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Spampinato S, Tanderup K, Marinovskij E, Axelsen S, Pedersen EM, Pötter R, Lindegaard JC, Fokdal L. MRI-based contouring of functional sub-structures of the lower urinary tract in gynaecological radiotherapy. Radiother Oncol 2020; 145:117-124. [DOI: 10.1016/j.radonc.2019.12.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 11/15/2019] [Accepted: 12/15/2019] [Indexed: 01/21/2023]
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Yin Z, Tang S, Shi J, Chen F, Li Z, Wu J, Jen Y. A specially designed domed-cones template for needles (seeds) fixation and incline insertion in prostate implant brachytherapy. J Appl Clin Med Phys 2016; 17:428–439. [PMID: 26894355 PMCID: PMC5690229 DOI: 10.1120/jacmp.v17i1.5833] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Revised: 10/06/2015] [Accepted: 09/21/2015] [Indexed: 11/23/2022] Open
Abstract
The construction of a conventional prostate needle (seeds) implant template restricts needles tilting or incline insertion when it is necessary to approach a seminal vesicle or to avoid the obstruction of symphysis pubis. To overcome the disadvantages of conventional templates, we developed a special template for guiding needles incline insertion and fixation for prostate needle implant. Phantom needles implantation was performed. Two acrylic boards, each 7.5 cm in width by 7.5 cm in length and 0.5 cm thickness, were drilled with a set of domed holes and cones with embedded template ball inside this combination to provide firm grip and fixation in prostate needle implantation. The specially designed domed-cones combination acrylic board provides a needle of up to 60° rotation flexibility application. Some areas that could not be covered in a conventional parallel needle holes template could now be covered by using this new template. The covering index of prostate radiation dosage is up to 84.5%. The specially designed domed-cones acrylic board combination provides not only a reliable means of needle fixation and rotational function, but also a superior dose distribution in the anterior portion of the prostate and good coverage of a seminal vesicle. This special template is a feasible design for prostate needles or seeds implant brachytherapy.
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Affiliation(s)
- Zhao‐Sheng Yin
- Radiotherapy Center, Chenzhou No.1 People's HospitalHunanChina
| | - Shi‐Qiang Tang
- Radiotherapy Center, Chenzhou No.1 People's HospitalHunanChina
| | - Jun‐Wen Shi
- Radiotherapy Center, Chenzhou No.1 People's HospitalHunanChina
| | - Fen Chen
- Radiotherapy Center, Chenzhou No.1 People's HospitalHunanChina
| | - Zi‐Wei Li
- Radiotherapy Center, Chenzhou No.1 People's HospitalHunanChina
| | - Jia‐Ming Wu
- Radiotherapy Center, Chenzhou No.1 People's HospitalHunanChina
- Department of Radiation OncologyYee‐Ren HospitalTao Yuan CityTaiwan
| | - Yee‐Min Jen
- Radiotherapy Center, Chenzhou No.1 People's HospitalHunanChina
- Department of Radiation OncologyYee‐Ren HospitalTao Yuan CityTaiwan
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Murciano-Goroff YR, Wolfsberger LD, Parekh A, Fennessy FM, Tuncali K, Orio PF, Niedermayr TR, Suh WW, Devlin PM, Tempany CMC, Sugar EHN, O'Farrell DA, Steele G, O'Leary M, Buzurovic I, Damato AL, Cormack RA, Fedorov AY, Nguyen PL. Variability in MRI vs. ultrasound measures of prostate volume and its impact on treatment recommendations for favorable-risk prostate cancer patients: a case series. Radiat Oncol 2014; 9:200. [PMID: 25205146 PMCID: PMC4261899 DOI: 10.1186/1748-717x-9-200] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 09/02/2014] [Indexed: 11/10/2022] Open
Abstract
Background Prostate volume can affect whether patients qualify for brachytherapy (desired size ≥20 mL and ≤60 mL) and/or active surveillance (desired PSA density ≤0.15 for very low risk disease). This study examines variability in prostate volume measurements depending on imaging modality used (ultrasound versus MRI) and volume calculation technique (contouring versus ellipsoid) and quantifies the impact of this variability on treatment recommendations for men with favorable-risk prostate cancer. Methods We examined 70 patients who presented consecutively for consideration of brachytherapy for favorable-risk prostate cancer who had volume estimates by three methods: contoured axial ultrasound slices, ultrasound ellipsoid (height × width × length × 0.523) calculation, and endorectal coil MRI (erMRI) ellipsoid calculation. Results Average gland size by the contoured ultrasound, ellipsoid ultrasound, and erMRI methods were 33.99, 37.16, and 39.62 mLs, respectively. All pairwise comparisons between methods were statistically significant (all p < 0.015). Of the 66 patients who volumetrically qualified for brachytherapy on ellipsoid ultrasound measures, 22 (33.33%) did not qualify on ellipsoid erMRI or contoured ultrasound measures. 