Ablative Fractional Laser Enhances Artificial or Natural Daylight Photodynamic Therapy of Actinic Field Cancerization: A Randomized and Investigator-initiated Half-side Comparative Study.

Artificial daylight photodynamic therapy is a near-painless treatment for actinic keratoses, which can be performed indoors using a controlled light dose. Daylight photodynamic therapy is approved only for treatment of grade I-II actinic keratoses. The aim of this study was to evaluate whether fractional laser pre-treatment improves the outcomes of daylight photodynamic therapy for actinic keratoses of all grades. In addition, the study compared the outcomes of artificial and natural daylight photodynamic therapy. This randomized single-blinded split-side comparative study included 60 patients with ≥ 2 actinic keratoses of the head. Fractional laser pre-treatment was assigned randomly for actinic keratoses on 1 side of the head and, subsequently, the entire treatment area was treated with artificial or natural daylight photodynamic therapy. Fractional laser-mediated daylight photodynamic therapy achieved significantly higher complete clearance (50.0% vs 30.3%, p = 0.04), partial clearance (78.6% vs 50.0%, p < 0.01) and lesion-specific clearance (86.2% vs 70.2%, p < 0.01) than daylight photodynamic therapy alone at the 6-month follow-up. No significant differences were found in the outcomes of artificial vs natural daylight photodynamic therapy or grade I lesions vs grade II-III lesions. Thus, fractional laser pre-treatment appears to significantly increase the efficacy of artificial and natural daylight photodynamic therapy, and to be suitable for treatment of actinic keratoses of all grades.

FPI Based Hyperspectral Imager for the Complex Surfaces-Calibration, Illumination and Applications.

Hyperspectral imaging (HSI) applications for biomedical imaging and dermatological applications have been recently under research interest. Medical HSI applications are non-invasive methods with high spatial and spectral resolution. HS imaging can be used to delineate malignant tumours, detect invasions, and classify lesion types. Typical challenges of these applications relate to complex skin surfaces, leaving some skin areas unreachable. In this study, we introduce a novel spectral imaging concept and conduct a clinical pre-test, the findings of which can be used to develop the concept towards a clinical application. The SICSURFIS spectral imager concept combines a piezo-actuated Fabry-Pérot interferometer (FPI) based hyperspectral imager, a specially designed LED module and several sizes of stray light protection cones for reaching and adapting to the complex skin surfaces. The imager is designed for the needs of photometric stereo imaging for providing the skin surface models (3D) for each captured wavelength. The captured HS images contained 33 selected wavelengths (ranging from 477 nm to 891 nm), which were captured simultaneously with accordingly selected LEDs and three specific angles of light. The pre-test results show that the data collected with the new SICSURFIS imager enable the use of the spectral and spatial domains with surface model information. The imager can reach complex skin surfaces. Healthy skin, basal cell carcinomas and intradermal nevi lesions were classified and delineated pixel-wise with promising results, but further studies are needed. The results were obtained with a convolutional neural network.

Differentiating Malignant from Benign Pigmented or Non-Pigmented Skin Tumours-A Pilot Study on 3D Hyperspectral Imaging of Complex Skin Surfaces and Convolutional Neural Networks.

Several optical imaging techniques have been developed to ease the burden of skin cancer disease on our health care system. Hyperspectral images can be used to identify biological tissues by their diffuse reflected spectra. In this second part of a three-phase pilot study, we used a novel hand-held SICSURFIS Spectral Imager with an adaptable field of view and target-wise selectable wavelength channels to provide detailed spectral and spatial data for lesions on complex surfaces. The hyperspectral images (33 wavelengths, 477-891 nm) provided photometric data through individually controlled illumination modules, enabling convolutional networks to utilise spectral, spatial, and skin-surface models for the analyses. In total, 42 lesions were studied: 7 melanomas, 13 pigmented and 7 intradermal nevi, 10 basal cell carcinomas, and 5 squamous cell carcinomas. All lesions were excised for histological analyses. A pixel-wise analysis provided map-like images and classified pigmented lesions with a sensitivity of 87% and a specificity of 93%, and 79% and 91%, respectively, for non-pigmented lesions. A majority voting analysis, which provided the most probable lesion diagnosis, diagnosed 41 of 42 lesions correctly. This pilot study indicates that our non-invasive hyperspectral imaging system, which involves shape and depth data analysed by convolutional neural networks, is feasible for differentiating between malignant and benign pigmented and non-pigmented skin tumours, even on complex skin surfaces.

Pulsed Dye Laser-mediated Photodynamic Therapy is Less Effective than Conventional Photodynamic Therapy for Actinic Field Cancerization: A Randomized Half-side Comparative Study.

Previous research presents pulsed dye laser-mediated photodynamic therapy as a promising alternative to conventional red-light photodynamic therapy. In this study, 60 patients with 2 or more actinic keratoses randomly received either of these treatments on each side of the head. A physician blinded to the treatment evaluated treatment response at 6 months for each lesion, as completely, partially or not healed. Significantly lower complete clearance rates (10.3% vs 44.9%) and lesion-specific complete clearance rates were found for pulsed dye laser-mediated photodynamic therapy (47.9%) vs conventional red-light photodynamic therapy (73.4%). Significantly lower pain scores were found for pulsed dye laser-mediated photodynamic therapy, with a mean numerical rating of 2.3, compared with 4.1 for conventional red-light photodynamic therapy. The study population had a mean of 7.9 lesions, and 78% of patients had been treat-ed previously for actinic keratoses on the treatment area. To conclude, in a population with severe sun dam-age, pulsed dye laser-mediated photodynamic therapy seems less effective than conventional red-light photo-dynamic therapy. Pulsed dye laser-mediated photodynamic therapy may still be a treatment option for patients who are not compliant with conventional red-light photodynamic therapy.

Evaluating complications in below-knee skin cancer surgery after introduction of preoperative appointments: A 2-year retrospective cohort study.

Below-knee dermatological surgery has a high risk of complications such as wound infection, bleeding, and necrosis. In this study, we evaluated the impact of preoperative appointments on complication risks. We searched the medical records of the Helsinki University Central Hospital (HUS) Dermatosurgery unit for all below-knee surgeries during 2016, when no preoperative nurse appointments were carried out, and compared it with 2018, when preoperative appointments for risk patients were introduced. The study included 187 patients in 2016 and 179 patients in 2018, of whom 68 (about one third) attended preoperative appointments. At the appointments, risk factors were evaluated, and compression therapy was introduced when possible. The results show complication rates of 13.4% in 2016 vs 10.1% in 2018 (P = .33), despite significantly higher risks in the 2018 patient group. The odds ratio for complications in appointment attendees vs non-attendees was reduced after adjustments to 0.58; however, this was insignificant (P = .47). The odds of complications for skin grafts were considerably higher: 11.33 vs other surgery techniques (P = .00). In conclusion, the introduction of preoperative appointments appeared to reduce complications in below-knee surgery. For graft reconstructions, complication risk is high, even with carefully planned pre- and postoperative care. Further studies are needed to evaluate preventable risk factors of below-knee graft reconstructions.