO-MRI). Tc99 and BD was used in parallel and all nodes with a superparamagnetic and/or radioactive signal were harvested and analyzed. Results: Fifteen patients were included and the SLNB procedure was successful in all patients (27 SLNs removed). All superparamagnetic SLNs were visualized by MRI corresponding to the same nodes on scintigraphy. Micrometastatic deposits were identified in four SLNs taken from three patients, and SPIO-MRI correctly predicted two of the metastases. There was an association between MRI artefacts in the lymph node and the dose SPIO given. Discussion: It is feasible to detect SLN in patients with melanoma using a low dose of SPIO injected intracutaneously compared with the standard dual technique. A low dose of SPIO reduces the lymph node MRI artefacts, opening up for a non-invasive assessment of SLN status in patients with cancer. © 2022 The Authors
|
|
| 6. |
- Munem, Marwa, et al.
(författare)
-
Chemical imaging of aggressive basal cell carcinoma using time-of-flight secondary ion mass spectrometry.
- 2018
-
Ingår i: Biointerphases. - : American Vacuum Society. - 1934-8630 .- 1559-4106. ; 13:3
-
Tidskriftsartikel (refereegranskat)abstract
- A set of basal cell carcinoma samples, removed by Mohs micrographic surgery and pathologically identified as having an aggressive subtype, have been analyzed using time-of-flight secondary ion mass spectrometry (SIMS). The SIMS analysis employed a gas cluster ion beam (GCIB) to increase the sensitivity of the technique for the detection of intact lipid species. The GCIB also allowed these intact molecular signals to be maintained while surface contamination and delocalized chemicals were removed from the upper tissue surface. Distinct mass spectral signals were detected from different regions of the tissue (epidermis, dermis, hair follicles, sebaceous glands, scar tissue, and cancerous tissue) allowing mass spectral pathology to be performed. The cancerous regions of the tissue showed a particular increase in sphingomyelin signals that were detected in both positive and negative ion mode along with increased specific phosphatidylserine and phosphatidylinositol signals observed in negative ion mode. Samples containing mixed more and less aggressive tumor regions showed increased phosphatidylcholine lipid content in the less aggressive areas similar to a punch biopsy sample of a nonaggressive nodular lesion.
|
|
| 7. |
- Nilsson, Kelly Dimovska, et al.
(författare)
-
TOF-SIMS imaging reveals tumor heterogeneity and inflammatory response markers in the microenvironment of basal cell carcinoma
- 2020
-
Ingår i: Biointerphases. - : American Vacuum Society. - 1934-8630 .- 1559-4106. ; 15:4
-
Tidskriftsartikel (refereegranskat)abstract
- Basal cell carcinoma (BCC) is the most common skin malignancy. In fact, it is as common as the sum of all other skin malignancies combined and the incidence is rising. In this focused and histology-guided study, tissue from a patient diagnosed with aggressive BCC was analyzed by imaging mass spectrometry in order to probe the chemistry of the complex tumor environment. Time-of-flight secondary ion mass spectrometry using a (CO2)(6 k)(+)gas cluster ion beam allowed a wide range of lipid species to be detected. Their distributions were then imaged in the tissue that contained small tumor islands that were histologically classified as more/less aggressive. Maximum autocorrelation factor (MAF) analysis highlighted chemical differences between the tumors and the surrounding stroma. A closer inspection of the distribution of individual ions, selected based on the MAF loadings, showed heterogeneity in signal between different microtumors, suggesting the potential of chemically grading the aggressiveness of each individual tumor island. Sphingomyelin lipids were found to be located in stroma containing inflammatory cells.
|
|
| 8. |
- Paoli, John, 1975, et al.
(författare)
-
Hyperspectral Imaging for Non-invasive Diagnostics of Melanocytic Lesions.