38 patients (54.28%) had PSA density ≤0.15 ng/dl as calculated using ellipsoid ultrasound volumes, compared to 34 (48.57%) and 38 patients (54.28%) using contoured ultrasound and ellipsoid erMRI volumes, respectively. Conclusions The ultrasound ellipsoid and erMRI ellipsoid methods appeared to overestimate ultrasound contoured volume by an average of 9.34% and 16.57% respectively. 33.33% of those who qualified for brachytherapy based on ellipsoid ultrasound volume would be disqualified based on ultrasound contoured and/or erMRI ellipsoid volume. As treatment recommendations increasingly rely on estimates of prostate size, clinicians must consider method of volume estimation.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Paul L Nguyen
- Brigham and Women's Hospital, Radiation Oncology, 75 Francis Street, Boston, MA 02115, USA.
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4
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A level set based algorithm to reconstruct the urinary bladder from multiple views. Med Eng Phys 2013; 35:1819-24. [PMID: 23726217 DOI: 10.1016/j.medengphy.2013.05.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 04/29/2013] [Accepted: 05/01/2013] [Indexed: 11/23/2022]
Abstract
The urinary bladder can be visualized from different views by imaging facilities such as computerized tomography and magnetic resonance imaging. Multi-view imaging can present more details of this pelvic organ and contribute to a more reliable reconstruction. Based on the information from multi-view planes, a level set based algorithm is proposed to reconstruct the 3D shape of the bladder using the cross-sectional boundaries. The algorithm provides a flexible solution to handle the discrepancies from different view planes and can obtain an accurate bladder surface with more geometric details.
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Sparks R, Bloch BN, Feleppa E, Barratt D, Madabhushi A. Fully Automated Prostate Magnetic Resonance Imaging and Transrectal Ultrasound Fusion via a Probabilistic Registration Metric. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2013; 8671. [PMID: 24353393 DOI: 10.1117/12.2007610] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
In this work, we present a novel, automated, registration method to fuse magnetic resonance imaging (MRI) and transrectal ultrasound (TRUS) images of the prostate. Our methodology consists of: (1) delineating the prostate on MRI, (2) building a probabilistic model of prostate location on TRUS, and (3) aligning the MRI prostate segmentation to the TRUS probabilistic model. TRUS-guided needle biopsy is the current gold standard for prostate cancer (CaP) diagnosis. Up to 40% of CaP lesions appear isoechoic on TRUS, hence TRUS-guided biopsy cannot reliably target CaP lesions and is associated with a high false negative rate. MRI is better able to distinguish CaP from benign prostatic tissue, but requires special equipment and training. MRI-TRUS fusion, whereby MRI is acquired pre-operatively and aligned to TRUS during the biopsy procedure, allows for information from both modalities to be used to help guide the biopsy. The use of MRI and TRUS in combination to guide biopsy at least doubles the yield of positive biopsies. Previous work on MRI-TRUS fusion has involved aligning manually determined fiducials or prostate surfaces to achieve image registration. The accuracy of these methods is dependent on the reader's ability to determine fiducials or prostate surfaces with minimal error, which is a difficult and time-consuming task. Our novel, fully automated MRI-TRUS fusion method represents a significant advance over the current state-of-the-art because it does not require manual intervention after TRUS acquisition. All necessary preprocessing steps (i.e. delineation of the prostate on MRI) can be performed offline prior to the biopsy procedure. We evaluated our method on seven patient studies, with B-mode TRUS and a 1.5 T surface coil MRI. Our method has a root mean square error (RMSE) for expertly selected fiducials (consisting of the urethra, calcifications, and the centroids of CaP nodules) of 3.39 ± 0.85 mm.
