Autofluorescence Visualization Research Articles

Diagnostic value of objective VELscope fluorescence methods in distinguishing oral cancer from oral potentially malignant disorders (OPMDs)

BackgroundThe VELscope fluorescence method has been applied to the identification and detection of oral potentially malignant disorders, but autofluorescence visualization lacks objectivity and its diagnostic value varies greatly. The effectiveness of VELscope in detection of the cancer risk in oral potentially malignant disorders at different lesion sites remains unclear, given that only a few studies have investigated the value of VELscope for detecting high- and low-risk lesions in oral potentially malignant disorders. This study used the objective VELscope fluorescence method based on quantitative analysis to investigate its value in oral potentially malignant disorders for: (I) detecting oral cancer; (II) distinguishing high-risk lesions from low-risk lesions; and (III) measuring differences in oral cancer diagnostic accuracy between different sites.MethodsConventional oral examination and subjective and objective VELscope examinations were performed on 59 oral potentially malignant disorders; autofluorescence results were compared with histopathological diagnosis.ResultsThe sensitivity of subjective and objective VELscope fluorescence methods for detecting oral cancer in oral potentially malignant disorders was 76.9% and 65.4%, respectively; specificity for distinguishing high-risk from low-risk lesions in oral potentially malignant disorders was 50.0% and 82.1%, respectively; and sensitivity for detecting oral cancer in oral potentially malignant disorders of lining mucosa was 81.0%, higher than that of the masticatory mucosa.ConclusionsThe identification ability for low-risk lesions can be improved by combining it with objective autofluorescence. Autofluorescence has different screening abilities in different parts of the oral mucosa.

Evaluation of autofluorescence visualization system in the delineation of oral squamous cell carcinoma surgical margins

IntroductionDelineating the margins of Oral squamous cell carcinoma (OSCC) is a critical step for optimaltumor resection. The aim of this study was to evaluate the accuracy of lesion surgical margin identification using autofluorescence visualization. Materials and MethodsThirty patients with OSCC were included in this study. For each lesion, the fluorescence loss boundary was determined using VELscope before ablative surgical resection (with a 1.5-2cm safety margin) was performed. A total of 126 samples were obtained from 30 surgical specimens, each containing the tissue from the fluorescence loss boundary to surgical margin. The status of each sample was determined by oral pathologists and the staining intensities of Ki-67, E-cadherin, and Vimentin at the fluorescence loss boundary and surgical margin were evaluated by immunohistochemistry. ResultsFluorescence loss regions were identified in all patients. Of the 126 samples collected, HE staining identified 77 normal epithelia (61.1%), 26 mild dysplasia (20.6%), 17 severe dysplasia (13.4%) and 6 carcinomas in situ (4.9%). A significant correlation was found between the differentiation grade of tumor cells and the pathological status of the surgical marginal specimens (P<0.05). Forty-two of the 126 samples were randomly selected for further immunohistochemical staining. No significant differences were seen in Ki-67, E-cadherin, or Vimentin expression at the fluorescence loss boundary or surgical margin, however, the proteins’ expression level was positively correlated with the degree of dysplasia (P<0.01). ConclusionAutofluorescence visualization has potential as a simple surgical margin setting device for OSCC and may help delineate the superficial area of OSCC with acceptable accuracy. However, when considering the inherent limitations of this system, we suggest that the approach should only be applied under certain conditions, such as when dealing with superficial, well-differentiated lesions.

Autofluorescence visualization of the oral malignant lesions

The aim of the present paper was to observe the main features of the autofluorescence emission of the oral epithelial carcinomas. The study included four patients aged 38-61 years with the oral epithelial carcinomas located at a cheek, a floor of the mouth, a bottom lip. All the diagnoses were later confirmed histologically. The oral cavity was inspected traditionally and then using autofluorescence visualization. For autofluorescence emission excitation we used the home-made LED-based device emitting near 400 nm. The tissue autofluorescence was visualized in the broad and narrow spectral bands. In comparison with the healthy mucosa the pathological lesions showed the large losses of the green autofluorescence emissions ("dark sport effect") which have been visualized at both spectral bands. The visualization in the broad spectral band allowed to reveal that three lesions had the local sites of red fluorescence of the endogenous porphyrins traditionally connected with the local inflammation. Autofluorescence stomatoscopy is not only important but also mandatory for oncological screening and should be widely used as the additional method of oral mucosa examination in the common dental practice.

