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| 2. |
- Azar, Jimmy, et al.
(författare)
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Microarray Core Detection by Geometric Restoration
- 2012
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Ingår i: Analytical Cellular Pathology. - 0921-8912 .- 1878-3651. ; 35:5-6, s. 381-393
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Tidskriftsartikel (refereegranskat)abstract
- Whole-slide imaging of tissue microarrays (TMAs) holds the promise of automated image analysis of a large number of histopathological samples from a single slide. This demands high-throughput image processing to enable analysis of these tissue samples for diagnosis of cancer and other conditions. In this paper, we present a completely automated method for the accurate detection and localization of tissue cores that is based on geometric restoration of the core shapes without placing any assumptions on grid geometry. The method relies on hierarchical clustering in conjunction with the Davies-Bouldin index for cluster validation in order to estimate the number of cores in the image wherefrom we estimate the core radius and refine this estimate using morphological granulometry. The final stage of the algorithm reconstructs circular discs from core sections such that these discs cover the entire region of each core regardless of the precise shape of the core. The results show that the proposed method is able to reconstruct core locations without any evidence of localization error. Furthermore, the algorithm is more efficient than existing methods based on the Hough transform for circle detection. The algorithm's simplicity, accuracy, and computational efficiency allow for automated high-throughput analysis of microarray images.
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| 3. |
- Bill-Axelson, Anna, et al.
(författare)
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Radical Prostatectomy or Watchful Waiting in Early Prostate Cancer
- 2014
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Ingår i: New England Journal of Medicine. - Waltham : Massachusetts Medical Society. - 0028-4793 .- 1533-4406. ; 370:10, s. 932-942
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundRadical prostatectomy reduces mortality among men with localized prostate cancer; however, important questions regarding long-term benefit remain. MethodsBetween 1989 and 1999, we randomly assigned 695 men with early prostate cancer to watchful waiting or radical prostatectomy and followed them through the end of 2012. The primary end points in the Scandinavian Prostate Cancer Group Study Number 4 (SPCG-4) were death from any cause, death from prostate cancer, and the risk of metastases. Secondary end points included the initiation of androgen-deprivation therapy. ResultsDuring 23.2 years of follow-up, 200 of 347 men in the surgery group and 247 of the 348 men in the watchful-waiting group died. Of the deaths, 63 in the surgery group and 99 in the watchful-waiting group were due to prostate cancer; the relative risk was 0.56 (95% confidence interval [CI], 0.41 to 0.77; P=0.001), and the absolute difference was 11.0 percentage points (95% CI, 4.5 to 17.5). The number needed to treat to prevent one death was 8. One man died after surgery in the radical-prostatectomy group. Androgen-deprivation therapy was used in fewer patients who underwent prostatectomy (a difference of 25.0 percentage points; 95% CI, 17.7 to 32.3). The benefit of surgery with respect to death from prostate cancer was largest in men younger than 65 years of age (relative risk, 0.45) and in those with intermediate-risk prostate cancer (relative risk, 0.38). However, radical prostatectomy was associated with a reduced risk of metastases among older men (relative risk, 0.68; P=0.04). ConclusionsExtended follow-up confirmed a substantial reduction in mortality after radical prostatectomy; the number needed to treat to prevent one death continued to decrease when the treatment was modified according to age at diagnosis and tumor risk. A large proportion of long-term survivors in the watchful-waiting group have not required any palliative treatment. (Funded by the Swedish Cancer Society and others.) The randomized Swedish trial of prostatectomy versus watchful waiting in disease detected mainly clinically (not by PSA screening) continues to show a benefit for early prostatectomy. The number of men younger than 65 needed to treat to prevent one death is now four. The Scandinavian Prostate Cancer Group Study Number 4 (SPCG-4), a randomized trial of radical prostatectomy versus watchful waiting in men with localized prostate cancer diagnosed before the era of prostate-specific antigen (PSA) testing, showed a survival benefit of radical prostatectomy as compared with observation at 15 years of follow-up.(1) By contrast, the Prostate Cancer Intervention versus Observation Trial (PIVOT), initiated in the early era of PSA testing, showed that radical prostatectomy did not significantly reduce prostate cancer-specific or overall mortality after 12 years.(2) PSA screening profoundly changes the clinical domain of study. Among other considerations, the substantial additional lead time ...