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Affiliation(s)
- Rachel Sparks
- Department of Biomedical Engineering, Rutgers University ; Department of Biomedical Engineering, Case Western Reserve University
| | - B Nicolas Bloch
- Department of Radiology, Boston Medical Center & Boston University
| | - Ernest Feleppa
- Lizzi Center for Biomedical Engineering, Riverside Research
| | - Dean Barratt
- Centre for Medical Image Computing, University College London
| | - Anant Madabhushi
- Department of Biomedical Engineering, Case Western Reserve University
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6
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Novel Approach to Segment the Inner and Outer Boundaries of the Bladder Wall in T2-Weighted Magnetic Resonance Images. Ann Biomed Eng 2011; 39:2287-97. [DOI: 10.1007/s10439-011-0324-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 05/03/2011] [Indexed: 10/18/2022]
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7
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Kershaw LE, Logue JP, Hutchinson CE, Clarke NW, Buckley DL. Late tissue effects following radiotherapy and neoadjuvant hormone therapy of the prostate measured with quantitative magnetic resonance imaging. Radiother Oncol 2008; 88:127-34. [DOI: 10.1016/j.radonc.2008.02.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2007] [Revised: 02/15/2008] [Accepted: 02/15/2008] [Indexed: 11/28/2022]
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Abstract
In this article the current issues of diagnosis and detection of prostate cancer are reviewed. The limitations for current techniques are highlighted and some possible solutions with MR imaging and MR-guided biopsy approaches are reviewed. There are several different biopsy approaches under investigation. These include transperineal open magnet approaches to closed-bore 1.5T transrectal biopsies. The imaging, image processing, and tracking methods are also discussed. In the arena of therapy, MR guidance has been used in conjunction with radiation methods, either brachytherapy or external delivery. The principles of the radiation treatment, the toxicities, and use of images are outlined. The future role of imaging and image-guided interventions lie with providing a noninvasive surrogate for cancer surveillance or monitoring treatment response. The shift to minimally invasive focal therapies has already begun and will be very exciting when MR-guided focused ultrasound surgery reaches its full potential.
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Affiliation(s)
- Clare Tempany
- Department of Radiology, Brigham & Women's Hospital, Boston, MA 02115, USA.
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9
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D'Amico AV, Halabi S, Tempany C, Titelbaum D, Philips GK, Loffredo M, McMahon E, Sanford B, Vogelzang NJ, Small EJ. Tumor volume changes on 1.5 tesla endorectal MRI during neoadjuvant androgen suppression therapy for higher-risk prostate cancer and recurrence in men treated using radiation therapy results of the phase II CALGB 9682 study. Int J Radiat Oncol Biol Phys 2007; 71:9-15. [PMID: 18037582 DOI: 10.1016/j.ijrobp.2007.09.033] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2007] [Revised: 09/20/2007] [Accepted: 09/20/2007] [Indexed: 11/16/2022]
Abstract
PURPOSE We prospectively determined whether the change in tumor volume (TV) during 2 months of neoadjuvant androgen suppression therapy (nAST) measured using conventional 1.5 Tesla endorectal magnetic resonance imaging (eMRI) was associated with the risk of recurrence after radiation (RT) and 6 months of AST. PATIENTS AND METHODS Between 1997 and 2001, 180 men with clinical stage T1c-T3cN0M0 adenocarcinoma of the prostate were registered. Fifteen were found to be ineligible and the institutional MR radiologist could not assess the TV in 32, leaving 133 for analysis. Multivariable Cox regression analysis was used to assess whether a significant association existed between eMRI-defined TV progression during nAST and time to recurrence adjusting for prostate-specific antigen (PSA) level, Gleason score (8 to 10 or 7 vs. 6 or less) and stage (T3 vs. T1-2). RESULTS After a median follow up of 6.7 years and adjusting for known prognostic factors, there was a significant increase in the risk of PSA failure (HR, 2.3 [95% CI, 1.1-4.5; p = 0.025) in men with eMRI-defined TV progression during nAST. Specifically, adjusted estimates of PSA failure were significantly higher (p = 0.032) in men with, compared with men without, eMRI-defined TV progression reaching 38% vs. 19%, respectively, by 5 years. CONCLUSION Eradicating intraprostatic hormone refractory prostate cancer (HRPC) by maximizing local control and randomized trials assessing whether survival is improved when agents active against HRPC are combined with maximal local therapy are needed in men who progress based on eMRI during nAST.