Toxoplasmagondii oocysts, Giardia cysts and Cryptosporidium oocysts in outdoor swimming pools in Brazil.

The accidental ingestion of treated recreational water is an important transmission route of waterborne protozoa worldwide. The present study aimed to provide the first evaluation of swimming pools in Brazil, analysing the presence of pathogenic protozoa (Toxoplasma gondii, Cryptosporidium spp. and Giardia spp.) by parasitological and molecular methods. A total of 57 samples were collected from 21 public swimming pools, either directly from the pool or filter backwash water and concentrated using the membrane filtration technique. Giardia cysts and Cryptosporidium oocysts were visualized by direct immunofluorescence assay after purification by immunomagnetic separation. Toxoplasma gondii oocysts were detected by autofluorescence visualization using the supernatant discarded during the purification step as a sample. Positive samples were submitted to molecular analysis. The molecular markers were used: SSU-rRNA, tpi, gdh and bg, for Giardia DNA amplification, and 18S rRNA gene fragment amplification was used for the Cryptosporidium oocysts. The 529-bp repeat element (REP529) fragment and the 35-fold repetitive B1 gene were employed as a target for T.gondii. Amplified products were submitted to sequencing and phylogenetic analysis. Giardia cysts were detected in 19.0% and Cryptosporidium oocysts in 9.5% of swimming pools. In one swimming pool (4.7%), both protozoa were detected on at least one occasion. Structures similar to T.gondii oocysts were detected in 33.3% of the samples, ranging from one to 23 per slide. Giardia was confirmed by DNA amplification in three swimming pools; Giardia duodenalis Assemblage A was identified by the phylogenetic positioning of the β-giardin gene. Toxoplasma gondii DNA was detected in 14.2% of swimming pools. The present study represents the first report of the occurrence of T.gondii oocysts in swimming pools. Recreational activity in swimming pools contaminated by chlorine-resistant protozoa can represent a high risk of infection for bathers and swimmers.

Detection accuracy for epithelial dysplasia using an objective autofluorescence visualization method based on the luminance ratio

The autofluorescence visualization method (AVM) uses blue excitation light to assist in the diagnosis of epithelial dysplasia. It detects epithelial dysplasia as a black area, which is known as fluorescence visualization loss (FVL). In this study, we evaluated the detection accuracy for epithelial dysplasia of the tongue using the objective AVM and assessed its possible clinical utility. Seventy-nine tongue specimens clinically suspected to have leukoplakia or squamous cell carcinoma (SCC) were analyzed. First, the AVM was subjectively performed using the Visually Enhanced Lesion scope (VELscope), and the iodine-staining method was then performed. After biopsy, the histopathological results and the luminance ratio between the lesion and healthy tissue were compared, and a receiver operating characteristic curve was created. The cutoff value for the objective AVM was determined; the lesion was considered FVL-positive or -negative when the luminance ratio was higher or lower than the cutoff value, respectively. The histopathological diagnoses among the 79 specimens were SCC (n=30), leukoplakia with dysplasia (n=34), and leukoplakia without dysplasia (n=15). The cutoff value of the luminance ratio was 1.62, resulting in 66 FVL-positive and 13 FVL-negative specimens. The luminance ratio was significantly higher in the epithelial dysplasia-positive than -negative group (P<0.000 1). The objective AVM showed much higher consistency between histopathological results than did the two methods (kappa statistic=0.656). In conclusion, objective autofluorescence visualization has a potential as an auxiliary method for diagnosis of epithelial dysplasia.

