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1.
Cancer ; 121(6): 817-27, 2015 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-25204551

RESUMEN

The authors review methods for image-guided diagnosis and therapy that increase precision in the detection, characterization, and localization of many forms of cancer to achieve optimal target definition and complete resection or ablation. A new model of translational, clinical, image-guided therapy research is presented, and the Advanced Multimodality Image-Guided Operating (AMIGO) suite is described. AMIGO was conceived and designed to allow for the full integration of imaging in cancer diagnosis and treatment. Examples are drawn from over 500 procedures performed on brain, neck, spine, thorax (breast, lung), and pelvis (prostate and gynecologic) areas and are used to describe how they address some of the many challenges of treating brain, prostate, and lung tumors. Cancer 2015;121:817-827. © 2014 American Cancer Society.


Asunto(s)
Diagnóstico por Imagen/métodos , Imagen Multimodal/métodos , Neoplasias/diagnóstico , Diagnóstico por Imagen/instrumentación , Humanos , Imagen Multimodal/instrumentación , Neoplasias/diagnóstico por imagen , Neoplasias/terapia , Radiografía
2.
Radiology ; 274(1): 170-80, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25222067

RESUMEN

PURPOSE: To determine the detection rate, clinical relevance, Gleason grade, and location of prostate cancer ( PCa prostate cancer ) diagnosed with and the safety of an in-bore transperineal 3-T magnetic resonance (MR) imaging-guided prostate biopsy in a clinically heterogeneous patient population. MATERIALS AND METHODS: This prospective retrospectively analyzed study was HIPAA compliant and institutional review board approved, and informed consent was obtained. Eighty-seven men (mean age, 66.2 years ± 6.9) underwent multiparametric endorectal prostate MR imaging at 3 T and transperineal MR imaging-guided biopsy. Three subgroups of patients with at least one lesion suspicious for cancer were included: men with no prior PCa prostate cancer diagnosis, men with PCa prostate cancer who were undergoing active surveillance, and men with treated PCa prostate cancer and suspected recurrence. Exclusion criteria were prior prostatectomy and/or contraindication to 3-T MR imaging. The transperineal MR imaging-guided biopsy was performed in a 70-cm wide-bore 3-T device. Overall patient biopsy outcomes, cancer detection rates, Gleason grade, and location for each subgroup were evaluated and statistically compared by using χ(2) and one-way analysis of variance followed by Tukey honestly significant difference post hoc comparisons. RESULTS: Ninety biopsy procedures were performed with no serious adverse events, with a mean of 3.7 targets sampled per gland. Cancer was detected in 51 (56.7%) men: 48.1% (25 of 52) with no prior PCa prostate cancer , 61.5% (eight of 13) under active surveillance, and 72.0% (18 of 25) in whom recurrence was suspected. Gleason pattern 4 or higher was diagnosed in 78.1% (25 of 32) in the no prior PCa prostate cancer and active surveillance groups. Gleason scores were not assigned in the suspected recurrence group. MR targets located in the anterior prostate had the highest cancer yield (40 of 64, 62.5%) compared with those for the other parts of the prostate (P < .001). CONCLUSION: In-bore 3-T transperineal MR imaging-guided biopsy, with a mean of 3.7 targets per gland, allowed detection of many clinically relevant cancers, many of which were located anteriorly.


Asunto(s)
Biopsia Guiada por Imagen , Imagen por Resonancia Magnética Intervencional/métodos , Neoplasias de la Próstata/patología , Anciano , Medios de Contraste , Gadolinio DTPA , Humanos , Interpretación de Imagen Asistida por Computador , Masculino , Persona de Mediana Edad , Perineo , Estudios Prospectivos
3.
J Magn Reson Imaging ; 37(5): 1035-54, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23606141

RESUMEN

Magnetic resonance (MR) examinations of men with prostate cancer are most commonly performed for detecting, characterizing, and staging the extent of disease to best determine diagnostic or treatment strategies, which range from biopsy guidance to active surveillance to radical prostatectomy. Given both the exam's importance to individual treatment plans and the time constraints present for its operation at most institutions, it is essential to perform the study effectively and efficiently. This article reviews the most commonly employed modern techniques for prostate cancer MR examinations, exploring the relevant signal characteristics from the different methods discussed and relating them to intrinsic prostate tissue properties. Also, a review of recent articles using these methods to enhance clinical interpretation and assess clinical performance is provided. J. Magn. Reson. Imaging 2013;37:1035-1054. © 2013 Wiley Periodicals, Inc.


