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This section highlights selected specific new recommendations and/or updates that have been published during the very last years in the fields of stereotactic radiotherapy, pediatrics, lung cancer, gynecologic and breast cancer, as well as in the area of radiation oncology of urogenital cancer.

The historical treatment for stage I non-small cell lung cancer is surgical. Parenchymal amputation is not always possible due to cardiopulmonary comorbidities and stereotactic radiotherapy is one of the alternatives to an invasive procedure. The excellent results observed for inoperable tumors raised the question of this treatment in operable patients. This article presents the data in these two situations and the future perspectives.

Stereotactic radiotherapy and radiosurgery allow delivery of high irradiation doses in a limited volume. These techniques are specially adapted to brain and nervous pathologies. Indication are not only cancers and tumors but also non tumor tissues such as arteriovenous malformations. In some case purpose of stereotactic radiotherapy is solely functional, for example for trigeminal neuralgia. We detail the questions that raise treatment of these non-tumor pathologies. These pathologies imply a multidisciplinary approach that associate radiation oncologists, neuro-radiologist and neurosurgeons.

The incidence of primary hepatic tumours is increasing and the reference treatments by liver transplantation or surgical resection do not allow to compensate for this increase because of the lack of grafts, or the low proportion of initially resectable tumours. The challenges for radiotherapy of primary liver tumors are multiple: physical, biological, medical and technological. Liver stereotactic body radiotherapy is sometimes the only local treatment option and is progressively finding its place for these tumors, even if the recognition of the indications would deserve a better standardization of international recommendations. The heterogeneity of practices and techniques is a major obstacle to the development of randomized studies, despite the excellent oncological results published. The latest ASTRO 2022 guidelines, the recent publication of the guidelines from the French society for radiation oncology on external radiotherapy and brachytherapy procedures ("RecoRad™ 2.0"), and the inclusion in prospective clinical trials will help to homogenize protocols and improve recognition of the technique. The first data from the new techniques of adaptive radiotherapy and MR-guided radiotherapy, whose objectives are to improve targeting and reduce liver or gastrointestinal toxicity, confirm the excellent results of liver SBRT and allow the potential indications to be extended to locations that were previously difficult to treat.

This review of the literature provides an overview of the combination of stereotactic radiotherapy (SBRT) with immune checkpoint inhibitors (ICI) and tyrosine kinase inhibitors (TKI) in oligo-progressive non-small cell lung neoplasia. This combination showed local control of 76-100% and distant response rates of 8-60%. They reported progression-free survival of 2.7-24 months and overall survival of 13.4-41.2 months. All-grade toxicity rates ranged from 0% to 42%, with grade≥3 toxicity ranging from 0% to 14%. The combination of SBRT with ICI or TKIs exhibits a safe profile with high rates of local control with this combination. This could delay the use of a new line of systemic therapy in these patients with often limited therapeutic resources.Cette revue de la littérature réalise un état des lieux de l’association de la radiothérapie stéréotaxique (SBRT) aux inhibiteurs de points de contrôle immunitaire (IPCI) et inhibiteurs de la tyrosine kinase (ITK) dans les néoplasies pulmonaires non à petites cellules en oligoprogression. Cette association montrait un contrôle local entre 76 et 100 % et un taux de réponse à distance entre 8 et 60 %. Elle était associée à une survie sans progression de 2,7 à 24 mois et une survie globale de 13,4 à 41,2 mois. Les taux de toxicité tous grades confondus étaient de 0 à 42 %, dont ceux de grade ≥ 3 entre 0 et 14 %. L’association de la SBRT aux IPCI ou ITK arbore un profil de sécurité avec des taux élevés de contrôle local avec cette combinaison. Cela pourrait retarder le recours à une nouvelle ligne de traitement systémique chez ces patients aux ressources thérapeutiques souvent limitées.

