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Background UltraViolet-C (UV-C) lamps may be used to supplement current hospital cleaning and disinfection of surfaces contaminated by SARS-CoV-2. Our aim is to provide some practical indications for the correct use of UV-C lamps. Methods We studied three UV-C lamps, measuring their spatial irradiance and emission over time. We quantify the error that is committed by calculating the irradiation time based exclusively on the technical data of the lamps or by making direct irradiance measurements. Finally, we tested specific dosimeters for UV-C. Results Our results show that the spatial emission of UV-C lamps is strongly dependent on the power of the lamps and on the design of their reflectors. Only by optimizing the positioning and calculating the exposure time correctly, is it possible to dispense the dose necessary to obtain SARS-CoV-2 inactivation. In the absence of suitable equipment for measuring irradiance, the calculated irradiation time can be underestimated. We therefore consider it precautionary to increase the calculated times by at least 20%. Conclusion To use UV-C lamps effectively, it is necessary to follow a few simple precepts when choosing, positioning and verifying the lamps. In the absence of instruments dedicated to direct verification of irradiance, photochromic UV-C dosimeters may represent a useful tool for easily verifying that a proper UV-C dose has been delivered.

We performed an in-depth analysis of the virucidal effect of discrete wavelengths: UV-C (278 nm), UV-B (308 nm), UV-A (366 nm) and violet (405 nm) on SARS-CoV-2. By using a highly infectious titer of SARS-CoV-2 we observed that the violet light-dose resulting in a 2-log viral inactivation is only 10−4 times less efficient than UV-C light. Moreover, by qPCR and fluorescence in situ hybridization (FISH) approach we verified that the viral titer typically found in the sputum of COVID-19 patients can be completely inactivated by the long UV-wavelengths corresponding to UV-A and UV-B solar irradiation. The comparison of the UV action spectrum on SARS-CoV-2 to previous results obtained on other pathogens suggests that RNA viruses might be particularly sensitive to long UV wavelengths. Our data extend previous results showing that SARS-CoV-2 is highly susceptible to UV light and offer an explanation to the reduced incidence of SARS-CoV-2 infection seen in the summer season.SYNOPSISUV-A, UV-B and violet wavelengths kill SARS-CoV-2, supporting the sterilizing effects of the solar pump on human pathogens and the explanation of the seasonality of the COVID-19 pandemic.

We performed an in-depth analysis of the virucidal effect of discrete wavelengths: UV-C (278 nm), UV-B (308 nm), UV-A (366 nm) and violet (405 nm) on SARS-CoV-2. By using a highly infectious titer of SARS-CoV-2 we observed that the violet light-dose resulting in a 2-log viral inactivation is only 104 times less efficient than UV-C light. Moreover, by qPCR (quantitative Polymerase chain reaction) and fluorescence in situ hybridization (FISH) approach we verified that the viral titer typically found in the sputum of COVID-19 patients can be completely inactivated by the long UV-wavelengths corresponding to UV-A and UV-B solar irradiation. The comparison of the UV action spectrum on SARS-CoV-2 to previous results obtained on other pathogens suggests that RNA viruses might be particularly sensitive to long UV wavelengths. Our data extend previous results showing that SARS-CoV-2 is highly susceptible to UV light and offer an explanation to the reduced incidence of SARS-CoV-2 infection seen in the summer season.

Background UltraViolet-C (UV-C) lamps may be used to supplement current hospital cleaning and disinfection of surfaces contaminated by SARS-CoV-2. Our aim is to provide some practical indications for the correct use of UV-C lamps. Methods We studied three UV-C lamps, measuring their spatial irradiance and emission over time. We quantify the error that is committed by calculating the irradiation time based exclusively on the technical data of the lamps or by making direct irradiance measurements. Finally, we tested specific dosimeters for UV-C. Results Our results show that the spatial emission of UV-C lamps is strongly dependent on the power of the lamps and on the design of their reflectors. Only by optimizing the positioning and calculating the exposure time correctly, is it possible to dispense the dose necessary to obtain SARS-CoV-2 inactivation. In the absence of suitable equipment for measuring irradiance, the calculated irradiation time can be underestimated. We therefore consider it precautionary to increase the calculated times by at least 20%. Conclusion To use UV-C lamps effectively, it is necessary to follow a few simple precepts when choosing, positioning and verifying the lamps. In the absence of instruments dedicated to direct verification of irradiance, photochromic UV-C dosimeters may represent a useful tool for easily verifying that a proper UV-C dose has been delivered.

