The effect of reactive atypia/inflammation on the laser-induced fluorescence diagnosis of non-dysplastic Barrett's esophagus.

BACKGROUND AND OBJECTIVES: Differential Normalized Fluorescence (DNF) technique has been used to distinguish high-grade dysplasia from non-dysplastic Barrett's esophagus. This technology may assist gastroenterologists in targeting biopsies, reducing the number of biopsies using the standard protocol. In the presence of reactive atypia/inflammation, it becomes difficult for the pathologist to differentiate non-dysplastic Barrett's esophagus from Barrett's esophagus with low-grade dysplasia. Before DNF technique may be used to guide target biopsies, it is critical to know whether reactive atypia/inflammation in non-dysplastic Barrett's may result in false positives. This study was conducted to determine whether DNF technique is adversely affected by the presence of reactive atypia/inflammation in non-dysplastic Barrett's esophagus resulting in false positives. STUDY DESIGN/MATERIALS AND METHODS: Four hundred ten-nanometer laser light was used to induce autofluorescence of Barrett's mucosa in 49 patients. The clinical study included 37 males and 12 females. This was a blinded retrospective data analysis study. A total of 303 spectra were collected and matched to non-dysplastic Barrett's biopsy results. One hundred seventy-five spectra were collected from areas with a pathology of non-dysplastic Barrett's esophagus with reactive atypia/inflammation. One hundred twenty-eight spectra were collected from areas with non-dysplastic Barrett's esophagus without reactive changes/inflammation. The spectra were analyzed using the DNF Index at 480 nm and classified as positive or negative using the threshold of -0.75 × 10(-3). RESULTS: Using DNF technique, 92.6% of non-dysplastic samples with reactive atypia/inflammation were classified correctly (162/175). 92.2% of non-dysplastic samples without reactive atypia/inflammation were classified correctly (118/128). Comparing the ratios of false positives among the two sample groups, there was not a statistically significant difference between the two groups. CONCLUSION: Using DNF technique for classification of non-dysplastic Barrett's mucosa does not result in false-positive readings due to reactive atypia/inflammation. Target biopsies guided by DNF technique may drastically reduce the number of pinch biopsies using the standard biopsy protocol.

Detection of dysplasia in Barrett's esophagus with in vivo depth-resolved nuclear morphology measurements.

BACKGROUND & AIMS: Patients with Barrett's esophagus (BE) show increased risk of developing esophageal adenocarcinoma and are routinely examined using upper endoscopy with biopsy to detect neoplastic changes. Angle-resolved low coherence interferometry (a/LCI) uses in vivo depth-resolved nuclear morphology measurements to detect dysplasia. We assessed the clinical utility of a/LCI in the endoscopic surveillance of patients with BE. METHODS: Consecutive patients undergoing routine surveillance upper endoscopy for BE were recruited at 2 endoscopy centers. A novel, endoscope-compatible a/LCI system measured the mean diameter and refractive index of cell nuclei in esophageal epithelium at 172 biopsy sites in 46 patients. At each site, an a/LCI measurement was correlated with a concurrent endoscopic biopsy specimen. Each biopsy specimen was assessed histologically and classified as normal, nondysplastic BE, indeterminate for dysplasia, low-grade dysplasia (LGD), or high-grade dysplasia (HGD). The a/LCI data from multiple depths were analyzed to evaluate its ability to differentiate dysplastic from nondysplastic tissue. RESULTS: Pathology characterized 5 of the scanned sites as HGD, 8 as LGD, 75 as nondysplastic BE, 70 as normal tissue types, and 14 as indeterminate for dysplasia. The a/LCI nuclear size measurements separated dysplastic from nondysplastic tissue at a statistically significant (P < .001) level for the tissue segment 200 to 300 µm beneath the surface with an accuracy of 86% (147/172). A receiver operator characteristic analysis indicated an area under the curve of 0.91, and an optimized decision point gave 100% (13/13) sensitivity and 84% (134/159) specificity. CONCLUSIONS: These preliminary data suggest a/LCI is accurate in detecting dysplasia in vivo in patients with BE.