Brain metastases (BM) are a common occurrence of systemic cancers. Technical improvements in neuroimaging offer additional tools for an early detection of BM, to target them precisely and differentiate these lesions from other cerebral pathologies. The therapeutic tools have also evolved from neurosurgery and whole brain therapy to include stereotactic radiosurgery, targeted and immune therapies. Given the numerous treatment options available, a multidisciplinary approach is essential to offer the patient a personalized approach to optimize the sequence and combination of treatments to offer the best outcome possible. This article aims to review key elements of diagnosis, risk stratification and modern treatment paradigms in the diagnosis and management of BM.

Brain metastases (BM) are a common occurrence of systemic cancers. Technical improvements in neuroimaging offer additional tools for an early detection of BM, to target them precisely and differentiate these lesions from other cerebral pathologies. The therapeutic tools have also evolved from neurosurgery and whole brain therapy to include stereotactic radiosurgery, targeted and immune therapies. Given the numerous treatment options available, a multidisciplinary approach is essential to offer the patient a personalized approach to optimize the sequence and combination of treatments to offer the best outcome possible. This article aims to review key elements of diagnosis, risk stratification and modern treatment paradigms in the diagnosis and management of BM.Les métastases cérébrales (MC) sont une manifestation fréquente des cancers systémiques. Les améliorations des techniques de radiologie offrent des options supplémentaires pour détecter de manière précoce les MC, les cibler avec précision et les différencier d’autres pathologies. Les outils thérapeutiques se sont également élargis pour inclure des techniques de radiothérapie stéréotaxiques, des thérapies ciblées et des immunothérapies. Au vu des nombreuses options de traitement pour les patients souffrant de MC, une approche multidisciplinaire doit impérativement être favorisée pour personnaliser le traitement de chaque patient et améliorer le pronostic. Cet article décrit les éléments clés du diagnostic, de la stratification du risque et les paradigmes modernes de la prise en charge et des traitements des patients avec MC.

Radiation retinopathy is an occlusive vascular pathology following radiotherapy, generally targeted on the eye or peri-ocular structures. Despite increasingly precise techniques (stereotactic radiosurgery, proton therapy, etc.), the inclusion of the retina in the radiation field is sometimes unavoidable. This can lead to a severe pathology, which can ultimately cause blindness or even the anatomical loss of the eye when neovascular glaucoma occurs, due to the abnormal proliferation of neovessels. Radiation retinopathy have been described for more than a century, but it has recently seen great advances in both diagnosis and treatment. The advances of efficient and less invasive examinations in our clinical practice, such as OCT-angiography, allows for easier screening and diagnosis at earlier stages. Thus a new approach to the pathology is necessary, first of all through new definitions and classifications including previously undetected minimal forms. Furthermore, the recent appearance of intravitreal therapies by injection of anti-VEGF or dexamethasone implants has drastically changed the visual prognosis of these patients, who were previously treated only by retinal photocoagulation of the ischaemic areas. Recent studies have even shown the effectiveness of these new molecules in preventing the development of radiation retinopathy. This review of the literature provides an update on this disease and details how these recent diagnostic and therapeutic developments may play a role in the management of this complication.

Stereotactic radiotherapy is an ever more common technique, regardless of the location treated. However, spinal stereotactic radiotherapy requires a particular technicality in order to ensure its proper realization. There is now a large literature defining the type of imaging to be used, the dose to be delivered and the delineation of target volumes. This technique can achieve a significant local control and an interesting analgesic efficiency. However, its place in relation to conventional radiotherapy remains limited because it requires MRI imaging and a significantly longer patient management during the treatment fraction. In this context, it is currently mainly restricted to oligometastatic patients or for re-irradiations.