Abstract LB-248: Minimally-invasive “cytology-on-chip” assay combined with continuous risk index for screening and surveillance of oral cancer in patients with Fanconi anemia

Abstract Fanconi Anemia (FA) is an autosomal recessive disorder caused by mutations of DNA repair genes. The risk of oral cancer (OC) among FA patients is 800-times higher than in the general population, occurring at younger ages. Hematopoietic stem cell transplantation (HSCT), which greatly extends the life-expectancy in FA patients further increases the risk of OC in these patients. Patients with FA cannot tolerate chemo-and radiation therapy; hence, early detection of OC is critical to improve survival. Objective: To investigate the role of a numerical index for monitoring OC progression applied to FA patients in combination with a microfluidic “cytology-on-chip” assay and autofluorescence visualization (AFV) using VELscope (Visually Enhanced Lesion scope). Methods: Patients attending the Meeting for Adults with FA, held in Baltimore, Maryland in March 2014 underwent a conventional oral examination followed by AFV. Transepithelial brush samples of mucosal lesions suspected of being oral potentially malignant disorders (OPMD) were obtained using Orcellex® brush (Rovers Medical Devices, Oss, The Netherlands) and transported in ThinPrep® CytoLyt® for cytology-on-chip assays. A numerical OC risk index (0-100) developed and validated on 506 prospectively recruited non-FA patients with OPMD was applied to site-matched brush biopsy samples of FA patients. Results: A total of 28 FA patients (Age range: 18-61 yrs., M = 9, F = 19) participated in this study, of whom 13 have had HSCT. The majority of these lesions (89%) revealed loss of fluorescence (LOF+ve) with AFV. Compared to a cohort of prospectively recruited non-FA patients with OPMD (mean = 36.71, SD = 33.60), the mean OC risk index score for FA patients was 50.66 (SD = 32.83). Additionally, HSCT-recipient FA patients exhibited higher risk index scores (mean = 58.69, SD = 32.16) compared to non -HSCT-recipient FA patients (mean = 40.34, SD = 33.08). The frequency of nuclear aberrations such as micronuclei, bi- and poly-nucleated cells was significantly higher in FA patient cells than healthy controls and significantly higher in LOF+ve compared to LOV-negative OPMD. Two samples exhibited significantly higher WBC (white blood cell) counts, an indicator of inflammation; both were from LOF+ve OPMD found in HSCT-recipient FA patients. Conclusion: FA patients who are HSCT recipients have significantly higher OC risk index scores as well as increased prevalence of LOF+ve OPMD that demonstrate higher incidence of nuclear aberrations and inflammation. These findings are consistent with recent reports that HSCT in FA patients increases their risk for oral cancer. Therefore, use of the OC numerical index and cytology-on-chip assay in combination with AFV may improve the efficacy of conventional oral examination for long-term surveillance of OC in this high-risk patient population, while minimizing unwarranted scalpel biopsies. Citation Format: Timothy J. Abram, Pierre N. Floriano, Rameez Raja, Nancy Bass, Anne Gillenwater, Nadarajah Vigneswaran, John T. McDevitt. Minimally-invasive “cytology-on-chip” assay combined with continuous risk index for screening and surveillance of oral cancer in patients with Fanconi anemia. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-248.

The detection of oral pre- malignant lesions with an autofluorescence based imaging system (VELscope™) - a single blinded clinical evaluation.

ObjectiveThe disease specific five-year survival rate especially for patients with advanced oral cancer has not improved significantly over the period of time. The most effective way of combating this dilemma is an early detection, diagnosis and eradication of early-stage lesions and their precursors. The use of VELscope® using an autofluorescence as a diagnostic tool might be useful in early detection of oral malignant lesions.Materials and methods120 patients with suspicious oral premalignant lesions were examined with two examination methods. They were randomly divided into two groups. Group 1 was examined conventional with white-light and group 2 was examined additionally to the white-light-examination with an autofluorescence visualization device, VELscope®. Biopsies were obtained from all suspicious areas identified in both examination groups (n = 52). The diagnostic strategies were compared regarding sensitivity and specificity.ResultsBased upon the result, use of the VELscope® leads to a higher sensitivity (22.0%), but regarding specificity the additional use of the VELscope® is inferior (8.4%).ConclusionThe VELscope device is a simple, non-invasive test of the oral mucosa, which can help the experienced clinician to find oral precursor malignant lesions.

