Preclinical Aspects of [89Zr]Zr-DFO-Rituximab: A High Potential Agent for Immuno-PET Imaging.

Background: An early diagnosis of cancer can lead to choosing more effective treatment and increase the number of cancer survivors. In this study, the preparation and preclinical aspects of [89Zr]Zr-DFO-Rituximab, a high-potential agent for PET imaging of Non- Hodgkin Lymphoma (NHL), were evaluated.

Methods: DFO was conjugated to rituximab monoclonal antibody (mAb), and DFO-rituximab was successfully labeled with zirconium-89 (89Zr) at optimized conditions.

Assessing the stability and discriminative ability of radiomics features in the tumor microenvironment: Leveraging peri-tumoral regions in vestibular schwannoma.

Purpose: The tumor microenvironment (TME) plays a crucial role in tumor progression and treatment response. Radiomics offers a non-invasive approach to studying the TME by extracting quantitative features from medical images. In this study, we present a novel approach to assess the stability and discriminative ability of radiomics features in the TME of vestibular schwannoma (VS).

AutoCorNN: An Unsupervised Physics-Aware Deep Learning Model for Geometric Distortion Correction of Brain MRI Images Towards MR-Only Stereotactic Radiosurgery.

Geometric distortions in brain MRI images arising from susceptibility artifacts at air-tissue interfaces pose a significant challenge for high-precision radiation therapy modalities like stereotactic radiosurgery, necessitating sub-millimeter accuracy. To achieve this goal, we developed AutoCorNN, an unsupervised physics-aware deep-learning model for correcting geometric distortions. Two publicly available datasets, the MPI-Leipzig Mind-Brain-Body with 318 subjects, and the Vestibular Schwannoma-SEG dataset, encompassing 242 patients were utilized.

Optimized Production of Re-HYNIC-Bombesin: New Therapeutic Agent for GRPR Targeting.

Purpose: One of the most interesting methods to deliver therapeutic doses of ionizing radiation to tumor sites is radiolabeled compounds. Bombesin peptide binds to gastrin-releasing peptide receptors (GRPRs) with great affinity. Through its appropriate physical characteristics and accessibility as the W/Re generator, Re can be effectively used to develop a therapeutic radio complex.

Hydrogen nanobubbles: A novel approach toward radio-sensitization agents.

Background: Ocular melanoma is a rare kind of eye malignancy that threatens the patient's eyesight. Radiotherapy and surgical removal are the most commonly used therapeutic modalities, and nanomedicine has lately entered this field. Brachytherapy using Ruthenium-106 ( Ru) ophthalmic plaques has been used for decades to treat ocular melanoma, with the applicator placed on the patient's eyes until the prescribed dose reaches the tumor apex.

Estimation of Human Absorbed Dose of Re-Hynic-Bombesin Based on Biodistribution Data in Rats.

Background: HYNIC-Bombesin (BBN) is a potential peptide for targeted radionuclide therapy in gastrin-releasing peptide receptor (GRPr)-positive malignancies. The Re-HYNICBBN is a promising radiopharmaceutical for use in prostate cancer therapy.

Objective: The aim of this study was to estimate the absorbed dose due to Re-HYNIC-BBN radio-complex in human organs based on bio-distribution data of rats.

A novel analytical method for computing dose from kilovoltage beams used in Image-Guided radiation therapy.

Purpose: A modified convolution/superposition algorithm is proposed to compute dose from the kilovoltage beams used in IGRT. The algorithm uses material-specific energy deposition kernels instead of water-energy deposition kernels.

Methods: Monte Carlo simulation was used to model the Elekta XVI unit and determine dose deposition characteristics of its kilovoltage beams.

The role of deep learning-based survival model in improving survival prediction of patients with glioblastoma.

This retrospective study has been conducted to validate the performance of deep learning-based survival models in glioblastoma (GBM) patients alongside the Cox proportional hazards model (CoxPH) and the random survival forest (RSF). Furthermore, the effect of hyperparameters optimization methods on improving the prediction accuracy of deep learning-based survival models was investigated. Of the 305 cases, 260 GBM patients were included in our analysis based on the following criteria: demographic information (i.

Dose characteristics of Au-198 eye brachytherapy applicator: A Monte Carlo study.

