Assessment of total annual effective doses to representative person, for authorised and accidental releases from the Nuclear Medicine Department at Cattinara Hospital (Trieste, Italy).

Purpose: Clinical procedures in a Nuclear Medicine Department produce radioactive liquid and solid waste. Regarding waste release into the environment from an authorised hospital, it is mandatory to verify the compliance with European Directive 2013/59/EURATOM, adopted by the Italian Government via the Legislative Decree 101/2020.

Methods: Different activity release pathways into the environment from Trieste Nuclear Medicine Department have been analysed: liquid waste from patients' excreta discharged by sewage treatment system into the sea, and atmospheric releases following solid waste incineration.

Neutron and photon out-of-field doses at cardiac implantable electronic device (CIED) depths.

The accuracy of an out-of-field dose from an Elekta Synergy accelerator calculated using the X-ray Voxel Monte Carlo (XVMC) dose algorithm in the Monaco treatment planning system (TPS) for both low-energy (6 MV) and high-energy (15 MV) photons at cardiac implantable electronic device (CIED) depths was investigated through a comparison between MCNPX simulated out-of-field doses and measured out-of-field doses using three high spatial and sensitive active detectors. In addition, total neutron equivalent dose and fluence at CIED depths of a 15-MV dose from an Elekta Synergy accelerator were calculated, and the corresponding CIED relative neutron damage was quantified. The results showed that for 6-MV photons, the XVMC dose algorithm in Monaco underestimated out-of-field doses in all off-axis distances (average errors: -17% at distances X < 10 cm from the field edge and -31% at distances between 10 < X ≤ 16 cm from the field edge), with an increasing magnitude of underestimation for high-energy (15 MV) photons (up to 11%).

A multicenter dosimetry study to evaluate the imaging dose from Elekta XVI and Varian OBI kV-CBCT systems to cardiovascular implantable electronic devices (CIEDs).

The increasing use of daily CBCT in radiotherapy has raised concerns about the additional dose delivered to the patient, and it can also become a concern issue for those patients with cardiovascular implantable electronic devices (CIEDs) (Pacemaker [PM] and Implantable Cardioverter Defibrillator [ICD]). Although guidelines highly recommend that the cumulative dose received by CIEDs should be kept as low as possible, and a safe threshold based on patient risk classification needs to be respected, this additional imaging dose is not usually considered. Four centers with different dosimetry systems and different CBCT imaging protocols participated in this multicenter study to investigate the imaging dose to the CIEDs from Elekta XVI and Varian OBI kV-CBCT systems.

Evaluation of localized region-based segmentation algorithms for CT-based delineation of organs at risk in radiotherapy.

Background And Purpose: In radiation therapy, defining the precise borders of cancerous tissues and adjacent normal organs has a significant effect on the therapy outcome. Deformable models offer a unique and robust approach to medical image segmentation. The objective of this study was to investigate the reliability of segmenting organs-at-risk (OARs) using three well-known local region-based level-set techniques.

New simple and low-cost methods for periodic checks of Cyclone® Plus Storage Phosphor System.

The recent large use of the Cyclone® Plus Storage Phosphor System, especially in European countries, as imaging system for quantification of radiochemical purity of radiopharmaceuticals raised the problem of setting the periodic controls as required by European Legislation. We described simple, low-cost methods for Cyclone® Plus quality controls, which can be useful to evaluate the performance measurement of this imaging system.

In vivo dosimetry and shielding disk alignment verification by EBT3 GAFCHROMIC film in breast IOERT treatment.

Intraoperative electron radiation therapy (IOERT) cannot usually benefit, as conventional external radiotherapy, from software systems of treatment planning based on computed tomography and from common dose verify procedures. For this reason, in vivo film dosimetry (IVFD) proves to be an effective methodology to evaluate the actual radiation dose delivered to the target. A practical method for IVFD during breast IOERT was carried out to improve information on the dose actually delivered to the tumor target and on the alignment of the shielding disk with respect to the electron beam.

Analytical functions for beta and gamma absorbed fractions of iodine-131 in spherical and ellipsoidal volumes.

Background: The beta and gamma absorbed fractions in organs and tissues are the important key factors of radionuclide internal dosimetry based on Medical Internal Radiation Dose (MIRD) approach.

Objectives: The aim of this study is to find suitable analytical functions for beta and gamma absorbed fractions in spherical and ellipsoidal volumes with a uniform distribution of iodine-131 radionuclide.

Methods: MCNPX code has been used to calculate the energy absorption from beta and gamma rays of iodine-131 uniformly distributed inside different ellipsoids and spheres, and then the absorbed fractions have been evaluated.

Thyroid volume's influence on energy deposition from (131)I calculated by Monte Carlo (MC) simulation.

Background: It is well known that the success of the radiomethabolic (131)I treatment of hyperthyroidism could depend on the absorbed dose to the thyroid. It is, thus, very important to calculate the individual radiation dose as accurately as possible for different masses of thyroid lobes. The aim of this work is to evaluate the influence of thyroid volume on the energy deposition from beta and gamma rays of (131)I by Monte Carlo (MC) simulation.

Indoor radon measurement and effective dose assessment of 150 apartments in Mashhad, Iran.

Environmental monitoring and indoor radon measurement are important for public health, to estimate the cancer risk of respiratory system and, if necessary, to suggest proper methods that reduce indoor radon level. In this research, indoor radon concentration in the air has been measured in 150 apartments in Mashhad city. The result demonstrates about 94.

Dosimetric evaluation of a 320 detector row CT scanner unit.

Background: The technologic improvements in Multislice scanners include the increment in the X-ray beam width. Some new CT scanners are equipped with a 320 detector row which allows a longitudinal coverage of 160 mm and a total of 640 slices for a single rotation. When such parameters are used the length of the traditional pencil chamber (10 cm) is no more appropriate to measure the standard weighted computed tomography dose index (CTDI(w)) value.

Calculation of energy deposition, photon and neutron production in proton therapy of thyroid gland using MCNPX.

In this study, the MCNPX code has been used to simulate a proton therapy in thyroid gland, in order to calculate the proton energy deposition in the target region. As well as, we have calculated the photon and neutron production spectra due to proton interactions with the tissue. We have considered all the layers of tissue, from the skin to the thyroid gland, and an incident high energy pencil proton beam.

Monte Carlo simulation of intrinsic count rate performance of a scintillation camera for diagnostic images.

This paper describes Monte Carlo simulation of intrinsic count rate performance of a scintillation gamma camera. MCNP Monte Carlo code was employed to calculate pulse height spectrum and detector efficiency. A custom code written in Fortran language was then developed to simulate, by Monte Carlo method, the distortion in pulse height spectrum due to the pile-up effect for paralyzable and nonparalyzable systems.