- 2022
-
Ingår i: Acta dermato-venereologica. - : Medical Journals Sweden AB. - 1651-2057 .- 0001-5555. ; 102
-
Tidskriftsartikel (refereegranskat)abstract
- Malignant melanoma poses a clinical diagnostic problem, since a large number of benign lesions are excised to find a single melanoma. This study assessed the accuracy of a novel non-invasive diagnostic technology, hyperspectral imaging, for melanoma detection. Lesions were imaged prior to excision and histopathological analysis. A deep neural network algorithm was trained twice to distinguish between histopathologically verified malignant and benign melanocytic lesions and to classify the separate subgroups. Furthermore, 2 different approaches were used: a majority vote classification and a pixel-wise classification. The study included 325 lesions from 285 patients. Of these, 74 were invasive melanoma, 88 melanoma in situ, 115 dysplastic naevi, and 48 non-dysplastic naevi. The study included a training set of 358,800 pixels and a validation set of 7,313 pixels, which was then tested with a training set of 24,375 pixels. The majority vote classification achieved high overall sensitivity of 95% and a specificity of 92% (95% confidence interval (95% CI) 0.024-0.029) in differentiating malignant from benign lesions. In the pixel-wise classification, the overall sensitivity and specificity were both 82% (95% CI 0.005-0.005). When divided into 4 subgroups, the diagnostic accuracy was lower. Hyperspectral imaging provides high sensitivity and specificity in distinguishing between naevi and melanoma. This novel method still needs further validation.
|
|
| 9. |
- Paoli, John, 1975, et al.
(författare)
-
Nonsurgical Options for the Treatment of Basal Cell Carcinoma.
- 2019
-
Ingår i: Dermatology practical & conceptual. - : Mattioli1885. - 2160-9381. ; 9:2, s. 75-81
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this review article is to summarize the effectiveness, potential adverse events, and indications of the main nonsurgical treatment alternatives for basal cell carcinoma.An extensive literature review was carried out. The most relevant articles were discussed and selected by the authors in order to provide a brief but evidence-based overview of the most common nonsurgical methods used for treating basal cell carcinoma.Although surgery and Mohs micrographic surgery are often considered the optimal treatment options for basal cell carcinoma, these tumors can also be treated successfully with destructive techniques (eg, curettage alone, cryosurgery, or electrodesiccation), photodynamic therapy, topical drugs (eg, 5-fluorouracil, imiquimod, or ingenol mebutate), radiotherapy, or hedgehog pathway inhibitors. When choosing between these alternatives, physicians must take into consideration the tumor's size, location, and histopathological subtype. Special care should be taken when treating recurrent tumors. Furthermore, physician experience is of great importance when using destructive techniques. Finally, patient preference, potential adverse events, and cosmetic outcome should also be considered.Dermatologists and physicians treating basal cell carcinoma should have knowledge of and experience with the large arsenal of therapeutic alternatives available for the successful, safe, and individualized management of patients with basal cell carcinoma.
|
|
| 10. |
- Polesie, Sam, et al.
(författare)
-
Can Dermoscopy Be Used to Predict if a Melanoma Is In Situ or Invasive?
- 2021
-
Ingår i: Dermatology Practical & Conceptual. - : Mattioli1885. - 2160-9381. ; 11:3
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The preoperative prediction of whether melanomas are invasive or in situ can influence initial management. Objectives: This study evaluated the accuracy rate, interobserver concordance, sensitivity and specificity in determining if a melanoma is invasive or in situ, as well as the ability to predict invasive melanoma thickness based on clinical and dermoscopic images. Methods: In this retrospective, single-center investigation, 7 dermatologists independently reviewed clinical and dermoscopic images of melanomas to predict if they were invasive or in situ and, if invasive, their Breslow thickness. Fleiss' and Cohen's kappa (kappa) were used for interobserver concordance and agreement with histopathological diagnosis. Results: We included 184 melanomas (110 invasive and 74 in situ). Diagnostic accuracy ranged from 67.4% to 76.1%. Accuracy rates for in situ and invasive melanomas were 57.5% (95% confidence interval [I], 53.1%-61.8%) and 81.7% (95% CI, 78.8%-84.4%), respectively. Interobserver concordance was moderate (kappa = 0.47; 95% CI, 0.44-0.51). Sensitivity for predicting invasiveness ranged from 63.6% to 91.8% for 7 observers, while specificity was 32.4%-82.4%. For all correctly predicted invasive melanomas, agreement between predictions and correct thickness over or under 1.0 mm was moderate (kappa = 0.52; 95% CI, 0.45-0.58). All invasive melanomas incorrectly predicted by any observer as in situ had a thickness <1.0 mm. All 32 melanomas >1.0 mm were correctly predicted to be invasive by all observers. Conclusions: Accuracy rates for predicting thick melanomas were excellent, melanomas inaccurately predicted as in situ were all thin, and interobserver concordance for predicting in situ or invasive melanomas was moderate. Preoperative dermoscopy of suspected melanomas is recommended for choosing appropriate surgical margins.
|
|
| 11. |
|
|
| 12. |
- Polesie, Sam, et al.