Purpose: The use of ocular plaques is a promising treatment option for eye melanoma brachytherapy. Although several studies have been done on various ocular plaques, little is known about the dose characterization of Au plaque.

Materials And Method: The full mathematical model of the eye phantom, tumor, Ru/Rh CCA, and Au plaque were simulated using the Monte Carlo MCNPX code.

Generation of material-specific energy deposition kernels for kilovoltage x-ray dose calculations.

Purpose: Dose calculation of kilovoltage x rays used in Image-Guided Radiotherapy has been investigated in recent years using various methods. Among these methods are model-based ones that suffer from inaccuracies in high-density materials and at interfaces when used in the kilovoltage energy range. The main reason for this is the use of water energy deposition kernels and simplifications employed such as density scaling in heterogeneous media.

An in silico study on the effect of host tissue at brachytherapy dose enhancement by gold nanoparticles.

Purpose: Iridium-192 brachytherapy dose enhancement by gold nanoparticles was investigated in five different tumor tissues to observe the tissue-related differences as an effective environmental factor in the applications of nanoparticles as radio-enhancer agents.

Methods And Materials: The brachytherapy high-dose-rate source of BEBIG Ir-192, a tumor volume with five different tissues including water, Plexiglas, soft tissue, adipose, and bone with and without a uniform distribution of gold nanoparticles were mimicked by MCNPX Monte Carlo simulation code using lattice feature. Dose enhancement factors in the tumor volume were measured separately regarding the types of tissue, and a previous study using GEometry ANd Tracking 4 simulation was used for result validation.

The protective effect of oleuropein against radiation-induced cytotoxicity, apoptosis, and genetic damage in cultured human lymphocytes.

Purpose: The aim of this study was to evaluate the effects of oleuropein radiation protection and to find an effective radioprotector.

Materials And Method: Human mononuclear cells were treated with oleuropein at the concentration of 100 μM (optimum concentration), incubated for 24 h, and then exposed to 2 Gy gamma-rays. The anti-radiation effect of oleuropein was assessed by MTT assay, flow cytometry, comet assay, and micronucleus (MN) assay.

Impact of image preprocessing methods on reproducibility of radiomic features in multimodal magnetic resonance imaging in glioblastoma.

To investigate the effect of image preprocessing, in respect to intensity inhomogeneity correction and noise filtering, on the robustness and reproducibility of the radiomics features extracted from the Glioblastoma (GBM) tumor in multimodal MR images (mMRI). In this study, for each patient 1461 radiomics features were extracted from GBM subregions (i.e.

Radiolabeling of Biogenic Magnetic Nanoparticles with Rhenium-188 as a Novel Agent for Targeted Radiotherapy.

Use of nanoparticles as carriers of anticancer drugs is a suitable way for targeted drug delivery and reduction of the side effects. This research focuses on a novel drug carrier for therapeutic goals by the bacterial magnetic nanoparticles (magnetosomes). The unique characteristics of magnetosomes make them ideal nanobiotechnological materials.

Induction of Apoptosis by a Combination of 2-Deoxyglucose and Metformin in Esophageal Squamous Cell Carcinoma by Targeting Cancer Cell Metabolism.

Background: Both mitochondrial dysfunction and aerobic glycolysis are signs of growing aggressive cancer. If altered metabolism of cancer cell is intended, using the glycolysis inhibitor (2-deoxyglucose (2DG)) would be a viable therapeutic method. The AMP-activated protein kinase (AMPK), as a metabolic sensor, could be activated with metformin and it can also launch a p53-dependent metabolic checkpoint and might inhibit cancer cell growth.

Prospective evaluation of the early effects of radiation on the auditory system frequencies of patients with head and neck cancers and brain tumors after radiotherapy.

Patients with head and neck cancer after radiotherapy often suffer disability such as hearing disorders. In this study, the effect of radiotherapy (RT) on hearing function of patients with head and neck cancer after RT was determined according to the total dose delivered to specific parts of the auditory system. A total of 66 patients treated with primary or postoperative radiation therapy for various cancers in the head and neck region were selected.

Comparison between performance of single-fiber reflectance spectroscopy (SFRS) system and colposcopy: a phase III trial.