OP117: Autofluorescence visualization for detecting potentially malignant white oral mucosal lesions

Introduction White or white-red oral mucosal lesions (WOL) are considered to be potentially malignant disorders. While heterogeneous appearance and presence of dysplastic changes portend a higher risk of progression, homogeneous WOLs can also sometimes progress to invasive cancer (CA). We evaluated the utility of autofluorescence visualization (AFV) in the detection of ‘high-risk’ WOLs. Methods A total of 146 patients with WOLs were evaluated at the Oral Cancer Screening Clinic at Roswell Park Cancer Institute, Buffalo, NY, USA. The patients underwent conventional white-light evaluation (WLE), AFV, and lesion risk stratification as ‘suspicious’ or ‘non-suspicious’ on either light evaluation. All lesions were biopsied for histopathology diagnosis. Results A total of 255 WOL were detected, including 75 homogeneous leukoplakia/white lesions, 40 verrucous leukoplakia, 19 leuko-erythroplakia, 86 leukoplakia with ulcer/focal erythema, 28 lichenoid lesions and 7 treatment-related white scars. Histopathology diagnoses showed, 71 normal/benign lesions, 100 mild dysplasia (MiD), 19 moderate dysplasia (MoD), 20 severe dysplasia (SD), 13 carcinoma in situ (CIS) and 32 CA. Of the 255 WOLs, 138 and 223 were suspicious on WLE and AFV, respectively. The sensitivity and specificity of WLE in detecting WOLs with dysplasia/CA were 54% and 46%, respectively. On AFV, the sensitivity was 89% and the specificity was 17%. When the 75 homogenous WOLs were evaluated separately, 46 had dysplasia/CA (34 MiD, 6 MoD, 3 SD, 2 CIS and 1 CA). Of these 46 lesions, only 9 (8 MiD and 1 CIS) were missed (non-suspicious) on AFV. The sensitivity and specificity of AFV in detecting homogenous WOLs with dysplasia/CA were 80% and 37%, respectively. Conclusion While AFV is useful in detecting ‘high-risk’ potentially malignant oral lesions, it is not as efficient in discriminating between high-risk and low-risk lesions. AFV, in its current stage of development, may only be effective when used in a selective high-risk patient population.

OP115: Sensitivity and specificity of autofluorescent screening in addition to white light exam across anatomical subsites of the oral cavity and oropharynx

Adjuncts to clinical examination are critical in detecting oral potentially malignant disorders and cancers at the earliest, most treatable stages. Autofluorescence visualization (AFV) in addition to standard white light examination (WLE) may be useful in early detection. Sensitivity and specificity for detecting premalignant lesions and cancers may vary by anatomical site based on location, diversity of tissue composition, and visual and mechanical access. High-risk patients with suspicious lesions or recently diagnosed untreated oral/oropharyngeal cancers underwent examination with WLE followed by AFV. Biopsies were obtained from suspicious areas on either exam plus negative controls and underwent histopathologic diagnosis and grade stratification. The oral cavity/oropharynx was divided into six anatomical subsites and sensitivity/specificity were calculated for WLE, AFV, and WLE + AFV. □2analysis was used to calculate differences in sensitivity across anatomical sites. A total of 169 patients provided 546 biopsies. The sensitivity of detecting LGLs with WLE was statistically different in the oral tongue (21%) compared to gingiva (50%, p = 0.01), FOM (47%, p = 0.03) and RMT/alveolar ridge (48%, p = 0.007). AFV detection of LGLs of the oral tongue (56%) were significantly lower than gingiva (88%, p = 0.01) and oropharynx (81%, p = 0.03). Gingiva was significantly different from buccal mucosa (88%, 62%, p = 0.04). Sensitivity of WLE + AFV LGL detection of the oral tongue was significantly different than gingiva (63%, 88%, p = 0.04) and oropharynx (95%, p = 0.001). The buccal mucosa significantly differed from the oropharynx (66%, 95%, p = 0.004). The oral tongue (80% HGLs, 88% cancers) differed significantly from the buccal mucosa (100%, p = 0.02) and oropharynx (100%, p = 0.03). AFV offers variable utility for detecting premalignant lesions and cancers across oral cavity/or pharyngeal anatomical subsites. The oral tongue may have the lowest sensitivity when compared to other subsites.

