Koljenovic, S.

Method development: Raman spectroscopy-based histopathology of oral mucosa (Article)

2013-05-17T00:00:00Z

An earlier and more accurate detection of (small) cancerous and precancerous lesions in the oral cavity is essential to improve the prognosis of oral squamous cell carcinomas. Raman spectroscopy is being pursued as a potential method to realize this improvement, since the technique provides objective information on a biochemical level and can be used for real-time guidance of the diagnostic procedure. Since oral mucosal tissue is inhomogeneous and comprises different layers and histological structures, a good understanding of the signal contributions of the individual layers and structures is required for an accurate interpretation of in vivo tissue spectra measurement volumes. The aim of this study was to create a standardized method to collect and analyse the spectral contributions of individual histopathological structures in oral mucosa. The method is based on Raman microspectroscopic mapping of unstained frozen tissue sections and subsequent histopathological annotation of the features in the resulting Raman images. The obtained annotated reference spectra were used as input in an unsupervised hierarchical cluster analysis in order to determine the spectral characteristics and variance within one histo(patho)logical structure. The described method resulted in an annotated database of Raman spectral characteristics of individual histopathological structures encountered in oral tissue. This database can be used as input for the development of classification and quantification algorithms, in order to achieve a high specificity and sensitivity for clinical diagnostic instruments. Additionally, this database can be used to optimize the exact location and measurement volume of in vivo measurements.

Frequency of non-histologically diagnosed basal cell carcinomas in daily Dutch practice (Article)

2012-01-04T00:00:00Z

Background Population-based basal cell carcinoma (BCC) incidences are based on cancer registry data; however, these only include histologically diagnosed tumours. Objectives First, to investigate the number of subsequent non-histologically diagnosed BCC(s) in patients with a first histologically diagnosed BCC in 2004. Secondly, to observe differences in tumour characteristics between subsequent histologically and subsequent non-histologically diagnosed BCC(s). Methods All patients, from four hospitals located in the serving area of the Eindhoven Cancer Registry, with a first histologically diagnosed BCC in 2004 (n=1290) were selected. A linkage was made with PALGA, the nationwide network and registry of histo- and cytopathology, to obtain pathology reports of subsequent histologically diagnosed BCC(s) up to 1 November 2010. Patient records were extracted from the participating dermatology departments and reviewed up to 1 November 2010 to identify non-histologically diagnosed BCC(s). Results Overall, 33.2% of the 1089 followed up patients developed subsequent histologically and/or non-histologically diagnosed BCCs. In total, 1974 BCCs were observed of which 1833 were histologically and 141 were non-histologically diagnosed BCCs. The distribution of tumour site and subtype differed significantly between subsequent histologically and subsequent non-histologically diagnosed BCCs. Conclusions The total burden of BCC is underestimated by the absence of data on the occurrence of non-histologically diagnosed BCCs in daily dermatological practice. It is pivotal for Dutch healthcare policy makers to acknowledge this to make accurate BCC-related cost estimates. © 2012 The Authors. Journal of the European Academy of Dermatology and Venereology

Cumulative risks and rates of subsequent basal cell carcinomas in the Netherlands (Article)

2011-10-01T00:00:00Z

Background The incidence of multiple basal cell carcinomas (BCCs) is not well documented. Objectives To calculate the cumulative risks, rates and risk factors for the development of subsequent histologically confirmed BCCs. Methods For this cohort study the Dutch nationwide network and registry of histopathology and cytopathology (PALGA) was used. The first 2483 patients diagnosed with a first histologically confirmed BCC in the year 2004 were followed for 5 years. Multifailure survival models were used to study whether gender or age affected the risk of developing subsequent tumours. Results During our observational period, the 2483 patients developed a total of 3793 histologically confirmed BCCs. The 5-year cumulative risk of developing one or more subsequent BCCs was 29·2%. Incidence rates were 25 318 per 100 000 person-years in the first 6 months after first BCC diagnosis, decreasing to 6953 per 100 000 person-years after 5 years of follow-up. Males compared with females had a 30% [adjusted hazard ratio (HR) 1·30, 95% CI (confidence interval) 1·11-1·53] higher risk of developing multiple BCCs and those aged 65-79 years had more than 80% (adjusted HR 1·81, 95% CI 1·37-2·41) higher risk of having subsequent tumours compared with patients younger than 50 years. Conclusions The high incidence rate of subsequent BCCs among patients with a first BCC is highest in the first months after diagnosis of the first BCC but persists long term, indicating that patients with BCC should undergo full-body skin examinations at first presentation and subsequent follow-up visits. Special attention should be paid to males and persons of older age at index lesion.

