Correction: Brochet et al. A Quantitative Comparison between Shannon and Tsallis-Havrda-Charvat Entropies Applied to Cancer Outcome Prediction. 2022, , 436.

Alexandre Huat, Sébastien Thureau, David Pasquier, Isabelle Gardin, Romain Modzelewski, David Gibon, Juliette Thariat and Vincent Grégoire were not included as authors in the original publication [...

A Quantitative Comparison between Shannon and Tsallis-Havrda-Charvat Entropies Applied to Cancer Outcome Prediction.

In this paper, we propose to quantitatively compare loss functions based on parameterized Tsallis-Havrda-Charvat entropy and classical Shannon entropy for the training of a deep network in the case of small datasets which are usually encountered in medical applications. Shannon cross-entropy is widely used as a loss function for most neural networks applied to the segmentation, classification and detection of images. Shannon entropy is a particular case of Tsallis-Havrda-Charvat entropy.

Radiomics: Principles and radiotherapy applications.

Radiomics is defined as the extraction of a large quantity of quantitative image features. The different radiomic indexes that have been proposed in the literature are described as well as the various factors that have an impact on the robustness of these indexes. We will see that several hundred quantitative features can be extracted per lesion and imaging modality.

[Siriade 2.0: An e-learning platform for radiation oncology contouring].

Purpose: In 2008, the French national society of radiation oncology (SFRO) and the association for radiation oncology continued education (AFCOR) created Siriade, an e-learning website dedicated to contouring.

Material And Methods: Between 2015 and 2017, this platform was updated using the latest digital online tools available. Two main sections were needed: a theoretical part and another section of online workshops.

Impact of consensus contours from multiple PET segmentation methods on the accuracy of functional volume delineation.

Purpose: The aim of this study was to evaluate the impact of consensus algorithms on segmentation results when applied to clinical PET images. In particular, whether the use of the majority vote or STAPLE algorithm could improve the accuracy and reproducibility of the segmentation provided by the combination of three semiautomatic segmentation algorithms was investigated.

Methods: Three published segmentation methods (contrast-oriented, possibility theory and adaptive thresholding) and two consensus algorithms (majority vote and STAPLE) were implemented in a single software platform (Artiview®).

[Delineation variation of lung cancer in conformal radiotherapy among radiation oncology residents after an educational course: a prospective study].

Purpose: During the French national course of radiotherapy, delineation stations were at disposition for the residents. A comparative study of delineation and doses prescribed for a clinical case of lung carcinoma is reported before and after the completion of a theoretical education.

Methods: For this comparative study, 120 residents divided in 30 groups, have delineated the case before and after a lecture of radio-anatomy and a presentation of volumes and doses.

Inter-clinician variability in making dosimetric decisions in pediatric treatment: a balance between efficacy and late effects.

Purpose: To investigate variability of clinical target volume (CTV) delineation and deviations according to doses delivered in normal tissue for abdominal tumor irradiation in children.

Material And Methods: For a case of nephroblastoma six French pediatric radiation oncologists outlined post-operative CTV, on the same dosimetric CT scan according to the International Society for Pediatric Oncology 2001 protocol. On a reference CTV and organs at risk (OAR), we performed dosimetric planning with the constraints as 25.

MRI definition of target volumes using fuzzy logic method for three-dimensional conformal radiation therapy.

Purpose: Three-dimensional (3D) volume determination is one of the most important problems in conformal radiation therapy. Techniques of volume determination from tomographic medical imaging are usually based on two-dimensional (2D) contour definition with the result dependent on the segmentation method used, as well as on the user's manual procedure. The goal of this work is to describe and evaluate a new method that reduces the inaccuracies generally observed in the 2D contour definition and 3D volume reconstruction process.

Volume delineation by fusion of fuzzy sets obtained from multiplanar tomographic images.

Techniques of three-dimensional (3-D) volume delineation from tomographic medical imaging are usually based on 2-D contour definition. For a given structure, several different contours can be obtained depending on the segmentation method used or the user's choice. The goal of this work is to develop a new method that reduces the inaccuracies generally observed.

[Comparison of conventional and conformational dosimetry in radiotherapy of cerebral neoplasms].

Purpose: We prospectively compared a conventional treatment planning (PT2D) and 3-dimensional conformal treatment planning (PT3D) for radiotherapy of cerebral tumours.

Patients And Methods: Patients treated between 1/10/98 and 1/4/99 by irradiation for cerebral tumours were analysed. For each case, we planned PT2D using conventional orthogonal x-ray films, and afterward, PT3D using CT scan.

3D reconstruction of the encapsulating contour of arteriovenous malformations for radiosurgery using digital subtraction angiography.

Purpose: Treatment planning for radiosurgery depends on the precise definition of radiation target volumes. For vascular pathologies such as arteriovenous malformations (AVM), the most usual technique remains standard X-ray projection imaging, most often carried out under stereotactic conditions. To further benefit from the advantages of two-dimensional digital subtraction angiography (DSA), the authors have developed a method for determining the three-dimensional shape of arteriovenous malformations from two views.

[Dosimetry with radiosensitive gels in radiotherapy. Methods].

The goal of conformal radiotherapy is to concentrate the dose in a well-defined volume by avoiding the neighbouring healthy structures. This technique requires powerful treatment planning software and a rigorous control of estimated dosimetry. The usual dosimetric tools are not adapted to visualize and validate complex 3D treatment.