Asunto(s)
Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/instrumentación , Imagen por Resonancia Magnética/métodos , Próstata/patología , Neoplasias de la Próstata/patología , Predicción , Humanos , Masculino
4.
Eur Urol Oncol ; 6(2): 160-182, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36710133

RESUMEN

BACKGROUND: Active surveillance (AS) is recommended for low-risk and some intermediate-risk prostate cancer. Uptake and practice of AS vary significantly across different settings, as does the experience of surveillance-from which tests are offered, and to the levels of psychological support. OBJECTIVE: To explore the current best practice and determine the most important research priorities in AS for prostate cancer. DESIGN, SETTING, AND PARTICIPANTS: A formal consensus process was followed, with an international expert panel of purposively sampled participants across a range of health care professionals and researchers, and those with lived experience of prostate cancer. Statements regarding the practice of AS and potential research priorities spanning the patient journey from surveillance to initiating treatment were developed. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Panel members scored each statement on a Likert scale. The group median score and measure of consensus were presented to participants prior to discussion and rescoring at panel meetings. Current best practice and future research priorities were identified, agreed upon, and finally ranked by panel members. RESULTS AND LIMITATIONS: There was consensus agreement that best practice includes the use of high-quality magnetic resonance imaging (MRI), which allows digital rectal examination (DRE) to be omitted, that repeat standard biopsy can be omitted when MRI and prostate-specific antigen (PSA) kinetics are stable, and that changes in PSA or DRE should prompt MRI ± biopsy rather than immediate active treatment. The highest ranked research priority was a dynamic, risk-adjusted AS approach, reducing testing for those at the least risk of progression. Improving the tests used in surveillance, ensuring equity of access and experience across different patients and settings, and improving information and communication between and within clinicians and patients were also high priorities. Limitations include the use of a limited number of panel members for practical reasons. CONCLUSIONS: The current best practice in AS includes the use of high-quality MRI to avoid DRE and as the first assessment for changes in PSA, with omission of repeat standard biopsy when PSA and MRI are stable. Development of a robust, dynamic, risk-adapted approach to surveillance is the highest research priority in AS for prostate cancer. PATIENT SUMMARY: A diverse group of experts in active surveillance, including a broad range of health care professionals and researchers and those with lived experience of prostate cancer, agreed that best practice includes the use of high-quality magnetic resonance imaging, which can allow digital rectal examination and some biopsies to be omitted. The highest research priority in active surveillance research was identified as the development of a dynamic, risk-adjusted approach.


Asunto(s)
Antígeno Prostático Específico , Neoplasias de la Próstata , Masculino , Humanos , Consenso , Espera Vigilante/métodos , Neoplasias de la Próstata/diagnóstico , Neoplasias de la Próstata/terapia , Neoplasias de la Próstata/patología , Investigación
5.
Radiology ; 259(1): 39-56, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21436096

RESUMEN

Focused ultrasound surgery (FUS) is a noninvasive image-guided therapy and an alternative to surgical interventions. It presents an opportunity to revolutionize cancer therapy and to affect or change drug delivery of therapeutic agents in new focally targeted ways. In this article the background, principles, technical devices, and clinical cancer applications of image-guided FUS are reviewed.