EORTC Melanoma Group sentinel node protocol identifies high rate of submicrometastases according to Rotterdam Criteria (Article)

2010-09-01T00:00:00Z

Sentinel node (SN) status is the most important prognostic factor for disease-free survival (DFS) and overall survival (OS) in stages I-II melanoma. We evaluated the positive sentinel node identification rate of the EORTC Melanoma Group (MG) protocol as well as its capacity to identify minimal tumour burden, according to the Rotterdam Criteria in 421 consecutive patients. Correlations between primary tumour characteristics and SN tumour burden were investigated. The same 2 pathologists worked up all SNs according to the EORTC MG protocol and tumour burden was scored according to the Rotterdam Criteria (<0.1 mm, 0.1-1.0 mm and >1.0 mm for the largest diameter of the largest metastasis in the SN). The positive SN detection rate was 28.7% with a false negative rate of 10.4% at a median Breslow thickness of 2.1 mm. The high positive identification rate of about 30% of the EORTC MG protocol has been confirmed in this study. The protocol is sensitive and identifies submicrometastases (<0.1 mm) in a high percentage (18%). The variables SN tumour load, non-SN (NSN) status and ulceration of the primary were independent prognostic factors for DFS and OS in the multivariate analysis. At a median follow-up time of 4.3 years patients with minimal tumour burden (<0.1 mm) had a 5 year OS rate of 91%, virtually identical to 90% for SN-negative patients. The NSN positivity rate of 0% in these patients indicates that they may be spared a completion lymph node dissection (CLND) and its morbidity.

Incidence and trends of cutaneous malignancies in the Netherlands, 1989-2005 (Article)

2010-07-01T00:00:00Z

Epidemiology of rare cutaneous malignancies in the general population is poorly documented. This descriptive study aimed to estimate the incidence and trends of all skin malignancies between 1989 and 2005. Data on skin tumors were extracted from the Netherlands Cancer registry (except for basal cell carcinoma (BCC) dataonly available from Comprehensive Cancer Centre South) and categorized according to the International Classification of Diseases for Oncology, third edition, codes. Age-standardized incidence rates (European standardized population rate, ESR) per 100,000 person-years were calculated per year and for the period between 2001 and 2005. Estimated annual percentage changes (EAPCs) were estimated by Poisson regression models. A total of 356,620 skin tumors were diagnosed between 1989 and 2005. Excluding BCC, squamous cell carcinoma (SCC), and melanoma, the remaining skin tumors constituted about 2% of all skin malignancies. The incidence of melanoma showed the steepest increase (EAPC, 4.0%), and ESR was close to that observed for SCC (EAPC, 2.3%) between 2001 and 2005 (17.1 versus 19.6). Hematolymphoid tumors (ESR0.74) were mainly cutaneous T-cell lymphomas (60.8%). No significant increases in incidence were observed for lymphomas, and appendageal, fibromatous, and myomatous carcinomas during 1989-2005. In addition to keratinocytic cancers and melanoma, there is a wide variety of skin tumors that constitute <2% of all skin malignancies. The incidence of UV-related skin tumors increased significantly and more steeply than did those of other skin malignancies.

