FUZZ-IEEE 2009
Methods of Interpretation of a Non-stationary Fuzzy System for the Treatment of Breast Cancer
Xiao-Ying Wang1, Jonathan M. Garibaldi1, Shang-Ming Zhou2, Robert I. John2
1 The University of Nottingham, Nottingham, UK2 De Montfort University, Leicester, UK
Speaker: Dr. Xiao-Ying Wang (Sally)Supervisor: Dr. Jon Garibaldi
FUZZ-IEEE 2009
Outline
IntroductionIntroduction
Data Description
Non-stationary FS
Type-1 FS
NS FS Output NS FS Output ProcessingProcessing
Experiments
Conclusions
• Breast Cancer treatment decision making• Multidisciplinary team
(oncologist, radiologist, surgeon, pathologist)
• Computational intelligence techniques in breast cancer diagnosis and decision making
• Uncertain and imprecise terms • Traditional fuzzy methods (Type-1, Type-2)• Non-stationary fuzzy sets
IntroductionIntroduction
An example of a non-stationary fuzzy set with multiple instantiations
)8,5,2,(xmf
)8,5,2,(xmf
Non-stationary FS
(2)
))(),(),(,( 321 tptptpxmf
An example of a non-stationary fuzzy set with multiple instantiations
20
1
0.02function on distributi Normal
)()()()(
functions Perturb
321
321
n
kkkk
tftftftf
Non-stationary FS
(3)
An outline of a non-stationary fuzzy inference system
Non-stationary FS
(1)
?
• Breast cancer post operative (adjuvant) treatment decision data • From City Hospital Nottingham Breast Institute
(multidisciplinary team)
Attributes + Treatment decisions
(1310 real patients cases)
Data Description
(1)
• Attributes: Patients’ age Lymph node stage, the number of positive lymph
node found from samples Nottingham prognostic index (NPI) value -an indication of how successful treatment might be
-NPI = (0.2 x tumour diameter in cms) + lymph node stage + tumour grade Estrogen receptor (ER) test result Vascular invasion test result
Data Description
(2)
• Treatment DecisionsHormone therapyRadiotherapyChemotherapyFurther operationFollow up
Data Description
(3)
Clinical guideline for adjuvant therapy following surgery
Data Description
(4)
Fuzzy rules derived directly from the clinical guidelines
Type-1 FS(3)
Type-1 FS(1)
No [0, 55]Maybe (55,56] Yes (56, 100)
Type-1 FS(2)
• Confusion matrix obtained by the original type-1 fuzzy system
Type-1 FS(4)
Agreement:
(982+2+124)/1310 = 84.6%
• Type-1 fuzzy system (FS) Non-stationary FS• Perturbation function – normal distribution
standard deviation iteration = 30
• Output processing methods:– Existing non-stationary FS output approach– method– method
NS FS Output NS FS Output ProcessingProcessing
(1)(1)
0.1 ... 0.02, ,01.0
MajorityMajority
Sum-avgSum-avg
Ns-avgNs-avg
Ns-avgNs-avg
NS FS Output NS FS Output ProcessingProcessing
(2)(2)
NS FS Output NS FS Output ProcessingProcessing
(3)(3)
Sum-avgSum-avg
NS FS Output NS FS Output ProcessingProcessing
(4)(4)MajorityMajority
The number of agreements obtained over a range of variation for the three output processing methods
Experiments(1)
MajorityMajority
Sum-avgSum-avg
Ns-avgNs-avg
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1
No.
of
Agr
eem
ent
1150
1140
1130
1120
1110
1100
1000
The best confusion matrices obtained for the three different methods of Output Interpretation
Experiments(2)
Ns-avgNs-avg Sum-avgSum-avg MajorityMajority
Advantage on output of NS FS
• Improvement of accuracy• Best no. of agreement achieved on sd = 0.08
• Breast cancer follow up (adjuvant) treatment • Type-1, Type-2, non-stationary FS• Non-stationary FS applies to decision making• Proposed two new ways to interpret NS FS
Output processing.• Majority method improves the accuracy of a
NS FS
Conclusions
• Represent variation within FIS• Variation comparison between FIS and real
clinical experts• Potential other output processing methods in
NS FS
Future work
References• B. Kovalerchuk, E. Triantaphyllou, J. F. Ruiz, and J. Clayton, “Fuzzy logic in computer-aided
breast cancer diagnosis: Analysis of lobulation,” Artificial Intelligence in Medicine, vol. 11, no. 1, pp. 75–85, 1997.
• C. A. Pena-Reyes and M. Sipper, “A fuzzy-genetic approach to breast cancer diagnosis,” Artificial Intelligence in Medicine, vol. 17, pp. 131–135, 1999.
• H. A. Abbass, “An evolutionary artificial neural networks approach for breast cancer diagnosis,” Artificial Intelligence in Medicine, vol. 23, no. 3, pp. 265–181, 2002.
• X. Xiong, Y. Kim, Y. Baek, D. W. Rhee, and S.-H. Kim, “Analysis of breast cancer using data mining and statistical techniques,” in Proceedings of 6th Intelligence Conference on Software Engineering (SNPD/SWQN’05), Maryland, USA, 2005, pp. 82–87.
• S.-M. Zhou, R. I. John, X.-Y. Wang, J. M. Garibaldi, and I. O. Ellis, “Compact fuzzy rules induction and feature extraction using SVM with particle swarms for breast cancer treatments,” in Proceedings of the IEEE Congress on Evolutionary Computation (CEC 2008), Hong Kong, China, 2008, pp. 1469–1475.
• J. M. Garibaldi, M. Jaroszewski, and S. Musikasuwan, “Non-stationary fuzzy sets,” IEEE Transations on Fuzzy Systems, vol. 16 (4), pp. 1072–1086, 2008.
FUZZ-IEEE 2009
Literature
• Fuzzy sets to represent the opinions for radiologists in analysing two important features from the American College of Radiology Breast Imaging Lexicon [Kovalerchuk et al 1997]
• Fuzzy-genetic method to Wisconsin BC diagnosis data. Genetic algorithm was used to generate a fuzzy inference system [Pena-Reyes and Sipper 1999]
• Evolutionary arificial neural network for BC diagnosis [Abbass 2002]
• Data mining for decision trees and association rules to discover unsuspected relationship within BC data [Xiong 2005]
• Particle swarming optimisation within a support vector machine for recommending treatments in BC [Zhou et al 2008]
How to process the output of NS FS
Average
What’s NS FS ?
A fuzzy system where the variability is introduced through the random alterations to the parameters of the membership functions
over time