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Affiliation(s)
- Anthony V D'Amico
- Department of Radiation Oncology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Boston, MA 02215, USA.
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10
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Kundra V, Silverman PM, Matin SF, Choi H. Imaging in Oncology from The University of Texas M. D. Anderson Cancer Center: Diagnosis, Staging, and Surveillance of Prostate Cancer. AJR Am J Roentgenol 2007; 189:830-44. [PMID: 17885053 DOI: 10.2214/ajr.07.2011] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
OBJECTIVE The purpose of this article is to discuss the epidemiology, risk factors, and presentation of prostate cancer. After reviewing the prostate anatomy, the article will show how imaging plays an important role in establishing the diagnosis, staging, and monitoring the therapeutic response in prostate cancer, with a focus on adenocarcinomas. CONCLUSION Imaging studies, in the appropriate laboratory and clinical context, contribute essential information that enhances the capacity to provide individualized risk stratification, a suitable treatment strategy, and monitoring for the patient with prostate cancer.
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Affiliation(s)
- Vikas Kundra
- Department of Radiology, The University of Texas M. D. Anderson Cancer Center, Box 57, 1515 Holcombe Blvd., Houston, TX 77030, USA.
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11
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Affiliation(s)
- Vikas Kundra
- Department of Radiology, The University of Texas, M. D. Anderson Cancer Center, Division of Diagnostic Imaging, Houston, TX 77030, USA.
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12
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Lagerburg V, Moerland MA, Konings MK, van de Vosse RE, Lagendijk JJW, Battermann JJ. Development of a tapping device: a new needle insertion method for prostate brachytherapy. Phys Med Biol 2006; 51:891-902. [PMID: 16467585 DOI: 10.1088/0031-9155/51/4/009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The purpose of this study is to develop and test a tapping device for needle insertion for prostate brachytherapy. This device will tap the needle into the prostate with a certain, well-defined, amount of momentum, instead of the currently used method of pushing the needle. Because of the high needle insertion velocity, we expect prostate motion and deformation to be less compared to current methods. We measured the momentum that is applied when manually tapping the needle into the prostate and found a mean momentum of 0.50 +/- 0.07 N s. The tapping device is pneumatically driven and we found that the delivered momentum increased linearly with the applied air pressure. The efficacy of the tapping device was tested on a piece of beef, placed on a freely moving and rotating platform. A significant correlation was found between the applied pressure and the rotation and displacement of the beef. Displacements and rotations were minimal for the highest pressure (4 bar) and amounted to only 2 mm and 6 degrees, respectively. Higher air pressures will further reduce displacements and rotations.