Stereotaxic radiotherapy is performed regularly for the irradiation of non-spine bone metastases, but its place is not well understood.This article in stereotaxic radiotherapy of non-spine bones oligometastases presents the current scientific data relating to the indications, to virtual simulation, to the delineation of target volumes, to the total dose and fractionation, to the efficacy and tolerance.Oligometastatic patients are classified into 4 categories: oligorecurrences, oligometastasis, oligopersistence, oligoprogression. The prognosis will be evaluated according to the following characteristics: primary tumor, quantitative characteristics, kinetics, qualitative characteristics. The delineation of GTV includes extensions to the soft tissue and bone marrow with the aid of MRI and PET. The CTV corresponds to a margin of 2 to 5mm and the PTV to a margin of 2mm. The most widely used irradiation schemes are: 1 single fraction of 18 to 24Gy/1 fr; 24Gy/2 fr; 27 to 30Gy/3 fr; 30 to 35Gy/5 fr. Stereotaxis provides 90% local control at 1 year and good pain control. The side effects are not very marked.Stereotaxic radiotherapy is feasible, non-invasive, minimally toxic and effective with good local control and good pain relief. The main issue remains selecting the patients most likely to benefit from it.

Hypofractionated stereotactic radiotherapy and stereotactic radiosurgery are major therapeutic weapons in the brain, whether for tumor, vascular or functional treatments. They tend increasingly to democratize and to become standard treatments. However, human brain anatomy is very complex and not limited to the currently described organs at risk. Diffusion tensor imaging (DTI) tractography is a simple tool that enables to identify reproducibly big white matter fiber tracts. Not only does tractography allow a redefinition of organs at risk in the brain, but it would also allow the identification of new targets, such as the ventral intermediate nucleus (Vim) within the thalamus for treatment of movement disorders. We present here a review of the role of tractography and the anatomy, function and currently described dose-effect relationships of white matter fiber tracts with a major functional impact: the pyramidal tract for motor ability, the optic radiation for vision and the arcuate fasciculus for language.

Stereotactic radiotherapy is used for patients with oligometastases from colorectal cancer. It results in good local tumour control, especially for hepatic and pulmonary metastases, subject to a sufficiently high biologically effective dose, and is well-tolerated. It can be associated with other local treatments such as surgery or radiofrequency as part of combined treatments, in order to increase patient survival.

Oligometastatic prostate cancer is among the most studied oligometastatic cancers in the literature. However few prospective studies have assessed stereotactic body radiotherapy (SBRT) for prostate cancer oligometastases. Two randomised phase II trials show a progression-free survival benefit compared with observation. Prospective registry data show very good local control and low toxicity too. Inclusion in ongoing trials should be strongly encouraged to define the role of SBRT in addition to systemic therapy. Radiation therapy to the primary tumour has been studied in randomised trials and provides an overall survival benefit in patients with low metastatic burden. The benefit is inversely correlated with the number of bone lesions using conventional imaging, up to three metastases. Radiotherapy to the primary tumour is recommended by the learned societies for patients with low metastatic burden. Its role in combination with second generation anti androgen therapy needs to be clarified.

Extracranial stereotactic radiotherapy has developed recently, since the years 1990-2000. Devices specifically dedicated to this type of treatment were then developed and shared the favors of radiation oncologists: Tomotherapy® and especially Cyberknife®, which offered the advantage of "tracking" with the possibility of real time motion correction, allowing an increase in the precision of targeting volumes. Recently, the latest generations of linear accelerators (Linac) have been developed, integrating much higher dose rates, an improved ballistic precision with a very short treatment duration time and the possibility of real time motion management (with notably the possibility of adaptive radiotherapy in real time with the development of "MLC tracking"). So are Linacs able to perform equivalent (not inferior) extracranial stereotactic radiotherapy treatments to those with Cyberknife®, the historical gold standard in this field? This article presents a comparison of these two treatment devices, by successively considering dose distributions in the irradiated volume, distant received doses from this volume (including the "integral dose"), problems linked to the duration of the sessions and those linked to motion management.