Photodynamic therapy of Barrett's esophagus: ablation of Barrett's mucosa and reduction in p53 protein expression after treatment.

BACKGROUND: The effectiveness of photodynamic therapy (PDT) for ablation of high grade dysplasia (HGD) in Barrett's esophagus (BE) is typically reported histologically. Following successful PDT, Barrett's mucosa is replaced with neosquamous mucosa. The objective of this study was to compare the expression of p53 protein in neosquamous mucosa as compared to that in HGD samples not treated with PDT. PATIENTS AND METHODS: The patients were divided into two groups. Group I patients (n = 12) had been treated with PDT for HGD and provided 23 biopsy samples of neosquamous mucosa. Group II patients (n = 10) had not received any ablative therapies for BE and provided 14 HGD samples. The immunohistochemical (IHC) staining for p53 protein was performed using mouse anti-human monoclonal antibody DO-1. The degree of p53 protein expression in the cell nuclei was scored using an established IHC scoring system (0 for negative samples and range of 2 to 8 for positive samples). RESULTS: The HGD samples showed diffuse strong p53 staining. The median IHC score for HGD was 7.0. The median IHC score for neosquamous mucosa following PDT was 4.0, with positive scores indicating weak staining in the basal layer of the neosquamous samples. There was significantly lower p53 expression in the neosquamous samples compared to that in the HGD samples (p < 0.001). CONCLUSION: Significantly lower p53 protein expression was detected in neosquamous mucosa of patients who had received PDT for HGD, suggesting a decreased risk for neoplastic progression after treatment.

Circumferential ablation of Barrett's esophagus that contains high-grade dysplasia: a U.S. Multicenter Registry.

BACKGROUND: The management strategies for Barrett's esophagus (BE) that contains high-grade dysplasia (HGD) include intensive endoscopic surveillance, photodynamic therapy, thermal ablation, EMR, and esophagectomy. OBJECTIVE: To assess the safety and effectiveness of endoscopic circumferential balloon-based ablation by using radiofrequency energy for treating BE HGD. DESIGN: Multicenter U.S. registry. SETTING: Sixteen academic and community centers; treatment period from September 2004 to March 2007. PATIENTS: Patients with histologic evidence of intestinal metaplasia (IM) that contained HGD confirmed by at least 2 expert pathologists. A prior EMR was permitted, provided that residual HGD remained in the BE region for ablation. INTERVENTION: Endoscopic circumferential ablation with follow-up esophageal biopsies to assess the histologic response to treatment. OUTCOMES: Histologic complete response (CR) end points: (1) all biopsy specimen fragments obtained at the last biopsy session were negative for HGD (CR-HGD), (2) all biopsy specimens were negative for any dysplasia (CR-D), and (3) all biopsy specimens were negative for IM (CR-IM). RESULTS: A total of 142 patients (median age 66 years, interquartile range [IQR] 59-75 years) who had BE HGD (median length 6 cm, IQR 3-8 cm) underwent circumferential ablation (median 1 session, IQR 1-2). No serious adverse events were reported. There was 1 asymptomatic stricture and no buried glands. Ninety-two patients had at least 1 follow-up biopsy session (median follow-up 12 months, IQR 8-15 months). A CR-HGD was achieved in 90.2% of patients, CR-D in 80.4%, and CR-IM in 54.3%. LIMITATIONS: A nonrandomized study design, without a control arm, a lack of centralized pathology review, ablation and biopsy technique not standardized, and a relatively short-term follow-up. CONCLUSIONS: Endoscopic circumferential ablation is a promising modality for the treatment of BE that contains HGD. In this multicenter registry, the intervention safely achieved a CR for HGD in 90.2% of patients at a median of 12 months of follow-up.