Asunto(s)
Terapia por Ultrasonido/métodos , Terapia por Ultrasonido/tendencias , Ultrasonografía Intervencional/métodos , Ultrasonografía Intervencional/tendencias , Humanos
7.
J Magn Reson Imaging ; 30(5): 1052-8, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19856437

RESUMEN

PURPOSE: To apply an intensity-based nonrigid registration algorithm to MRI-guided prostate brachytherapy clinical data and to assess its accuracy. MATERIALS AND METHODS: A nonrigid registration of preoperative MRI to intraoperative MRI images was carried out in 16 cases using a Basis-Spline algorithm in a retrospective manner. The registration was assessed qualitatively by experts' visual inspection and quantitatively by measuring the Dice similarity coefficient (DSC) for total gland (TG), central gland (CG), and peripheral zone (PZ), the mutual information (MI) metric, and the fiducial registration error (FRE) between corresponding anatomical landmarks for both the nonrigid and a rigid registration method. RESULTS: All 16 cases were successfully registered in less than 5 min. After the nonrigid registration, DSC values for TG, CG, PZ were 0.91, 0.89, 0.79, respectively, the MI metric was -0.19 +/- 0.07 and FRE presented a value of 2.3 +/- 1.8 mm. All the metrics were significantly better than in the case of rigid registration, as determined by one-sided t-tests. CONCLUSION: The intensity-based nonrigid registration method using clinical data was demonstrated to be feasible and showed statistically improved metrics when compare to only rigid registration. The method is a valuable tool to integrate pre- and intraoperative images for brachytherapy.


Asunto(s)
Braquiterapia/métodos , Imagen por Resonancia Magnética/métodos , Próstata/patología , Próstata/efectos de la radiación , Neoplasias de la Próstata/radioterapia , Anciano , Algoritmos , Encéfalo/patología , Diagnóstico por Imagen/métodos , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Modelos Estadísticos , Neoplasias de la Próstata/patología , Reproducibilidad de los Resultados , Factores de Tiempo
8.
Radiology ; 249(1): 187-94, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18695211

RESUMEN

PURPOSE: To retrospectively assess the magnetic resonance (MR) imaging predictors of success at reducing uterine leiomyoma volume and achieving patient symptom relief 12 months after MR imaging-guided focused ultrasound surgery. MATERIALS AND METHODS: This single-center retrospective analysis of 71 symptomatic fibroids in 66 women was approved by the institutional review board and was HIPAA-compliant. Patients were treated with MR imaging-guided focused ultrasound surgery. The volume of treated fibroid and nonperfused volume (NPV) were calculated with software, while symptom outcome was assessed with a symptom severity score (SSS). Fibroids were classified as hyperintense or hypointense relative to skeletal muscle on pretreatment T2-weighted MR images. RESULTS: Baseline volume of treated fibroids was 255.5 cm(3) +/- 201.7 (standard deviation), and baseline SSS was 61.5 +/- 14.9. Both pretreatment fibroid signal intensity (SI) and posttreatment NPV predicted 12-month volume reduction independently: Fibroids with an NPV of at least 20% or with low SI both showed significantly larger volume reduction (17.0% +/- 13.0 and 17.2% +/- 20.1, respectively) than fibroids with an NPV less than 20% or with high SI (10.7% +/- 18.2 and no significant change, respectively). Patients whose fibroids demonstrated an NPV of at least 20% also experienced a larger decrease in SSS than did patients with fibroids with an NPV less than 20% (50.1% +/- 19.8 vs 32.6% +/- 29.9). CONCLUSION: Fibroids with low SI on pretreatment T2-weighted MR images were more likely to shrink than were ones with high SI. The larger the NPV immediately after treatment, the greater the volume reduction and symptom relief were. These findings may help both in selecting appropriate patients for MR-guided focused ultrasound surgery and in predicting patient outcome.