Pancreatic cancer has poor prognosis and a continuously growing incidence. By 2030, it should become the second cause of death by cancer worldwide and in France. The only curative treatment is surgery that is achievable in only 20% of patients at the time of initial diagnosis, with a high rate of incomplete resection. Neoadjuvant treatments using chemotherapy with or without radiotherapy are more often admitted to play an important role by selecting non-progressing cases who will benefit from surgery, by increasing the number of complete resection, and by making locally advanced and borderline tumours accessible to resection. However, the role of radiotherapy is still debated. Because of its dosimetric advantages, its short total duration, and its good tolerance with reduced volumes of irradiation, stereotactic radiotherapy has been largely studied. Compared to chemoradiotherapy, this technique could improve the therapeutic index helping to preserve the general status of patients in order to give them access to secondary surgery. It remains a promising technique still under evaluation, to be delivered ideally, as part of a clinical trial, or within an experimented team.

Still an emerging approach a few years ago, stereotactic body radiation therapy (SBRT) has ranked as a valid option for the treatment of localized prostate cancer. Inherent properties of prostatic adenocarcinoma (low α/β) make it the perfect candidate. We propose a critical review of the literature trying to put results into perspective to identify their strengths, limits and axes of development. Technically sophisticated, the stereotactic irradiation of the prostate is well tolerated. Despite the fact that median follow-up of published data is still limited, ultra-hypofractionated radiotherapy seems very efficient for the treatment of low and intermediate risk prostate cancers. Data seem satisfying for high-risk cancers as well. New developments are being studied with a main interest in treatment intensification for unfavorable intermediate risk and high-risk cancers. Advantage is taken of the sharp dose gradient of stereotactic radiotherapy to offer safe reirradiation to patients with local recurrence in a previously irradiated area.

Radiotherapy established itself in the 20th century as an essential modality in the fight against cancer. The major technological advances of the last decades have allowed a considerable improvement in the therapeutic window. They have also paved the way for stereotactic radiotherapy and new indications. The aim of this article is to enable readers to understand external radiotherapy in 2021 and to understand the challenges of tomorrow. Three areas of improvement in the discipline will be described, the optimization of the prescribed therapeutic dose, the improvement of the distribution of this dose and, finally, the better understanding of radiobiology. For each of these axes, the current implications will be described as well as those which could/should have a major impact on the radiotherapy. FLASH radiotherapy will also be discussed.La radiothérapie s’est installée au 20ème siècle comme une modalité incontournable dans la lutte contre le cancer. Les avancées technologiques majeures des dernières décennies ont permis une amélioration considérable de la fenêtre thérapeutique. Elles ont également ouvert la voie à la radiothérapie stéréotaxique et à de nouvelles indications. Cet article a pour objectif de permettre aux lecteurs de comprendre la radiothérapie externe en 2021 et d’en appréhender les enjeux de demain. Trois axes d’amélioration de la discipline seront décrits, l’optimisation de la dose thérapeutique prescrite, l’amélioration de la distribution de cette dose et, finalement, la meilleure compréhension de la radiobiologie. Pour chacun de ces axes, des implications actuelles seront données ainsi que celles qui pourraient/ devraient avoir un impact sur la radiothérapie future. La radiothérapie FLASH sera, par exemple, abordée.

The oligometastatic disease concept suggests that patients with a limited number of metastases have a favorable prognosis. Radical local treatment of oligometastatic patients has then increased given developments in imaging (mainly positron emission tomography and brain magnetic resonance imaging) and access to effective and better tolerated treatments. Stereotactic radiotherapy has the advantage of being noninvasive, allowing a good rate of local control and a limited number of side effects. A better definition of oligometastatic disease, particularly for non-small cell lung cancer (NSCLC), has recently been published. For patients with NSCLC, two randomized phase II trials also suggested that the addition of a radical local treatment results in encouraging survival data, with a good safety profile. A single-arm phase II finally showed a benefit when combining a radical local treatment with an anti-PD1 immunotherapy. This review describes the definitions of oligometastatic disease, the main prospective findings including radiation therapy, and prospects for oligometastatic NSCLC patients.

