Magnetic Resonance Image Guided Brachytherapy

Tanderup, Kari; Viswanathan, Akila N.; Kirisits, Christian; Frank, Steven J.

doi:10.1016/j.semradonc.2014.02.007

Cited by 108 publications

(86 citation statements)

References 78 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Associations with outcome were demonstrated for two cohorts recruited over a time period of 11 years, during which MR image-guided brachytherapy has been implemented in our hospital and replaced brachytherapy based on 2D X-ray imaging (36). Moreover, the second cohort was analyzed with another Illumina array generation, which required data transformation prior to classification.…”

Section: Discussionmentioning

confidence: 99%

Integrative Analysis of DCE-MRI and Gene Expression Profiles in Construction of a Gene Classifier for Assessment of Hypoxia-Related Risk of Chemoradiotherapy Failure in Cervical Cancer

Fjeldbo

Julin

Lando

et al. 2016

Clinical Cancer Research

View full text Add to dashboard Cite

Purpose: A 31-gene expression signature reflected in dynamic contrast enhanced (DCE)-MR images and correlated with hypoxia-related aggressiveness in cervical cancer was identified in previous work. We here aimed to construct a dichotomous classifier with key signature genes and a predefined classification threshold that separated cervical cancer patients into a more and less hypoxic group with different outcome to chemoradiotherapy.Experimental Design: A training cohort of 42 patients and two independent cohorts of 108 and 131 patients were included. Gene expression data were generated from tumor biopsies by two Illumina array generations (WG-6, HT-12). Technical transfer of the classifier to a reverse transcription quantitative PCR (RT-qPCR) platform was performed for 74 patients. The amplitude A Brix in the Brix pharmacokinetic model was extracted from DCE-MR images of 64 patients and used as an indicator of hypoxia.Results: Classifier candidates were constructed by integrative analysis of A Brix and gene expression profiles in the training cohort and evaluated by a leave-one-out cross-validation approach. On the basis of their ability to separate patients correctly according to hypoxia status, a 6-gene classifier was identified. The classifier separated the patients into two groups with different progression-free survival probability. The robustness of the classifier was demonstrated by successful validation of hypoxia association and prognostic value across cohorts, array generations, and assay platforms. The prognostic value was independent of existing clinical markers, regardless of clinical endpoints.Conclusions: A robust DCE-MRI-associated gene classifier has been constructed that may be used to achieve an early indication of patients' risk of hypoxia-related chemoradiotherapy failure.

show abstract

Section: Discussionmentioning

confidence: 99%

Integrative Analysis of DCE-MRI and Gene Expression Profiles in Construction of a Gene Classifier for Assessment of Hypoxia-Related Risk of Chemoradiotherapy Failure in Cervical Cancer

Fjeldbo

Julin

Lando

et al. 2016

Clinical Cancer Research

View full text Add to dashboard Cite

show abstract

“…7 Magnetic resonance imaging (MRI) is increasingly used for treatment planning due to the improved visualization of tumors and the surrounding critical organs. 8 International standards for contouring locally advanced cervical cancer rely on MRI.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of an active magnetic resonance tracking system for interstitial brachytherapy

et al. 2015

Self Cite

View full text Add to dashboard Cite

Purpose: In gynecologic cancers, magnetic resonance (MR) imaging is the modality of choice for visualizing tumors and their surroundings because of superior soft-tissue contrast. Real-time MR guidance of catheter placement in interstitial brachytherapy facilitates target coverage, and would be further improved by providing intraprocedural estimates of dosimetric coverage. A major obstacle to intraprocedural dosimetry is the time needed for catheter trajectory reconstruction. Herein the authors evaluate an active MR tracking (MRTR) system which provides rapid catheter tip localization and trajectory reconstruction. The authors assess the reliability and spatial accuracy of the MRTR system in comparison to standard catheter digitization using magnetic resonance imaging (MRI) and CT. Methods: The MRTR system includes a stylet with microcoils mounted on its shaft, which can be inserted into brachytherapy catheters and tracked by a dedicated MRTR sequence. Catheter tip localization errors of the MRTR system and their dependence on catheter locations and orientation inside the MR scanner were quantified with a water phantom. The distances between the tracked tip positions of the MRTR stylet and the predefined ground-truth tip positions were calculated for measurements performed at seven locations and with nine orientations. To evaluate catheter trajectory reconstruction, fifteen brachytherapy catheters were placed into a gel phantom with an embedded catheter fixation framework, with parallel or crossed paths. The MRTR stylet was then inserted sequentially into each catheter. During the removal of the MRTR stylet from within each catheter, a MRTR measurement was performed at 40 Hz to acquire the instantaneous stylet tip position, resulting in a series of three-dimensional (3D) positions along the catheter's trajectory. A 3D polynomial curve was fit to the tracked positions for each catheter, and equally spaced dwell points were then generated along the curve. High-resolution 3D MRI of the phantom was performed followed by catheter digitization based on the catheter's imaging artifacts. The catheter trajectory error was characterized in terms of the mean distance between corresponding dwell points in MRTR-generated catheter trajectory and MRI-based catheter digitization. The MRTR-based catheter trajectory reconstruction process was also performed on three gynecologic cancer patients, and then compared with catheter digitization based on MRI and CT. trajectories were reconstructed by MRTR. Compared with MRI-based digitization, the mean 3D error of MRTR-generated trajectories was 1.5 ± 0.5 mm with an in-plane error of 0.7 ± 0.2 mm and a tip error of 1.7 ± 0.5 mm. MRTR resolved ambiguity in catheter assignment due to crossed catheter paths, which is a common problem in image-based catheter digitization. In the patient studies, the MRTR-generated catheter trajectory was consistent with digitization based on both MRI and CT. Conclusions: The MRTR system provides accurate catheter tip localization and trajectory reconstructio...

show abstract

“…Similarly, the position and orientation of the needle at 2 are (0, 5, 8) and (-2, -0.5, -4), respectively. The calculated paths for ball joints revealed that 1 traveled between the points (-5, 5, 0) and (4,6,0). Similarly, 2 moved between the points (-4, 4, 4) and (2, 5.5, 4).…”

Section: Resultsmentioning

confidence: 99%

Design and Simulation of Robotic Needle Guide for Transperineal Prostate Biopsy

Dehghani

Zhang

Kulkarni

et al. 2018

2018 Design of Medical Devices Conference

View full text Add to dashboard Cite

Prostate cancer is the third leading cause of cancer-related death for males in the United States [1]. Over three million Americans with prostate cancer were reported in 2016 [2] marking the prostate cancer as the most prevalent cancer among males in the US. In 2016, 180,890 new cases and 26,120 deaths were reported [1]. The prostate is a male reproductive gland located in the pelvis and surrounded by the rectum posteriorly and the bladder superiorly.

show abstract

Magnetic Resonance Image Guided Brachytherapy

Cited by 108 publications

References 78 publications

Integrative Analysis of DCE-MRI and Gene Expression Profiles in Construction of a Gene Classifier for Assessment of Hypoxia-Related Risk of Chemoradiotherapy Failure in Cervical Cancer

Integrative Analysis of DCE-MRI and Gene Expression Profiles in Construction of a Gene Classifier for Assessment of Hypoxia-Related Risk of Chemoradiotherapy Failure in Cervical Cancer

Evaluation of an active magnetic resonance tracking system for interstitial brachytherapy

Design and Simulation of Robotic Needle Guide for Transperineal Prostate Biopsy

Contact Info

Product

Resources

About