Asunto(s)
Leiomioma/terapia , Imagen por Resonancia Magnética , Terapia por Ultrasonido , Neoplasias Uterinas/terapia , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Estudios Retrospectivos
9.
Obstet Gynecol ; 110(2 Pt 1): 279-87, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17666601

RESUMEN

OBJECTIVE: To assess several measures of the long-term outcome of magnetic resonance-guided focused ultrasound surgery for symptomatic uterine leiomyomata. METHODS: Data on 359 women completing 24-month follow-up in all clinical trials of magnetic resonance-guided focused ultrasound surgery for uterine leiomyomata were analyzed. Quality of life outcomes, measured by the symptom severity score of the Uterine Fibroid Symptoms Quality Of Life Questionnaire were assessed for 24 months after treatment. Clinical endpoints, including uterine shrinkage, the need for additional leiomyoma treatment, and the time to additional leiomyoma treatment, were all assessed. The nonperfused volume ratio after treatment, calculated from the gadolinium-enhanced magnetic resonance imaging after treatment and the best measure of tissue necrosis after treatment, was used to assess outcome based on completeness of leiomyoma ablation. RESULTS: Women undergoing magnetic resonance-guided focused ultrasound surgery for symptomatic uterine leiomyomata have durable symptom relief, as measured by the symptom severity score at 24 months, with significantly greater improvement with more complete ablation (P<.001). Survival analysis demonstrates a significant reduction in the percentage of women undergoing additional leiomyoma treatment (P=.001) in women in the high nonperfused volume group. The mean shrinkage and mean residual nonperfused volume ratio are both significantly above zero at 6 months in the high nonperfused volume group (P<.001). The incidence of adverse events is low. However, for women with minimal treatment, the risk of additional procedures is high. CONCLUSION: Magnetic resonance-guided focused ultrasound surgery is an effective treatment for uterine leiomyomata and results in sustained symptomatic relief. LEVEL OF EVIDENCE: III.


Asunto(s)
Leiomioma/cirugía , Terapia por Ultrasonido/métodos , Neoplasias Uterinas/cirugía , Adulto , Ensayos Clínicos Fase III como Asunto , Femenino , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética , Persona de Mediana Edad , Satisfacción del Paciente , Calidad de Vida , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Terapia por Ultrasonido/efectos adversos
10.
Magn Reson Imaging ; 24(5): 563-8, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16735177

RESUMEN

Detailed measurements of water diffusion within the prostate over an extended b-factor range were performed to assess whether the standard assumption of monoexponential signal decay is appropriate in this organ. From nine men undergoing prostate MR staging examinations at 1.5 T, a single 10-mm-thick axial slice was scanned with a line scan diffusion imaging sequence in which 14 equally spaced b factors from 5 to 3,500 s/mm(2) were sampled along three orthogonal diffusion sensitization directions in 6 min. Due to the combination of long scan time and limited volume coverage associated with the multi-b-factor, multidirectional sampling, the slice was chosen online from the available T2-weighted axial images with the specific goal of enabling the sampling of presumed noncancerous regions of interest (ROIs) within the central gland (CG) and peripheral zone (PZ). Histology from prescan biopsy (n=9) and postsurgical resection (n=4) was subsequently employed to help confirm that the ROIs sampled were noncancerous. The CG ROIs were characterized from the T2-weighted images as primarily mixtures of glandular and stromal benign prostatic hyperplasia, which is prevalent in this population. The water signal decays with b factor from all ROIs were clearly non-monoexponential and better served with bi- vs. monoexponential fits, as tested using chi(2)-based F test analyses. Fits to biexponential decay functions yielded intersubject fast diffusion component fractions in the order of 0.73+/-0.08 for both CG and PZ ROIs, fast diffusion coefficients of 2.68+/-0.39 and 2.52+/-0.38 microm(2)/ms and slow diffusion coefficients of 0.44+/-0.16 and 0.23+/-0.16 um(2)/ms for CG and PZ ROIs, respectively. The difference between the slow diffusion coefficients within CG and PZ was statistically significant as assessed with a Mann-Whitney nonparametric test (P<.05). We conclude that a monoexponential model for water diffusion decay in prostate tissue is inadequate when a large range of b factors is sampled and that biexponential analyses are better suited for characterizing prostate diffusion decay curves.


