Design and automation of specific geometric quality controls for cone-radiosurgery treatments.

PURPOSE: The Varian TrueBeam STx linac can be equipped with BrainLAB stereotactic cones and ExacTrac imaging system for SRS treatments. However, these two third-party systems lack integration in a self-performance diagnosis tool dedicated to the SRS platform. The aim of this work was to design and automate essential geometric tests considering the complete set of cones with diameter range from 4 to 15 mm. METHODS: EPID-based tests were focused on the cone alignment, the radiation isocentricity and the isocenters congruence. Images acquired with or without the BrainLAB pointer were analysed using the Hough transform and morphological filtering operations, after assessment of the algorithm accuracy using simulated images. The new Machine QA program was experimented over one year. RESULTS: A subpixel resolution of 0.02 mm was found for the circular-field center detection algorithm. The tests results did not depend on the pointer location. The maximum deviations reported were in accordance with the AAPM SRS guidelines. The accurate localization of the linac radiation isocenter allowed for guidance of the ExacTrac calibration. A misalignment reaching 0.2 mm was measured for all cones but one, highlighting the benefit of systematizing this control before each patient SRS treatment. CONCLUSION: An effective in-house QA program dedicated to SRS cones was developed to supplement the standard machine performance check on our mixed SRS platform. Specific geometric tests even include the smallest 4-mm cone, which could be of great interest for future clinical indications such as the radiosurgery of functional disorders.

[Organic troubles with psychiatric symptoms: What is the appropriate childhood and adolescence psychiatric care? Reflections on disimmune encephalitis cases]. / Troubles organiques à expression psychiatrique, quel soin pédopsychiatrique ? Réflexions autour de cas d'encéphalites dysimmunitaires.

Organic mental disorders are different and further revealed by increasingly advanced research. They are nevertheless misunderstood, without consensus, and raise clinical, diagnostic, and therapeutic questions. These disorders require effective collaboration between practitioners such as pediatricians and child psychiatrists. The subject should not disappear behind the complexity related to the clinical expression of these symptoms. Based on three cases of autoimmune encephalitis, we offer a reflection on the management and assessment of these diseases by a multidisciplinary team with the intention of providing optimal management. The aim of this paper is to override an initial divide posed by a particular clinical presentation. We would like to shed light on the place and legitimacy of child psychiatrists and their clinical expertise. This does not exclude the need for care of the symptoms, considering each subject and her experience. Follow-up is necessary because of the possible, often traumatic, functional and psychological consequences. Finally, the presence of each professional should be specified when the psychiatric symptoms appear to be the result of an organic disease in order to better support the subject in his suffering body.