Automatic analysis of virtual slides to help in the determination of well established prognostic parameters in breast carcinomas

Transcription

1 Loews hotel Le Concorde, Quebec Canada August 3-5, 2011 H.I.Q Automatic analysis of virtual slides to help in the determination of well established prognostic parameters in breast carcinomas N Elie 1, V Becette 2, B Plancoulaine 1, H Pezeril 2, M Brecin 2, Y Denoux 2, J Chasle 2, C Bor 2, P Herlin 1. 1-"Histo-Imagerie Quantitative" Team,GRECAN, EA 1772, IFR146 ICORE University of Caen Basse-Normandie, François Baclesse Cancer Centre, Caen, France. 2-Pathology Department, François Baclesse Cancer Centre, Caen, France. 1

2 Aim Implementation of a image processing strategy to automate all the steps leading to the histological grading of breast cancer on virtual slide. Loews hotel Le Concorde, Quebec Canada 2

3 Histological grading of breast cancer Tumor grading system combines tubule formation, nuclear pleomorphism and mitotic activity : Tubule Formation Majority of tumor (>75%) 1 Moderate Degree (10-75%) 2 Little or None (<10%) 3 Nuclear Pleomorphism Small regular uniform cells 1 Moderate Nuclear Variation 2 Marked Nuclear Variation 3 Mitotic Count 0-9* Mitoses / 10 fields * Mitoses / 10 fields 2 20* or > Mitoses / 10 fields 3 *the limits depend on the size of the field Histological Grade Low Grade (I) 3-5 Intermediate Grade (II) 6-7 High Grade (III) 8-9 Low grade : = Grade I High grade : = Grade III Loews hotel Le Concorde, Quebec Canada 3

4 Study 370 patients operated between 1991 and 1995 two successive histological slides were stained One slide stained with H&E This slide is given to the pathologist to visually determine the grade of Elston and Ellis under the microscope. One slide immunostained for identification of mitotic figures (phosphohistone-h3 antibody ). This slide is devoted to image analysis for an automated determination of the grade. Validation Comparison of the prognostic values of these two scores. Evaluation of the prognostic value of the automatic histological grade. Loews hotel Le Concorde, Quebec Canada 4

5 Why not using H&E slide?? Images : C.Blanc-Fournier P.Herlin Prophase Telophase Loews hotel Le Concorde, Quebec Canada 5

6 Elston and Ellis grading automated strategy [ High Resolution dpi] Virtual Slide x20 [2] Nuclear Pleomorphism Segmentation of nuclei in the islets Use of the stereological volume weigthed mean volume technique Sub-sampling [3] Mitotic Count (b) High resolution Enumeration of mitotic figures on 10 contiguous fields (mimecking visual method) [1] Tubule Formation Automatic location of tumor cell islets Analysis of the islets to determine the score (a) Low resolution Search of all immunostained objects (potentially mitotic figures) Automated identification of Hot spot [ Low Resolution dpi] Based on patent : FR (A1)/WO/2010/ Loews hotel Le Concorde, Quebec Canada 6

7 Technical validation strategy : Quality Control To validate the choice of algorithms and cut-offs we used on ten images : Stereological probes to compute specificity/sensitivity A receiver operating characteristic (ROC) curve Manual identification with stereology Automatic Identification (Image Analysis) Quality Control FN TN TP FP TN Herlin P et al. 10th Europ Congress on Telepath, 4nd Int Congress on Virtual Microsc, Vilnius, Lithuania 1-3 July, 2010 Loews hotel Le Concorde, Quebec Canada 7

8 Tubule formation: Image Analysis Segmentation Morphometric parameters - Numerical density of holes in cancer compartment - Perimeter of cancer compartment divided by area of cancer compartment - Ratio between number of holse in cancer compartment and number of cancer compartment Loews hotel Le Concorde, Quebec Canada 8

9 Tubule formation: Quality control and validation Comparison of sensitivities and specificities of different segmentation algorithms of tumor cell islets Survival curves based on "tubule formation score determined by image analysis p< Score 1 Score 3 time(month) The best method allows to only characterize score 1 and score 3 Survival curves based on "tubule formation" score determined by a Pathologist p=0, Score 1 Score 2 Score 3 Time (month) Loews hotel Le Concorde, Quebec Canada 9

10 Nuclear Pleomorphism : Image Analysis systematic uniform random sampling Nuclei segmentation Cancer areas only Cancer Nuclei Virtual slide x20 Segmentation of epithelial islets volume-weighted mean volume and shape factor : Costar Stereological estimation of the volume-weighted mean volume of arbitrary particles observed on random sections. Gundersen HJ, Jensen EB.J Microsc May;138(Pt 2): Loews hotel Le Concorde, Quebec Canada 10

11 Nuclear Pleomorphism : Validation Determination of cut-offs with ROC curves to separate score 1, score 2 and score Survival curves based on pleomorphism score determined by image analysis score 1 score 2 score 3 p= p<10-4 Time (month) Survival curves based on pleomorphism score determined by a Pathologist 100 score 1 score 2 score 3 time(month) Loews hotel Le Concorde, Quebec Canada 11

12 Mitotic count : Image Analysis [4] Counting of mitotic figures in 10 fields [1] [2] [5] Defines the Mitosis score [3] 1. Immunolabelled objects (red dots) 2. Hot spot (yellow outline) 3. Ten selected fields (orange outline) Loews hotel Le Concorde, Quebec Canada 12

13 Mitotic count : Quality control and validation Sensitivity of detection of mitosis figures Image Analysis Number of mitotic figures Pathologist versus Image Analysis Spearman s correlation r=0.75 p< Method 1 Method 2 Method 3 Method 4 Method 5 Pathologist Survival curves based on Mitotic count score determined by image analysis Survival curves based on score Mitotic count" score determined by a Pathologist score 1 score 2 score 3 score 1 score 2 score 3 p= p<10-4 time(month) time(month) Loews hotel Le Concorde, Quebec Canada 13

14 Results of determination of Histological Grade Survival curves based on Histologic Grade determined by image analysis p=0,0004 Grade Grade I I Grade II Grade II Grade III Grade III Survival curves based on Histologic Grade determined by a Pathologist p<10-4 Grade I Grade I Grade Grade II II Grade Grade III III Time (month) Time (month) Loews hotel Le Concorde, Quebec Canada 14

15 Discussion It is necessary : To improve the automatic determination of the "tubule formation score. To compare the choice of the Hot Spot done by the pathologist and by image analysis. To compare of the pathologist and image analysis scores performed on immunostained slides. Study discordant cases (Grade I vs. Grade III) To test the procedure on a multi-centric collections of tumors. Loews hotel Le Concorde, Quebec Canada 15

16 Thanking «Histo-Imagerie Quantitative» Team Université Caen Basse-Normandie Benoît Plancoulaine Philippe Belhomme Myriam Oger Julien Roger F.Baclesse Cancer centre Paulette Herlin Nicolas Elie Pathology department Catherine Bor Jean-Jacques Michels Jacques Chasle Jacques Marnay Mylène Brecin Others participants Véronique Becette Yves Denoux Support Loews hotel Le Concorde, Quebec Canada 16