Professional ethics in the French medical physicist community: Survey results and implications.

Introduction: Since 2017, in France, medical physicists (MP) are finally defined by law as health professionals and as such, the roles and responsibilities of an MP lean on those medical professional ethics but MPs lack initial or continuing training in this subject. In order to find out how our colleagues feel about this subject, the following survey was conducted.

Methods: French Society of Medical Physics (SFPM) designed a web survey addressed to its members and non-members concerning ethics based on the 2013 AAPM work; experience and training were highlighted as particularly important within the survey structure.

Sarcoma cell-specific radiation sensitization by titanate scrolled nanosheets: insights from physicochemical analysis and transcriptomic profiling.

This study aimed to explore the potential of metal oxides such as Titanate Scrolled Nanosheets (TNs) in improving the radiosensitivity of sarcoma cell lines. Enhancing the response of cancer cells to radiation therapy is crucial, and one promising approach involves utilizing metal oxide nanoparticles. We focused on the impact of exposing two human sarcoma cell lines to both TNs and ionizing radiation (IR).

Practical and technical key challenges in head and neck adaptive radiotherapy: The GORTEC point of view.

Anatomical variations occur during head and neck (H&N) radiotherapy (RT) treatment. These variations may result in underdosage to the target volume or overdosage to the organ at risk. Replanning during the treatment course can be triggered to overcome this issue.

Changes in intra-nuclear mechanics in response to DNA damaging agents revealed by time-domain Brillouin micro-spectroscopy.

How DNA damage and repair processes affect the biomechanical properties of the nucleus interior remains unknown. Here, an opto-acoustic microscope based on time-domain Brillouin spectroscopy (TDBS) was used to investigate the induced regulation of intra-nuclear mechanics. With this ultrafast pump-probe technique, coherent acoustic phonons were tracked along their propagation in the intra-nucleus nanostructure and the complex stiffness moduli and thicknesses were measured with an optical resolution.

Aberrations of plane-symmetrical mirror systems with freeform surfaces. Part II: closed-form aberration formulas.

The aberrations of reflective optical systems with planar symmetry are investigated in the most general case, with freeform surfaces and possibly different locations of the tangential and sagittal object and image. In this second and last paper, closed-form expressions are derived for the aberrations created by an individual mirror. We study two-mirror off-axis telescopes and establish a new family of designs that we show is simultaneously free of constant coma, linear astigmatism, and quadratic distortions (including smile and keystone).

Aberrations of plane-symmetrical mirror systems with freeform surfaces. Part I: generalized ray-tracing equations.

The aberrations of reflective optical systems with one plane of symmetry are investigated in the most general case, with freeform surfaces and possibly different locations of the tangential and sagittal object and image. In this first paper in a series of two, we establish generalized ray-tracing equations including transverse aberrations up to the third order in ray coordinates. The ray-tracing treatment allows us to overcome difficulties linked to the non-existence of a suitable astigmatic wavefront reference.

Use of metrics to quantify IMRT and VMAT treatment plan complexity: A systematic review and perspectives.

Purpose: Fixed-field intensity modulated radiation therapy (FF-IMRT) or volumetric modulated arc therapy (VMAT) beams complexity is due to fluence fluctuation. Pre-treatment Quality Assurance (PTQA) failure could be linked to it. Several plan complexity metrics (PCM) have been published to quantify this complexity but in a heterogeneous formalism.

Photochemistry on the Space Station-Aptamer Resistance to Space Conditions: Particles Exposure from Irradiation Facilities and Real Exposure Outside the International Space Station.

Some microarray-based instruments that use bioaffinity receptors such as antibodies or aptamers are under development to detect signatures of past or present life on planetary bodies. Studying the resistance of such instruments against space constraints and cosmic rays in particular is a prerequisite. We used several ground-based facilities to study the resistance of aptamers to various types of particles (protons, electrons, neutrons, and carbon ions) at different energies and fluences.

High performance modelling of the transport of energetic particles for photon radiotherapy.

This work consists of the validation of a new Grid Based Boltzmann Solver (GBBS) conceived for the description of the transport and energy deposition by energetic particles for radiotherapy purposes. The entropic closure and a compact mathematical formulation allow our code (M1) to calculate the delivered dose with an accuracy comparable to the Monte-Carlo (MC) codes with a computational time that is reduced to the order of few minutes without any special processing power requirement. A validation protocol with heterogeneity inserts has been defined for different photon sources.

Transplantation of hESC-derived hepatocytes protects mice from liver injury.

Background: Hepatic cell therapy has become a viable alternative to liver transplantation for life-threatening liver diseases. However, the supply of human hepatocytes is limited due to the shortage of suitable donor organs required to isolate high-quality cells. Human pluripotent stem cells reflect a potential renewable source for generating functional hepatocytes.

Dose calculation accuracy of different image value to density tables for cone-beam CT planning in head & neck and pelvic localizations.

Purpose: We aimed to identify the most accurate combination of phantom and protocol for image value to density table (IVDT) on volume-modulated arc therapy (VMAT) dose calculation based on kV-Cone-beam CT imaging, for head and neck (H&N) and pelvic localizations.

Methods: Three phantoms (Catphan(®)600, CIRS(®)062M (inner phantom for head and outer phantom for body), and TomoTherapy(®) "Cheese" phantom) were used to create IVDT curves of CBCT systems with two different CBCT protocols (Standard-dose Head and Standard Pelvis). Hounsfield Unit (HU) time stability and repeatability for a single On-Board-Imager (OBI) and compatibility of two distinct devices were assessed with Catphan(®)600.

Operating wavelengths optimization for a spaceborne lidar measuring atmospheric CO2.

The Advanced Space Carbon and Climate Observation of Planet Earth (A-SCOPE) mission, a candidate for the next generation of European Space Agency Earth Explorer Core Missions, aims at measuring CO(2) concentration from space with an integrated path differential absorption (IPDA) lidar. We report the optimization of the lidar instrument operating wavelengths, building on two performance models developed to assess measurement random errors from the instrument, as well as knowledge errors on geophysical and spectral parameters required for the measurement processing. A promising approach to decrease sensitivity to water vapor errors by 1 order of magnitude is reported and illustrated.

Infrared specular reflection spectroscopy of rough metallic substrates.

A study of the infrared reflectance of rough metallic surfaces is presented. We show that one reflectance measurement, made in the specular direction under specific conditions, allows the accurate calculation of the shape of the roughness histogram. As a theoretical background, we use modified expressions from Kirchhoff theory for surface scattering.

Voxeldoes: a computer program for 3-D dose calculation in therapeutic nuclear medicine.

A computer program, VoxelDose, was developed to calculate patient specific 3-D-dose maps at the voxel level. The 3-D dose map is derived in three steps: (i) The SPECT acquisitions are reconstructed using a filtered back projection method, with correction for attenuation and scatter; (ii) the 3-D cumulated activity map is generated by integrating the SPECT data; and (iii) a 3-D dose map is computed by convolution (using the Fourier Transform) of the cumulated activity map and corresponding MIRD voxel S values. To validate the VoxelDose software, a Liqui-Phil abdominal phantom with four simulated organ inserts and one spherical tumor (radius 4.