Masoom A Haider

University of Toronto, Toronto, Ontario, Canada

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Publications (230)690.34 Total impact

  • A. Chung, C. Scharfenberger, F. Khalvati, A. Wong, M. A. Haider
    International Conference on Image Analysis and Recognition (ICIAR), Niagara Falls, ON, Canada; 07/2015
  • E. Li, M. J. Sha fiee, Audrey Chung, Farzad Khalvati, Alexander Wong, Masoom A. Haider
    International Society for Magnetic Resonance in Medicine (ISMRM), Toronto, ON, Canada; 06/2015
  • Annual Meeting of International Society for Magnetic Resonance in Medicine (ISMRM), Toronto, ON, Canada; 06/2015
  • Annual Meeting of Inter- national Society for Magnetic Resonance in Medicine (ISMRM), Toronto, ON, Canada; 06/2015
  • D. S. Cho, F. Khalvati, A. Wong, M. A. Haider
    Annual Meeting of International Society for Magnetic Resonance in Medicine (ISMRM), Toronto, ON, Canada; 06/2015
  • International Symposium on BIOMEDICAL IMAGING (ISBI), Brookklyn, NY, USA; 04/2015
  • Alexander Wong, Farzad Khalvati, Masoom A. Haider
    International Symposium on Biomedical Imaging (ISBI), Brooklyn, NY, USA; 04/2015
  • Annual meeting of Society of Thoracic Radiology, Carlsbad, CA, USA; 03/2015
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    ABSTRACT: Background In active surveillance (AS) patients: (i) To compare the ability of a multiparametric MRI (mpMRI)-ultrasound biopsy system to detect clinically significant (CS) prostate cancer with systematic 12-core biopsy (R-TRUSBx), and (ii) To assess the predictive value of mpMRI with biopsy as the reference standard. Methods Seventy-two men on AS prospectively underwent 3T mpMRI . MRI-ultrasound fusion biopsy (UroNavBx) and R-TRUSBx was performed. CS cancer was defined using two thresholds: 1) GS7 (CS7) and 2) GS=6 with >50% involvement (GS6). CS cancer detection rates and predictive values were determined. ResultsCS7 cancers were found in 19/72 (26%), 7 (37%) identified by UroNavBx alone, 2 (11%) by R-TRUSBx alone (P=0.182). UroNav targeted biopsy was 6.3x more likely to yield a core positive for CS7 cancer compared with R-TRUSBx (25% of 141 versus 4% of 874, P<0.001). Upgrading of GS occurred in 15/72 patients (21%), 13 (87%) detected by UroNavBx and 10 (67%) by R-TRUSBx. The NPV of mpMRI for CS7 cancer was 100%. MRI suspicion level significantly predicted CS cancer on multivariate analysis (OR 3.6, P<0.001). Conclusion UroNavBx detected CS cancer with far fewer cores compared with R-TRUSBx, and mpMRI had a perfect negative predictive value in this population. J. Magn. Reson. Imaging 2015;41:220-225. (c) 2014 Wiley Periodicals, Inc.
    Journal of Magnetic Resonance Imaging 01/2015; 41(1). DOI:10.1002/jmri.24710 · 2.79 Impact Factor
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    ABSTRACT: Pivotal phase III trials have positioned angiogenesis inhibitors as first-line therapy for the management of most advanced or metastatic renal cell carcinomas (mRCC). Approaches to second-line therapy, however, remain more controversial with respect to drug selection and drug sequencing. In this study we evaluated mRCC patients who were initially treated on the first-line National Cancer Institute (NCI) trial with the highly potent vascular endothelial growth factor receptor tyrosine kinase inhibitor (TKI), cediranib, to determine the efficacy and tolerability of subsequent therapies. Twenty-eight (65.1%) of the 43 patients enrolled on the first-line cediranib trial were known to receive second-line therapy, most commonly sunitinib (n = 21), with 4 (14%), 2 (7%) and 1 (3%) patients receiving temsirolimus, sorafenib, and interleukin, respectively. Of these, 14 (50%) went on to have 3 or more lines of therapy. The progression-free survival (PFS) proportion (PFS) at 1 year from starting second line was 30% (14.5%-47.9%). Longer duration of first-line cediranib treatment was modestly associated with longer duration of second-line treatment (Spearman rho 0.26). Patients who discontinued cediranib for toxicity were less likely to receive second-line sunitinib. In this real world evaluation, sequential use of TKIs for the management of mRCC was common. PFS with sequential TKIs was similar to observed and published results for any second-line therapy. Prior toxicity affected treatment patterns and the frequent use of at least 3 lines of therapy underscores the need for prospective sequencing trials in this disease.
