Fluorescence Diagnostics of Colon Malignant and Premalignant Lesions Using 5-Aminolevulinic Acid

Abstract

Improvement of colon cancer diagnosis is a very important medical problem. Methods of fluorescence diagnosis (FD) with 5-aminolevulinic acid (5-ALA) have been used in detection of early cancer on the surface of mucosa. The objective of the study was to estimate the effectiveness of FD with 5-ALA in the detection of malignant lesions in the colon. From 2008 to 2010 full examinations have been performed in 78 patients suffering from colon polyps. For the study we used drug Alasens based on 5-ALA. Fluorescence colonoscopy with Alasens was made using the visual assessment of fluorescence images in combination with local fluorescence spectroscopy. The results of FD were compared with those of final histopathological study. The application of the method during colonoscopy allows specifying diagnosis, identifying areas of colon tumors transformation, and also showing a place for targeted biopsy. Sensitivity and specificity of FD with Alasens were 94.9% and 62.5%, respectively. The application of local fluorescence spectroscopy as a step of the combined approach allows increasing the specificity of fluorescence colonoscopy from 62.5% up to 93.7%.

Photodynamic diagnosis and photodynamic therapy of colorectal cancer in vitro and in vivo

“…63 Within, another study performed by Filonenko et al (2014) from 2008 to 2010, full PDD examinations were performed on 78 patients suffering from colon polyps using an alasens 5-ALA based PS. 64 Using spectro-uorescence colonoscopy PDD results were compared to patients histopathological results, noting a sensitivity of 94.9% and a specify of 62.5%, suggesting this method of diagnosis was specic at identifying areas of colon tumors transformation, as well as allowed for direct imaging and location of targeted polyps for biopsy. 64 However, in further studies the utilization of alasens 5-ALA PDD in combination with CRC PDT treatment applications proved unsuccessful.…”

“…64 Using spectro-uorescence colonoscopy PDD results were compared to patients histopathological results, noting a sensitivity of 94.9% and a specify of 62.5%, suggesting this method of diagnosis was specic at identifying areas of colon tumors transformation, as well as allowed for direct imaging and location of targeted polyps for biopsy. 64 However, in further studies the utilization of alasens 5-ALA PDD in combination with CRC PDT treatment applications proved unsuccessful. 64 Within, studies performed by Namikawa et al (2015) intraoperative 5-ALA PDD was performed on 26 CRC lesions in 21 patients and 1 g of 5-ALA was administered orally, before surgery.…”

“…64 However, in further studies the utilization of alasens 5-ALA PDD in combination with CRC PDT treatment applications proved unsuccessful. 64 Within, studies performed by Namikawa et al (2015) intraoperative 5-ALA PDD was performed on 26 CRC lesions in 21 patients and 1 g of 5-ALA was administered orally, before surgery. 65 Aer surgical removal polyps were examined using an endoscopic PDD system, and red illuminated-positive polyps were compared with pathological results.…”

Macroscopic and microscopic fluorescence spectroscopy of colorectal benign and malignant lesions - diagnostically important features

“…Up to nowadays, there is a limited number of autofluorescent properties of normal mucosa, benign and malignant GIT lesions' studies using EEM and SFS techniques [9,12]. Some research groups used single excitation sources [4][5][6], few discrete excitation wavelengths [7], or proposed usage of exogenous fluorescent markers to allow good visualization and discrimination of GIT tissue types including usage of photosensitizers [14], or multiplex molecular fluorescent markers [15]. However, such approaches require application of exogenous markers, being more time-consuming and expensive, which decrease their applicability for initial endoscopic observation procedures in patients in situ [2,16,17].…”

The impact of electrode resistance on the biogalvanic characterisation technique

“…Successful imaging typically requires the application of a contrasting agent. Within fluorescence imaging, indocyanine green (ICG) and 5-aminolevulinic acid (5-ALA) have ordinarily been used (Stummer et al 2006 , Schaafsma et al 2011 , Taruttis and Ntziachristos 2012 , Filonenko et al 2014 , Kondo et al 2014 ). A number of alternatives such as photoacoustic imaging are concurrently under investigation (De La Zerda et al 2008 , Taruttis and Ntziachristos 2012 , Mehrmohammadi et al 2013 ).…”