8 results on '"Beets‐Tan, RG"'
Search Results
2. MRI and Diffusion-weighted MRI Volumetry for Identification of Complete Tumor Responders After Preoperative Chemoradiotherapy in Patients With Rectal Cancer: A Bi-institutional Validation Study.
- Author
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Lambregts DM, Rao SX, Sassen S, Martens MH, Heijnen LA, Buijsen J, Sosef M, Beets GL, Vliegen RA, and Beets-Tan RG
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- Adenocarcinoma pathology, Adult, Aged, Aged, 80 and over, Diffusion Magnetic Resonance Imaging, Female, Follow-Up Studies, Humans, Male, Middle Aged, Neoplasm Staging, Prospective Studies, Rectal Neoplasms pathology, Rectum surgery, Remission Induction, Sensitivity and Specificity, Treatment Outcome, Adenocarcinoma therapy, Chemoradiotherapy, Adjuvant, Magnetic Resonance Imaging methods, Neoadjuvant Therapy, Rectal Neoplasms therapy, Rectum pathology, Tumor Burden
- Abstract
Background: Retrospective single-center studies have shown that diffusion-weighted magnetic resonance imaging (DWI) is promising for identification of patients with rectal cancer with a complete tumor response after neoadjuvant chemoradiotherapy (CRT), using certain volumetric thresholds., Objective: This study aims to validate the diagnostic value of these volume thresholds in a larger, independent, and bi-institutional patient cohort., Methods: A total of 112 patients with locally advanced rectal cancer (2 centers) treated with a long course of CRT were enrolled. Patients underwent standard T2W-magnetic resonance imaging and DWI, both pre- and post-CRT. Two experienced readers independently determined pre-CRT and post-CRT tumor volumes (cm) on T2W-magnetic resonance image and diffusion-weighted magnetic resonance image by means of freehand tumor delineation. Tumor volume reduction rates (Δvolume) were calculated. Previously determined T2W and DWI threshold values for prevolume, postvolume, and Δvolume were tested to "prospectively" assess their respective diagnostic value in discriminating patients with a complete tumor response from patients with residual tumor., Results: Twenty patients had a complete response. Using the average measurements between the 2 readers, areas under the curve for the pre-/post-/Δvolumes was 0.73/0.82/0.78 for T2W-magnetic resonance imaging and 0.77/0.92/0.86 for DWI, respectively. For T2W-volumetry, sensitivity and specificity using the predefined volume thresholds were 55% and 74% for pre-, 60% and 89% for post-, and 60% and 86% for Δvolume. For DWI volumetry, sensitivity and specificity were 65% and 76% for pre-, 70% and 98% for post-, and 70% and 93% for Δvolume., Conclusions: Previously established DWI volume thresholds can be reproduced with good results. Post-CRT DWI volumetry offers the best results for the detection of patients with a complete response after CRT with an area under the curve of 0.92, sensitivity of 70%, and specificity of 98%.
- Published
- 2015
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3. Translabial three-dimensional ultrasonography compared with magnetic resonance imaging in detecting levator ani defects.