Herein, the performance of single-fiber reflectance spectroscopy (SFRS) in detection of cervical pre-cancerous squamous intraepithelial lesions (SIL) was compared with colposcopy. Based on the previous results obtained from 167 samples and finding the contributing parameters in differentiating SILs from non-SILs, a user-friendly interface was developed to detect the SILs using SFRS system. Detection of SILs in 301 patients was performed by both SFRS system and routine colposcopy.

EVALUATION OF RADIATION ABSORBED DOSE AND IMAGE QUALITY IN DIFFERENT RETROSPECTIVE-ECG GATING ACQUISITION METHODS OF CARDIAC CT ANGIOGRAPHY.

Cardiac computed tomography angiography (CCTA) studies have risen concern of radiobiological effects over the patients. Therefore, estimating radiation doses absorbed during CCTA is important. In this study, we compared radiation dose and image quality by using three different retrospective electrocardiography (ECG) protocols.

Dependence of micronuclei assay on the depth of absorbed dose.

Aim: The purpose of the present study is to investigate the dependence of micronuclei response on the depth of absorbed dose.

Background: One of the most common cytogenetic methods used for radiation dosimetry is micronuclei (MN). Being less complex and faster than other methods are two remarkable advantages of the MN method which make it suitable for monitoring of population.

Edge-illumination x-ray phase contrast imaging with Pt-based metallic glass masks.

Edge-illumination x-ray phase contrast imaging (EI XPCI) is a non-interferometric phase-sensitive method where two absorption masks are employed. These masks are fabricated through a photolithography process followed by electroplating which is challenging in terms of yield as well as time- and cost-effectiveness. We report on the first implementation of EI XPCI with Pt-based metallic glass masks fabricated by an imprinting method.

Evaluating the performance of TG-43 protocol in esophageal HDR brachytherapy viewpoint to trachea inhomogeneity.

Aim: The aim of this study is to evaluate the effect of air within trachea on dose calculations of esophageal HDR brachytherapy treatment planning.

Background: Dose calculations in esophageal HDR brachytherapy treatment planning systems are greatly based on TG-43 protocol which in all materials are considered to be water equivalent.

Materials And Methods: A cylindrical PMMA phantom with a tube in the center (neck equivalent phantom) accompanied by Flexitron HDR brachytherapy system was used in this study.

Commissioning of beam shaper applicator for conformal intraoperative electron radiotherapy.

Beam shaper is a newly designed device for beam shaping in IOERT. The aim of this study is evaluating the performance of this device for conformal IOERT and preparing it for clinical applications. Dosimetric characteristics for different combinations of energy/field size were determined by ionometric dosimetry, film dosimetry and Monte Carlo simulation.

Enhancing radiosensitivity of TE1, TE8, and TE 11 esophageal squamous carcinoma cell lines by Hdm2-siRNA targeted gene therapy in vitro.

Introduction: Human double minute2 (hdm2) level increases in most human malignancies. Therefore, inhibition of tumor growth and also induction of radiosensitivity may be provided by hdm2 inhibitors. The effects of hdm2-siRNA on hdm2 protein expression, cell apoptosis rate, and radiosensitivity of human esophageal squamous cell carcinoma (ESCC) were studied.

Dose response characteristics of a novel CCD camera-based electronic portal imaging device comparison with OCTAVIUS detector.

Aim: Dosimetric properties of a CCD camera-based Electronic Portal Imaging Device (EPID) for clinical dosimetric application have been evaluated. Characteristics obtained by EPID also compared with commercial 2D array of ion chambers.

Materials And Methods: Portal images acquired in dosimetry mode then exported raw fluence or uncorrected images were investigated.

Comparing the dosimetric characteristics of the electron beam from dedicated intraoperative and conventional radiotherapy accelerators.

The specific design of the mobile dedicated intraoperative radiotherapy (IORT) accelerators and different electron beam collimation system can change the dosimetric characteristics of electron beam with respect to the conventional accelerators. The aim of this study is to measure and compare the dosimetric characteristics of electron beam produced by intraoperative and conventional radiotherapy accelerators. To this end, percentage depth dose along clinical axis (PDD), transverse dose profile (TDP), and output factor of LIAC IORT and Varian 2100C/D conventional radiotherapy accelerators were measured and compared.