Asunto(s)
Algoritmos , Agua Corporal/metabolismo , Imagen de Difusión por Resonancia Magnética/métodos , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Neoplasias de la Próstata/diagnóstico , Neoplasias de la Próstata/metabolismo , Anciano , Simulación por Computador , Humanos , Masculino , Tasa de Depuración Metabólica , Modelos Biológicos , Próstata/metabolismo , Próstata/patología , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
11.
Top Magn Reson Imaging ; 16(5): 355-68, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16924169

RESUMEN

We review our experience using an open 0.5-T magnetic resonance (MR) interventional unit to guide procedures in the prostate. This system allows access to the patient and real-time MR imaging simultaneously and has made it possible to perform prostate biopsy and brachytherapy under MR guidance. We review MR imaging of the prostate and its use in targeted therapy, and describe our use of image processing methods such as image registration to further facilitate precise targeting. We describe current developments with a robot assist system being developed to aid radioactive seed placement.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Espectroscopía de Resonancia Magnética/métodos , Neoplasias de la Próstata/diagnóstico , Neoplasias de la Próstata/terapia , Biopsia , Braquiterapia , Medios de Contraste , Humanos , Masculino , Selección de Paciente , Robótica
12.
Med Image Anal ; 9(2): 145-62, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15721230

RESUMEN

During neurosurgical procedures the objective of the neurosurgeon is to achieve the resection of as much diseased tissue as possible while achieving the preservation of healthy brain tissue. The restricted capacity of the conventional operating room to enable the surgeon to visualize critical healthy brain structures and tumor margin has lead, over the past decade, to the development of sophisticated intraoperative imaging techniques to enhance visualization. However, both rigid motion due to patient placement and nonrigid deformations occurring as a consequence of the surgical intervention disrupt the correspondence between preoperative data used to plan surgery and the intraoperative configuration of the patient's brain. Similar challenges are faced in other interventional therapies, such as in cryoablation of the liver, or biopsy of the prostate. We have developed algorithms to model the motion of key anatomical structures and system implementations that enable us to estimate the deformation of the critical anatomy from sequences of volumetric images and to prepare updated fused visualizations of preoperative and intraoperative images at a rate compatible with surgical decision making. This paper reviews the experience at Brigham and Women's Hospital through the process of developing and applying novel algorithms for capturing intraoperative deformations in support of image guided therapy.


Asunto(s)
Algoritmos , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/cirugía , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Neurocirugia/métodos , Técnica de Sustracción , Cirugía Asistida por Computador/métodos , Elasticidad , Humanos , Cuidados Intraoperatorios/métodos , Movimiento , Proyectos de Investigación , Utah
13.
Magn Reson Imaging ; 33(5): 525-30, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25687187

RESUMEN

OBJECTIVES: To evaluate the performance of T2 mapping in discriminating prostate cancer from normal prostate tissue in the peripheral zone using a practical reduced field-of-view MRI sequence requiring less than 3 minutes of scan time. MATERIALS AND METHODS: Thirty-six patients with biopsy-proven peripheral zone prostate cancer without prior treatment underwent routine multiparametric MRI at 3.0T with an endorectal coil. An Inner-Volume Carr-Purcell-Meiboom-Gill imaging sequence that required 2.8 minutes to obtain data for quantitative T2 mapping covering the entire prostate gland was added to the routine multiparametric protocol. Suspected cancer (SC) and suspected healthy (SH) tissue in the peripheral zone were identified in consensus by three radiologists and were correlated with available biopsy results. Differences in mean T2 values in SC and SH regions-of-interest (ROIs) were tested for significance using unpaired Student's two-tailed t-test. The area under the receiver operating characteristic curve was used to assess the optimal threshold T2 value for cancer discrimination. RESULTS: ROI analyses revealed significantly (p<0.0001) shorter T2 values in SC (85.4±12.3ms) compared to SH (169.6±38.7ms). An estimated T2 threshold of 99ms yielded a sensitivity of 92% and a specificity of 97% for prostate cancer discrimination. CONCLUSIONS: Quantitative values derived from this clinically practical T2-mapping sequence allow high precision discrimination between healthy and cancerous peripheral zone in the prostate.


Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética , Próstata/patología , Neoplasias de la Próstata/diagnóstico , Anciano , Humanos , Interpretación de Imagen Asistida por Computador/métodos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Curva ROC , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
15.
Med Phys ; 30(9): 2390-8, 2003 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-14528961

RESUMEN

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.