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Affiliation(s)
- V Lagerburg
- Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
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13
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Lagerburg V, Moerland MA, Lagendijk JJW, Battermann JJ. Measurement of prostate rotation during insertion of needles for brachytherapy. Radiother Oncol 2005; 77:318-23. [PMID: 16289399 DOI: 10.1016/j.radonc.2005.09.018] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2005] [Revised: 08/31/2005] [Accepted: 09/22/2005] [Indexed: 11/15/2022]
Abstract
BACKGROUND AND PURPOSE The purpose of this study is to investigate whether prostate rotation due to needle insertion for prostate brachytherapy is predictable and if so, to quantify this rotation, and to see whether locking needles reduce the magnitude of prostate rotation. PATIENTS AND METHODS The measurements are done at the beginning of the procedure for brachytherapy with a Foley catheter in situ. After a needle is inserted into the prostate, a 3D ultrasound scan is made. Then the seeds are delivered using RAPID Strands (Oncura), and the needle is withdrawn. A second 3D scan is made. The needle and seed positions are determined in these scans. To determine the rotation of the prostate, the angle between the needle and the seed trajectory is calculated. RESULTS The prostate rotations have been measured in 16 patients, eight without the use of locking needles and eight with locking needles. In total 62 needles were inserted. The maximum rotation was 13.8 degrees and occurred in the coronal plane when no locking needles were used with a significant correlation (P<0.01, R=0.637) between the place of insertion and rotation. It was shown that the method (with or without locking needles) had a significant (P<0.001) influence on the rotation in the coronal plane. Rotations in the sagittal plane ranged from -8.5 degrees to +10.2 degrees without correlation with the insertion point of the needle or the use of locking needles. CONCLUSIONS This study showed that prostate rotation during needle insertion for prostate brachytherapy is relatively large and unpredictable. Locking needles reduce prostate rotation in the coronal plane, but not in the sagittal plane. Minimising this rotation is necessary for accurate seed delivery, especially when a robotic implantation technique is used.
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Affiliation(s)
- Vera Lagerburg
- Department of Radiotherapy, University Medical Center Utrecht, Utrecht, The Netherlands.
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14
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Qayyum A, Coakley FV, Lu Y, Olpin JD, Wu L, Yeh BM, Carroll PR, Kurhanewicz J. Organ-Confined Prostate Cancer: Effect of Prior Transrectal Biopsy on Endorectal MRI and MR Spectroscopic Imaging. AJR Am J Roentgenol 2004; 183:1079-83. [PMID: 15385308 DOI: 10.2214/ajr.183.4.1831079] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Our aim was to determine the effect of prior transrectal biopsy on endorectal MRI and MR spectroscopic imaging findings in patients with organ-confined prostate cancer. MATERIALS AND METHODS Endorectal MRI and MR spectroscopic imaging were performed in 43 patients with biopsy-proven prostate cancer before radical prostatectomy confirming organ-confined disease. For each sextant, two independent reviewers scored the degree of hemorrhage on a scale from 1 to 5 and recorded the presence or absence of capsular irregularity. A spectroscopist recorded the number of spectrally degraded voxels in the peripheral zone. The outcome variables of capsular irregularity and spectral degradation were correlated with the predictor variables of time from biopsy and degree of hemorrhage after biopsy. RESULTS Capsular irregularity was unrelated to time from biopsy or to degree of hemorrhage. Spectral degradation was inversely related to time from biopsy (p < 0.01); the mean percentage of degraded peripheral zone voxels was 18.5% within 8 weeks of biopsy compared with 7% after 8 weeks. Spectral degradation was unrelated to the degree of hemorrhage. CONCLUSION In organ-confined prostate cancer, capsular irregularity can be seen at any time after biopsy and is independent of the degree of hemorrhage, whereas spectral degradation is seen predominantly in the first 8 weeks after biopsy. MRI staging criteria and guidelines for scheduling studies after biopsy may require appropriate modification.
