***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND AND OBJECTIVES Optical coherence tomography ( OCT ) permits high-resolution imaging of tissue subsurfaces up to 2 mm in depth . The purpose of this study was to evaluate the accuracy and reproducibility of OCT in the characterization of cervical intraepithelial neoplasia ( CIN ) and to distinguish between different CIN grade s. STUDY DESIGN / MATERIAL S AND METHODS Colposcopy-guided OCT images were taken from unsuspicious and suspicious areas in women with suspected CIN . Each woman then underwent directed biopsies . All OCT images were separately evaluated by two blinded investigators and later compared to the corresponding histology based on a 6- grade classification ( normal , inflammation , CIN 1 , CIN 2 , CIN 3 , squamous carcinoma ) . Sensitivity and specificity of OCT  in detecting CIN were determined . To assess the interobserver agreement , kappa coefficients were calculated from the ratings of each investigator for each OCT image seen . RESULTS A total of 210 OCT  images were compared with the corresponding histology in 120 women undergoing colposcopy for suspected CIN .  Sensitivity calculated for both investigators was 98 % and 96 % respectively with the threshold at CIN1 and 86 % and 84 % respectively with the threshold at CIN2 . Thirty nine ( 38 ) false positive results reduced the specificity to 39 % and 41 % respectively with the threshold at CIN1 . Defining the threshold at CIN2 the specificity increased to 64 % and 60 % respectively . Unweighted kappa from a dichotomous classification with the threshold at CIN1 was 0.69 ( 95 % CI , 0.54 - 0.84 ) and 0.62 ( 95 % CI , 0.51 - 0.73 ) with the threshold at CIN2 . CONCLUSION OCT is highly sensitive in identifying pre-invasive and invasive cancer of the uterine cervix . Improvements in resolution and the development of new light sources and optics may improve the specificity as well as the differentiation of cervical dysplasia . The interobserver agreement was substantial OBJECTIVE To assess whether the use of a novel optical detection system ( ODS ) as an adjunct to colposcopy increases the detection of biopsy-confirmed CIN 2,3 . METHODS This is a multicenter two-arm r and omized trial comparing colposcopy alone with colposcopy plus a pre-commercial ODS system that utilizes fluorescence , white light tissue reflectance , and cervical video imaging .  Patients were recruited from 13 colposcopy clinics in a variety of practice setting s. 2299 women referred for the evaluation of an abnormal cervical cytology were r and omized with stratification by cytology ; subsequently 113 women were excluded for a variety of reasons . The main study outcomes were differences in true-positive rates ( CIN 2,3 and cancer identified ) and false-positive rates between the study arms . RESULTS The true-positive ( TP ) rates were 14.4 % vs. 11.4 % ( p=0.035 , one-sided ) for the combined colposcopy and ODS arm compared to colposcopy-only arm , respectively , in women with either an atypical squamous cell ( ASC ) or low- grade squamous intraepithelial lesion ( LSIL ) cytology result . TP rates were similar between the two arms among women referred for the evaluation of HSIL . The 26.5 % gain in true-positives observed with the use of ODS and colposcopy among women referred for an ASC or LSIL cytology was achieved with only a fractional increase in number of biopsies obtained per patient ( 0.30 ) and a modest increase in false-positive rate ( 4 % ) . In the combined colposcopy and ODS arm among women with ASC or LSIL , the PPV of biopsies indicated by ODS was 15.0 % and the PPV of biopsies indicated by colposcopy was 15.2 % . Joint hypothesis testing indicates that ODS and colposcopy provides benefit compared to colposcopy alone among women with ASC or LSIL . CONCLUSIONS Combining ODS with colposcopy provides a clinical ly meaningful increase in the detection of CIN 2,3 in women referred for the evaluation of mildly abnormal cytology results Objective : Our aim was to present our initial clinical experience using a novel exoscopically based colposcopy system ( VITOM ) for the evaluation of cervical , vulvar , and vaginal diseases . Material s and Methods : Women referred to the Charite Cervix Center , Charite University , Berlin , Germany , were included . Patients with abnormal Pap smear results , vulvar lesions , or a biopsy report of neoplasia of the lower genital tract were included into the study . The VITOM was used for colposcopic evaluation and directed biopsies .  