The potential virucidal effects of UV-C irradiation on SARS-CoV-2 were experimentally evaluated for different illumination doses and virus concentrations (1000, 5, 0.05 MOI). Both virus inactivation and replication inhibition were investigated as a function of these parameters.At a virus density comparable to that observed in SARS-CoV-2 infection, an UV-C dose of just 3.7 mJ/cm2 was sufficient to achieve a 3-log inactivation,and complete inhibition of all viral concentrations was observed with 16.9 mJ/cm2. These results could explain the epidemiological trends of COVID-19 and are important for the development of novel sterilizing methods to contain SARS-CoV-2 infection.

To evaluate the effects of display pixel pitch and maximum luminance on intra- and inter-observer reproducibility and observer performance when evaluating chest lesions and bone fractures. This was a multi-institutional study for a retrospective interpretation of selected digital radiography images. Overall, 82 images were selected by senior radiologists, including 50 cases of chest lesions and 32 cases of bone fractures. These images were displayed at two pixel pitches (0.212 and 0.165 mm size pixels) and two maximum luminance values (250 and 500 cd/m2) and reviewed twice by senior and junior radiologists. All the observers had to indicate the likelihood of the presence of the lesions and to rate the relative confidence of their assessment. Cohen Kappa statistic was computed to estimate the reproducibility in correctly identifying lesions; for multi-reader-multi-case (MRMC) analysis, weighted Jackknife Alternative Free-response Receiver Operating Characteristic (wJAFROC) statistical tools was applied. The intra-radiologist and inter-observer reproducibility values were the highest for the 0.165 mm size pixel at 500 cd/m2 display, for both chest lesions and bone fractures evaluations. As regards chest lesions, observer performances were significantly greater with 0.165 mm size pixel display at 500 cd/m2 than with lower maximum luminance and/or larger pixel pitch displays. Concerning bone fractures, the performance obtained with 0.212 mm size pixel display at 250 cd/m2 was statistically lower than that obtained with 0.165 mm sixe pixel display at 500 cd/m2. Our results indicate that an increased maximum luminance level and a decreased pixel pitch of medical-grade display improve the accuracy of detecting both chest lesions and bone fractures.

Background An increase in naturally-occurring porphyrins has been described in the blood of subjects bearing different kinds of tumors, including colorectal, and this is probably related to a systemic alteration of heme metabolism induced by tumor cells. The aim of our study was to develop an artificial neural network (ANN) classifier for early detection of colorectal adenocarcinoma based on plasma porphyrin accumulation and risk factors. Methods We measured the endogenous fluorescence of blood plasma in 100 colorectal adenocarcinoma patients and 112 controls using a conventional spectrofluorometer. Height, weight, personal and family medical history, use of alcohol, red meat, vegetables and tobacco were all recorded. An ANN model was built up from demographic data and from the integral of the fluorescence emission peak in the range 610–650 nm. We used the Receiver Operating Characteristic (ROC) curve to assess performance in distinguishing colorectal adenocarcinoma patients and controls. A liquid chromatography-high resolution mass spectrometry (LC-HRMS) analytical method was employed to identify the agents responsible for native fluorescence. Results The fluorescence analysis indicated that the integral of the fluorescence emission peak in the range 610–650 nm was significantly higher in colorectal adenocarcinoma patients than controls (p

Rationale and Objectives This study evaluates the influence of the calibrated luminance level of medical displays in the detectability of microcalcifications and spiculated lesions in digital breast tomosynthesis images. Materials and Methods Four models of medical displays with calibrated maximum and minimum luminance, respectively, ranging from 500 to 1000 cd/m 2 and from 0.5 to 1.0 cd/m 2 , were investigated. Forty-eight studies were selected by a senior radiologist: 16 with microcalcifications, 16 with spiculated lesions, and 16 without lesions. All images were anonymized and blindly evaluated by one senior and two junior radiologists. For each study, lesion presence or absence and localization statements, interpretative difficulty level, and overall quality were reported. Cohen's kappa statistic was computed between monitors and within or between radiologists to estimate the reproducibility in correctly identifying lesions; for multireader-multicase analysis, the weighted jackknife alternative free-response receiver operating characteristic statistical tool was applied. Results Intraradiologist reproducibility ranged from 0.75 to 1.00. Interreader as well as reader-truth agreement values were >0.80 and higher with the two 1000 cd/m 2 luminance displays than with the lower luminance displays for each radiologist. Performances in the detectability of breast lesions were significantly greater with the 1000 cd/m 2 luminance displays when compared to the display with the lowest luminance value ( P value Conclusions Our findings highlight the role of display luminance level on the accuracy of detecting breast lesions.