(författare)
-
Discrimination Between Invasive and In Situ Melanomas Using Clinical Close-Up Images and a De Novo Convolutional Neural Network
- 2021
-
Ingår i: Frontiers in Medicine. - : Frontiers Media SA. - 2296-858X. ; 8
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Melanomas are often easy to recognize clinically but determining whether a melanoma is in situ (MIS) or invasive is often more challenging even with the aid of dermoscopy. Recently, convolutional neural networks (CNNs) have made significant and rapid advances within dermatology image analysis. The aims of this investigation were to create a de novo CNN for differentiating between MIS and invasive melanomas based on clinical close-up images and to compare its performance on a test set to seven dermatologists. Methods: A retrospective study including clinical images of MIS and invasive melanomas obtained from our department during a five-year time period (2016-2020) was conducted. Overall, 1,551 images [819 MIS (52.8%) and 732 invasive melanomas (47.2%)] were available. The images were randomized into three groups: training set (n = 1,051), validation set (n = 200), and test set (n = 300). A de novo CNN model with seven convolutional layers and a single dense layer was developed. Results: The area under the curve was 0.72 for the CNN (95% CI 0.66-0.78) and 0.81 for dermatologists (95% CI 0.76-0.86) (P < 0.001). The CNN correctly classified 208 out of 300 lesions (69.3%) whereas the corresponding number for dermatologists was 216 (72.0%). When comparing the CNN performance to each individual reader, three dermatologists significantly outperformed the CNN. Conclusions: For this classification problem, the CNN was outperformed by the dermatologist. However, since the algorithm was only trained and validated on 1,251 images, future refinement and development could make it useful for dermatologists in a real-world setting.
|
|
| 13. |
- Polesie, Sam, et al.
(författare)
-
Frequency of Publication of Dermoscopic Images in Inter-observer Studies: A Systematic Review
- 2021
-
Ingår i: Acta dermato-venereologica. - : Medical Journals Sweden AB. - 1651-2057 .- 0001-5555. ; 101:12
-
Tidskriftsartikel (refereegranskat)abstract
- Research interest in dermoscopy has accelerated, but the complete dermoscopic image sets used for inter-observer investigations for skin tumors are not often shared to the reader. The aim of this systematic review was to analyze what proportion of images depicting skin tumors are shared in the manuscripts of studies investigating inter-observer variation in the assessment of dermoscopic features and/or patterns. The Embase, MEDLINE, and Scopus databases were screened for eligible studies published from inception to July 2, 2020. For included investigations we extracted the proportion of lesion images presented in the manuscripts and or supplements. Overall, we included 61 studies (52 original investigations and 9 concise reports) in the time period of 1997 to 2020. These investigations combined, included 14,124 skin tumors of which 373 (3%) images were shared. Since data sharing must be promoted, this investigation should be a wake-up call for the dermatology research community and editorial offices.
|
|
| 14. |
- Polesie, Sam, et al.
(författare)
-
Interobserver Agreement on Dermoscopic Features and their Associations with In Situ and Invasive Cutaneous Melanomas.
