[Spinal stereotactic body radiotherapy: French assessment in 2016]. / État des lieux de la radiothérapie en conditions stéréotaxiques vertébrale en France en 2016.

PURPOSE: Stereotactic body radiotherapy to vertebral column remains uncommon practice and only relevant in selected group of patients. The main objective of the study was to describe the current state of medical practices of stereotactic body radiotherapy to vertebral column in France in 2016 and to assess the diversity of practices to identify areas for improvement and establish a common database set for this technique. MATERIALS AND METHODS: A questionnaire was written with contribution of a medical physicist, a radiation oncologist, an information technologist and a radiotherapy resident. The questionnaire was distributed online to a radiation oncologists and a medical physicists partner of selected French radiotherapy specialized centres that provide stereotactic body radiotherapy to vertebral metastasis from April to June 2016. The questionnaire surveyed the following topics: patients' selection, simulation, targeted volume and organs at risk delineation, prescription, dosimetric implementation and image guidance. RESULTS: A total of 31 centres were surveyed. Seventy eight per cent of centres (n=21) completed the questionnaire. The "ideal" patient for spine stereotactic radiotherapy according to these institutions has a good performance status, a long life expectancy, controlled primary tumour with oligometastatic spread. The most prescribed protocol was 30Gy in three fractions. For clinical target volume delineation, about two thirds of centres used the International Spine Radiosurgery Consortium (ISRC) recommendations (Noël G et al.,2006). CONCLUSION: This study identified some consistency of practices in some aspects despite the lack of consensus guidelines. Nevertheless, further studies are needed to establish consensus of planning and treatment.

[Frameless set-up with ExacTrac® system for stereotactic radiotherapy of brain metastasis: Descriptive study from five French centres]. / Repositionnement par le système ExacTrac® pour l'irradiation sans cadre invasif de métastases cérébrales en conditions stéréotaxiques : étude descriptive de cinq centres français.

PURPOSE: This study aimed to analyse the positioning protocols with the ExacTrac® system, associated with a dedicated linear accelerator such as Novalis®, for stereotactic treatment of brain metastases in several French centres. MATERIALS AND METHODS: A survey, including three questions about the prescription of irradiation and twenty-one questions about how the ExacTrac® system is used, was sent to nine French centres owning a dedicated Novalis® accelerator. Five centres have accepted to participate in the study. RESULTS: All centres checked the positioning before each treatment's bow, with residual mismatch tolerances of 0.5 to 0.7mm for the translations and 0.5 to 1° for the rotations. All centres except one also realised orthogonal planar images of classic incidences to help operators ensure proper isocentre positioning. Prescribed doses were 20Gy in one fraction, 30Gy and 33Gy in three fractions or 34Gy in four fractions, mainly depending on the size of the lesion. Finally, a physician validated the images at the treatment station before starting the irradiation. CONCLUSIONS: The practices of the different centres concerning the positioning protocols were rather homogeneous, in agreement with the literature data on ExacTrac® system's accuracy, as well as proposed fractionations. The systematic medical validation at the treatment station may, however, be questioned because of the waiting time between the doctor's call and validation itself and because of its usefulness; indeed, corrections by the radiation oncologist are very rare and in some centres, non-existent.

[Feasibility and toxicity of a single fraction high-dose-rate brachytherapy followed by a course of EBRT for localized prostate cancer: a retrospective study. The Polyclinique Courlancy experience]. / Faisabilité et toxicité d'une séance unique de curiethérapie de haut débit de dose suivie d'une irradiation externe dans le cancer localisé de la prostate : étude rétrospective de la polyclinique de Courlancy.

PURPOSE: Evaluate the feasibility and toxicity of radiation dose escalation delivered with a single fraction high-dose-rate (HDR) brachytherapy boost followed by external beam radiotherapy for intermediate and high risk localized prostate cancer - a retrospective study. PATIENTS AND METHODS: Between December 2004 and December 2008, 61 patients with intermediate risk or high-risk localized prostate cancer received a single 10 Gy fraction of interstitial HDR brachytherapy followed by a 64 Gy course of external beam radiation therapy. Dose volume histograms, conformity index and side effects were systematically analyzed. RESULTS: HDR brachytherapy dosimetric criteria were respected. Early side effects (< or = 3 months after full treatment): 30 % reported grade 2 or grade 3 urinary toxicity and 26 % reported grade 2 or grade 3 bowel toxicity were reported. Late side effects (> 3 months): 12 % reported grade 2 or grade 3 urinary toxicity and 5 % reported grade 2 or grade 3 bowel toxicity were reported. No patients reported any grade 4 late toxicity events. Three months after treatment, 7 % grade 1, 25 % grade 2 and 39 % grade 3 erectile dysfunction were reported. CONCLUSION: Our monofractionation protocol is an easy technique to implement logistically. Acute and late toxicities are acceptable and comparable to those published by various teams mostly using multifractionation protocols. A longer follow-up is required to assess the effect of this dose escalation protocol on long-term biological control.