    11/2014; 8(11-12):398-402. DOI:10.5489/cuaj.2426
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    ABSTRACT: Photodynamic therapy (PDT) can be employed as a focal therapy for prostate cancer. Dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) can potentially help identify tumour recurrence after failed external-beam radiotherapy (EBRT). The purpose of this study was to determine the ability of DCE-MRI to predict early response to PDT salvage treatment. Patients with post-EBRT prostate cancer recurrence were prospectively enrolled into a Phase I/II trial of PDT using WST09. A 15-patient subgroup of this cohort undergoing 1.5T DCE-MRI at baseline and 1-week post-PDT was retrospectively analyzed. The reference standard was prostate biopsy obtained 6 months post-PDT. Analysis was performed on a patient-by-patient basis, by prostate gland halves, and by prostate sextants. Biopsy 6 months post-PDT identified cancer in 10/15 patients (66.7%), and in 24/90 sextants (26.7%). Residual cancer was identified in 22/37 sextants (59.5%) identified as being involved at baseline. DCE-MRI at 1 week correctly predicted recurrent disease with a sensitivity of 100% (10/10), specificity of 60% (3/5), positive predictive value of 83.3% (10/12), negative predictive value of 100% (3/3), and an overall accuracy of 86.7%, (13/15). When analysis was performed on prostate halves, the sensitivity and negative predictive value remained at 100%, with an improvement in specificity to 88.2% (15/17). The overall accuracy of DCE-MRI was similar regardless of analysis method: 86.7% on a patient-by-patient basis, 86.7% by prostate half and 83.3% by sextant. Changes in prostate-specific antigen (PSA) did not correlate to response. DCE-MRI shows promise as a tool to predict successful outcome when performed 1 week post-PDT and could potentially be used to inform the need for re-treatment at an early time-point.
    10/2014; 8(9-10):E708-E714. DOI:10.5489/cuaj.2176
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    ABSTRACT: In this work, we present a new multi-parametric magnetic resonance imaging (MP-MRI) texture feature model for automatic detection of prostate cancer. In addition to commonly used imaging sequences in conventional MP-MRI, namely T2-weighted MRI (T2w) and diffusion-weighted imaging (DWI), our proposed MP-MRI texture feature model uses computed high-b DWI (CHB-DWI) and a new diffusion imaging sequence called correlated diffusion imaging (CDI). A set of texture features was calculated for both the conventional MP-MRI and new MP-MRI texture feature model. We evaluated the performance of the proposed MP-MRI texture feature model via leave-one-patient-out cross-validation using a Bayesian classifier trained on cancerous and healthy tissue samples obtained from real clinical MP-MRI datasets. The proposed MP-MRI texture feature model outperformed the conventional model (i.e., T2w+DWI) with regard to cancer detection accuracy.