Combined optical coherence tomography and intravascular ultrasound radio frequency data analysis for plaque characterization. Classification accuracy of human coronary plaques in vitro (Article)

2010-04-15T00:00:00Z

This study was performed to characterize coronary plaque types by optical coherence tomography (OCT) and intravascular ultrasound (IVUS) radiofrequency (RF) data analysis, and to investigate the possibility of error reduction by combining these techniques. Intracoronary imaging methods have greatly enhanced the diagnostic capabilities for the detection of high-risk atherosclerotic plaques. IVUS RF data analysis and OCT are two techniques focusing on plaque morphology and composition. Regions of interest were selected and imaged with OCT and IVUS in 50 sections, from 14 human coronary arteries, sectioned post-mortem from 14 hearts of patients dying of non-cardiovascular causes. Plaques were classified based on IVUS RF data analysis (VH-IVUSTM), OCT and the combination of those. Histology was the benchmark. Imaging with both modalities and coregistered histology was successful in 36 sections. OCT correctly classified 24; VH-IVUS 25, and VH-IVUS/OCT combined, 27 out of 36 cross-sections. Systematic misclassifications in OCT were intimal thickening classified as fibroatheroma in 8 cross-sections. Misclassifications in VH-IVUS were mainly fibroatheroma as intimal thickening in 5 cross-sections. Typical image artifacts were found to affect the interpretation of OCT data, misclassifying intimal thickening as fibroatheroma or thin-cap fibroatheroma. Adding VH-IVUS to OCT reduced the error rate in this study.

Imaging atherosclerotic plaque composition with intracoronary optical coherence tomography (Article)

2009-11-01T00:00:00Z

Optical coherence tomography (OCT) allows highly accurate diagnosis of atherosclerotic plaques, including measurement of the thickness of fibrous caps, permitting an assessment of the risk of rupture. While the OCT image presents morphological information in highly resolved detail, it relies on interpretation by trained readers for the identification of tissue type. We developed a method for quantitative classification of atherosclerotic plaque constituents. The optical attenuation coefficient μtdistinguishes different tissue types: necrotic core and macrophage infiltration exhibit strong attenuation, μt≥10 mm-1, while calcific and fibrous tissue have a lower μt≈2-5 mm-1.

Towards oncological application of Raman spectroscopy (Article)

2009-02-01T00:00:00Z

As the possibilities in the treatment of cancer continue to evolve, its early detection and correct diagnosis are becoming increasingly important. Froum the early detection of cancer to the guidance of oncosurgical procedures new sensitive in vivo diagnostic tools are much needed. Many studies report the Raman spectroscopic detection of malignant and premalignanl tissues in different sites of the body with high sensitivities. The great appeal of this technique lies in its potential for in vivo clinical implementation. We present an overview of the in vitro and in vivo work on the oncological application of Raman spectroscopy and discuss its potential as a new tool in the clinico-oncological practice. Opportunities for integration of Raman spectroscopy in oncological cure and care as a real-time guidance tool during diagnostic (i.e. biopsy) and therapeutic (surgical resection) modalities as well as technical shortcomings are discussed from a clinicians point of view. Hut lire Rinnan application lor real-time tumor-border

Raman spectroscopic characterization of porcine brain tissue using a single fiber-optic probe (Article)

2007-01-15T00:00:00Z

Accurate targeting of diseased and healthy tissue has significantly been improved by MRI/CT-based navigation systems. Recently, intraoperative MRI navigation systems have proven to be powerful tools for the guidance of the neurosurgical operations. However, the widespread use of such systems is held back by the costs, the time consumption during operation, and the need for MR-compatible surgical devices. Raman spectroscopy is a nondestructive optical technique that enables real-time tissue identification and classification and has proved to be a powerful diagnostic tool in a large number of studies. In the present report, we have investigated the possibility of distinguishing different brain structures by using a single fiber-optic probe to collect Raman scattered light in the high-wavenumber region of the spectrum. For the Raman measurements, 7 pig brains were sliced in the coronal plain and Raman spectra were obtained of 11-19 anatomical structures. Adjacent brain structures could be distinguished based on their Raman spectra, reflecting the differences in their biochemical composition and illustrating the potential Raman spectroscopy holds as a guidance tool during neurosurgical procedures.