Bio

Clinical Focus


  • Diagnostic Radiology

Academic Appointments


Professional Education


  • Medical Education:Stanford University School of Medicine (1998) CA
  • Residency:Stanford University School of Medicine (2003) CA
  • Board Certification: Diagnostic Radiology, American Board of Radiology (2003)
  • Internship:Pennsylvania State University - College of Medicine (1999) PA

Publications

Journal Articles


  • Why Are Patients Noncompliant With Follow-Up Recommendations After MRI-Guided Core Needle Biopsy of Suspicious Breast Lesions? AJR. American journal of roentgenology Thompson, M. O., Lipson, J., Daniel, B., Harrigal, C., Mullarkey, P., Pal, S., Thompson, A. C., Ikeda, D. 2013; 201 (6): 1391-1400

    Abstract

    OBJECTIVE. The objective of this study was to investigate patient and breast MRI characteristics associated with noncompliance with recommended follow-up after MRI-guided core needle biopsy of suspicious breast lesions. MATERIALS AND METHODS. A retrospective review was performed of 576 breast lesions biopsied under MRI guidance between 2007 and 2010. Patient follow-up was obtained from the medical record and from contact with referring physicians. RESULTS. Of 415 women who underwent 576 MRI-guided core needle biopsies for suspicious breast lesions, 123 (29.6%) patients representing 154 of 576 (26.7%) lesions were noncompliant with recommended excision or 6-month MRI follow-up. Referring physicians provided information for 63% (97/154) of lesions in noncompliant patients, of which 49.5% (48/97) were followed by mammography instead of excision or MRI. Noncompliance with MRI follow-up was significantly associated with referral for biopsy by outside hospital physicians (odds ratio [OR], 2.40; p = 0.0001) and with referral for screening MRI (1.46; p = 0.093) and biopsy of a focus or foci lesion (1.63; p = 0.088). Among 178 lesions in patients compliant with follow-up MRI after MRI-guided core needle biopsy, 7.9% (14/178) had abnormal follow-up MRI results, half of which (3.9%, 7/178) were found on repeat biopsy to be high-risk or malignant. CONCLUSION. Institutions performing MRI-guided core biopsies should be aware that patients referred from outside institutions are more likely to be noncompliant with recommended follow-up. Strategies to improve follow-up should include educating patients on the difference between mammography and MRI follow-up.

    View details for DOI 10.2214/AJR.12.10282

    View details for PubMedID 24261382

  • Freehand MRI-Guided Preoperative Needle Localization of Breast Lesions After MRI-Guided Vacuum-Assisted Core Needle Biopsy Without Marker Placement JOURNAL OF MAGNETIC RESONANCE IMAGING van de Ven, S. M., Lin, M. C., Daniel, B. L., Sareen, P., Lipson, J. A., Pal, S., Dirbas, F. M., Ikeda, D. M. 2010; 32 (1): 101-109

    Abstract

    To evaluate the feasibility of magnetic resonance imaging (MRI)-guided preoperative needle localization (PNL) of breast lesions previously sampled by MRI-guided vacuum-assisted core needle biopsy (VACNB) without marker placement.We reviewed 15 women with 16 breast lesions undergoing MRI-guided VACNB without marker placement who subsequently underwent MRI-guided PNL, both on an open 0.5T magnet using freehand techniques. Mammograms and specimen radiographs were rated for lesion visibility; MRI images were rated for lesion visibility and hematoma formation. Imaging findings were correlated with pathology.The average prebiopsy lesion size was 16 mm (range 4-50 mm) with 13/16 lesions located in mammographically dense breasts. Eight hematomas formed during VACNB (average size 13 mm, range 8-19 mm). PNL was performed for VACNB pathologies of cancer (5), high-risk lesions (5), or benign but discordant findings (6) at 2-78 days following VACNB. PNL targeted the lesion (2), hematoma (4), or surrounding breast architecture (10). Wire placement was successful in all 16 lesions. Final pathology showed six cancers, five high-risk lesions, and five benign findings.MRI-guided PNL is successful in removing lesions that have previously undergone VACNB without marker placement by targeting the residual lesion, hematoma, or surrounding breast architecture, even in mammographically dense breasts.