Colposcopic findings were reported according to the criteria of the Committee on Nomenclature of the International Federation of Cervical Pathology and Colposcopy . Histologic diagnosis was described as normal , low- grade lesion , high- grade lesion ( including cervical intraepithelial neoplasia 2,3 , vulvar intraepithelial neoplasia 2,3 , vaginal intraepithelial neoplasia 2,3 ) , or cancer . Results : We recruited 76 patients ( 54 with cervical , 4 with vaginal , and 18 with vulvar disease ) to the prospect i ve study . Four patients were pregnant . Of patients with cervical disease , 29 % had a history of previous conization  and 3.7 % had a history of trachelectomy . The sensitivity , specificity , negative predictive value , and positive predictive value of the VITOM for cervical intraepithelial neoplasia 2 , 3 were 90 % , 77 % , 90 % and 77 % , respectively . Concordance of exocolposcopic impressions and histologic results was higher in high- grade lesions ( K = 0.68 , 95 % CI = 0.32 - 0.87 , p < .001 ) than in low- grade lesions ( K = 0.41 , 95 % CI = 0.1 - 0.41 , p < .05 ) . Conclusions : Exocolposcopy with the VITOM is accurate and shows good correlation to histologic findings in high- grade disease of the lower genital tract . The potential advantages include patient and trainee involvement in examination , decision making , and documentation Cervical intraepithelial neoplasia 3 ( CIN3 ) is the precursor of mostsquamous carcinomas and serves as a surrogate end point . However , small CIN3 lesions are rarely associated with concurrent invasion . We hypothesized that aggressive follow-up for cytology of atypical squamous cells of undetermined significance ( ASCUS ) or low- grade squamous intraepithelial lesion ( LSIL ) leads predominantly to detection of smaller CIN3 lesions than those usually associated with cancer . We assessed this hypothesis in a masked histopathologic review of 330 CIN3 lesions in the ASCUS LSILTriage Study , focusing on ASCUS referrals . ASCUS referrals underwent r and omized management [ colposcopy for repeat cytology of high- grade squamous intraepithelial lesion ( HSIL ) , colposcopy for oncogenic human papillomavirus ( HPV ) detection or repeat HSIL , or immediate colposcopy ] ; then all were followed with repeat cytology for 2 years , followed by colposcopy and aggressive treatment . We assessed all CIN3 lesions qualitatively and measured 39 of them . CIN3 lesions were overwhelmingly small . Compared with enrollment , lesions found at follow-up or exit involved fewer tissue fragments ( P < 0.01 ) and showed less diffuse gl and involvement ( P = 0.03 ) . CIN3 lesions found postenrollment after HPV testing involved the fewest tissue fragments [ versus immediate colposcopy ( P = 0.04 ) or repeat cytology of HSIL ( P = 0.02 ) ] , and none showed diffuse gl and involvement . The median distal-proximal length was 6.5 mm ( median replacement of total epithelium = 5 % ) in the 39 measured cases . We conclude that CIN3 lesions underlying ASCUS or LSIL generally lack features associated with invasion , particularly if managed using HPV testing , suggesting that aggressive management leads to early detection of CIN3 but probably prevents relatively few cancers in screened population The objective of this study was to assess the performance of cervical impedance spectroscopy in the detection of cervical intraepithelial neoplasia ( CIN ) using the new MKIII impedance probe . A prospect i ve observational study recruited women referred to colposcopy with an abnormal Papanicolaou smear . A pencil probe incorporating four gold electrodes was used to measure electrical impedance spectra from cervical epithelium . Colposcopy examinations , including probe positioning , were video recorded to allow for correlation between results obtained from colposcopic impression , histopathologic examination of colposcopic punch biopsies , and impedance measurements . Cervical impedance – derived parameters R , S , R/S , C , and Fc were assessed to see if significant difference in values obtained in CIN and normal epithelium existed . The performance of the probe in identifying women with CIN was also assessed . One hundred seventy-six women were recruited and 1168 points analyzed . Parameters R , S , and Fc showed significant separation of CIN or squamous intraepithelial lesion ( SIL ) from squamous , mature metaplastic , and columnar epithelium . Sensitivities of 74 % and specificity of 53 % can be achieved in identifying CIN 2/3 ( High- grade SIL ) in screened women . We conclude that cervical impedance spectrometry provides a potentially promising real-time screening tool for CIN with similar sensitivity and specificity to currently used screening