Hypofractionated radiotherapy of early-stage squamous cell carcinoma of the glottic larynx is a promising treatment option. This can be divided into radiotherapy with moderate hypofractionation (up to 2.5Gy per fraction), more intense hypofractionation (between 2.5 and 4.5Gy per fraction) and stereotactic radiotherapy (above 4.5Gy per fraction). Most studies evaluating moderate hypofractionation show a local control rate between 85 and 95%. Acute laryngeal toxicity is superior to conventional treatment, but only for grades 1 and 2, with no significant difference reported for severe toxicity. Stereotactic radiotherapy in this pathology is also an emerging entity, but some authors have reported significant toxicity. There are currently no standardized guidelines for treatment and management regimen. We conducted a systemic review of published prospective and retrospective trials to evaluate efficacy, toxicity, and discuss future directions.

New in radiotherapy of solid tumors. The new irradiation techniques integrate the latest technological developments in medical imaging and computer science, dosimetry, and linacs into the treatment procedure. They raise new hopes for the treatment of solid tumor pathologies. Three techniques seem particularly promising: intensity modulated radiotherapy, respiratory gating radiotherapy, and stereotactic radiotherapy. The emergence of artificial intelligence, and particularly its applications in the field of imaging, opens up a new field of research. The purpose of these different innovations is to achieve very high precision radiotherapy, which makes it possible to better adapt the radiation fields to the tumor and thus protect the critical organs.Nouveautés dans la radiothérapie des tumeurs solides. Les nouvelles techniques d’irradiation intègrent dans la procédure de traitement les derniers développements technologiques en matière d’imagerie et d’informatique médicales, de dosimétrie, et d’appareils de traitement. Elles suscitent des espoirs nouveaux pour le traitement des pathologies tumorales solides. Trois techniques semblent particulièrement prometteuses : la radiothérapie conformationnelle avec modulation d’intensité, l’irradiation avec asservissement respiratoire, et la radiothérapie en conditions stéréotaxiques. L’irruption de l’intelligence artificielle, et particulièrement de ses applications dans le domaine de l’imagerie, ouvre un nouveau champ de recherche. Ces différentes innovations ont pour vocation d’aboutir à une radiothérapie de très haute précision permettant de mieux adapter les champs d’irradiation à la tumeur et ainsi de protéger les organes critiques.

Stereotactic radiotherapy is a fundamental change from the conventional fractionated radiotherapy and represents a new therapeutic indication. Stereotactic radiotherapy is now a standard of care for inoperable patients or patients who refuse surgery. The results are encouraging with local control and survival rates very high in selected populations. The rate of late toxicity remains acceptable. Good tolerability makes it appropriate even for elderly and frail patients. In these fragile patients or in certain specific clinical situations, different surgical, radiotherapy or interventional radiology attitudes can be discussed on a case-by-case basis. These situations are considered in this article for the pulmonary, hepatic and prostatic localizations.

Stereotactic body radiation therapy (SBRT) for locally advanced pancreatic cancer (LAPC) is an emerging treatment option. Most studies showed local control of approximately 75% with no evidence of improved overall survival. Gastrointestinal toxicities could be significant, ranging up to 22% for acute toxicities≥grade 3+ and 44% for late toxicities≥grade 3+. Currently, no standardized guidelines for treatment and management scheme. We conducted a systemic review of published prospective and retrospective trials to evaluate the efficacy, safety, technical data, and discuss future directions.