    International Conference on Medical Image Computing and Computer Assisted Intervention (MICCAI), Computational Diffusion MRI Workshop,, Boston, Massachusetts, USA; 09/2014
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    ABSTRACT: Purpose To determine if the integration of diagnostic magnetic resonance (MR) imaging and MR-guided biopsy would improve target delineation for focal salvage therapy in men with prostate cancer. Materials and Methods Between September 2008 and March 2011, 30 men with biochemical failure after radiation therapy for prostate cancer provided written informed consent and were enrolled in a prospective clinical trial approved by the institutional research ethics board. An integrated diagnostic MR imaging and interventional biopsy procedure was performed with a 1.5-T MR imager by using a prototype table and stereotactic transperineal template. Multiparametric MR imaging (T2-weighted, dynamic contrast material-enhanced, and diffusion-weighted sequences) was followed by targeted biopsy of suspicious regions and systematic sextant sampling. Biopsy needle locations were imaged and registered to diagnostic images. Two observers blinded to clinical data and the results of prior imaging studies delineated tumor boundaries. Area under the receiver operating characteristic curve (Az) was calculated based on generalized linear models by using biopsy as the reference standard to distinguish benign from malignant lesions. Results Twenty-eight patients were analyzed. Most patients (n = 22) had local recurrence, with 82% (18 of 22) having unifocal disease. When multiparametric volumes from two observers were combined, it increased the apparent overall tumor volume by 30%; however, volumes remained small (mean, 2.9 mL; range, 0.5-8.3 mL). Tumor target boundaries differed between T2-weighted, dynamic contrast-enhanced, and diffusion-weighted sequences (mean Dice coefficient, 0.13-0.35). Diagnostic accuracy in the identification of tumors improved with a multiparametric approach versus a strictly T2-weighted or dynamic contrast-enhanced approach through an improvement in sensitivity (observer 1, 0.65 vs 0.35 and 0.44, respectively; observer 2, 0.82 vs 0.64 and 0.53, respectively; P < .05) and improved further with a 5-mm expansion margin (Az = 0.85 vs 0.91 for observer 2). After excluding three patients with fewer than six informative biopsy cores and six patients with inadequately stained margins, MR-guided biopsy enabled more accurate delineation of the tumor target volume be means of exclusion of false-positive results in 26% (five of 19 patients), false-negative results in 11% (two of 19 patients) and by guiding extension of tumor boundaries in 16% (three of 19 patients). Conclusion The integration of guided biopsy with diagnostic MR imaging is feasible and alters delineation of the tumor target boundary in a substantial proportion of patients considering focal salvage. © RSNA, 2014 Online supplemental material is available for this article.
    Radiology 09/2014; DOI:10.1148/radiol.14122681 · 6.21 Impact Factor
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    ABSTRACT: Normalized entropy is a strong predictor of patient survival rate for lung and renal cell cancers in CT images. In this work, we present a semi-automatic algorithm to compute the normalized entropy of lung metastasis from renal cell cancer via spatio-textural tumour classification. The proposed algorithm only requires a single click from the user to calculate the normalized entropy for tumours, thus, minimizing the amount of user intervention required. We evaluated the performance of the proposed approach in computing normalized entropy with respect to the normalized entropy calculated via manual clinical segmentation, and a correlation of 0.87 was achieved.
    International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Chicago, Illinois, USA; 08/2014
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    ABSTRACT: Multiparametric MRI has shown considerable promise as a diagnostic tool for prostate cancer grading. Diffusion-weighted MRI (DWI) has shown particularly strong potential for improving the delineation between cancerous and healthy tissue in the prostate gland. Current automated diagnostic methods using multiparametric MRI, however, tend to either use low-level features, which are difficult to interpret by radiologists and clinicians, or use highly subjective heuristic methods. We propose a novel strategy comprising a tumor candidate identification scheme and a hybrid textural/morphological feature model for delineating between cancerous and non-cancerous tumor candidates in the prostate gland via multiparametric MRI. Experimental results using clinical multiparametric MRI datasets show that the proposed strategy has strong potential as a diagnostic tool to aid radiologists and clinicians identify and detect prostate cancer more efficiently and effectively.
