Evaluation of Radiation Dose Effect on Lung Function Using Iodine Maps Derived From Dual-Energy Computed Tomography.

Purpose: There is interest in using dual-energy computed tomography (DECT) to evaluate organ function before and after radiation therapy (RT). The purpose of this study (trial identifier: NCT04863027) is to assess longitudinal changes in lung perfusion using iodine maps derived from DECT in patients with lung cancer treated with conventional or stereotactic RT.

Methods And Materials: For 48 prospectively enrolled patients with lung cancer, a contrast-enhanced DECT using a dual-source CT simulator was acquired pretreatment and at 6 and 12 months posttreatment.

The potential of photon-counting CT for quantitative contrast-enhanced imaging in radiotherapy.

The aim of this study is to use a simulation environment to evaluate the potential of using photon-counting CT (PCCT) against dual-energy CT (DECT) in the context of quantitative contrast-enhanced CT for radiotherapy. An adaptation of Bayesian eigentissue decomposition by Lalonde et al (2017 Med. Phys.

Dual-energy computed tomography for prediction of loco-regional recurrence after radiotherapy in larynx and hypopharynx squamous cell carcinoma.

Purpose: To investigate the role of quantitative pre-treatment dual-energy computed tomography (DECT) for prediction of loco-regional recurrence (LRR) in patients with larynx/hypopharynx squamous cell cancer (L/H SCC).

Methods: Patients with L/H SCC treated with curative intent loco-regional radiotherapy and that underwent treatment planning with contrast-enhanced DECT of the neck were included. Primary and nodal gross tumor volumes (GTVp and GTVn) were contoured and transferred into a Matlab® workspace.

Robust quantitative contrast-enhanced dual-energy CT for radiotherapy applications.

Purpose: The purpose of this study was to develop and validate accurate methods for determining iodine content and virtual noncontrast maps of physical parameters, such as electron density, in the context of radiotherapy.

Methods: A simulation environment is developed to compare three methods allowing extracting iodine content and virtual noncontrast composition: (a) two-material decomposition, (b) three-material decomposition with the conservation of volume constraint, and (c) eigentissue decomposition. The simulation allows comparing the performance of the methods using iodine-based contrast agent contents in tissues from a reference dataset with variable density and elemental composition.

Phase 1-2 Study of Dual-Energy Computed Tomography for Assessment of Pulmonary Function in Radiation Therapy Planning.

Purpose: To quantify lung function according to a dual-energy computed tomography (DECT)-derived iodine map in patients treated with radiation therapy for lung cancer, and to assess the dosimetric impact of its integration in radiation therapy planning.

Methods And Materials: Patients treated with stereotactic ablative radiation therapy for early-stage or intensity modulated radiation therapy for locally advanced lung cancer were prospectively enrolled in this study. A DECT in treatment position was obtained at time of treatment planning.

Assessing lung function using contrast-enhanced dual-energy computed tomography for potential applications in radiation therapy.

Purpose: There is an increasing interest in the evaluation of lung function from physiological images in radiation therapy treatment planning to reduce the extent of postradiation toxicities. The purpose of this work was to retrieve reliable functional information from contrast-enhanced dual-energy computed tomography (DECT) for new applications in radiation therapy. The functional information obtained by DECT is also compared with other methods using single-energy CT (SECT) and single-photon emission computed tomography (SPECT) with CT.

Genome-wide stochastic adaptive DNA amplification at direct and inverted DNA repeats in the parasite Leishmania.

Gene amplification of specific loci has been described in all kingdoms of life. In the protozoan parasite Leishmania, the product of amplification is usually part of extrachromosomal circular or linear amplicons that are formed at the level of direct or inverted repeated sequences. A bioinformatics screen revealed that repeated sequences are widely distributed in the Leishmania genome and the repeats are chromosome-specific, conserved among species, and generally present in low copy number.