Clinical evaluation of an autofluorescence diagnostic device for oral cancer detection

The prognosis for patients with oral squamous cell carcinoma remains poor despite advances in multimodal treatment concepts. Early diagnosis and treatment is the key to improved patient survival. A device (VELscope) that uses autofluorescence technology, allowing direct fluorescence visualization of the oral cavity, might be a useful tool for oral cancer detection or as an adjunct to standard clinical examination. A total of 289 patients with oral premalignant lesions were randomly divided into two groups for clinical examination of precancerous oral lesions. In group 1, 166 patients were examined conventionally with white light, and in group 2, 123 patients were examined with the autofluorescence visualization device (VELscope) in addition to the white light examination. Biopsies were obtained from all suspicious areas identified in both examination groups (n=52). In the first step, baseline characteristics of the two groups (only white light vs. white light and VELscope) were compared to exclude selection bias. In the second step, for the group examined with white light and VELscope (123 patients), the diagnostic strategies were compared with regard to sensitivity and specificity using biopsy as the gold standard. The results showed that using the VELscope leads to higher sensitivity (100% instead of 17%), but to lower specificity (74% instead of 97%). Thus, we can conclude that the VELscope is a useful new diagnostic device for detection of oral cancer diseases.

Abstract A15: Autofluorescence-guided detection of oropharyngeal neoplasms and precursor lesions

Abstract Introduction: The incidence of oropharyngeal (OP) cancer has been increasing, in contrast to the overall head and neck tumors, likely related to human papillomavirus infection (HPV). Early clinical detection of oral cavity (OC) and OP tumors and precursors is essential for early intervention and chemoprevention. Since the oropharynx is less accessible than the OC, altering the current screening practice may be necessary. The addition of autofluorescence visualization (AFV) to standard examination has proven valuable by accurately detecting low and high-grade preneoploastic lesions (LGLs, HGLs) and oral cancers but its value in the OP has not been studied to date. We aim to assess if adding AFV to routine white light exam (WLE) increases the detection of OP neoplasms and precursor lesions. Study Design: High-risk patients with suspicious OC or OP lesions or recently diagnosed, untreated carcinoma underwent examination with WLE followed by AFV at 405nm from a 10mm rigid endoscope. Biopsies were obtained from areas with positive suspicion on either WLE or AFV examinations. Lesions were stratified on central pathology review as benign, low-grade (parakeratosis with atypia (PKA) or mild dysplasia), high-grade (moderate dysplasia, severe dysplasia, or carcinoma in situ (CIS)), or cancer. Sensitivity and specificity were calculated for WLE, AFV, and WLE + AFV for all patients with an OP biopsy on the first visit. Results: A series of 143 patients under active surveillance at our institute were examined over 218 visits and a total of 664 biopsies were collected. Twenty-nine patients (20%) had 41 biopsies (6%) sampled from the OP or OC/OP junction as follows: 5 base of tongue (BOT), 17 soft palate (SP), 10 tonsil, 5 SP/tonsillar junction, 3 hard palate/SP junction, and 1 BOT/posterior lateral tongue junction. Of the 29 LGLs/HGLs on the tonsil/SP/BOT, 14/29 were missed on WLE and 3/29 were missed on AFV. Out of 13 LGLs/HGLs on the SP, 5/13 were missed on WLE and 2/13 were missed on AFV. One severe dysplasia and one CIS were missed on WLE of the SP but none were missed with AFV. Of the 11 LGLs/HGLs on the tonsil or SP/tonsillar junction, 5/11 were missed on WLE and none were missed on AFV. One moderate dysplasia was missed on WLE of the tonsils but none were missed on AFV. Out of 5 LGLs/HGLs on the BOT, 4/5 were missed on WLE and 1/5 was missed on AFV. For the BOT, 4 mild dysplasias were missed on WLE and one was missed on AFV. Overall, WLE alone vs. AFV alone vs. AFV+ WLE detected 35% vs. 85% vs. 95% of LGLs respectively. Of the LGLs, 7 were PKA and 13 were mild dysplasia. WLE alone vs. AFV alone vs. the addition of AFV+ WLE detected 75% vs. 100% vs. 100% of HGLs respectively. Of the HGLs, one was moderate dysplasia, 5 severe dysplasias and 6 were CIS. All 3 modalities 100% detected the 2 cancers. Seven biopsies were benign. The addition of AFV+WLE greatly improved sensitivity in detecting LGLs when compared with WLE alone (95% vs. 35%) and HGLs (100% vs. 75%). The specificity in detecting both LGLs and HGLs decreased from 85.7% with WLE to 42.9% with AFV+WLE. Conclusions: AFV has high sensitivity in detecting OP lesions that may have been missed by WLE. Multi-modality visualization has utility in detecting pre-malignant lesions that may serve as potential targets for chemoprevention or early intervention. The addition of AFV to WLE may be useful in screening patients for chemoprevention trials. Due to its low specificity, AFV may be best limited to screening high-risk populations. Citation Information: Cancer Prev Res 2011;4(10 Suppl):A15.

