Project SK-AT-00206, based on the bilateral scientific cooperation between Austria and Slovakia

Duration of the project: 07/2006 - 12/2007

Principal investigator (SK): Doc. RNDr. Viktor Witkovský, CSc. (IMS SAS)

Principal investigator (AT): prof. Anton Amman (MUI)

Project partners: Institute of Measurement Science of the Slovak Academy of Sciences (IMS SAS) and Medical University of Innsbruck, Austria (MUI)

Financial support (SK): 60 000,- SKK (2006)

Project Summary

There is strong evidence to suggest that particulate cancers can be detected by molecular analysis of exhaled air. Breath analysis represents a new diagnostic technique that is without risk for the patient even if repeated frequently and can provide information beyond conventional analysis of blood and urine. Recent results suggest that detection of different kinds of cancer is possible by means of breath analysis in very early stages of the disease.

In this project we concentrate on development of particular statistical algorithms for data analysis of breath gas concentration measurements based on proton transfer reaction mass spectrometry (PTR-MS). The main objective of this bilateral project is to incorporate young researchers from Slovakia and Austria into the scientific research connected with the EU project BAMOD. Further objectives of the project are:

• Research of well-defined and theoretically optimal procedures for dicrimination and classification of possible patients, using classical parametric methods, statistical non-parametric methods, methods based on general linear models, using penalties in classification algorithms.
• Research of sensitivity, specificity, positive and negative predictive values, ROC curves, with the aim to prove clinical effectiveness. The main mathematical task will be optimization of classification algorithms.
• Training of classification procedures. It is important to characterize distributional properties of selected measures (e.g. concentrations of certain compounds of exhaled breath), to find optimal method for variable selection based on different criteria. Typical values of selected compounds of exhaled breath will be characterized (estimated, tested, compared) for each of the considered groups.
• Analysis of basic statistical properties of multivariate data observed in cancer patients and healthy people from a control group (the groups will be further divided by factors as e.g. smoking, age, gender etc.).
• Research of suitable one-dimensional and multivariate statistical models and methods
• for analysis of data with unequal variances,
• for determination of the comparison reference value,
• for determination of the uncertainty of this value,
• for determination of the degree of equivalence of the involved laboratories.

Results

During a month stay of Mgr. Svorad Štolc at the Medical University of Innsbruck, Austria (August 2006) several experiments were conducted in order to reveal the distribution of measured values of concentrations of volatile compounds in exhaled breath of healthy individuals. More precisely, the experiments were aimed at characterization of reproducibility and stability of measurements by PTR-MS (proton-transfer-reaction mass spectrometry). The results showed certain problems with stability of measurements of some volatile components of breath.

Under this project also some theoretical mathematical-statistical tasks have been solved that were not a part of the project 6FP EU BAMOD (Breath-gas analysis for molecular-oriented detection of minimal diseases), but that were directly connected with its topic. The results were presented by the authors at conferences. In 2006 the planned visit of the Austrian partner at the IM SAS was not realized and thus the allocated financial funds were not used.

Publications

• ARENDACKÁ, B.: Analýza vydychovaných plynov za účelom detekcie rakoviny. DATASTAT 2006, 4.9.-7.9.2006, Kozov, ČR
• CIMERMANOVÁ K.: Analýza vydychovaných plynov. Štatistické charakteristiky vybraných plynných komponentov vydýchnutého vzduchu meraného pomocou PTR-MS. Konferencia ODAM 2006, 7.9.-8.9.2006, Olomouc, ČR. Prednáška
• CIMERMANOVÁ, K: Statistical characteristics of selected volatile compounds in breath samples measured by PTR-MS. In: International scientific meeting Breath Analysis in Physiology and Medicine, International Association for Breath Research, 4.9.-5.9.2006, Praha, ČR
• WITKOVSKÝ, V. - CIMERMANOVÁ, K.: Testovanie zhodnosti stredných hodnôt vzoriek dychu pre detekciu rakoviny pľúc. In: J. Hartmann, J. Michálek, editors, XVII. letní škola biometriky. Biometrické metody a modely v současné vědě a výzkumu. Lednice, ČR, 21. - 25. 8., 2006, 433-442.