    View details for DOI 10.1002/jmri.22148

    View details for Web of Science ID 000279439600013

    View details for PubMedID 20575077

  • Estrogen receptor-negative invasive breast cancer: Imaging features of tumors with and without human epidermal growth factor receptor type 2 overexpression RADIOLOGY Wang, Y., Ikeda, D. M., Narasimhan, B., Longacre, T. A., Bleicher, R. J., Pal, S., Jackman, R. J., Jeffrey, S. S. 2008; 246 (2): 367-375

    Abstract

    To prospectively determine if estrogen receptor (ER)-negative human epidermal growth factor receptor type 2 (HER2)-positive and ER-negative HER2-negative breast cancers have distinguishing clinical and imaging features with use of retrospectively identified patients and tissue samples.This HIPAA-compliant study was institutional review board approved. Informed consent was obtained from living patients and waived for deceased patients. Mean patient age at diagnosis was 53 years (range, 31-84 years). Clinical history; histopathologic, mammographic, and breast sonographic findings; and HER2 status as determined with immunohistochemistry or fluorescent in situ hybridization were evaluated in 56 women with ER-negative breast cancer. Imaging appearances and clinicopathologic characteristics were correlated with tumor HER2 status. P < .05 indicated a significant difference.Lesion margins on mammograms (P = .028) and sonograms (P = .023), calcifications on mammograms (P = .003), and clinical cancer stage at diagnosis (P = .029) were significantly associated with HER2 status. In contrast to ER-negative HER2-negative tumors, ER-negative HER2-positive tumors were more likely to have spiculated margins (56% vs 15%), be associated with calcifications (65% vs 21%), and be detected at a higher cancer stage (74% vs 57%).Biologic diversity of cancers may manifest in imaging characteristics, and, conversely, studying the range of imaging features of cancers may help refine current molecular phenotypes.

    View details for DOI 10.1148/radio1.2462070169

    View details for Web of Science ID 000252796300005

    View details for PubMedID 18180338

  • Mammographic screening in women at increased risk of breast cancer after treatment of Hodgkin's disease BREAST JOURNAL Kwong, A., Hancock, S. L., Bloom, J. R., Pal, S., Birdwell, R. L., Mariscal, C., Ikeda, D. M. 2008; 14 (1): 39-48

    Abstract

    Treatment regimens for Hodgkin's disease (HD) that have included radiation to lymph node regions in the thorax have contributed to high rates of long-term disease-free survival. However, incidental radiation exposure of breast tissue in young women has significantly increased the risk of breast cancer compared to expected rates in the general population. After informing patients about risks associated with previous treatment of HD, we studied screening mammograms and call-back rates in women at increased risk for developing breast cancer at a younger age. We contacted by mail a cohort of 291 women between 25 and 55 years of age who had received thoracic irradiation before 35 years of age for HD with or without chemotherapy. Subjects were offered information about risks identified after HD therapy with questionnaires to assess response to this information. Ten patients refused participation, 93 did not respond, and 21 were excluded after they reported a prior diagnosis of invasive (1) or in situ (2) breast cancer. One hundred and sixty seven women received information about secondary breast cancer risk and were advised to initiate or maintain mammographic screening. Available mammograms were reviewed by two radiologists and classified according to the ACR BI-RADS Mammography Lexicon. Abnormal findings were correlated to pathology results from biopsies. One hundred and fifteen subjects reported that they obtained new mammograms during the period of the study. Ninety-nine were available for secondary review. Patients were studied an average of 16.9 years after HD treatment (Range: 4.5-32.5 years) at an average of 41 years of age (range 25-55 years). High density breast tissue was identified in 60% (60/99). Seventeen of the women (17.2%) were recalled for further imaging. This was more common in women with heterogeneously dense breast tissue. Seven of those recalled (41%) were advised to undergo biopsies that identified ductal carcinoma in situ (DCIS) in one and benign findings in the others. Among 16 women whose mammograms were unavailable for review, three were diagnosed with DCIS; two of these had microscopic evidence of invasive breast cancer. The four in situ or microinvasive cancers were diagnosed in the study participants at 25-40 years of age and from 5 to 23 years after HD therapy. Biopsies were performed because mammograms detected microcalcifications without palpable abnormality in three of these cases. Women who have had thoracic nodal irradiation for Hodgkin's disease have an increased risk of developing secondary breast cancer at an unusually young age. As expected in younger women, high density breast tissue was common on mammography, and the recall and biopsy rates were unusually high. However, early mammographic screening facilitated diagnosis of in situ and early invasive cancer in 3.5% of our subjects.