Assessment of Tissue Autofluorescence and Reflectance for Oral Cavity Cancer Screening

Although approved by the US Food and Drug Administration for clinical use, the utility of handheld tissue reflectance and autofluorescence devices for screening head and neck cancer patients is poorly defined. There is limited published evidence regarding the efficacy of these devices. The authors investigated the sensitivity and specificity of these modalities compared with standard examination. Prospective, cross-sectional analysis. Tertiary care medical center. Patients who were treated previously for head and neck cancer (n = 88) between 2009 and 2010 were included. Patients were screened using white light visualization (standard of care) and compared with tissue reflectance and autofluorescence visualization. Screening results were compared with biopsy or long-term follow-up. Autofluorescence visualization had a specificity of 81% and a sensitivity of 50% for detecting oral cavity cancer, whereas white light visualization had a specificity of 98% and a sensitivity of 50%. Tissue reflectance visualization had low sensitivity (0%) and good specificity (86%). The power of this study was insufficient to compare the positive and negative predictive values of standard white light examination (50% and 98%, respectively) to tissue autofluorescence (11% and 97%) or reflectance (0% and 95%). In addition, stratification by previous radiation therapy found no statistically significant difference in screening results. Standard clinical lighting has a higher specificity than tissue reflectance and autofluorescence visualization for detection of disease in patients with a history of head and neck cancer. This study does not support the added costs associated with these devices.

Direct Visualization of Oral-Cavity Tissue Fluorescence as Novel Aid for Early Oral Cancer Diagnosis and Potentially Malignant Disorders Monitoring

Direct visualization of the oral tissue autofluorescence has been recently reviewed in several studies as a possible adjunctive tool for early recognition and diagnosis of potentially malignant and malignant oral disorders. The aims of this study were to assess: a) the value of a simple handheld device for tissue auto-fluorescence visualization of potentially malignant oral lesions; and b) the sensitivity, specificity and diagnostic accuracy of tested device, using histological examination as the gold standard. 175 consecutive patients, with at least one clinical oral lesion, were enrolled in the study. Clinical conventional inspections were performed for each patient by two blind operators. Then, oral biopsy and histological examination were performed. Pathologist was blind with respect to the autofluorescence results. The 175 histological assessments revealed no dysplasia, mild dysplasia, moderate/severe dysplasia and OSCC, in the 67.4%, 8.6%, 8%, 16% of cases, respectively. Oral lesions diagnosed as OSCC were found as positive under fluorescent light in the 96.4% of cases. Statistically significant correlation was observed between oral dysplastic lesions and the loss of tissue fluorescence (p-value=0.001). Low sensitivity values (60% and 71%) were recorded about the ability of the device in differentiating mild dysplasia vs. lack of dysplasia and moderate/severe dysplasia vs absence of dysplasia, respectively. The device tested in our study was found to not replace the histopathology procedure. However, we assessed its usefulness for oral tissue examination, especially within an oral medicine secondary care facility, before performing a biopsy and in monitoring oral lesions.

Autofluorescence-Guided Surveillance for Oral Cancer

Early detection of oral premalignant lesions (OPL) and oral cancers (OC) is critical for improved survival. We evaluated if the addition of autofluorescence visualization (AFV) to conventional white-light examination (WLE) improved the ability to detect OPLs/OCs. Sixty high-risk patients, with suspicious oral lesions or recently diagnosed untreated OPLs/OCs, underwent sequential surveillance with WLE and AFV. Biopsies were obtained from all suspicious areas identified on both examinations (n = 189) and one normal-looking control area per person (n = 60). Sensitivity, specificity, and predictive values were calculated for WLE, AFV, and WLE + AFV. Estimates were calculated separately for lesions classified by histopathologic grades as low-grade lesions, high-grade lesions (HGL), and OCs. Sequential surveillance with WLE + AFV provided a greater sensitivity than WLE in detecting low-grade lesions (75% versus 44%), HGLs (100% versus 71%), and OCs (100% versus 80%). The specificity in detecting OPLs/OCs decreased from 70% with WLE to 38% with WLE + AFV. Thirteen of the 76 additional biopsies (17%) obtained based on AFV findings were HGLs/OCs. Five patients (8%) were diagnosed with a HGL/OC only because of the addition of AFV to WLE. In seven patients, additional HGL/OC foci or wider OC margins were detected on AFV. Additionally, AFV aided in the detection of metachronous HGL/OC in 6 of 26 patients (23%) with a history of previously treated head and neck cancer. Overall, the addition of AFV to WLE improved the ability to detect HGLs/OCs. In spite of the lower specificity, AFV + WLE can be a highly sensitive first-line surveillance tool for detecting OPLs/OCs in high-risk patients.

