Visualization of basal cell carcinoma by fluorescence diagnosis and independent component analysis

Cost-effective device for locating and circumscribing superficial tumors with contrast enhancement and fluorescence quantification

BACKGROUND

Two Bispectral contrast enhancement approaches for the fluorescence diagnosis with chlorine-e6 and a wide field-of-view imaging system with fluorescence excitation at 405 nm and time-resolved background suppression were analyzed and compared.

METHODS

Two techniques for the contrast enhancement of a fluorescent video system (Red/Green (R/G) ratio and Red-Green (R-G)) with time-resolved background suppression for fluorescent diagnosis (FD) were tested in four patients with basal cell carcinoma (BCC).

RESULTS

The results of both contrast enhancement methods were compared for the diagnostic efficiency for FD of BCC. Both techniques successfully determined the boundaries of the lesions and the fluorescence intensity.

CONCLUSIONS

Both contrast enhancement modes have proven effective in identifying tumor borders in cases of low contrast in BCC FD with Ce6. While the Red/Green (R/G) mode provides sharper lesion borders, the Red minus Green (R-G) mode visualizes more fluorescent features and makes it easier to assess the lesion margins.

Monitoring PDT effects in basal cell carcinoma treatment using thermal imaging

BACKGROUND

One of the most frequent type of malignant skin lesion (almost 95 percent of all skin tumours) is basal cell carcinoma (BCC). It is often treated by radiotherapy using ionizing radiation as well by photodynamic therapy (PDT) which is a selective method directed only on cancer cells and well tolerated by patients.

MATERIALS AND METHODS

Eight male patients of the Department and Clinic of Internal Diseases, Angiology and Physical Medicine in Bytom, Medical University of Silesia, in Katowice, Poland suffering from basal cell carcinoma were monitored by thermovision during the photodynamic therapy. All lesions were diagnosed as superficial were confirmed by histopathological examination.

RESULTS

The dynamics of changes observed in the isotherm area during the therapy can provide physicians with additional information. The significant increase of observed isotherm area in comparison to the lesion area diagnosed by a physician was confirmed, which may be connected with the increased metabolism processes occurring in the tissue surrounded the lesion.

CONCLUSION

The obtained results based on the temperature gradient changes in the lesion vicinity area may bring some new information describing the range of biochemical and physiological processes occurring during photodynamic therapy.

Impact of various color LED flashlights and different lighting source to skin distances on the manual and the computer-aided detection of basal cell carcinoma borders

BACKGROUND/AIMS

Quantitative analysis based on digital skin image has been proven to be helpful in dermatology. Moreover, the borders of the basal cell carcinoma (BCC) lesions have been challenging borders for the automatic detection methods. In this work, a computer-aided dermatoscopy system was proposed to enhance the clinical detection of BCC lesion borders.

METHODS

Fifty cases of BCC were selected and 2000 pictures were taken. The lesion images data were obtained with eight colors of flashlights and in five different lighting source to skin distances (SSDs). Then, the image-processing techniques were used for automatic detection of lesion borders. Further, the dermatologists marked the lesions on the obtained photos.

RESULTS

Considerable differences between the obtained values referring to the photographs that were taken at super blue and aqua green color lighting were observed for most of the BCC borders. It was observed that by changing the SSD, an optimum distance could be found where that the accuracy of the detection reaches to a maximum value.

CONCLUSION

This study clearly indicates that by changing SSD and lighting color, manual and automatic detection of BCC lesions borders can be enhanced.

In-vivo optical detection of cancer using chlorin e6--polyvinylpyrrolidone induced fluorescence imaging and spectroscopy

Background

Photosensitizer based fluorescence imaging and spectroscopy is fast becoming a promising approach for cancer detection. The purpose of this study was to examine the use of the photosensitizer chlorin e6 (Ce6) formulated in polyvinylpyrrolidone (PVP) as a potential exogenous fluorophore for fluorescence imaging and spectroscopic detection of human cancer tissue xenografted in preclinical models as well as in a patient.

Methods

Fluorescence imaging was performed on MGH human bladder tumor xenografted on both the chick chorioallantoic membrane (CAM) and the murine model using a fluorescence endoscopy imaging system. In addition, fiber optic based fluorescence spectroscopy was performed on tumors and various normal organs in the same mice to validate the macroscopic images. In one patient, fluorescence imaging was performed on angiosarcoma lesions and normal skin in conjunction with fluorescence spectroscopy to validate Ce6-PVP induced fluorescence visual assessment of the lesions.

Results

Margins of tumor xenografts in the CAM model were clearly outlined under fluorescence imaging. Ce6-PVP-induced fluorescence imaging yielded a specificity of 83% on the CAM model. In mice, fluorescence intensity of Ce6-PVP was higher in bladder tumor compared to adjacent muscle and normal bladder. Clinical results confirmed that fluorescence imaging clearly captured the fluorescence of Ce6-PVP in angiosarcoma lesions and good correlation was found between fluorescence imaging and spectral measurement in the patient.

Conclusion

Combination of Ce6-PVP induced fluorescence imaging and spectroscopy could allow for optical detection and discrimination between cancer and the surrounding normal tissues. Ce6-PVP seems to be a promising fluorophore for fluorescence diagnosis of cancer.