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Affiliation(s)
- Aliya Qayyum
- Department of Radiology, University of California, San Francisco, 505 Parnassus Ave., San Francisco, CA 94143-0628, USA
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15
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Van Gellekom MPR, Moerland MA, Battermann JJ, Lagendijk JJW. MRI-guided prostate brachytherapy with single needle method—a planning study. Radiother Oncol 2004; 71:327-32. [PMID: 15172149 DOI: 10.1016/j.radonc.2004.03.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2003] [Revised: 02/16/2004] [Accepted: 03/01/2004] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND PURPOSE Magnetic resonance image (MRI)-guided prostate brachytherapy with a conventional closed MR scanner is hampered by the limited access to the prostate. To handle this problem, we have designed a new implantation method, based on a patient lying in a closed MR scanner, a robotic device to be placed between patient's legs, and one needle with one insertion point. MATERIALS AND METHODS The MRI-guided robotic system inserts the needle into the prostate to deliver the seeds. Each time, the needle will be retracted to the rotation point (in the body), and the insertion angle can be changed. The possible angles of the needle are limited by the geometry of the closed MR scanner and the presence of the symphysis, rectum and urethra. We have done a planning study to investigate the feasibility of this single needle method. RESULTS The treatment plans made with the single needle method showed the possibility to cover the prostate with the prescribed dose without piercing the urethra or rectum and without pubic bone interference. The plans were comparable to the plans made for the multi parallel needle method, and the 144Gy isodose enclosed the prostate with a margin of about 2 mm. The planned angles of the needle were within the range of possible angles. CONCLUSIONS This planning study has shown the feasibility of adequate prostate coverage with the divergent single needle method within the limited space inside the closed MR scanner.
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Affiliation(s)
- Marion P R Van Gellekom
- Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584CX Utrecht, The Netherlands
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Sanghani MV, Schultz D, Tempany CM, Titelbaum D, Renshaw AA, Loffredo M, Cote K, McMahon B, D'Amico AV. Quantifying the change in endorectal magnetic resonance imaging-defined tumor volume during neoadjuvant androgen suppression therapy in patients with prostate cancer. Urology 2003; 62:487-91. [PMID: 12946752 DOI: 10.1016/s0090-4295(03)00463-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVES To quantify the changes seen in the endorectal magnetic resonance imaging (erMRI)-defined prostate volume, predominant tumor volume, and secondary tumor volume during neoadjuvant total androgen suppression (TAS). METHODS Between July 1997 and April 2001, 152 consecutive patients with clinical Stage T1b-T3cNXM0 prostate cancer were treated with 6 months of TAS and external beam radiotherapy. erMRI was conducted before and after 2 months of neoadjuvant TAS. The median values and percentage of changes in the erMRI-measured prostate volume and primary and secondary tumor volumes during neoadjuvant TAS were calculated and compared, using the Wilcoxon matched-pairs signed-rank method, for the patients overall and stratified by pretreatment risk group. RESULTS All patients had a significant decline in their erMRI-defined median prostate volume (36.6 versus 25.7 cm(3), P <0.0001) during 2 months of neoadjuvant TAS. The median primary tumor volume decreased significantly in the intermediate-risk (0.77 versus 0.52 cm(3), P <0.0001) and high-risk (2.48 versus 0.83 cm(3), P <0.0001) patients. The median secondary tumor volume approached a significant decline in only the high-risk patients (0.45 versus 0.31 cm(3), P = 0.15). Fourteen percent of patients had an increase in their primary tumor volume during neoadjuvant TAS. CONCLUSIONS The erMRI-defined primary and secondary tumor volumes generally decreased in the study population during neoadjuvant TAS. However, 14% of patients had an increase in their primary tumor volume during androgen suppression therapy. The clinical significance of this awaits further study.