- 2021
-
Ingår i: Acta dermato-venereologica. - : Medical Journals Sweden AB. - 1651-2057 .- 0001-5555. ; 101:10
-
Tidskriftsartikel (refereegranskat)abstract
- Several melanoma-specific dermoscopic features have been described, some of which have been reported as indicative of in situ or invasive melanomas. To assess the usefulness of these features to differentiate between these 2 categories, a retrospective, single-centre investigation was conducted. Dermoscopic images of melanomas were reviewed by 7 independent dermatologists. Fleiss' kappa (κ) was used to analyse interobserver agreement of predefined features. Logistic regression and odds ratios were used to assess whether specific features correlated with melanoma in situ or invasive melanoma. Overall, 182 melanomas (101 melanoma in situ and 81 invasive melanomas) were included. The interobserver agreement for melanoma-specific features ranged from slight to substantial. Atypical blue-white structures (κ=0.62, 95% confidence interval 0.59-0.65) and shiny white lines (κ=0.61, 95% confidence interval 0.58-0.64) had a substantial interobserver agreement. These 2 features were also indicative of invasive melanomas >1.0 mm in Breslow thickness. Furthermore, regression/peppering correlated with thin invasive melanomas. The overall agreement for classification of the lesions as invasive or melanoma in situ was moderate (κ=0.52, 95% confidence interval 0.49-0.56).
|
|
| 15. |
- Starace, Michela, et al.
(författare)
-
Clinical and Dermoscopic Approaches to Diagnosis of Frontal Fibrosing Alopecia: Results From a Multicenter Study of the International Dermoscopy Society.
- 2022
-
Ingår i: Dermatology practical & conceptual. - : Mattioli1885. - 2160-9381. ; 12:1
-
Tidskriftsartikel (refereegranskat)abstract
- Frontal fibrosing alopecia (FFA) is a form of primary lymphocytic scarring alopecia characterized by a progressive recession of the fronto-temporal hairline. Although the clinical presentation of FFA is very typical, biopsy for histopathological examination is still recommended to confirm the diagnosis. Currently, a growing number of skin and mucosal inflammatory diseases are diagnosed with modern noninvasive techniques such as dermoscopy without the necessity of a biopsy.The International Dermoscopy Society (IDS) aimed to test the ability of its members to diagnose classic FFA through clinical and dermoscopic parameters and to compare acquired data to the largest cohort studies published since 1994.This is an observational, cross-sectional study describing patient demographics, clinical presentation and diagnostic tools used in a sample of FFA patients collected by IDS members. A literature search was then performed using Pubmed to review studies reporting more than 100 cases.IDS members submitted 188 cases demonstrating a predominant female population (98.4%). In 71.8% of the cases, the clinical presentation and the trichoscopic findings allowed for the diagnosis. Out of 24 revised studies, 13 showed that clinical and trichoscopic features were decisive for the diagnosis in almost all cases.Demographic and clinical data of our cohort were mostly comparable to previous reported data on FFA. The relevant role of the clinical and trichoscopic features in diagnosing FFA was confirmed by our study and the reviewed literature. Trichoscopy could be considered a worldwide-acknowledged non-invasive technique for the diagnosis of FFA.
|
|
| 16. |
- Zaar, Oscar, et al.
(författare)
-
A prospective, randomized, within-subject study of ALA-PDT for actinic keratoses using different irradiation regimes
- 2018
-
Ingår i: Photodermatology Photoimmunology & Photomedicine. - : Wiley. - 0905-4383. ; 34:5, s. 338-342
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundPhotodynamic therapy (PDT) can be used to treat large fields of actinic keratoses (AKs) with high clearance rates. A notable downside is the amount of pain that accompany the treatment. This study aimed to optimize the illumination protocol during conventional PDT in order to reduce pain without compromising treatment effectiveness. MethodsIn this prospective, randomized study with a split-face design, patients with, symmetrically distributed AKs were included. All patients were treated using a ALA 78mg/g gel. One side was illuminated with the Aktilite((R)) CL-128 lamp and the other side with the RhodoLED((R)) lamp in which the light intensity gradually increased to a maximum of 60%. Both sides received a total light dose of 37J/cm(2). Pain during the treatment was measured using a visual analogue scale. The clinical effectiveness of the 2 treated sides was assessed after 12weeks. ResultsTwenty-nine patients with 399 AKs were included. Illumination with the gradually increasing light intensity resulted in a decrease in the median visual analogue scale score by 1.1 points. Clearance rates were similar between the 2 lamps. ConclusionMinimizing the light intensity during the illumination phase of PDT reduces pain, while still preserving a high clearance rate of AKs.
|
|
| 17. |
- Zaar, Oscar, et al.
