A generalized model for monitor units determination in ocular proton therapy using machine learning: A proof-of-concept study.

Determining and verifying the number of monitor units is crucial to achieving the desired dose distribution in radiotherapy and maintaining treatment efficacy. However, current commercial treatment planning system(s) dedicated to ocular passive eyelines in proton therapy do not provide the number of monitor units for patient-specific plan delivery. Performing specific pre-treatment field measurements, which is time and resource consuming, is usually gold-standard practice.

Study of the responses and calibration procedures of neutron and gamma area and environmental detectors for use in proton therapy.

Ambient dose equivalent measurements with radiation protection instruments are associated to large uncertainties, mostly due to the energy dependence of the instrument response and to the dissimilarity between the spectra of the standard calibration source and the workplace field. The purpose of this work is to evaluate its impact on the performance of area and environmental detectors in the proton therapy environment, and to provide practical solutions whenever needed and possible. The study was carried out at the Centre Antoine Lacassagne (CAL) proton therapy site, and included a number of commercially available area detectors and a home-made environmental thermoluminescent dosimeter based on a polyethylene moderator loaded with TLD600H/TLD700H pairs.

Cataract Avoidance With Proton Therapy in Ocular Melanomas.

Purpose: The lens is a radiosensitive organ. Any dose of cephalic irradiation can give rise to radiation-induced cataracts. Contrary to other forms of radiotherapy, proton therapy (PT) can spare all or part of the lens due to accurate dose deposition.

Visual Outcomes of Parapapillary Uveal Melanomas Following Proton Beam Therapy.

Purpose: In parapapillary melanoma patients, radiation-induced optic complications are frequent and visual acuity is often compromised. We investigated dose-effect relationships for the optic nerve with respect to visual acuity after proton therapy.

Methods And Materials: Of 5205 patients treated between 1991 and 2014, those treated using computed tomography (CT)-based planning to 52 Gy (prescribed dose, not accounting for relative biologic effectiveness correction of 1.

Influence of Ionizing Radiation on Two Generations of Cochlear Implants.

The purpose of the present study was to test the behavior of two different generations of cochlear implant systems subjected to a clinical radiotherapy scheme and to determine the maximal acceptable cumulative radiation levels at which the devices show out-of-specification behaviors. Using stereotactic irradiation (Cyberknife, 6 MV photon beam), three Digisonic SP and three Neuro devices were submitted to 5 Gy doses that cumulated to 60 Gy (12 sessions) and 80 Gy (16 sessions), respectively. A follow-up series of irradiation was then applied, in which Digisonic SP devices received two additional fractions of 50 Gy each, cumulating to 160 Gy, and Neuro devices three additional fractions of 20, 40, and 150 Gy, cumulating to 290 Gy.

Proton beam therapy for presumed and confirmed iris melanomas: a review of 36 cases.

Background: To report the clinical features and outcomes of iris melanomas treated by proton beam therapy.

Materials And Methods: A retrospective study was conducted at the Croix-Rousse University Hospital of Lyon, Department of Ophthalmology, in 36 patients treated by proton beam therapy for presumed (n = 29) and confirmed (n = 7) iris melanomas between July 1997 and October 2010. Ciliary body melanomas with iris involvement were excluded.

Effects and consequences of Digisonic SP cochlear implant on radiotherapy planning.

The aim of this study was to assess dose attenuation by a Digisonic SP cochlear implant (CI) and evaluate its impact on treatment planning. The Digisonic CI was irradiated with 6 MV photons. Overall dose attenuation was assessed with MOSFET dosimeters and Gafchromic films.

[Advances in radiation oncology for metastatic bone disease].

Introduction: Irradiation of bone metastases primarily aims at alleviating pain, preventing fracture in the short term. The higher doses and more conformal dose distribution achievable while saving healthy tissue with new irradiation techniques have induced a paradigm shift in the management of bone metastases in a growing number of clinical situations.

Materials And Methods: A search of the English and French literature was conducted using the keywords: bone metastases, radiotherapy, interventional radiology, vertebroplasty, radiofrequency, chemoembolization.