The evaluation of incoherent artificial optical radiation (AOR) exposure in hospital environments is a complex task due to the variety of sources available. This study has been designed to provide a proposal for the precautionary assessment of the related risk. This survey suggested that, in our Institution, at least three kinds of AOR sources required specific investigations: ambient lighting, theatre operating lighting and ultraviolet radiation (UVR) sources. For each kind of evaluated sources a specific measurement approach was developed. All irradiance measurements were made using a commercial spectroradiometer. The obtained results were compared with the appropriate exposure limit values (ELVs) defined in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines and adopted by the European Directive 2006/25/EC. The risk related to the evaluated AOR exposure was finally assessed according to our risk matrix. According to our results, the emission of ambient lighting in the actual exposure conditions was always in accordance with the ELVs and the related risk was classifiable as not relevant. The risk related to the exposure to theatre operating lighting resulted not negligible, especially when two or more sources were used with focal spots overlapping on reflective objects. UVR sources emission may represent a health hazard depending, in particular, on the set up of the device containing the source. In case of laminar flow cabinets and closed transilluminators, if the UVR source is well contained within an enclosure with interlock, it presents no risk of exposure. Otherwise, the emission arising from UVR lamps, open transilluminators or sources not provided with interlock, may represent a risk classifiable as high even in the actual working conditions. The personal protective equipment used by workers were also assessed and their suitability was discussed.

In the present work we investigated the possible role of the native fluorescence of blood plasma in the management of colorectal cancer (CRC) and its feasibility as a new tumor marker. Sample of blood was collected from 248 asymptomatic blood donors and from 246 CRC patients. The native fluorescence of blood plasma was measured using a conventional spectrofluorimeter. The intensity of fluorescence of blood plasma at 623 nm (IF623), reasonably ascribed to endogenous porphyrins, was significantly higher in CRC patients than in healthy subjects. The diagnostic capability of IF623 in the discrimination between healthy subjects and CRC patients was tested by Receiving Operating Characteristic (ROC) curve analysis, which resulted in an Area Under the Curve (AUC) of 0.72+/-0.01. Fluorescence measurement of blood plasma might be considered diagnostically useful as a candidate for a new tumor marker for CRC management. The procedure is characterised by a great acceptability and by a very low cost, and might be used in a two-step screening wherein an IF623 positive result is followed by colonoscopy.

Various instruments based on acquisition and elaboration of images of pigmented skin lesions have been developed in an attempt to in vivo establish whether a lesion is a melanoma or not. Although encouraging, the response of these instruments, e.g. epiluminescence microscopy, reflectance spectrophotometry and fluorescence imaging, cannot currently replace the well-established diagnostic procedures. However, in place of the approach to instrumentally assess the diagnosis of the lesion, recent studies suggest that instruments should rather reproduce the assessment by an expert clinician of whether a lesion has to be excised or not. The aim of this study was to evaluate the performance of a spectrophotometric system to mimic such a decision. The study involved 1794 consecutively recruited patients with 1966 doubtful cutaneous pigmented lesions excised for histopathological diagnosis and 348 patients with 1940 non-excised lesions because clinically reassuring. Images of all these lesions were acquired in vivo with a multispectral imaging system. The data set was randomly divided into a train (802 reassuring and 1003 excision-needing lesions, including 139 melanomas), a verify (464 reassuring and 439 excision-needing lesions, including 72 melanomas) and a test set (674 reassuring and 524 excision-needing lesions, including 76 melanomas). An artificial neural network (ANN(1)) was set up to perform the classification of the lesions as excision-needing or reassuring, according to the expert clinicians' decision on how to manage each examined lesion. In the independent test set, the system was able to emulate the clinicians with a sensitivity of 88% and a specificity of 80%. Of the 462 correctly classified as excision-needing lesions, 72 (95%) were melanomas. No major variations in receiver operating characteristic curves were found between the test and the train/verify sets. On the same data set, a further artificial neural network (ANN(2)) was then architected to perform classification of the lesions as melanoma or non-melanoma, according to the histological diagnosis. Having set the sensitivity in recognizing melanoma to 95%, ANN(1) resulted to be significantly better in the classification of reassuring lesions than ANN(2). This study suggests that multispectral image analysis and artificial neural networks could be used to support primary care physicians or general practitioners in identifying pigmented skin lesions that require further investigations.