Development of a synchronous fluorescence imaging system and data analysis methods.

Although conventional autofluorescence spectroscopy, in which fluorescence emission spectra are recorded for fixed excitation wavelengths, has demonstrated good performance in tissue diagnosis, it suffers from prolonged data acquisition time and broad-band fluorescence features. Synchronous spectroscopy has been proposed to overcome the limitations of conventional fluorescence spectroscopy but has not been applied to imaging for tissue diagnosis in vivo. Our group has developed a synchronous fluorescence imaging system to combine the great diagnostic potential of synchronous spectroscopy and the large field of view of imaging for cancer diagnosis. This system has been tested in a mouse skin model to capture synchronous fluorescence images. A simple discriminant analysis method and a more complicated multi-variate statistical method have been developed to generate a single diagnostic image from a large number of raw fluorescence images. Moreover, it was demonstrated that the diagnostic image generated from synchronous data is comparable to that generated from full spectral data in classification accuracy.

Porfimer sodium photodynamic therapy for management of Barrett's esophagus with high-grade dysplasia.

Porfimer sodium photodynamic therapy (ps-PDT) for Barrett's esophagus is a powerful endoscopic treatment that can eliminate high-grade dysplasia (HGD) and Barrett's mucosa and reduce the risk of development of cancer in these patients. Ps-PDT typically results in destruction of Barrett's esophagus in the majority of the treated area. However, residual small island of Barrett's mucosa may persist after PDT. Therefore, adjuvant thermal ablation should be available during follow-up endoscopies for ablation of residual islands of Barrett's mucosa. PDT should be applied concurrent with effective proton pump inhibitor therapy. This article provides a practical guide for application of porfimer sodium balloon PDT for management of Barrett's esophagus with HGD. Recommendations are provided for patient selection and screening, delivery of PDT to include light dosimetry, methodology for follow-up endoscopies, as well as discussing the potential side effects and complications.

Development of an advanced hyperspectral imaging (HSI) system with applications for cancer detection.

An advanced hyper-spectral imaging (HSI) system has been developed having obvious applications for cancer detection. This HSI system is based on state-of-the-art liquid crystal tunable filter technology coupled to an endoscope. The goal of this unique HSI technology being developed is to obtain spatially resolved images of the slight differences in luminescent properties of malignant versus non-malignant tissues. In this report, the development of the instrument is discussed and the capability of the instrument is demonstrated by observing mouse carcinomas in-vivo. It is shown that the instrument successfully distinguishes between normal and malignant mouse skin. It is hoped that the results of this study will lead to advances in the optical diagnosis of cancer in humans.

An AOTF-based dual-modality hyperspectral imaging system (DMHSI) capable of simultaneous fluorescence and reflectance imaging.

An acousto-optic tunable filter (AOTF)-based system for dual-modality hyperspectral imaging (DMHSI) has been developed for use in characterization of normal and malignant mouse tissue. The system consists of a laser, endoscope, AOTF, and two cameras coupled with optics and electronics. Initial results show that the system can delineate normal and malignant mouse tissues real-time. The analysis shows that malignant tissues consistently exhibit less fluorescent intensity in the wavelength band from 440 to 540 nm with a peak intensity of around 490 nm. The analysis also shows key spectroscopic differences between normal and malignant tissues. Further, these results are compared to real-time spectroscopic data and show good correlation.

An educational tool for photodynamic therapy of Barrett esophagus with high-grade dysplasia: from screening through follow-up.

Photodynamic therapy using a centering balloon was recently approved by the Food and Drug Administration for ablation of Barrett esophagus with high-grade dysplasia. This article is an educational tool for the photodynamic therapy team, addressing four important steps involved with photodynamic therapy: screening for potential patients, patient education, treatment using the centering balloon, and follow-up after treatment. Each step ensures proper care for the patient requiring photodynamic therapy.