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Affiliation(s)
- Mona V Sanghani
- Department of Radiation Oncology, Brigham and Women's Hospital and Dana Farber Cancer Institute, Boston, Massachusetts 02115, USA
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17
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Chan I, Wells W, Mulkern RV, Haker S, Zhang J, Zou KH, Maier SE, Tempany CMC. Detection of prostate cancer by integration of line-scan diffusion, T2-mapping and T2-weighted magnetic resonance imaging; a multichannel statistical classifier. Med Phys 2003; 30:2390-8. [PMID: 14528961 DOI: 10.1118/1.1593633] [Citation(s) in RCA: 174] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
A multichannel statistical classifier for detecting prostate cancer was developed and validated by combining information from three different magnetic resonance (MR) methodologies: T2-weighted, T2-mapping, and line scan diffusion imaging (LSDI). From these MR sequences, four different sets of image intensities were obtained: T2-weighted (T2W) from T2-weighted imaging, Apparent Diffusion Coefficient (ADC) from LSDI, and proton density (PD) and T2 (T2 Map) from T2-mapping imaging. Manually segmented tumor labels from a radiologist, which were validated by biopsy results, served as tumor "ground truth." Textural features were extracted from the images using co-occurrence matrix (CM) and discrete cosine transform (DCT). Anatomical location of voxels was described by a cylindrical coordinate system. A statistical jack-knife approach was used to evaluate our classifiers. Single-channel maximum likelihood (ML) classifiers were based on 1 of the 4 basic image intensities. Our multichannel classifiers: support vector machine (SVM) and Fisher linear discriminant (FLD), utilized five different sets of derived features. Each classifier generated a summary statistical map that indicated tumor likelihood in the peripheral zone (PZ) of the prostate gland. To assess classifier accuracy, the average areas under the receiver operator characteristic (ROC) curves over all subjects were compared. Our best FLD classifier achieved an average ROC area of 0.839(+/-0.064), and our best SVM classifier achieved an average ROC area of 0.761(+/-0.043). The T2W ML classifier, our best single-channel classifier, only achieved an average ROC area of 0.599(+/-0.146). Compared to the best single-channel ML classifier, our best multichannel FLD and SVM classifiers have statistically superior ROC performance (P=0.0003 and 0.0017, respectively) from pairwise two-sided t-test. By integrating the information from multiple images and capturing the textural and anatomical features in tumor areas, summary statistical maps can potentially aid in image-guided prostate biopsy and assist in guiding and controlling delivery of localized therapy under image guidance.
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Affiliation(s)
- Ian Chan
- Surgical Planning Laboratory, Department of Radiology, Division of MRI, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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18
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Tsai A, Yezzi A, Wells W, Tempany C, Tucker D, Fan A, Grimson WE, Willsky A. A shape-based approach to the segmentation of medical imagery using level sets. IEEE TRANSACTIONS ON MEDICAL IMAGING 2003; 22:137-154. [PMID: 12715991 DOI: 10.1109/tmi.2002.808355] [Citation(s) in RCA: 303] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We propose a shape-based approach to curve evolution for the segmentation of medical images containing known object types. In particular, motivated by the work of Leventon, Grimson, and Faugeras, we derive a parametric model for an implicit representation of the segmenting curve by applying principal component analysis to a collection of signed distance representations of the training data. The parameters of this representation are then manipulated to minimize an objective function for segmentation. The resulting algorithm is able to handle multidimensional data, can deal with topological changes of the curve, is robust to noise and initial contour placements, and is computationally efficient. At the same time, it avoids the need for point correspondences during the training phase of the algorithm. We demonstrate this technique by applying it to two medical applications; two-dimensional segmentation of cardiac magnetic resonance imaging (MRI) and three-dimensional segmentation of prostate MRI.
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Affiliation(s)
- Andy Tsai
- Massachusetts Institute of Technology, Laboratory for Information and Decision Systems, Department of Electrical Engineering, Room 35-427, 127 Massachusets Ave., Cambridge 02139, USA.
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Abstract
MR imaging of the bladder can now be routinely and easily performed with consistent quality. The latest techniques provide high-resolution images of the soft tissue contrast and the ability to perform dynamic contrast imaging and functional pelvic floor studies. MR imaging fits in as a complimentary tool to cystoscopy and to conventional pelvic floor dynamic studies and can provide a unique imaging perspective of the bladder. It is important, however, to remain cognizant of the limitations of its use in tumor detection and discrimination.
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Affiliation(s)
- Leo P Lawler
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, 601 North Caroline Street, Room 3240F, Baltimore, MD 21287, USA.