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Notten KJB, Kluivers KB, Fütterer JJ, Schweitzer KJ, Stoker J, Mulder FE, Beets-Tan RG, Vliegen RFA, Bossuyt PM, Kruitwagen RFPM, Roovers JWR, and Weemhoff M
- Subjects
- Adult, Aged, Female, Humans, Imaging, Three-Dimensional, Middle Aged, Prospective Studies, Ultrasonography, Pelvic Floor diagnostic imaging, Pelvic Organ Prolapse diagnostic imaging
- Abstract
Objective: To assess the diagnostic performance of translabial three-dimensional ultrasonography in detecting major levator ani defects in women with pelvic organ prolapse compared with magnetic resonance imaging (MRI) and to assess the interobserver agreement in detecting levator ani defects with translabial three-dimensional ultrasonography., Methods: In a multicenter cohort study, 140 women indicated for primary surgery of pelvic organ prolapse quantification stage II or more cystocele were included. Patients undergoing mesh surgery or concomitant stress incontinence surgery were excluded. All consenting patients underwent translabial three-dimensional ultrasonography and MRI of the pelvic floor before surgery. Two observers (out of a pool of four observers) assessed translabial three-dimensional ultrasound images; two other observers (out a pool of five observers) assessed MRIs for levator ani muscle damage. In case of disagreement, the images were discussed in a consensus meeting., Results: Of the 135 scans, 45 major levator ani defects were detected on ultrasonogram (33.3%) and 32 were confirmed at MRI (23.7%). Of the 41 major levator ani defects detected on MRI, nine were missed at translabial three-dimensional ultrasonogram. Sensitivity was 0.78 (32 of 41) (95% confidence interval [CI] 0.65-0.91) and specificity was 0.86 (81 of 94) (95% CI 0.79-0.93) in detecting major levator ani defects with translabial three-dimensional ultrasonography compared with MRI. There was good agreement scoring levator ani defects on translabial three-dimensional ultrasonography, with a κ of 0.67 (95% CI 0.58-0.76); agreement in recognizing major levator ani defects was moderate, with a κ of 0.53 (95% CI 0.37-0.69)., Conclusion: Translabial three-dimensional ultrasonography shows reasonable agreement with MRI in detecting major levator defects. Because of the moderate interobserver agreement, it will be difficult to implement ultrasonography in daily practice., Clinical Trial Registration: Netherlands Trial Register, www.trialregister.nl, NTR2220.
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- 2014
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4. Magnetization transfer ratio: a potential biomarker for the assessment of postradiation fibrosis in patients with rectal cancer.
- Author
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Martens MH, Lambregts DM, Papanikolaou N, Heijnen LA, Riedl RG, zur Hausen A, Maas M, Beets GL, and Beets-Tan RG
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- Aged, Aged, 80 and over, Algorithms, Biomarkers, Feasibility Studies, Female, Humans, Male, Middle Aged, Neoplasm, Residual diagnosis, Neoplasm, Residual prevention & control, Reproducibility of Results, Sensitivity and Specificity, Chemoradiotherapy adverse effects, Image Interpretation, Computer-Assisted methods, Magnetic Resonance Imaging methods, Radiation Pneumonitis diagnosis, Radiation Pneumonitis etiology, Rectal Neoplasms diagnosis, Rectal Neoplasms radiotherapy
- Abstract
Objectives: Magnetization transfer-magnetic resonance imaging (MT-MRI) uses differences in the magnetization interaction of the free "unbound" water protons and the macromolecular-bound protons. The aim of this study was to evaluate whether the magnetization transfer ratio (MTR) may be used to identify fibrosis in patients with rectal cancer treated with chemoradiotherapy., Materials and Methods: This study was part of a rectal cancer imaging study, which was approved by the local institutional review board. Twenty-six patients, treated with neoadjuvant chemoradiotherapy, underwent a standard MRI including T2-weighted sequences and a diffusion-weighted sequence. An axially oriented MT sequence was performed at the center of the (former) tumor location. Regions of interest were manually drawn on the MT-MRI (with reference to the T2-weighted and diffusion-weighted images), covering areas of residual tumor, fibrosis, or the normal or edematous rectal wall. The results were compared with that of the histopathological examination. Differences in MTR between the 4 tissue types were analyzed, and a receiver operating characteristic (ROC) curve was generated to assess the diagnostic potential., Results: Thirty-eight regions of interest were analyzed on the MT-MRI. The mean (SD) MTR of the fibrosis was 37.7% (2.7%), which was significantly higher than that of the residual tumor (29.6% [4.2%]; P < 0.001), the normal rectal wall (30.3% [4.7%]; P = 0.003), and the edematous rectal wall (18.2% [4.0%]; P < 0.001). The use of MTR resulted in an area under the ROC-curve of 0.96, a sensitivity of 88%, and a specificity of 90% for the diagnosis of fibrosis., Conclusions: Magnetization transfer ratio can be used to discriminate postradiation fibrosis from residual tumor and the normal rectal wall after chemoradiotherapy. Magnetization transfer imaging can thus be a promising tool for the unsolved dilemma of interpreting postradiation fibrosis in rectal cancer.
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- 2014
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5. Noninvasive nodal staging in patients with breast cancer using gadofosveset-enhanced magnetic resonance imaging: a feasibility study.