Different technological tools have been developed to aid in the diagnosis of pigmented skin lesions, including cameras working with conventional RGB colour systems, epiluminescence microscopy and spectrophotometric methods using visible and near infrared wavelengths. All the different procedures should provide in an objective and reproducible fashion quantitative measurements of the colour and shape features of a given skin mole. At present, many devices have been introduced in experimental stages for clinical diagnosis, mainly used to provide to the clinicians an objective, computer-assisted second opinion. As for any diagnostic instruments, optical devices should also be subjected to a dedicated quality assurance protocol in order to evaluate the response repeatability of each device (intra-instrument agreement) and to check the accordance among the responses of different devices (inter-instrument agreement). The aim of this study was to design a quality assurance protocol for optical devices dedicated to image analysis of pigmented skin lesions and, in case, to detect cutaneous melanoma by using suitable tissue-like phantoms as standard references that enable testing of both hardware and software components. As an example, we report the results of intra-instrument and inter-instrument agreement when the protocol was applied on a series of 30 SpectroShade instruments, a novel optical device based on multi-spectral image analysis of colour and shape features of pigmented skin lesion.

Aims and background We designed a comparative planning study aimed at quantifying the advantages of intensity-modu-lated radiotherapy (IMRT) over the conventional 3-field technique (3FT) and a 5-field conformal technique (5FCT) for head and neck (HN) cancer. Methods We selected 9 patients treated at our institution with curative radiotherapy for a HN cancer. For all cases 4 plans were generated: 2 plans using the “standard” techniques (3FT and 5FCT), a third plan using IMRT, and a fourth “mixed” plan using IMRT followed by a conventional boost. Results Our study confirmed literature data on the ability of IMRT to significantly decrease the dose received by organs at risk, compared with previous techniques. Target coverage was systematically better with 5FCT and IMRT than with 3FT. However, the increase in coverage of both PTV2 and PTV1 was only about 3-5% and this was achieved at the price of a similar increase in maximum dose (D1%). Volumetric parameters (V100%, V95%) were much more sensitive in detecting the improvement with IMRT. Conclusions The improvement of target coverage attained by IMRT, as compared with conventional and conformal techniques, might be overestimated by data currently available in the medical literature. If treatment with conventional techniques is planned using all tools provided by currently available fully 3-D planning systems, excellent target coverage can be obtained.

The aim of this research was to evaluate the performance of a new spectroscopic system in the diagnosis of melanoma. This study involves a consecutive series of 1278 patients with 1391 cutaneous pigmented lesions including 184 melanomas. In an attempt to approach the 'real world' of lesion population, a further set of 1022 not excised clinically reassuring lesions was also considered for analysis. Each lesion was imaged in vivo by a multispectral imaging system. The system operates at wavelengths between 483 and 950 nm by acquiring 15 images at equally spaced wavelength intervals. From the images, different lesion descriptors were extracted related to the colour distribution and morphology of the lesions. Data reduction techniques were applied before setting up a neural network classifier designed to perform automated diagnosis. The data set was randomly divided into three sets: train (696 lesions, including 90 melanomas) and verify (348 lesions, including 53 melanomas) for the instruction of a proper neural network, and an independent test set (347 lesions, including 41 melanomas). The neural network was able to discriminate between melanomas and non-melanoma lesions with a sensitivity of 80.4% and a specificity of 75.6% in the 1391 histologized cases data set. No major variations were found in classification scores when train, verify and test subsets were separately evaluated. Following receiver operating characteristic (ROC) analysis, the resulting area under the curve was 0.85. No significant differences were found among areas under train, verify and test set curves, supporting the good network ability to generalize for new cases. In addition, specificity and area under ROC curve increased up to 90% and 0.90, respectively, when the additional set of 1022 lesions without histology was added to the test set. Our data show that performance of an automated system is greatly population dependent, suggesting caution in the comparison with results reported in the literature. In our opinion, scientific reports should provide, at least, the median values of thickness and dimension of melanomas, as well as the number of small (6 mm) melanomas.