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Hirose M, Bharatha A, Hata N, Zou KH, Warfield SK, Cormack RA, D'Amico A, Kikinis R, Jolesz FA, Tempany CMC. Quantitative MR imaging assessment of prostate gland deformation before and during MR imaging-guided brachytherapy. Acad Radiol 2002; 9:906-12. [PMID: 12186439 DOI: 10.1016/s1076-6332(03)80460-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
RATIONALE AND OBJECTIVES The authors performed this study to document the deformations that occur between pretreatment magnetic resonance (MR) imaging and intraoperative MR imaging during brachytherapy. MATERIALS AND METHODS MR images obtained at 1.5 and 0.5 T in 10 patients with prostate cancer were analyzed for changes in the shape and substructure of the prostate. Three-dimensional models of the prostate were obtained. The authors measured anteroposterior dimension; total gland, peripheral zone, and central gland volumes; transverse dimension; and superoinferior height. RESULTS Gland deformations were seen at visual inspection of the three-dimensional models. The anteroposterior dimension of the total gland, central gland, and peripheral zone increased from 1.5- to 0.5-T imaging (median dimension, 4.9, 1.5, and 1.8 mm, respectively), and the increase was greatest in the peripheral zone (P < .05, all comparisons). There was a decrease in the transverse dimension from 1.5- to 0.5-T imaging (median, 4.5 mm; P < .005). The total gland volume and the superoinferior height did not show a statistically significant change. CONCLUSION There were significant deformations in the shape of the prostate, especially in the peripheral zone, between the two imaging studies. The likely causes of the shape change are differences in rectal filling (endorectal coil used in 1.5-T studies vs obturator in 0.5-T studies) and/or changes in patient position (supine vs lithotomy). These findings suggest that pretreatment images alone may not be reliable for accurate therapy planning. It may be useful to integrate pre-and intraoperative data.
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Affiliation(s)
- Masanori Hirose
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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Bharatha A, Hirose M, Hata N, Warfield SK, Ferrant M, Zou KH, Suarez-Santana E, Ruiz-Alzola J, D'Amico A, Cormack RA, Kikinis R, Jolesz FA, Tempany CM. Evaluation of three-dimensional finite element-based deformable registration of pre- and intraoperative prostate imaging. Med Phys 2001; 28:2551-60. [PMID: 11797960 DOI: 10.1118/1.1414009] [Citation(s) in RCA: 189] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
In this report we evaluate an image registration technique that can improve the information content of intraoperative image data by deformable matching of preoperative images. In this study, pretreatment 1.5 tesla (T) magnetic resonance (MR) images of the prostate are registered with 0.5 T intraoperative images. The method involves rigid and nonrigid registration using biomechanical finite element modeling. Preoperative 1.5 T MR imaging is conducted with the patient supine, using an endorectal coil, while intraoperatively, the patient is in the lithotomy position with a rectal obturator in place. We have previously observed that these changes in patient position and rectal filling produce a shape change in the prostate. The registration of 1.5 T preoperative images depicting the prostate substructure [namely central gland (CG) and peripheral zone (PZ)] to 0.5 T intraoperative MR images using this method can facilitate the segmentation of the substructure of the gland for radiation treatment planning. After creating and validating a dataset of manually segmented glands from images obtained in ten sequential MR-guided brachytherapy cases, we conducted a set of experiments to assess our hypothesis that the proposed registration system can significantly improve the quality of matching of the total gland (TG), CG, and PZ. The results showed that the method statistically-significantly improves the quality of match (compared to rigid registration), raising the Dice similarity coefficient (DSC) from prematched coefficients of 0.81, 0.78, and 0.59 for TG, CG, and PZ, respectively, to 0.94, 0.86, and 0.76. A point-based measure of registration agreement was also improved by the deformable registration. CG and PZ volumes are not changed by the registration, indicating that the method maintains the biomechanical topology of the prostate. Although this strategy was tested for MRI-guided brachytherapy, the preliminary results from these experiments suggest that it may be applied to other settings such as transrectal ultrasound-guided therapy, where the integration of preoperative MRI may have a significant impact upon treatment planning and guidance.
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Affiliation(s)
- A Bharatha
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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