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| 4. |
- Bill-Axelson, Anna, et al.
(författare)
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Radical prostatectomy versus watchful waiting in early prostate cancer.
- 2011
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Ingår i: The New England journal of medicine. - : Massachussetts Medical Society. - 1533-4406 .- 0028-4793. ; 364:18, s. 1708-17
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Forskningsöversikt (refereegranskat)abstract
- In 2008, we reported that radical prostatectomy, as compared with watchful waiting, reduces the rate of death from prostate cancer. After an additional 3 years of follow-up, we now report estimated 15-year results.
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| 5. |
- Carlbom, Ingrid, et al.
(författare)
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Picro-Sirius-HTX Stain for Blind Color Decomposition of Histopathological Prostate Tissue
- 2014
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Ingår i: Proc, IEEE 11th International Symposium on Biomedical Imaging (ISBI) 2014. - 9781467319591 ; , s. 282-285
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Konferensbidrag (refereegranskat)abstract
- Gleason grading is the most widely used system for determining the severity of prostate cancer. The Gleason grade is determined visually under a microscope from prostate tissue that is most often stained with Hematoxylin-Eosin (H&E). In an earlier study we demonstrated that this stain is not ideal for machine learning applications, but that other stains, such as Sirius-hematoxylin (Sir-Htx), may perform better. In this paper we illustrate the advantages of this stain over H&E for blind color decomposition. When compared to ground truth defined by an experienced pathologist, the relative root-mean-square errors of the color decomposition mixing matrices for Sir-Htx are better than those for H&E by a factor of two, and the Pearson correlation coefficients of the density maps resulting from the decomposition of Sir-Htx-stained tissue gives a 99% correlation with the ground truth. Qualitative examples of the density maps confirm the quantitative findings and illustrate that the density maps will allow accurate segmentation of morphological features that determine the Gleason grade.
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| 6. |
- Gavrilovic, Milan, et al.
(författare)
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Blind Color Decomposition of Histological Images
- 2013
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Ingår i: IEEE Transactions on Medical Imaging. - 0278-0062 .- 1558-254X. ; 32:6, s. 983-994
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Tidskriftsartikel (refereegranskat)abstract
- Cancer diagnosis is based on visual examination under a microscope of tissue sections from biopsies. But whereas pathologists rely on tissue stains to identify morphological features, automated tissue recognition using color is fraught with problems that stem from image intensity variations due to variations in tissue preparation, variations in spectral signatures of the stained tissue, spectral overlap and spatial aliasing in acquisition, and noise at image acquisition. We present a blind method for color decomposition of histological images. The method decouples intensity from color information and bases the decomposition only on the tissue absorption characteristics of each stain. By modeling the charge-coupled device sensor noise, we improve the method accuracy. We extend current linear decomposition methods to include stained tissues where one spectral signature cannot be separated from all combinations of the other tissues' spectral signatures. We demonstrate both qualitatively and quantitatively that our method results in more accurate decompositions than methods based on non-negative matrix factorization and independent component analysis. The result is one density map for each stained tissue type that classifies portions of pixels into the correct stained tissue allowing accurate identification of morphological features that may be linked to cancer.
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| 7. |
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| 8. |
- Grundmark, Birgitta, et al.