    International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Chicago, Illinois, USA; 08/2014
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    ABSTRACT: The clinical use of conventional ultrasonography (US) in autosomal dominant polycystic kidney disease (ADPKD) is currently limited by reduced diagnostic sensitivity, especially in at-risk subjects younger than 30 years of age. In this single-center prospective study, we compared the diagnostic performance of MRI with that of high-resolution (HR) US in 126 subjects ages 16-40 years born with a 50% risk of ADPKD who underwent both these renal imaging studies and comprehensive PKD1 and PKD2 mutation screening. Concurrently, 45 healthy control subjects without a family history of ADPKD completed the same imaging protocol. We analyzed 110 at-risk subjects whose disease status was unequivocally defined by molecular testing and 45 unaffected healthy control subjects. Using a total of >10 cysts as a test criterion in subjects younger than 30 years of age, we found that MRI provided both a sensitivity and specificity of 100%. Comparison of our results from HR US with those from a previous study of conventional US using the test criterion of a total of three or more cysts found a higher diagnostic sensitivity (approximately 97% versus approximately 82%) with a slightly decreased specificity (approximately 98% versus 100%) in this study. Similar results were obtained in test subjects between the ages of 30 and 40 years old. These results suggest that MRI is highly sensitive and specific for diagnosis of ADPKD. HR US has the potential to rival the diagnostic performance of MRI but is both center- and operator-dependent.
    Journal of the American Society of Nephrology 07/2014; 26(3). DOI:10.1681/ASN.2014030297 · 9.47 Impact Factor
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    ABSTRACT: Patients with colorectal cancer with liver metastases undergo hepatic resection with curative intent. Positron emission tomography combined with computed tomography (PET-CT) could help avoid noncurative surgery by identifying patients with occult metastases. To determine the effect of preoperative PET-CT vs no PET-CT (control) on the surgical management of patients with resectable metastases and to investigate the effect of PET-CT on survival and the association between the standardized uptake value (ratio of tissue radioactivity to injected radioactivity adjusted by weight) and survival. A randomized trial of patients older than 18 years with colorectal cancer treated by surgery, with resectable metastases based on CT scans of the chest, abdomen, and pelvis within the previous 30 days, and with a clear colonoscopy within the previous 18 months was conducted between 2005 and 2013, involving 21 surgeons at 9 hospitals in Ontario, Canada, with PET-CT scanners at 5 academic institutions. Patients were randomized using a 2 to 1 ratio to PET-CT or control. The primary outcome was a change in surgical management defined as canceled hepatic surgery, more extensive hepatic surgery, or additional organ surgery based on the PET-CT. Survival was a secondary outcome. Of the 263 patients who underwent PET-CT, 21 had a change in surgical management (8.0%; 95% CI, 5.0%-11.9%). Specifically, 7 patients (2.7%) did not undergo laparotomy, 4 (1.5%) had more extensive hepatic surgery, 9 (3.4%) had additional organ surgery (8 of whom had hepatic resection), and the abdominal cavity was opened in 1 patient but hepatic surgery was not performed and the cavity was closed. Liver resection was performed in 91% of patients in the PET-CT group and 92% of the control group. After a median follow-up of 36 months, the estimated mortality rate was 11.13 (95% CI, 8.95-13.68) events/1000 person-months for the PET-CT group and 12.71 (95% CI, 9.40-16.80) events/1000 person-months for the control group. Survival did not differ between the 2 groups (hazard ratio, 0.86 [95% CI, 0.60-1.21]; P = .38). The standardized uptake value was associated with survival (hazard ratio, 1.11 [90% CI, 1.07-1.15] per unit increase; P < .001). The C statistic for the model including the standardized uptake value was 0.62 (95% CI, 0.56-0.68) and without it was 0.50 (95% CI, 0.44-0.56). The difference in C statistics is 0.12 (95% CI, 0.04-0.21). The low C statistic suggests that the standard uptake value is not a strong predictor of overall survival. Among patients with potentially resectable hepatic metastases of colorectal adenocarcinoma, the use of PET-CT compared with CT alone did not result in frequent change in surgical management. These findings raise questions about the value of PET-CT scans in this setting. clinicaltrials.gov Identifier: NCT00265356.