Myocardial scar-related ventricular tachycardia is a serious and potentially life-threatening arrhythmia. The prevention of sudden rhythmic death and ventricular tachycardia recurrence relies on implantable cardioverter defibrillator (ICD), anti-arrhythmic drugs and more recently on radiofrequency catheter ablation. Nevertheless, these approaches have their own risk of adverse events and complications, with a recurrence rate up to 50 % at 2 years. Stereotactic body radiotherapy, delivered in a single dose of 25Gy, has emerged as a new therapeutic tool in the management of highly refractory ventricular tachycardia. In 2017, the very first prospective 5-patient cohort suffering from recurrent ventricular tachycardia on structural heart disease (40 % of ischemic cardiomyopathy) who benefited from cardiac stereotactic body radiotherapy was published. After stereotactic body radiotherapy, the authors observed a strong ventricular tachycardia burden reduction at 12 months, with no major side effects. Since then, around 100 cases have been described in the literature, particularly in the prospective ENCORE-VT study, with positive short- and medium-term outcomes in terms of safety and ventricular tachycardia burden reduction. Recently, another American prospective 5-patient series, published in March 2020, mitigated these results since all patients presented a ventricular tachycardia recurrence at 12 months despite an initial reduction in ventricular tachycardia burden. This article describes the use of stereotactic body radiotherapy in refractory VT, the rationale of the technique, its implementation, preliminary results and potential acute and long-term consequences.

Stereotactic body radiotherapy (SBRT) of prostate cancer is associated with rectal toxicities, which can be reduced by using a hydrogel spacer. The object of this retrospective study was to show the feasibility of spacer placement under local anesthesia and utility of hydrogel spacer to reduce the dose to the rectal wall.We collected data from all patients with localised prostate cancer treated with SBRT (40Gy in 5 fractions) between 2018 and 2020. A hydrogel spacer (SpaceOAR®) was placed depending on the availability of the product. We collected dosimetric data for target volumes and organs at risk. We calculated mean values, which were compared using non-parametric tests.Among 35 patients, mean age was 75 years. Seventeen had a spacer placed, with a mean space created of 10mm. No complication was reported during the intervention. High doses to the rectal wall were significantly lower in spacer group (V38: 0.39 cmSpacer procedure under local anesthesia was well tolerated. Hydrogel spacer allowed to reduce doses to the rectum while improving PTV coverage.

Metastases are the most common brain tumors. After surgery, stereotactic radiotherapy (SRT) of the resection cavity is the standard of care. Data from two randomized trials indicate that SRT to the surgical bed is an effective treatment in reducing local failure as compared with observation, while reducing the risk of cognitive deterioration and maintaining quality of life as compared with whole brain radiation therapy. Local control appears higher after hypofractionated SRT compared to single-fraction SRT. Several questions such as target volumes, the optimal regimen in particular for large tumor bed, strategies to reduce the risk of lepto-meningeal recurrence, and the treatment sequence still need to be answered.

Brachytherapy is part of the treatment of locally advanced cervical cancers, accounting for about half of the total delivered dose. The benefit of dose escalation is the most important in advanced cases or if the tumor has responded poorly. The use of interstitial implantations makes it possible to reach doses of the order of 85 to 90Gy (including external beam radiotherapy contribution) in most patients, through image-guided approaches. Brachytherapy delivery is one of the quality criteria for patient care. To date, no data allow us to consider as an alternative the use of external boost through intensity-modulated or stereotactic body radiotherapy. Indeed, the doses delivered to the tumor and the capacity to spare normal tissues remains lower, as compared to what is permitted by brachytherapy. It is therefore appropriate for centers that do not have access to the technique to establish networks with centers where brachytherapy is performed, to allow each patient to have access to the technique. It is also necessary to promote brachytherapy teaching. The issue of reimbursement will be crucial in the coming years to maintain expertise that is today insufficiently valued in its financial aspects, but has a very high added value for patients.

Cholangiocarcinomas are digestive tumors whose incidence remains low and have poor prognosis. The benefits of adjuvant radiochemotherapy and radiotherapy have never been demonstrated in any phase III randomized controlled trial. Chemotherapy with capecitabine 6 months is the standard of care in adjuvant setting. Radiochemotherapy is validated in R1 patients. It is not recommended in neoadjuvant situations given the lack of evidence. Chemotherapy and radiochemotherapy are validated in adjuvant or locally advanced diseases. Stereotactic radiation therapy offers an interesting perspective, at the cost of significant digestive toxicities, requiring evaluation in randomized trials.