(författare)
-
Dermoscopy of porokeratosis: results from a multicentre study of the International Dermoscopy Society
- 2021
-
Ingår i: Journal of the European Academy of Dermatology and Venereology. - : Wiley. - 0926-9959 .- 1468-3083. ; 35:10, s. 2091-2096
-
Tidskriftsartikel (refereegranskat)abstract
- Background The diagnosis of porokeratosis can be challenging, and knowledge about its dermoscopic features is limited. Objectives To describe the dermoscopic features of porokeratosis of Mibelli and disseminated superficial actinic porokeratosis (DSAP) and the frequency of these features in a larger case series. The interobserver concordance was also assessed. Methods In this retrospective cohort study, members of the International Dermoscopy Society contributed macroscopic and dermoscopic images of histopathologically verified cases of porokeratosis of Mibelli or DSAP. Three observers independently reviewed the collected images to identify the presence of predefined dermoscopic features. Following this, a consensus meeting was held to agree upon which dermoscopic features were present in each lesion. Results In total, 78 clinical and dermoscopic images of porokeratoses were collected. The most common dermoscopic feature was keratin rim, which was present in 74 lesions (92.3%). The most common vascular structures were dotted or glomerular vessels which were present in almost half of the cases (48.7%). Other relatively frequent dermoscopic findings were as follows: non-peripheral scales (44.9%), grey-brown dots or pigmentation along the keratin rim (38.5%), and light-brown pigmentation within the keratin rim (33.3%). Shiny white structures and blood spots or erosions along the keratin rim were findings never before described in porokeratosis and were detected in 16.7% and 17.9% of the lesions, respectively. Dermoscopic findings in porokeratosis of Mibelli and DSAP were similar except for fewer blood spots or erosions along the keratin rim and more light-brown pigmentation within the keratin rim in DSAP. The interobserver concordance ranged from 0.44 (moderate) to 0.84 (almost perfect). Conclusions The dermoscopic hallmark of porokeratosis is the keratin rim, a finding also allowing for almost perfect interobserver agreement. Pigmentation or erosions along the keratin rim, vascular structures, as well as scales, pigmentation or shiny white structures within the keratin rim are additional dermoscopic clues.
|
|
| 18. |
- Zaar, Oscar, et al.
(författare)
-
Effectiveness of photodynamic therapy in Bowen's disease: a retrospective observational study in 423 lesions
- 2017
-
Ingår i: Journal of the European Academy of Dermatology and Venereology. - : Wiley. - 0926-9959. ; 31:8, s. 1289-1294
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundPhotodynamic therapy (PDT) is a well-known technique that is often used for treating superficial precancerous and cancerous skin lesions. However, only a handful of studies, with a relatively small number of treated lesions, have been carried out on the effectiveness of PDT for Bowen's disease (BD). ObjectivesThis study aimed to assess the effectiveness and recurrence risk of PDT in the treatment of BD. The secondary objectives were to determine what factors affected the response rates and the cosmetic result of the treatment. MethodIn this retrospective observational study, the electronic patient charts at Sahlgrenska University Hospital (SUH) in Gothenburg, Sweden, were searched to find all patients diagnosed with BD who were treated with PDT between 1 January 2002 and 31 December 2014. Data were collected regarding clinical response at the first follow-up visit, recurrences during later follow-up visits and other relevant patient and tumour characteristics. ResultsIn total, 423 BD lesions in 335 patients were included in the study. The mean FU duration was 11.2 months (range 0.2-151 months). The complete response rate at the first FU visit was 77.5% for all BD lesions. During later FU visits, another 60 recurrences were observed, which resulted in a recurrence rate of 18.3%. Thus, the overall clearance rate after FU was 63.4% for all BD lesions. Significant risk factors for unsuccessful treatment in this study were large lesion size (>2 cm) and a single PDT session. ConclusionThis study shows that PDT is a relatively effective treatment modality for BD.
