Dosimetric impact of dual-energy CT tissue segmentation for low-energy prostate brachytherapy: a Monte Carlo study.

Dosimetric impact of dual-energy CT tissue segmentation for low-energy prostate brachytherapy: a Monte Carlo study. Phys Med Biol. 2017 Dec 20;: Authors: Remy C, Lalonde A, Béliveau-Nadeau D, Carrier JF, Bouchard H Abstract {\color{red}The purpose of this study is} to evaluate the impact of a novel tissue characterization method using dual-energy over single-energy computed tomography (DECT and SECT) on Monte Carlo (MC) dose calculations for low-dose rate (LDR) prostate brachytherapy performed in a patient like geometry. A virtual patient geometry is created using contours from a real patient pelvis CT scan, where known elemental compositions and varying densities are overwritten in each voxel. A second phantom is made with additional calcifications. \textcolor{red}{Both phantoms are the ground truth with which all results are compared.} Simulated CT images are generated \textcolor{red}{from them} using attenuation coefficients taken from the XCOM database with a 100 kVp spectrum for SECT and 80 and 140Sn kVp for DECT. Tissue segmentation for Monte Carlo dose calculation is made using a stoichiometric calibration method for the simulated SECT images. For the DECT images, Bayesian eigentissue decomposition is used. A LDR prostate brachytherapy plan is defined with $ ^{125}$I sources and then calculated using the EGSnrc user-code Brachydose for each case. Dose distributions and dose-volume histograms (DVH) are compared to ground truth to assess...
Source: Physics in Medicine and Biology - Category: Physics Authors: Tags: Phys Med Biol Source Type: research

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We presented the physics preparations and clinical workflow required for implementing MRI-based HDR IBT (MRI-HDR-IBT) of gynecologic cancer patients in a high-volume brachytherapy center. The present document is designed to focus on the clinical steps required from a physicist's standpoint. Those steps include: (a) testing IBT equipment with MRI scanner, (b) preparation of templates and catheters, (c) preparation of MRI line markers, (d) acquisition, importation and registration of MRI images, (e) development of treatment plans and (f) treatment evaluation and documentation. The checklists of imaging acquisition, registrat...
Source: Journal of Applied Clinical Medical Physics - Category: Physics Authors: Tags: J Appl Clin Med Phys Source Type: research
Abstract We developed a fast and fully-automated, multi-criteria treatment planning workflow for high dose rate brachytherapy (HDR-BT). In this workflow, the patient-CT with catheter reconstructions and dwell positions are imported from the clinical TPS into a novel system for automated dwell time optimisation. The optimised dwell times are then imported into the clinical TPS. The aims of automation were 1) planner-independent, enhanced plan quality, 2) short optimisation times. Our in-house developed system for fully automated, multi-criteria external beam radiotherapy (EBRT) treatment planning (Erasmus-iCycle) w...
Source: Physics in Medicine and Biology - Category: Physics Authors: Tags: Phys Med Biol Source Type: research
ConclusionsThe texture analysis of pretreatment [18F]FDG PET/CT provided more information than conventional PET parameters for predicting patient prognosis of locally advanced salivary gland carcinoma treated with interstitial brachytherapy. The minimum intensity was a risk factor for PFS, and LRE was a favorable factor in prognostic prediction according to the primary results.
Source: EJNMMI Research - Category: Radiology Source Type: research
Conclusions: Cesium-131 interstitial brachytherapy is feasible and does not pose major radiation safety concerns; it should be considered as a treatment option for previously irradiated patients with recurrent, resectable HNC. PMID: 31435429 [PubMed]
Source: Journal of Contemporary Brachytherapy - Category: Cancer & Oncology Tags: J Contemp Brachytherapy Source Type: research
Conclusion: For immobilized malignant tumors, 3D-printed template can be used reproducibly. The dose parameters in preplan can be achieved easily and satisfactorily by 3D-printed template guided brachytherapy, and it may become an easily reproducible standardized procedure in the future.
Source: Journal of Cancer Research and Therapeutics - Category: Cancer & Oncology Authors: Source Type: research
In this study we evaluate the lesion detection efficacy of18F-DCFPyL PET/CT in patients with BCR and determine the detection efficacy as a function of their PSA value.MethodsA total of 248 consecutive patients were evaluated and underwent scanning with18F-DCFPyL PET/CT for BCR between November 2016 and 2018 in two hospitals in the Netherlands. Patients were examined after radical prostatectomy (52%), external-beam radiation therapy (42%) or brachytherapy (6%). Imaging was performed 120  min after injection of a median dose of 311 MBq18F-DCFPyL.ResultsIn 214 out of 248 PET/CT scans (86.3%), at least one lesion sug...
Source: European Journal of Nuclear Medicine and Molecular Imaging - Category: Nuclear Medicine Source Type: research
Authors: Shi XX, Pang HW, Ren PR, Sun XY, Wu JB, Lin S Abstract Purpose: To evaluate safety, feasibility, and efficacy of template-assisted 192Ir-based stereotactic ablative brachytherapy (SABT), combined with surgery for peripheral non-small cell lung cancer (NSCLC). Material and methods: Patients with pathologically confirmed operable peripheral NSCLC, who underwent template-assisted SABT (30 Gy delivered in one fraction) and were scheduled for tumor resection 4-6 weeks after SABT were included in this study. The perioperative adverse reactions of SABT were recorded to evaluate safety and feasibility of SABT ...
Source: Journal of Contemporary Brachytherapy - Category: Cancer & Oncology Tags: J Contemp Brachytherapy Source Type: research
Conclusions: The distancing of the adjacent OARs allows a higher D100 value of CTV, therefore allowing for more efficient local control. PMID: 31139224 [PubMed]
Source: Journal of Contemporary Brachytherapy - Category: Cancer & Oncology Tags: J Contemp Brachytherapy Source Type: research
592Objectives: 18F-rhPSMA-7 is a new theranostic PSMA-targeting agent which allows fast radiolabeling with 18F and radiometals. This retrospective analysis investigates the efficacy of 18F-rhPSMA-7 PET/computed tomography (CT) in patients with biochemical recurrence of prostate cancer following curative-intent primary treatment with external beam radiotherapy (EBRT) or brachytherapy. Methods: Datasets from patients with non-castrate biochemical recurrence of prostate cancer after treatment with EBRT or brachytherapy who underwent 18F-rhPSMA-7 PET/CT at either the Technical University Munich or Ludwig-Maximillian University...
Source: Journal of Nuclear Medicine - Category: Nuclear Medicine Authors: Tags: Prostate Diagnosis I Source Type: research
To assess the impact of rectal hydrogel spacer on prostate and rectal dosimetry as determined by CT Scan imaging for low-dose-rate brachytherapy.
Source: Brachytherapy - Category: Cancer & Oncology Authors: Source Type: research
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