Abstract B56: Autofluorescence visualization to screen for premalignant and malignant lesions of oral cavity and oropharynx

Abstract B56 Objective To determine if the addition of autofluorescence (AF) visualization to conventional white light exam (WL) improves the efficiency in detecting pre-malignant and malignant lesions in the oral cavity of high risk patients, compared to WL exam alone. Methods A total of 47 patients underwent the screening procedure at the department of Dentistry and Head and Neck Surgery at Roswell Park Cancer Institute, between October 2006 and June 2007, either to investigate suspicious oral lesions or to identify any co-existing lesions in patients with a recently diagnosed untreated oral pre-malignant lesions or cancer of oral cavity. Four patients had a second exam at least 6 months after the initial visit, making up a total of 51 screening visits. The patients underwent a comprehensive oral exam with an autofluorescence device which was equipped with WL source, an AF source (blue excitation light at 405 nm and imaging at 530-550 &amp; 630-650 nm) and a video camera. Any area that looked fluorescent green was classified as normal and any area that showed loss of fluorescence (grey or black) was considered to be suspicious on AF. All oral exams were performed by one dentist and the biopsies were reviewed by the same pathologist. A total of 170 lesions were identified on either WL or AF and biopsied, and 1 contra-lateral control biopsy from a normal looking area was taken per visit. For convenience of analysis, the pathologic diagnoses were grouped into four categories: (1) ‘benign lesions’(BL) - normal/ unremarkable samples with benign conditions and parakeratosis without atypia (2) ‘low grade lesions’(LGL) - parakeratosis with atypia and mild dysplasia (3) ‘high grade lesions’(HGL) - moderate dysplasia (MD), severe dysplasia (SD) and CIS (4) ‘Carcinoma’(CA). These groups contributed 48, 129, 26 and 15 biopsies respectively. Results On lesion-by-lesion basis, while WL exam did not identify 8 HGLs (4 MD and 4 CIS), AF missed only one HGL (1 MD). Similarly, WL exam did not identify 4 CAs, whereas AF exam missed only 1 cancerous lesion. On combined sequential screening by WL followed by AF (WL+AF), none of the HGLs or CAs was missed. For the LGLs, the sensitivity improved from 44% with WL to 63% with AF and 76% with WL+AF exam. Similarly, sensitivity for detecting HGLs increased from 69% with WL to 96 and 100% with AF and WL+AF, respectively. For CAs, the sensitivity improved from 73% to 93 and 100% with AF and WL+AF respectively. The negative predictive value of WL for HGLs and CAs was 96 and 97% respectively, which increased to 100% with AF alone. The specificity for HGLs and CAs was superior with WL at 75% compared to 52% with AF alone. The addition of AF to WL increased the relative sensitivity by 83%, 47% and 45% in identifying LGLs, HGLs and CAs respectively. One per-person basis, we examined the efficiency of AF in identifying the highest grade lesion in a person. While, WL missed the highest grade lesions in 2 patients with MD, 2 with CIS and 4 with CAs; AF did not miss the worst lesion in any patient with a HGL or CA. The efficacy of AF in identifying the highest grade lesion in each individual was 100%. Conclusion Our results demonstrate that sequential exam by AFL visualization following a WL exam is very efficient in identifying pre-malignant and malignant oral lesions not detected with WL alone. This technique has the potential as a non-invasive and effective tool for oral cancer screening. Citation Information: Cancer Prev Res 2008;1(7 Suppl):B56.