Optimization of light dosimetry for photodynamic therapy of Barrett's esophagus: efficacy vs. incidence of stricture after treatment.

BACKGROUND: Photodynamic therapy (PDT) may be used to ablate high-grade dysplasia/early stage cancer (HGD/T1) in patients with Barrett's esophagus. PDT may result in esophageal stricture. This nonrandomized, unblinded, dose de-escalation study in consecutive patients was designed to determine the lowest light dose effective for ablation of HGD/T1 while reducing the incidence of stricture. METHODS: A total of 113 patients received an injection of porfimer sodium (2 mg/kg). Three days later, 630 nm light was delivered by using a 20-mm-diameter PDT balloon at doses of 115 J/cm (n=59), 105 J/cm (n=18), 95 J/cm (n=17), or 85 J/cm (n=19). Treatment efficacy was determined by obtaining biopsy specimens of the treated area 3 months later. The incidence of stricture was determined by the need for esophageal dilation to treat dysphagia. A stricture was considered severe if 6 or more dilations were required. RESULTS: The incidence of severe stricture was related to the light dose. At 115 J/cm, 15.3% of patients developed severe strictures compared with 5.3% to 5.6% of those treated with the lower doses. At a light dose of 115 J/cm, 17.0% of patients had residual HGD/T1. Light doses of 105 J/cm, 95 J/cm, and 85 J/cm resulted in residual HGD/T1 in 33.3%, 29.4%, and 31.6% of patients, respectively. None of the observations were statistically significant. CONCLUSIONS: Decreasing the light dose below 115 J/cm appeared to result in a reduced incidence rate of severe stricture but higher relative frequencies of residual HGD/T1 in Barrett's esophagus.

Photodynamic therapy for Barrett's esophagus with dysplasia and/or early stage carcinoma: long-term results.

BACKGROUND: Photodynamic therapy has been shown to eliminate Barrett's dysplasia. This report presents long-term follow-up data after photodynamic therapy of Barrett's esophagus with high-grade dysplasia, low-grade dysplasia, or early stage carcinoma. METHODS: Porfimer-photodynamic therapy was performed in 103 patients. The Nd:YAG laser was used to photoablate small areas of residual or untreated Barrett's mucosa. Acid suppression was maintained in all patients (omeprazole, 20 mg twice a day). RESULTS: Mean follow-up was 50.65 (SD 20.57) months (range 2-122 months). For the 82 patients not lost to follow-up, mean follow-up was 58.5 (12.89) months (range 41-132 months). After photodynamic therapy, the length of Barrett's mucosa decreased by a mean of 6.92 cm (range 1-22 cm). Of the 65 patients with high-grade dysplasia, 60 (94%) had elimination of high-grade dysplasia. Three (4.6%) patients developed subsquamous adenocarcinoma. Subsquamous, nondysplastic, metaplastic epithelium was found in 4 patients (4.9%). Strictures occurred in 18% with one session of photodynamic therapy, and 50% with two treatments, 30% overall. For the 103 patients, intention-to-treat success rates were 92.9%, 77.5%, and 44.4% for, respectively, low-grade dysplasia, high-grade dysplasia, and early stage carcinoma groups. CONCLUSION: Porfimer-photodynamic therapy with supplemental Nd:YAG photoablation and continuous treatment with omeprazole reduces the length of Barrett's mucosa, eliminates high-grade dysplasia, and, by comparison with historical data, may reduce the expected frequency of carcinoma.

Laser-induced fluorescence spectroscopy for in vivo diagnosis of non-melanoma skin cancers.