Early detection and prompt excision of cutaneous melanoma is of paramount importance to improve patient survival, and the clinician should be aware of the clinical features that suggest the presence of a malignant lesion. The clinical diagnosis is mainly based on observation of the colour and shape of a given skin lesion. Unfortunately, evaluation of a pigmented lesion is to a large extent subjective and is closely related to the experience of the clinician. To overcome this problem, optical imaging techniques using different instrumentation (i.e. colour video camera, epiluminescence microscopy, reflectance spectrophotometry) and computer image analysis have been proposed in an attempt to provide quantitative measurements in an objective and reproducible fashion. The different procedures employed to perform the diagnosis automatically all have a common denominator: mimicking the eye and the brain of the clinician by image processing and computerized analysis programs, respectively. Sensitivity and specificity data reported in the literature suggest that the computer-based diagnosis of melanoma does not greatly differ from the diagnostic capability of an expert clinician, and is independent of the optical acquisition method employed to analyse the lesions. Most of the computer-processed morphometric variables useful in automated diagnosis are not recognizable nor can be objectively evaluated by the human eye, except that of lesion dimension. However, several questions should be answered before assessing the actual usefulness, including the potential and limitations, of computer-based diagnostic procedures. The purpose of this study was to briefly review the different kinds of instrumentation being used to diagnose melanoma, and to raise questions and whenever possible provide answers in an attempt to establish whether there will be a future for these computerized systems.

Realistic, pigmented skin simulants (“phantoms”) can be useful in optimizing dermal laser procedures and for laser surgical training. Diffuse reflectance of skin pigmented lesions depends on the amount and distribution of the absorbing/diffusing chromophores, mainly hemoglobin and melanin, embedded in the skin layers. The reason why diffuse reflectance of benign melanocytic lesions is different from that of melanoma is still unclear. In an attempt to explain such a difference, phantoms able to simulate the diffuse reflectance of both types of pigmented skin lesions have been developed. The basic material for lesion- and skin-like phantoms is a transparent silicone rubber in which Al2O3 particles, melanin, and different types of cosmetic powders were added as diffusers and absorbers. Slabs with a minimal thickness of 100 μm were prepared to mimic lesions with different thicknesses and the skin layered structures. The optical properties of tissue phantom components, i.e., total attenuation, absorption, and ...

Background: Successful treatment of melanoma depends directly on early diagnosis. Such a diagnosis is based on clinical examination and dermatoscopy. Recently, automated instruments for melanoma detection are under development. Objective: To prospectively evaluate the diagnostic possibilities provided by clinical and dermatoscopic examinations and by a computerized telespectrophotometric system (TS). Methods: The study involves a consecutive series of 298 patients with 313 cutaneous pigmented lesions (66 melanomas and 247 non-melanoma lesions). Each lesion was subjected to the triple diagnostic evaluation, before surgery. Results were expressed in terms of sensitivity and specificity of each kind of evaluation. Results: Clinical evaluation had sensitivity and specificity values of 86 and 77%, respectively, whereas dermatoscopy gave corresponding values of 91 and 74%. TS assessment resulted in a sensitivity of 80% and a specificity of 49%. Differences between clinical and dermatoscopic diagnoses lacked statistical significance (p = 0.22), whereas there was a significant difference comparing both clinical and TS evaluations (p < 0.01) and dermatoscopic and TS evaluations (p < 0.01). Combining clinical and dermatoscopic evaluations, a sensitivity of 97% was achieved. Addition of TS has not changed this figure. Conclusions: Results of this study confirm and stress the importance of dermatoscopy in the diagnosis of melanoma. Clinical evaluation coupled with dermatoscopy can be considered the cornerstone of such a diagnosis. Although TS is able to achieve interesting results, at present it cannot significantly compete with any of the other tested methods.

Amelanotic cutaneous melanoma (ACM) often defies clinical diagnosis because of the lack of pigmentation. In an attempt to find diagnostic clues, we retrospectively studied the clinical features of 15 thin (< 1 mm thick or Clark level I) ACM lesions. The clinical features of early ACMs are identified and illustrated to enable early diagnosis and cure of these lesions. The typical early lesion presents as an asymmetric macula, which may be uniformly pinkish or reddish or, more often, has faint light pigmentation (tan, brown or grey) at the periphery; it has borders that may be well- or ill-defined. In our study, these features suggested the correct clinical diagnosis in only a minority (40%) of cases. Nine cases in this series were also subjected to dermatoscopy. By this technique we identified, as constant feature, the presence of small red dots, evenly distributed or grouped on a whitish or pink-red background. Our results show the importance of dermatoscopy in the evaluation of equivocal pink or reddish lesions. Red dots seen with this technique can be an important sign for the diagnosis of thin ACM. Since this sign does not appear to be pathognomonic, the presence of an associated pigmentary network can be decisive in the differential diagnosis.