(författare)
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The Metabolic Syndrome and the Risk of Prostate Cancer under Competing Risks of Death from Other Causes
- 2010
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - 1055-9965 .- 1538-7755. ; 19:8, s. 2088-2096
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Tidskriftsartikel (refereegranskat)abstract
- Background:Associations between metabolic syndrome (MetS) components and prostate cancer development have not been studied comprehensively; results have been divergent. Using the National Cholesterol Education Program Adult Treatment panel III (NCEP) and International Diabetes Federation (IDF) definitions of the MetS, we investigated such associations taking competing risks of death into consideration.Methods:In the prospective Uppsala Longitudinal Study of Adult Men of 2,322 Caucasian men with 34 years of follow-up baseline, MetS measurements at age 50 years were used. Cumulative incidence of prostate cancer and death with/without the MetS were calculated. Competing risk of dying was taken into account by calculating the conditional probability of prostate cancer with/without the MetS.Results:Two hundred and thirty-seven prostate cancers were identified. Prostate cancer probability by age 80 years with baseline MetS compared with without MetS was nonsignificantly higher [5.2 percent units (confidence interval (CI), -0.8% to 11.3%; NCEP); 2.7 percent units (CI, -2.7% to 8.0%; IDF)]; cumulative incidence proportions of death was significantly higher [19.3 percent units (CI, 13.4-25.3%; NCEP); 15.3 percent units (CI, 9.5-21.1%; IDF)]; and conditional probability of prostate cancer considering death from other causes was significantly higher [7.3 percent-units (CI, 0.2-14.5%); odds ratio of 1.64 (CI, 1.03-2.23; NCEP)] and nonsignificantly higher [5.0 percent-units (CI, -1.6% to 11.6%); odds ratio of 1.43 (CI, 0.89-1.90; IDF].Conclusions:The MetS by the NCEP definition is associated with prostate cancer, taking the competing risk of early death from other causes into account. Impact: The results further highlight the public health effect of the increasing prevalence of MetS and the importance of considering competing risks when studying risk factors for cancer.
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| 9. |
- Isfoss, Björn L, et al.
(författare)
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Diagnosis of intraurothelial neoplasia : Interobserver variation and the value of individual histopathologic attributes
- 2011
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Ingår i: Analytical and Quantitative Cytology and Histology. - 0884-6812. ; 33:2, s. 75-81
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To determine interobserver variation in histopathologic diagnosis of carcinoma in situ (CIS) and dysplasia (collectively intraurothelial neoplasia [IUN]) of the bladder and identify histomorphologic features important for diagnosis. STUDY DESIGN: A total of 272 consecutive bladder tissue samples were re-evaluated blindly by two general pathologists and one uropathologist for IUN. Discrepancies were resolved jointly. Fifteen histopathologic attributes were evaluated for prediction of diagnosis. Followup revealed recurrence and progression rates for each diagnostic category. RESULTS: Thirty-six percent of specimens contained no evaluable flat mucosa; 51% percent of specimens from papillary urothelial neoplasia (PUN) cases showed CIS. General pathologists detected 56-69% of CIS and 8-42% of dysplasia. Histopathologic features most predictive for CIS were nuclear size, variation in nuclear shape, loss of maturation, loss of polarity, and architectural disorder. None of these individually or in combination exceeded general pathologists' diagnostic accuracy. IUN was not predictive of recurrence or progress. CONCLUSION: Using material mostly consisting of flat mucosa gratuitously provided in PUN resection specimens, IUN carries no prognostic value. General histopathologists detect IUN poorly to moderately, and the five most discriminatory histomorphologic features are insufficient for diagnosis. Interobserver agreement for dysplasia is dismal. Absent flat mucosa in PUN resections predicts recurrence.
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| 10. |
- Isfoss, Björn L, et al.
(författare)
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Simplification of grading papillary urothelial neoplasia using a reduced set of diagnostic features
- 2011
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Ingår i: Analytical and Quantitative Cytology and Histology. - 0884-6812. ; 33:2, s. 68-74
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To determine whether a reduced set of the histopathologic features used in internationally accepted classifications is capable of accurately grading papillary urothelial neoplasms (PUN). STUDY DESIGN: All surgical specimens from urinary bladders received during a 2-year period were reexamined by an expert uropathologist for assessing the accuracy of original nonexpert PUN grading and staging. Thirteen histopathologic features entailing 32 attributes were evaluated with regard to prediction of expert grade. Patients were followed for 35-59 months (mean, 47). RESULTS: A total of 88 PUN specimens could be analyzed completely including follow-up specimens. Agreement between original and expert grade was 71% for low-grade and 87% for high-grade PUN, with overall kappa = 0.53. The histomorphologic features most predictive of expert grade were architectural disorder, variability of nuclear enlargement, and absence of umbrella cells. Neither individual histomorphologic attributes nor their combinations were as predictive of expert pathologist grade as original diagnoses. CONCLUSION: Improvements in PUN grading and prognostication are not likely to be accomplished by only reducing the number of histomorphologic features currently recommended by the World Health Organization and International Society of Urological Pathology.
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