BACKGROUND AND OBJECTIVES: Laser-induced fluorescence spectroscopy is a non-invasive technique previously used for detection of cancer in a variety of organ systems. The objective of this study was to determine whether in vivo laser-induced fluorescence spectroscopy alone at the visible excitation wavelength of 410 nm could be used to detect non-melanoma skin cancers. STUDY DESIGN/MATERIALS AND METHODS: The system consisted of a nitrogen/dye laser tuned at 410 nm, an optical multichannel analyzer, and a fiber optic probe for excitation of tissue and collection of fluorescence emission. Two hundred and seventy nine measurements were performed from normal and abnormal tissues in 49 patients. Patients were classified as having either skin types I, II, or III. Biopsy of the abnormal tissues were then performed. Each measurement was assigned as either normal, basal cell carcinoma (BCC), squamous cell carcinoma (SCC), pre-cancerous, or benign. Total emission photon count was used as the discriminating index. A threshold value was calculated to separate normal tissue indices from indices of cancer tissues. The classification accuracy of each data point was determined using the threshold value. RESULTS: Cancers were classified 93, 89, and 78% correctly in patients with skin types I, II, and III, respectively. Normal tissues were classified 93, 88, and 50% correctly in patients with skin types I, II, and III, respectively. Using the same threshold, pre-cancerous spectra were classified 78 and 100% correctly in skin types I and III, respectively. Benign lesions were classified 100, 46, and 27% correctly in patient with skin types I, II, and III, respectively. CONCLUSIONS: In vivo laser induced fluorescence spectroscopy at 410 nm excitation and using the intensity of emission signal is effective for detection of BCC, SCC, and actinic keratosis, specially in patients with light colored skin.

Photodynamic therapy using Verteporfin (benzoporphyrin derivative monoacid ring A, BPD-MA) and 630 nm laser light in canine esophagus.

BACKGROUND AND OBJECTIVE: Verteporfin is a new photosensitizer with short-term skin photosensitivity. The objective of this preclinical study was to find the light dose that effectively ablates canine esophageal mucosa when delivered 30 minutes after Verteporfin injection. STUDY DESIGN/MATERIALS AND METHODS: Verteporfin was administered intravenously (0.75 mg/kg). 630 nm light from KTP/Dye laser was delivered using an esophageal Photodynamic therapy (PDT) balloon. In Phase I study, animals were treated 30 minutes after drug injection using 40, 60, and 80 J/cm to find the desired light dose. Using results from phase I and application of reciprocity principle (light dose vs. plasma concentration of drug), additional light doses were calculated for delivery at other times. In phase II, animals were treated at 15, 60, and 120 minutes, using the calculated light doses of 60, 145, and 200 J/cm, respectively. Animals were followed for 2 days to 4 weeks. RESULTS: In Phase I, 80 J/cm at 30 minutes induced total mucosal ablation. In Phase II, light doses of 60, 145, and 200 J/cm induced similar mucosal injuries when delivered at 15, 60, and 120 minutes, respectively. CONCLUSIONS: Effective mucosal ablation in canine esophagus was achieved using Verteporfin and 630 nm light doses of 60, 80, 145, and 200 J/cm when delivered at 15, 30, 60, and 120 minutes after the drug injection, respectively.

Photodynamic therapy response in cats with cutaneous squamous cell carcinoma as a function of fluence.

The response of advanced stage cutaneous squamous cell carcinomas (SCC) following treatment with photodynamic therapy (PDT) has been poor. It was the aim of this pilot study to determine whether an increase in the delivered fluence (i.e. energy density) would improve the duration of tumour remission in cats with advanced-stage SCC. Tumours were treated with aluminium phthalocyanine tetrasulphonate (AlPcS4 ) PDT at a fluence of either 100 J cm-2 or 200 J cm-2 and tumour response was evaluated at regular intervals. Those feline tumours treated with a fluence of 100 J cm-2 (n= 8) had a significantly shorter median remission duration (69 days; range 0-619 days) than those feline tumours treated with 200 J cm-2 (n= 6; 522 days; range 151-1057 days). It is our conclusion that a fluence of 200 J cm-2 is well tolerated and more effective when treating cats with advanced stage cutaneous SCC.