Aims and Background Noninvasive diagnostic methods such as dermoscopy, sonography, palpation or combined approaches have been developed in an attempt to preoperatively estimate melanoma thickness. However, the clinical presentation is often complex and the evaluation subjective. Multispectral image analysis of melanomas allows selection of features related to the content and distribution of absorbers, mainly melanin and hemoglobin, present within the lesion. Hence, it is reasonable to assume that the same features might be useful to predict melanoma thickness. Methods A multispectral image system was used to analyze in vivo 1939 pigmented skin lesions. The lesion selection was based on clinical and/or dermoscopic features that supported a suspicion for melanoma. All the lesions were then subjected to surgery for the histopathological diagnosis, and 250 were melanomas. From the multispectral images of the melanomas, we selected 12 features, seven of which were used to train and test an artificial neural network on 155 and 95 melanomas, respectively. Results Sensitivity (i.e., melanoma ≥0.75 mm thick correctly classified) and specificity (i.e., melanoma Conclusions Our approach provides results similar to those obtained with other methods and has the advantage that it is not related to the expertise of the clinician. In addition, the physical interpretation of the selected features suggests a possible role of spectrophotometry as an objective method to study the natural history of the early phases of the disease.

The complex inner layered structure of skin influences the photon diffusion inside the cutaneous tissues and determines the reflectance spectra formation. Phantoms are very useful tools to understand the biophysical meaning of parameters involved in light propagation through the skin. To simulate the skin reflectance spectrum, we realized a multilayered skin-like phantom and a multilayered skin phantom with a melanoma-like phantom embedded inside. Materials used were Al(2)O(3) particles, melanin of sepia officinalis and a calibrator for haematology systems dispersed in transparent silicon. Components were optically characterized with indirect techniques. Reflectance phantom spectra were compared with average values of in vivo spectra acquired on a sample of 573 voluntary subjects and 132 pigmented lesions. The phantoms' reflectance spectra agreed with those measured in vivo, mimicking the optical behaviour of the human skin. Further, the phantoms were optically stable and easily manageable, and represented a valid resource in spectra formation comprehension, in diagnostic laser applications and simulation model implementation, such as the Monte Carlo code for non-homogeneous media.

Theoretical models of the signal detected by a CCD camera during hyperspectral imaging with an integrating sphere are derived using Markov chains with absorbing states. The models provide analytical expressions that describe the real reflectance of the sample as a function of the detected signal at each pixel of the image. Validation of the models was done by using reflectance standards and tissue phantoms. The models provide accurate analytical solutions for samples and spheres that are near-Lambertian reflectors.

Our aim in the present research is to investigate the diagnostic performance of artificial neural networks (ANNs) applied to multispectral images of cutaneous pigmented skin lesions as well as to compare this approach to a standard traditional linear classification method, such as discriminant function analysis. This study involves a series of 534 patients with 573 cutaneous pigmented lesions (132 melanomas and 441 nonmelanoma lesions). Each lesion was analyzed by a telespectrophotometric system (TS) in vivo, before surgery. The system is able to acquire a set of 17 images at selected wavelengths from 400 to 1040 nm. For each wavelength, five lesion descriptors were extracted, related to the criteria of the ABCD (for asymmetry, border, color, and dimension) clinical guide for melanoma diagnosis. These variables were first reduced in dimension by the use of factor analysis techniques and then used as input data in an ANN. Multivariate discriminant analysis (MDA) was also performed on the same dataset. The whole dataset was split into two independent groups: i.e., train (the first 400 cases, 95 melanomas) and verification set (last 173 cases, 37 melanomas). Factor analysis was able to summarize the data structure into ten variables, accounting for at least 90% of the original parameters variance. After proper training, the ANN was able to classify the population with 80% sensitivity, 72% specificity, and 78% sensitivity, 76% specificity for the train and validation set, respectively. Following ROC analysis, area under curve (AUC) was 0.852 (train) and 0.847 (verify). Sensitivity and specificity values obtained by the standard discriminant analysis classifier resulted in a figure of 80% sensitivity, 60% specificity and 76% sensitivity, 57% specificity for the train and validation set, respectively. AUC for MDA was 0.810 and 0.764 for the train and verify set, respectively. Classification results were significantly different between the two methods both for diagnostic scores and model stability, which was worse for MDA.