Asunto(s)
Algoritmos , Sistemas Especialistas , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Reconocimiento de Normas Patrones Automatizadas , Neoplasias de la Próstata/clasificación , Neoplasias de la Próstata/diagnóstico , Técnica de Sustracción , Análisis por Conglomerados , Imagen de Difusión por Resonancia Magnética/métodos , Humanos , Masculino , Modelos Biológicos , Modelos Estadísticos , Neoplasias de la Próstata/radioterapia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Resultado del Tratamiento
16.
Acad Radiol ; 10(12): 1359-68, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-14697004

RESUMEN

RATIONALE AND OBJECTIVES: The accuracy of diagnostic test and imaging segmentation is important in clinical practice because it has a direct impact on therapeutic planning. Statistical validations of classification accuracy was conducted based on parametric receiver operating characteristic analysis, illustrated on three radiologic examples, MATERIALS AND METHODS: Two parametric models were developed for diagnostic or imaging data. Example 1: A semi-automated fractional segmentation algorithm was applied to magnetic resonance imaging of nine cases of brain tumors. The tumor and background pixel data were assumed to have bi-beta distributions. Fractional segmentation was validated against an estimated composite pixel-wise gold standard based on multi-reader manual segmentations. Example 2: The predictive value of 100 cases of spiral computed tomography of ureteral stone sizes, distributed as bi-normal after a non-linear transformation, under two treatment options received. Example 3: One hundred eighty cases had prostate-specific antigen levels measured in a prospective clinical trial. Radical prostatectomy was performed in all to provide a binary gold standard of local and advanced cancer stages. Prostate-specific antigen level was transformed and modeled by bi-normal distributions. In all examples, areas under the receiver operating characteristic curves were computed. RESULTS. The areas under the receiver operating characteristic curves were: Example 1: Fractional segmentation of magnetic resonance imaging of brain tumors: meningiomas (0.924-0.984); astrocytomas (0.786-0.986); and other low-grade gliomas (0.896-0.983). Example 3: Ureteral stone size for treatment planning (0.813). Example 2: Prostate-specific antigen for staging prostate cancer (0.768). CONCLUSION: All clinical examples yielded fair to excellent accuracy. The validation metric area under the receiver operating characteristic curves may be generalized to evaluating the performances of several continuous classifiers related to imaging.


Asunto(s)
Neoplasias Encefálicas/diagnóstico , Imagen por Resonancia Magnética , Neoplasias de la Próstata/sangre , Curva ROC , Tomografía Computarizada por Rayos X , Cálculos Ureterales/diagnóstico por imagen , Algoritmos , Humanos , Masculino , Antígeno Prostático Específico/sangre , Prostatectomía , Neoplasias de la Próstata/cirugía
17.
Acad Radiol ; 11(2): 178-89, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14974593

RESUMEN

RATIONALE AND OBJECTIVES: To examine a statistical validation method based on the spatial overlap between two sets of segmentations of the same anatomy. MATERIALS AND METHODS: The Dice similarity coefficient (DSC) was used as a statistical validation metric to evaluate the performance of both the reproducibility of manual segmentations and the spatial overlap accuracy of automated probabilistic fractional segmentation of MR images, illustrated on two clinical examples. Example 1: 10 consecutive cases of prostate brachytherapy patients underwent both preoperative 1.5T and intraoperative 0.5T MR imaging. For each case, 5 repeated manual segmentations of the prostate peripheral zone were performed separately on preoperative and on intraoperative images. Example 2: A semi-automated probabilistic fractional segmentation algorithm was applied to MR imaging of 9 cases with 3 types of brain tumors. DSC values were computed and logit-transformed values were compared in the mean with the analysis of variance (ANOVA). RESULTS: Example 1: The mean DSCs of 0.883 (range, 0.876-0.893) with 1.5T preoperative MRI and 0.838 (range, 0.819-0.852) with 0.5T intraoperative MRI (P < .001) were within and at the margin of the range of good reproducibility, respectively. Example 2: Wide ranges of DSC were observed in brain tumor segmentations: Meningiomas (0.519-0.893), astrocytomas (0.487-0.972), and other mixed gliomas (0.490-0.899). CONCLUSION: The DSC value is a simple and useful summary measure of spatial overlap, which can be applied to studies of reproducibility and accuracy in image segmentation. We observed generally satisfactory but variable validation results in two clinical applications. This metric may be adapted for similar validation tasks.