|
|
| 19. |
- Zaar, Oscar
(författare)
-
Epidemiology, diagnostics and treatment of non-melanoma skin cancers
- 2018
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Skin cancer, including malignant melanoma and non-melanoma skin cancer (NMSC), is a growing problem due to the increasing incidence in Sweden and in other Caucasian populations. NMSCs are diagnosed as often as all other cancers combined and include basal cell carcinoma (BCC), squamous cell carcinoma (SCC), precursors to SCC such as Bowen’s disease (BD) and actinic keratosis (AK), as well as several rare skin cancers including Merkel cell carcinoma (MCC). The purpose of this thesis was to investigate novel aspects within the fields of epidemiology, diagnosis and treatment of NMSCs. In study I, the incidence and clinical characteristics of Swedish patients with MCC was explored. During the study period from 1993 to 2012, the age standardised incidence of MCC almost doubled with an increase of 73-85 % depending on the population used for age standardisation. The overall incidence for women and men per 100,000 persons, using the world population for age standardisation, rose from 0.11 to 0.19 between 1993 and 2012. In study II, the effectiveness of photodynamic therapy (PDT) for the treatment of BD was evaluated retrospectively for 423 lesions in 335 patients. The study showed that PDT was a relatively effective treatment with a complete clearance rate of 63.4 % after a median FU time of 11.2 months. BD lesions greater than 20 mm in size and a single session of PDT were factors associated with statistically worse outcome. In study III, a novel irradiation protocol in PDT for multiple AKs using a stepwise increase of light intensity, staying below 50 mW/cm2 during the whole treatment session, was compared to the conventional irradiation protocol to assess pain levels during treatment and effectiveness. Both protocols had the same total light dose of 37 J/cm2. The novel treatment protocol led to a small but statically significant decrease in pain ( 1.1 points on a visual analogue scale, p<0.01). However, the clearance rate with the new protocol was slightly but significantly lower than that of the conventional protocol (91.2 % vs 93.7 %, respectively) (p=0.04). In study IV, the chemical composition of lipids in BCCs was mapped using Time-of-Flight-Secondary-Ion-Mass-Spectrometry (ToF-SIMS). ToF-SIMS was able to identify different lipids in healthy and cancerous tissue. Furthermore, sphingomyelin lipids were found in aggressive BCCs whereas phosphatidylcholine lipids were observed in less aggressive tumours. In conclusion, the incidence of MCC has increased the last 20 years, PDT is a relatively effective treatment modality in BD, novel illumination protocols with lower light intensity can decrease pain in PDT and ToF-SIMS can be used to identify the lipid composition of BCCs.
|
|
| 20. |
- Zaar, Oscar, et al.
(författare)
-
Evaluation of the Diagnostic Accuracy of an Online Artificial Intelligence Application for Skin Disease Diagnosis.
- 2020
-
Ingår i: Acta dermato-venereologica. - : Medical Journals Sweden AB. - 0001-5555 .- 1651-2057. ; 100:16
-
Tidskriftsartikel (refereegranskat)abstract
- Artificial intelligence (AI) algorithms for automated classification of skin diseases are available to the consumer market. Studies of their diagnostic accuracy are rare. We assessed the diagnostic accuracy of an open-access AI application (Skin Image Search™) for recognition of skin diseases. Clinical images including tumours, infective and inflammatory skin diseases were collected at the Department of Dermatology at the Sahlgrenska University Hospital and uploaded for classification by the online application. The AI algorithm classified the images giving 5 differential diagnoses, which were then compared to the diagnoses made clinically by the dermatologists and/or histologically. We included 521 images portraying 26 diagnoses. The diagnostic accuracy was 56.4% for the top 5 suggested diagnoses and 22.8% when only considering the most probable diagnosis. The level of diagnostic accuracy varied considerably for diagnostic groups. The online application demonstrated low diagnostic accuracy compared to a dermatologist evaluation and needs further development.
|
|
| 21. |
- Zaar, Oscar, et al.
(författare)
-
Merkel cell carcinoma incidence is increasing in Sweden.
- 2016
-
Ingår i: Journal of the European Academy of Dermatology and Venereology : JEADV. - : Wiley. - 1468-3083 .- 0926-9959. ; 30:10, s. 1708-1713
-
Tidskriftsartikel (refereegranskat)abstract
- Merkel cell carcinoma (MCC) is a rare aggressive neuroectodermal skin cancer with a high recurrence rate and a high mortality rate. Risk factors for MCC are reported to include high age, UV exposure, Caucasian skin type and immunosuppression. The incidence is reported to be increasing.
|
|