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Schipper RJ, Smidt ML, van Roozendaal LM, Castro CJ, de Vries B, Heuts EM, Keymeulen KB, Wildberger JE, Lobbes MB, and Beets-Tan RG
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- Adult, Aged, Axilla, Contrast Media, Female, Humans, Lymphatic Metastasis, Middle Aged, Neoplasm Staging methods, Reproducibility of Results, Sensitivity and Specificity, Breast Neoplasms pathology, Carcinoma pathology, Carcinoma secondary, Gadolinium, Lymph Nodes pathology, Magnetic Resonance Imaging methods, Organometallic Compounds
- Abstract
Objectives: The objectives of this study were to evaluate whether the axillary lymph nodes show enhancement on magnetic resonance imaging (MRI) after gadofosveset administration, to assess the time to peak enhancement, and to determine the diagnostic performance of gadofosveset-enhanced MRI for axillary nodal staging., Materials and Methods: Ten women whose conditions had been diagnosed with invasive breast cancer (>2 cm) underwent both nonenhanced and gadofosveset-enhanced 3-dimensional T1-weighted axillary MRI. Signal intensity of the axillary lymph nodes and different adjacent tissues was measured, and relative signal intensity (rSI) was calculated. A Wilcoxon signed rank test was used to compare results of rSI between different time intervals. A radiologist evaluated all lymph nodes with regard to size, morphologic features, and gadofosveset uptake. All MRI-depicted lymph nodes were matched with the lymph nodes that were removed during surgery. Nodal status was investigated by a pathologist. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of gadofosveset-enhanced MRI for axillary lymph node staging were calculated., Results: After contrast administration, a significant signal increase was observed in the lymph nodes (P < 0.05). When compared with muscle or fat, rSI of the lymph nodes demonstrated a significant postcontrast peak enhancement between 11 minutes and 30 seconds and 20 minutes and 50 seconds (P < 0.05). A total of 152 lymph nodes were harvested during sentinel lymph node biopsy or axillary lymph node dissection, of which 116 were matched with the lymph nodes that were depicted on MRI. Histopathological examination resulted in 21 macrometastases and 8 micrometastases. Using contrast-enhanced MRI, 20 lymph nodes were rated as true positive; 83 as true negative; 4 as false positive; and 9 as false negative. This resulted in an overall node-by-node sensitivity, specificity, PPV, and NPV of 69%, 95%, 83%, and 90%, respectively. If the micrometastases were excluded from the analysis, MRI showed a sensitivity of 86% and a specificity of 94%. Calculated PPV and NPV were 75% and 97%, respectively., Conclusions: The axillary lymph nodes show enhancement on MRI after gadofosveset administration, with a peak enhancement between 11 minutes and 30 seconds and 20 minutes and 50 seconds. Diagnostic performance of gadofosveset-enhanced axillary lymph node imaging in patients with breast cancer is promising, but further studies need to confirm these results.
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- 2013
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6. Accuracy of gadofosveset-enhanced MRI for nodal staging and restaging in rectal cancer.