Asunto(s)
Neoplasias Encefálicas/patología , Interpretación Estadística de Datos , Imagen por Resonancia Magnética , Neoplasias de la Próstata/patología , Análisis de Varianza , Humanos , Masculino , Reproducibilidad de los Resultados , Estudios Retrospectivos
18.
Acad Radiol ; 9(8): 906-12, 2002 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12186439

RESUMEN

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.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Próstata/patología , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/radioterapia , Braquiterapia/métodos , Humanos , Imagenología Tridimensional , Cuidados Intraoperatorios , Masculino , Planificación de Atención al Paciente , Cuidados Preoperatorios , Próstata/efectos de la radiación , Neoplasias de la Próstata/diagnóstico , Neoplasias de la Próstata/cirugía , Reproducibilidad de los Resultados , Estudios Retrospectivos
19.
Int J Radiat Oncol Biol Phys ; 85(2): e101-7, 2013 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-23040223

RESUMEN

PURPOSE: To investigate whether 3-T esla (3T) multiparametric endorectal MRI (erMRI) can add information to established predictors regarding occult extraprostatic or high-grade prostate cancer (PC) in men with clinically localized PC. METHODS AND MATERIALS: At a single academic medical center, this retrospective study's cohort included 118 men with clinically localized PC who underwent 3T multiparametric erMRI followed by radical prostatectomy, from 2008 to 2011. Multivariable logistic regression analyses in all men and in 100 with favorable-risk PC addressed whether erMRI evidence of T3 disease was associated with prostatectomy T3 or Gleason score (GS) 8-10 (in patients with biopsy GS ≤7) PC, adjusting for age, prostate-specific antigen level, clinical T category, biopsy GS, and percent positive biopsies. RESULTS: The accuracy of erMRI prediction of extracapsular extension and seminal vesicle invasion was 75% and 95%, respectively. For all men, erMRI evidence of a T3 lesion versus T2 was associated with an increased odds of having pT3 disease (adjusted odds ratio [AOR] 4.81, 95% confidence interval [CI] 1.36-16.98, P=.015) and pGS 8-10 (AOR 5.56, 95% CI 1.10-28.18, P=.038). In the favorable-risk population, these results were AOR 4.14 (95% CI 1.03-16.56), P=.045 and AOR 7.71 (95% CI 1.36-43.62), P=.021, respectively. CONCLUSIONS: Three-Tesla multiparametric erMRI in men with favorable-risk PC provides information beyond that contained in known preoperative predictors about the presence of occult extraprostatic and/or high-grade PC. If validated in additional studies, this information can be used to counsel men planning to undergo radical prostatectomy or radiation therapy about the possible need for adjuvant radiation therapy or the utility of adding hormone therapy, respectively.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/cirugía , Factores de Edad , Anciano , Biopsia , Humanos , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Invasividad Neoplásica/patología , Estadificación de Neoplasias , Próstata/patología , Próstata/cirugía , Antígeno Prostático Específico/sangre , Prostatectomía/métodos , Neoplasias de la Próstata/sangre , Análisis de Regresión , Estudios Retrospectivos
20.
ISRN Obstet Gynecol ; 2011: 962621, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21647219

RESUMEN

We present a case of successful magnetic resonance imaging-guided focused ultrasound surgery (MRgFUS) of a uterine fibroid in a patient with extensive anterior abdominal wall surgical scars from two longitudinal laparotomies, a total colectomy and ileostomy. This case demonstrates that MRgFUS can be safely used in patients with an ostomy and significant abdominal wall scarring, but careful pretreatment planning and positioning during treatment is needed.

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