Successful treatment of melanoma depends directly on early diagnosis. Such a diagnosis is based on clinical examination and dermatoscopy. Recently, automated instruments for melanoma detection are under development.To prospectively evaluate the diagnostic possibilities provided by clinical and dermatoscopic examinations and by a computerized telespectrophotometric system (TS).The study involves a consecutive series of 298 patients with 313 cutaneous pigmented lesions (66 melanomas and 247 non-melanoma lesions). Each lesion was subjected to the triple diagnostic evaluation, before surgery. Results were expressed in terms of sensitivity and specificity of each kind of evaluation.Clinical evaluation had sensitivity and specificity values of 86 and 77%, respectively, whereas dermatoscopy gave corresponding values of 91 and 74%. TS assessment resulted in a sensitivity of 80% and a specificity of 49%. Differences between clinical and dermatoscopic diagnoses lacked statistical significance (p = 0.22), whereas there was a significant difference comparing both clinical and TS evaluations (p0.01) and dermatoscopic and TS evaluations (p0.01). Combining clinical and dermatoscopic evaluations, a sensitivity of 97% was achieved. Addition of TS has not changed this figure.Results of this study confirm and stress the importance of dermatoscopy in the diagnosis of melanoma. Clinical evaluation coupled with dermatoscopy can be considered the cornerstone of such a diagnosis. Although TS is able to achieve interesting results, at present it cannot significantly compete with any of the other tested methods.

Background and objective Modeling of light transport in tissue requires development of theoretical models and experimental procedures, as well as tissue-simulating phantoms. Our purpose was to develop a phantom that matches the optical characteristics of human skin in the visible and near infrared spectral range. Study design/materials and methods The phantom consists of a transparent silicone rubber in which Al(2)O(3) particles and a cosmetic powder are embedded. Layers with thickness as thin as 0.1 mm can be made. The optical properties of Al(2)O(3) particles and cosmetic powder, i.e., total attenuation, absorption and scattering coefficients, and phase function, have been determined in the visible and near infrared spectral range, by using direct and indirect techniques. Results By varying the concentration of scattering and absorbing particles, tissue-like layers can be produced with predictable optical properties. In particular, mixing at suitable concentration Al(2)O(3) particles and cosmetic powder with the silicone rubber, the optical properties of human skin have been simulated over a range of wavelengths from 400 to 1,000 nm. The comparison between the phantom diffuse reflectance spectrum and that of human skin, averaged over a sample of 260 patients, showed a good agreement. Conclusion The proposed technique allows to produce a stable and reproducible phantom, with accurately predictable optical properties, easy to make and to handle. This phantom is a useful tool for numerous applications involving light interaction with biologic tissue.

Aim and background Fluorescence spectroscopy of biomolecules is considered a promising method to discriminate in vivo normal tissue from malignant tissue at various sites including breast, cervix, lung, and colon. However, only few studies have been reported on the feasibility of exploiting fluorescence spectroscopy of blood to characterize pathological changes usable in diagnostic oncology. In this study, the fluorescence characteristics of human blood plasma have been studied in the visible spectral range in an attempt to discriminate patients with colorectal cancer from subjects of a control population. Patients and methods The study involved 341 subjects, including 169 blood donors with no evidence of disease, 143 patients bearing colorectal adenocarcinomas (36 in the colon, 38 in the sigmoid colon and 69 in the rectum), 11 patients with local relapse, 10 patients with familial adenomatous polyposis and 8 with single adenomas. Blood samples were collected from all subjects and plasma fluorescence spectrum was analyzed using a conventional spectrofluorometer. Results The intensity of a fluorescence emission peak around 615–635 nm, which could reasonably be ascribed to endogenous porphyrins, was significantly different between patients bearing colorectal cancer and blood donors. The diagnostic capacity of the method was tested by ROC analysis, which resulted in an area under the curve of 0.72, close to that reported for the CEA test. Conclusion These results, although preliminary, suggest the potential of fluorescence measurements of blood plasma as an additional method for diagnostic application in colon cancer.