Optical transfer diagnosis of pigmented lesions.

BACKGROUND: Optical transfer diagnosis is a novel melanoma detection system that uses morphologic-physiologic mapping. OBJECTIVE: To further evaluate the potential of optical transfer diagnosis for distinguishing benign from malignant pigmented melanocytic neoplasms. METHODS AND MATERIALS: Ninety-four patients with pigmented lesions suggestive of melanoma were referred for optical transfer diagnosis. After lesions were scanned with the camera, they were removed for histopathologic examination by two dermatopathologists each. From the recorded images, morphologic-physiologic maps were created with prediction models of light absorption and scattering by chromophores such as hemoglobin, keratin, and melanin at different epidermal and dermal depths. Entropy and relative entropy values derived from the morphologic-physiologic maps and a set of pure morphologic parameters were analyzed for output prediction of melanoma versus nonmelanoma. Dermoscopic images were reviewed and scored using the color, architecture, symmetry, and homogeneity (CASH) algorithm to assign a value of clinical atypia. RESULTS Of the 118 scanned and biopsied lesions (median CASH score 8), 11 were identified as melanoma or atypical melanocytic hyperplasia consistent with melanoma. For identification of melanomas, optical transfer diagnosis had a sensitivity of 100% and a specificity of 90%. CONCLUSIONS: This technology continues to be a promising adjunct to clinical skin cancer screening.

Optical transfer diagnosis of pigmented lesions: a pilot study.

OBJECTIVE: To evaluate the potential of a novel imaging technology, optical transfer diagnosis (OTD), for differentiation of benign from malignant pigmented melanocytic lesions. DESIGN: Patients with pigmented lesions suspicious for melanoma were referred for OTD. After scanning, lesions were biopsied for histopathologic examination, each by two separate dermatopathologists. To create morphologic-physiologic maps, the imaging system used the morphologic and physiologic parameters derived from prediction models of light absorption and scattering by chromophores such as hemoglobin, keratin, and melanin at different epidermal and dermal depths. The relative entropies were analyzed for output prediction of malignancy vs. nonmalignancy. SETTING: General dermatology clinic in a tertiary care academic medical center. PATIENTS: Fifty patients with suspected melanoma. INTERVENTION: OTD of pigmented lesions suspicious for melanoma, followed by biopsies for histopathologic examination. MAIN OUTCOME MEASURES: Histopathologic confirmation of malignant lesions identified by OTD as melanoma. RESULTS: Sixty-three pigmented suspicious lesions were scanned before being biopsied for histopathologic examination by the two dermatopathologists. Of the 63 lesions, five were identified as melanoma and 58 were found to be benign (including three seborrheic keratoses and 55 melanocytic nevi). OTD was able to identify the malignant lesions with 100% sensitivity and 94.8-96.6% specificity. CONCLUSIONS: Further study is indicated, but this technology is a promising adjunct to clinical skin cancer screening. Additionally, if the physiologic prediction models can be validated, OTD may facilitate the noninvasive study of some aspects of cutaneous physiology.

Changes in human skin after topical PDT with hexyl aminolevulinate.

BACKGROUND: Photodynamic therapy (PDT) induces physiological changes in human skin, but details and kinetics are not known. METHODS: Changes in human skin induced by PDT with red light in the presence of topically applied cream with the hexyl aminolevulinate (HAL) were investigated in the skin of five healthy volunteers. In addition to testing the effects of HAL-PDT three control studies were performed on the volunteers: (A) the HAL containing cream was applied to the skin without light exposure; (B) the cream without HAL was applied to the skin; (C) the skin was exposed to light in the absence of the cream. Reflectance spectra of the skin were measured in the wavelength region 300-600 nm before and after treatment. An advanced and new inverse radiative transfer model was used to determine changes induced in a number of skin parameters. RESULTS: The main discoveries were that the dermal blood concentration increased immediately after PDT, reached a maximum after 1-2 days, and then decreased. The blood oxygenation increased significantly immediately after PDT and then decreased. After PDT the melanosome concentration in the upper epidermis increased steadily. No such changes were observed in the control sites. CONCLUSIONS: Our results imply that HAL-PDT leads to increased vascularisation, oxygenation and melanin formation.