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Lambregts DM, Beets GL, Maas M, Kessels AG, Bakers FC, Cappendijk VC, Engelen SM, Lahaye MJ, de Bruïne AP, Lammering G, Leiner T, Verwoerd JL, Wildberger JE, and Beets-Tan RG
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- Adult, Aged, Aged, 80 and over, Chemotherapy, Adjuvant, Combined Modality Therapy, Female, Humans, Lymph Node Excision, Male, Middle Aged, Minimally Invasive Surgical Procedures, Neoadjuvant Therapy, Neoplasm Staging, Prognosis, Prospective Studies, Radiotherapy, Adjuvant, Rectal Neoplasms drug therapy, Rectal Neoplasms radiotherapy, Rectal Neoplasms surgery, Rectum pathology, Rectum surgery, Sensitivity and Specificity, Contrast Media, Gadolinium, Image Enhancement, Image Processing, Computer-Assisted, Lymph Nodes pathology, Lymphatic Metastasis pathology, Magnetic Resonance Imaging methods, Organometallic Compounds, Rectal Neoplasms pathology
- Abstract
Objective: To prospectively assess the accuracy of gadofosveset-enhanced magnetic resonance imaging (MRI) for nodal staging and restaging in rectal cancer., Background: Accurate preoperative assessment of nodal disease in rectal cancer impacts treatment management. Staging with modern imaging techniques (computed tomography, MRI and endorectal ultrasound) is insufficiently accurate for clinical decision making. This study aims to assess the accuracy of MRI using a novel lymph node magnetic resonance contrast, gadofosveset, for nodal staging and restaging in rectal cancer using a per node comparison with histology as the reference standard., Methods: Sixty-eight patients underwent gadofosveset-enhanced MRI at 1.5T. Twenty-six patients (primary staging group I) were treated with total mesorectal excision (with or without preoperative 5 × 5 Gy) and 42 (restaging group II) underwent a long course of chemoradiation followed by a restaging MRI and resection. Nodes were scored as benign or malignant by 2 radiologists (experienced and junior reader) first on standard MRI, then on gadofosveset-enhanced MRI. For group I the primary staging MRI was compared with histology. In group II the second, restaging MRI was compared with histology., Results: For the experienced reader, sensitivity, specificity, and area under the ROC-curve (AUC) improved from 76%, 82% and 0.84 on standard MRI to 80%, 97% and 0.96 on gadofosveset-MRI (P < 0.001). For the junior reader results improved from 69%, 85%, and 0.85 on standard MRI to 70%, 95%, and 0.93 on gadofosveset-MRI (P = 0.03). Interobserver agreement was good on both standard MRI (κ 0.73) and gadofosveset-MRI (κ 0.71)., Conclusions: This study shows high reproducibility and significantly improved accuracy compared to standard MRI for gadofosveset-enhanced MRI for nodal staging and restaging in rectal cancer.
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- 2011
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7. A comparison between the treatment of low rectal cancer in Japan and the Netherlands, focusing on the patterns of local recurrence.
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Kusters M, Beets GL, van de Velde CJ, Beets-Tan RG, Marijnen CA, Rutten HJ, Putter H, and Moriya Y
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- Aged, Combined Modality Therapy, Female, Humans, Japan, Male, Middle Aged, Netherlands, Rectal Neoplasms pathology, Neoplasm Recurrence, Local epidemiology, Rectal Neoplasms therapy
- Abstract
Purpose: Differences exist between Japan and The Netherlands in the treatment of low rectal cancer. The purpose of this study is to analyze these, with focus on the patterns of local recurrence., Methods: In The Netherlands, 755 patients were operated by total mesorectal excision (TME) for low rectal cancer, 379 received preoperative radiotherapy (RT+TME). Applying the same selection criteria resulted in 324 patients in the Japanese (NCCH) group, who received extended surgery consisting of lateral lymph node dissection and a wider abdominoperineal excision. The majority received no (neo) adjuvant therapy. Local recurrence images were examined by a radiologist and a surgeon., Results: Five-year local recurrence rates were 6.9% for the Japanese NCCH group, 5.8% in the Dutch RT+TME group, and 12.1% in the Dutch TME group. Recurrence rate in the lateral pelvis is 2.2%, 0.8%, and 2.7% in the Japanese, RT+TME group, and TME group, respectively. The incidence of presacral recurrences was low in the NCCH group (0.6%), compared with 3.7% and 3.2% in the RT+TME and TME groups, respectively., Conclusions: Both extended surgery and RT+TME result in good local control, as compared with TME alone. Preoperative radiotherapy can sterilize lateral extramesorectal tumor particles. A wider abdominoperineal resection probably results in less presacral local recurrence. Comparison of the results is difficult because of differences in patient groups.
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- 2009
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8. Fat embolism syndrome: yes or no?
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de Feiter PW, van Hooft MA, Beets-Tan RG, and Brink PR
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- Adult, Blood Gas Analysis, Cerebral Infarction diagnosis, Female, Humans, Magnetic Resonance Spectroscopy, Neurologic Examination, Purpura diagnosis, Sensitivity and Specificity, Syndrome, Tomography, X-Ray Computed, Embolism, Fat diagnosis, Embolism, Fat etiology, Tibial Fractures complications
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- 2007
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