    JAMA The Journal of the American Medical Association 05/2014; 311(18):1863-9. DOI:10.1001/jama.2014.3740 · 30.39 Impact Factor
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    ABSTRACT: To determine whether R2* values are a consistent predictor of hepatic iron concentration (HIC) in thalassemia patients by demonstrating a correlation between R2* relaxation rates and FerriScan-determined HIC. Eighty-eight patients with thalassemia major were retrospectively evaluated. All patients underwent FerriScan imaging and multiecho gradient echo imaging. The results from FerriScan analysis were fitted against R2* estimates using linear regression. There was a very strong linear correlation between R2* values and FerriScan-determined HIC (Spearman correlation of 0.976; 95% confidence interval [CI]: 0.963, 0.984). R2* values can predict HIC determined by FerriScan using a linear calibration curve. This technique may provide a potentially cost-saving alternative for hepatic iron determination and improve acceptance by referring physicians.J. Magn. Reson. Imaging 2013. © 2013 Wiley Periodicals, Inc.
    Journal of Magnetic Resonance Imaging 04/2014; 39(4). DOI:10.1002/jmri.24216 · 2.79 Impact Factor
  • Brachytherapy 03/2014; 13:S71. DOI:10.1016/j.brachy.2014.02.324 · 1.99 Impact Factor
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    ABSTRACT: Most small renal masses (SRMs) are diagnosed incidentally and have a low malignant potential. As more elderly patients and infirm patients are diagnosed with SRMs, there is an increased interest in active surveillance (AS) with delayed intervention. Patient and tumour characteristics relating to aggressive disease have not been well-studied. The objective was to determine predictors of growth of SRMs treated with AS. A multicentre prospective phase 2 clinical trial was conducted on 207 SRMs in 169 patients in 8 institutions in Canada from 2004 to 2009; in these patients treatment was delayed until disease progression. Patient and tumour characteristics were evaluated to determine predictors of growth of SRMs by measuring rates of change in growth (on imaging) over time. All patients underwent AS for presumed renal cell carcinoma (RCC) based on diagnostic imaging. We used the following factors to develop a predictive model of tumour growth with binary recursive partitioning analysis: patient characteristics (age, symptoms at diagnosis) and tumour characteristics (consistency [solid vs. cystic] and maximum diameter at diagnosis. With a median follow-up of 603 days, 169 patients (with 207 SRMs) were followed prospectively. Age, symptoms at diagnosis, tumour consistency and maximum diameter of the renal mass were not predictors of growth. This cohort was limited by lack of availability of patient and tumour characteristics, such as sex, degree of endophytic component and tumour location. Slow growth rates and the low malignant potential of SRMs have led to AS as a treatment option in the elderly and infirm population. In a large prospective cohort, we have shown that age, symptoms, tumour consistency and maximum diameter of the mass at diagnosis are not predictors of growth of T1a lesions. More knowledge on predictors of growth of SRMs is needed.
    Canadian Urological Association journal = Journal de l'Association des urologues du Canada 02/2014; 8(1-2):24-7. DOI:10.5489/cuaj.1483 · 1.92 Impact Factor

Publication Stats

4k Citations
690.34 Total Impact Points

Institutions

  • 2000–2015
    • University of Toronto
      • • Department of Medical Imaging
      • • Department of Surgery
      • • Department of Radiation Oncology
      Toronto, Ontario, Canada
  • 2012–2014
    • Sunnybrook Health Sciences Centre
      • Department of Medical Imaging
      Toronto, Ontario, Canada
  • 2005–2014
    • University Health Network
      • • Joint Department of Medical Imaging
      • • Department of Medical Imaging
      Toronto, Ontario, Canada
  • 2003–2013
    • The Princess Margaret Hospital
      Toronto, Ontario, Canada
  • 2002–2012
    • Mount Sinai Hospital, Toronto
      • Department of Medical Imaging
      Toronto, Ontario, Canada
  • 2010
    • Mount Sinai Hospital
      New York City, New York, United States
  • 2009–2010
    • Illinois Institute of Technology
      • Department of Electrical & Computer Engineering
      Chicago, IL, United States