    View details for Web of Science ID 000252124800006

    View details for PubMedID 18186864

  • MRI-guided needle localization of suspicious breast lesions: results of a freehand technique EUROPEAN RADIOLOGY van den Bosch, M. A., Daniel, B. L., Pal, S., Nowels, K. W., Birdwell, R. L., Jeffrey, S. S., Ikeda, D. M. 2006; 16 (8): 1811-1817

    Abstract

    Magnetic resonance imaging (MRI) can detect clinically and mammographically occult breast lesions. In this study we report the results of MRI-guided needle localization of suspicious breast lesions by using a freehand technique. Preoperative MRI-guided single-needle localization was performed in 220 patients with 304 MRI-only breast lesions at our hospital between January 1997 and July 2004. Procedures were performed in an open 0.5-T Signa-SP imager allowing real-time monitoring, with patient in prone position, by using a dedicated breast coil. MRI-compatible hookwires were placed in a noncompressed breast by using a freehand technique. MRI findings were correlated with pathology and follow-up. MRI-guided needle localization was performed for a single lesion in 150 patients, for two lesions in 56 patients, and for three lesions in 14 patients. Histopathologic analysis of these 304 lesions showed 104 (34%) malignant lesions, 51 (17%) high-risk lesions, and 149 (49%) benign lesions. The overall lesion size ranged from 2.0-65.0 mm (mean 11.2 mm). No direct complications occurred. Follow-up MRI in 54 patients showed that two (3.7%) lesions were missed by surgical biopsy. MRI-guided freehand needle localization is accurate and allows localization of lesions anterior in the breast, the axillary region, and near the chest wall.

    View details for DOI 10.1007/s00330-006-0214-5

    View details for Web of Science ID 000238860700022

    View details for PubMedID 16683117

Conference Proceedings


  • Compliance with recommended follow-up after fine-needle aspiration biopsy of nonpalpable breast lesions: A retrospective study Pal, S., Ikeda, D. M., Birdwell, R. L. RADIOLOGICAL SOC NORTH AMER. 1996: 71-74

    Abstract

    To determine compliance with recommendations for mammographic or surgical follow-up after fine-needle aspiration biopsy of non-palpable breast lesions.The authors reviewed the medical records of 419 patients in whom surgical or mammographic follow-up had been recommended after fine-needle aspiration biopsy. Mammographic, clinical, and follow-up findings were correlated with patient outcome. Of 466 lesions, 395 lesions in 359 patients (age range, 24-89 years; average age, 55 years) were nonpalpable and composed the study.Excisional biopsy was recommended in 141 cases (35.7%) and close-interval mammographic surveillance in 165 (41.8%). Biopsy was performed in 122 (86.5%) of the 141 cases in which it was recommended. Of 165 cases in which follow-up mammography was recommended, 84 (50.9%) were resolved at the close of the study. In the remaining cases, women either did not return (n = 24), were followed up elsewhere or moved (n = 35), were lost to follow-up by their physicians (n = 17), or were lost to follow-up for other reasons (n = 5).Noncompliance with follow-up recommendations is an important issue undermining the benefits of fine-needle aspiration biopsy. Difficulty in tracking patients hinders assessment of patient compliance.

    View details for Web of Science ID A1996VJ11400019

    View details for PubMedID 8816523

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