De novo adhesions with extraperitoneal endosurgical para-aortic lymphadenectomy versus transperitoneal laparoscopic para-aortic lymphadenectomy: a randomized experimental study.

Objective: The objective of this study was to compare the risk of adhesion formation and the site of postoperative adhesions after transperitoneal versus extraperitoneal laparoscopic para-aortic lymphadenectomy.

Study Design: A prospective study was conducted on 66 pigs, randomly allocated to 2 groups of 33 animals that underwent transperitoneal versus extraperitoneal laparoscopic para-aortic lymphadenectomy.

Results: No statistically significant difference was observed between the 2 techniques in terms of operating time, number of lymph nodes removed, and intraoperative and postoperative morbidity.

Automatic quality assessment protocol for MRI equipment.

The authors have developed a protocol and software for the quality assessment of MRI equipment with a commercial test object. Automatic image analysis consists of detecting surfaces and objects, defining regions of interest, acquiring reference point coordinates and establishing gray level profiles. Signal-to-noise ratio, image uniformity, geometrical distortion, slice thickness, slice profile, and spatial resolution are checked.

Beam collimation and bolusing material optimizations for 10boron neutron capture enhancement of fast neutron (BNCEFN): definition of the optimum irradiation technique.

Purpose: In boron-10 neutron capture enhancement of fast neutron irradiation (BNCEFN), the dose enhancement is correlated to the 10B concentration and thermal neutron flux. A new irradiation technique is presented to optimize the thermal neutron flux.

Methods And Materials: The coupled FLUKA and MCNP-4A Monte Carlo codes were used to simulate the neutron production and transport for the Nice and Orleans facilities.

[Stereotactic localization in medical imaging. Technical and methodologic aspects].

Stereotactic neurosurgery and stereotactic radiation therapy require the three-dimensional localization of lesions for biopsy or for treatment planning. The aim of this paper is the description of methods used in the different imaging modalities: x-ray teleradiography, digital subtracted angiography, computed tomography, and nuclear magnetic resonance imaging. The simple pin-target locating techniques are distinguished from those serving to the definition of volumes target necessary to treatment planning.

[Progress in dosage optimization for stereotactic radiosurgery].

Stereotactic radiosurgery is a technique for treatment of intracranial lesions requiring high precision in all steps--from image acquisition to final irradiation. One of most difficult steps is the treatment planning phase, consisting of determination of irradiation parameters sufficient to cover the target volume by avoiding sensitive volumes. A manual and empirical definition can be very long and difficult, especially in the case of complex target volumes situated in sensitive zones.

[Determination of target volume for dosimetric planning in stereotactic radiosurgery].

Stereotactic radiosurgery needs an accurate determination of the target volumes to be irradiated and of sensitive volumes to be spared: position, external boundaries, internal volume. These parameters can be obtained by using either projection imaging (radiographs, digital angiography), or tomographic imaging (magnetic resonance imaging, computerized tomography). The authors describe the methods used in these different imaging modalities and the problems encountered in target determination.

Assessment of image intensifier and distortion for DSA localization studies.

The authors present methods of correcting pincushion and S distortions of an image intensifier, and of measuring the geometrical parameters of the imaging device used for localization from digital subtraction angiography brain studies. Pincushion and S distortions of the image intensifier are corrected by a calibration grid. A test pattern is used to study effectiveness of the corrections.

Treatment planning optimization by conjugate gradients and simulated annealing methods in stereotactic radiosurgery.

Purpose: This paper presents a new optimization method of treatment planning in linac stereotactic radiosurgery.

Methods And Materials: On a workstation integrating x-rays, computed tomography (CT), magnetic resonance imaging (MRI), and digital subtracted angiography (DSA) images, we first determine the outlines of the target volume and surrounding healthy tissues to spare. To achieve complete optimization of the treatment plans, this method decomposes the optimization process in two steps.

A frameless stereotaxic localisation system using MRI, CT and DSA.

The authors present a method of stereotaxic localisation using magnetic resonance imaging (MRI) computerized tomography (CT) and digital subtracted angiography (DSA) which does not require localisation frams fixed to the patient's skull, but uses only four cranial landmarks corresponding to the holders of the neurosurgical stereotaxic frame. The method presents no major constraints in routine examinations. The geometrical distortions of the imaging devices are corrected.

Technical note: magnetic resonance imaging of agarose gel phantom for assessment of three-dimensional dose distribution in linac radiosurgery.

An agarose gel phantom is used to evaluate the spatial distribution of the dose delivered by a linac radiosurgery device. Dependence of the absorbed dose on the T1 relaxation time is checked. T1 magnetic resonance images show the close correspondence between the actual absorbed dose distribution and the dose distribution expected by the treatment planning.

Frameless method of stereotaxic localization with DSA.

Purpose: To improve a method of stereotaxic localization with digital subtraction angiography that does not require use of a localization frame fixed to the patient's skull during examination.

Materials And Methods: An independent, low-cost, stereotaxic computing system was devised. Software programs used magnetic resonance images, computed tomographic scans, and digitized radiographs of plastic bone implants with head landmarks to establish reference trihedrons in each imaging system, transpose target coordinates from one system to another, adjust surgical instruments, help plan radiation surgery, and compute and display isodose curves.

Validation of a new method for stereotactic localization using MR imaging.

Magnetic resonance is recognized as potentially the best imaging procedure for localization in stereotactic neurosurgery. However, special difficulties necessitate specific adaptation to localize targets in the stereotactic frame. We developed a new method for stereotactic localization.