Stereotactic lung radiosurgery has been carried out in the team at the Georges-François-Leclerc centre (CGFL) in Dijon since 2008 on a Truebeam® accelerator (Varian®) with the RPM technique.Fifty patients with primary T1-T2 stage lung cancer (n=30) or lung metastasis (n=20) were included in the study. Since 2014, 3 successive 4D scanners on D1, D2 and D3, have been produced in order to ensure the reproducibility of ITV (Internet Target Volume). The 3 ITVs are contoured (ITV 1, 2 and 3) from the MIP (Maximum Intensity Projection) of each of the 3 scanners. A global ITV is created from the ITV volumes of the 3 scanners (MIP 2 and 3 merged with MIP 1). A CBCT (Cone Beam Computerised Tomography) is performed at the start of each irradiation session to position the patient. The study consisted in analysing the relevance of the realisation of 3 different scanners before dosimetry to define the ITV and in comparing the volumes contoured on the different CBCT to the ITV to make sure that the tumour volume is well included in the ITV during the sessions.There is a strong correlation between the different ITVs 1, 2, 3 and global, as well as between the volumes obtained on the different CBCTs. The correlation coefficient between the different ITVs and the volumes contoured on CBCT was high for upper lobar lesions. In terms of tolerance, the FEV1 (Maximum volume expired during the first second) did not seem to be a significant factor influencing the correlation between the ITV and the volumes bypassed on CBCT.Performing a single 4D planification CT is sufficient to consider stereotactic lung irradiation, regardless of the location of the lung lesions. The correlation coefficient between ITV and CBCT was high for upper lobar lesions.

Stereotactic radiotherapy has become a standard in the management of patients with brain metastases; its main interest is to differ whole brain radiotherapy, provider of neurocognitive toxicity and to increase the rate of local control. The repetition of radiotherapy sessions under stereotactic conditions is not codified, neither on the number of technically and clinically possible sessions, nor on the maximum total number or volume of metastases to be treated. The purpose of this review is to analyse the data in the literature concerning repeated irradiations under stereotactic conditions. The second reirradiation in stereotactic condition shows satisfactory results in terms of overall survival, local control, and toxicity. However, we lack data for patients receiving more than two sessions of SRS as well as to define dose constraints to reirradiated healthy tissues. Prospective trials are still needed to validate the management of recurrent brain metastases after initial SRS.

Deux enquêtes précédentes ont été réalisées en 1995 et 1999 pour évaluer l’utilisation de la radiothérapie dans le traitement d’affections bénignes non-tumorales. En 2016, le même questionnaire a été utilisé et envoyé aux 24 centres du pays : 22 centres ont répondu. Une diminution très importante du nombre de patients a été observée : 360 patients pour l’année 2016 contre 954 en 1999 et 1113 en 1995. Les indications les plus fréquentes restent la prévention des chéloïdes, des formations osseuses hétérotopiques et de la gynécomastie. Une nouvelle indication est apparue : les névralgies du trijumeau traitées par radiochirurgie. La prévention des sténoses coronariennes et le traitement de la dégénérescence maculaire, indications fréquentes dans les enquêtes antérieures, ne sont plus retenus. Un grand consensus est observé concernant les indications potentielles mais aussi dans la non utilisation de la radiothérapie pour les maladies inflammatoires. [A survey of Belgian practice for non-malignant diseases] Two prior surveys were carried out in 1995 and 1999 to evaluate the use of radiotherapy in the treatment of non-malignant disease. In 2016, the same questionnaire was used and sent to the 24 centers of the country: 22 responded. A major decrease was observed in the number of patients treated: 360 in 2016 in contrast to 954 in 1999 and 1113 in 1995. The most frequent indications remain the prevention of heterotopic bone formation, keloids or gynecomastia. A new indication was observed: trigeminal nevralgia treated with radiosurgery. Two frequent indications in the past disappeared: the prevention of coronary restenosis and the macular degeneration. A great agreement was observed regarding the possible indications for radiotherapy but also to avoid it for inflammatory pathologies.