tests . Further research is ongoing to develop the probe for potential clinical use OBJECTIVE To evaluate the efficacy of an electrical impedance probe ( Epitheliometer ) in the diagnosis of high grade cervical intraepithelial neoplasia ( CIN ) in women referred with cervical smear abnormalities and to assess the effect of acetic acid ( AA ) and tissue boundaries on the measurements . METHODS A prospect i ve observational study was undertaken in the colposcopy clinic . One hundred and sixty-five women , either with a clinical indication or abnormal cervical cytology , were recruited into the study . A pencil type probe was used to record  impedance spectra  from 12 points on the cervix before and after the application of 5 % AA . Spectra were also recorded from tissue boundaries . Colposcopic examinations , including probe positioning , were video recorded to allow for correlations between histopathological diagnosis of colposcopically directed biopsies , colposcopic impression and the diagnosis based on impedance measurements . RESULTS Receiver operating characteristic ( ROC ) curves were derived . The areas under the curves ( AUCs ) to discriminate original squamous from high grade CIN were 0.80 ( pre AA ) and 0.79 ( post AA ) . Comparison of these curves showed no significant difference , indicating that application of AA does not produce a large change in spectra . The probe could distinguish tissue boundaries from homogeneous tissue points . CONCLUSION The Epitheliometer has the potential to be used as an adjunct to colposcopy in the diagnosis of high grade CIN . It has the advantage of real time results , decreasing the need for diagnostic cervical biopsies , and facilitates a wider use of the ' see and treat ' policy without the risk of overtreatment Fluorescence spectroscopy has shown promise for the in vivo , real-time detection of cervical neoplasia . However , selection of excitation wavelength has in the past been based on in vitro studies and the availability of light sources . The goal of this study was to determine optimal excitation wavelengths for in vivo detection of cervical neoplasia . Fluorescence excitation-emission matrices ( EEMs ) were measured in vivo from 351 sites in 146 patients . Data were analyzed in pairs of diagnostic classes to determine which combination of excitation wavelengths yields classification algorithms with the greatest sensitivity and specificity . We find that 330 - 340- , 350 - 380- , and 400 - 450-nm excitation yield the best performance . The sensitivity and specificity for discrimination of squamous normal tissue and high- grade squamous intraepithelial lesion ( HGSIL ) were 71 % and 77 % on cross validation using three excitation wavelengths . These results are comparable with those found in earlier in vivo studies ; however , in this study we find that the proportion of sample s which are HGSIL influences performance . Furthermore stratification of sample s within low- grade squamous intraepithelial lesion and HGSIL also appears to influence diagnostic performance . Future diagnostic studies should be carried out at these excitation wavelengths in larger groups so that data can be stratified by diagnostic subcategory , age and menopausal status . Similarly , large studies should be done in screening population Large phase II trials of fluorescence and reflectance spectroscopy using a fiber optic probe in the screening and diagnostic setting s for detecting cervical neoplasia have been conducted . We present accrual and histopathology data , instrumentation , data processing , and the preliminary results of interdevice consistencies throughout the progression of a trial . Patients were recruited for either a screening trial ( no history of abnormal Papanicolaou smears ) or a diagnostic trial ( a history of abnormal Papanicolaou smears ) . Colposcopy identified normal and abnormal squamous , column 
    Output:
    
An instrument that globally assesses the cervix , such as computer-assisted colposcopy , optical spectroscopy , and dynamic spectral imaging , would provided the most comprehensive estimate of disease and is therefore best suited when treatment is preferred .
Electrical impedance spectroscopy , confocal microscopy , and optical coherence tomography provide information at the cellular level to estimate histology and are therefore best suited when deferment of treatment is preferred .
If a device is to eventually replace the colposcope , it will likely combine technologies to best meet the needs of the target population , and as such , no single instrument may prove to be universally appropriate .