Radiothérapie intracérébrale en conditions stéréotaxiques

Stereotactic radiosurgery is used for treating several brain diseases. Radiosurgery is a non-invasive alternative to surgery for brain metastases, and randomized trials are on going to assess the role of radiosurgery. Radiosurgery has been advocated for patients with small benign meningioma or with vestibular schwannoma, but there is no proof of efficacy and safety of radiosurgery in comparison with other treatments. Radiosurgery can obliterate 80-90% of small arteriovenous malformations, but no information exists on the survival of treated compared with untreated patients. The limited information available suggests that radiosurgery should be fully evaluated in well-designed prospective studies.     

Radiochirurgie stéréotaxique des malformations artérioveineuses cérébrales

Radiosurgery as treatment for arteriovenous malformations has shown a good efficacy in reducing intracranial bleeding due to rupture. The choice of therapeutic modalities is based on evolutive risk and arteriovenous malformations volume, patient profile and risks stratification following therapeutic techniques (microsurgery, radiosurgery, embolization). Nidus size, arteriovenous malformations anatomical localization, prior embolization or bleeding, distributed dose are predictive factors for radiosurgery's good results and tolerance. This review article will highlight arteriovenous malformations radiosurgery indications and discuss recent irradiation alternatives for large arteriovenous malformation volumes.     

Épidémiologie des métastases cérébrales et tropisme cérébral

Recent progresses in chemotherapies and targeted therapies have improved survival in cancer patients. In this context of better-controlled systemic disease, brain metastases (BM) are emerging as a new challenge for the oncologist. However, BM epidemiology and biology remain largely unclear. Incidence of BM is increasing. This trend could be explained by improvement in the quality of neuro-imaging (MRI) and increased survival. Primary cancers associated with BM patients are mainly: lung, breast, renal, colorectal cancers and melanoma. Prevalence of BM is estimated at 9% although this figure is probably underestimated. Time from initial to BM diagnoses is increasing and BM is occurring more frequently in individuals with advanced-stage disease. Biology of BM remains poorly known. Interactions between circulated tumoral cells (CTC) and blood-brain-barrier (BBB) cells are required. Some cytokines may act as CTC attractants and promote BM formation. BM development also involves several steps (extravasations through non-fenestrated capillaries, local proliferation, neoangiogenesis…), which represent potential therapeutic targets.     

Boost et réirradiation stéréotaxiques des cancers des voies aérodigestives supérieures

Stereotactic radiotherapy is increasingly used in head and neck tumours, either as a boost for dose escalation/early salvage, or in the reirradiation setting. We aimed to assess the level of evidence for each clinical setting and to discuss the different dose and frationation regimens. A search of the French and English literature was performed on PubMed until December 2013. Stereotactic reirradiation of locally recurrent squamous cell carcinomas can be performed with overall survival rates of about 12 months with good quality of life, and acceptable toxicity, based on several phase 2 trials and retrospective studies. Nasopharyngeal carcinomas may be irradiated with even better control rates. Late severe toxicities yield up to 20–30%. Patient and tumour selection criteria (limited volume) and dose constraints to the carotids (cumulative dose 110 Gy or less, to avoid the risk of potentially lethal carotid blowout) must be carefully chosen. Fractionated regimens (at least five fractions) should be preferred (30 Gy in five fractions to 36 Gy in six fractions). Methods derived from stereotactic, intensity-modulated radiotherapy (IMRT) may be used with conventional fractionation for larger tumours. Stereotactic irradiation may be associated with cetuximab; data with chemotherapy or other targeted therapies are still lacking. Stereotactic irradiation is also used as a boost after 46 Gy IMRT in several institutions or for early salvage (8 to 10 weeks following full dose irradiation with evidence of residual tumour) in squamous or nasopharyngeal carcinomas. Such indications should be evaluated prospectively in clinical trials. Data in salivary gland and sinonasal neoplasms are still scarce. In conclusion, stereotactic body radiation therapy has the potential as a boost or in the reirradiation setting to improve local control in head and neck tumours. Careful hypofractionation with planning caring for the dose to the main vessels is highly recommended. Prospective studies with prolonged follow-up (at least 2 years) should be encouraged.     

Diagnostic différentiel entre récidive tumorale et radionécrose après radiothérapie stéréotaxique d’une métastase cérébrale

Magnetic resonance imaging (MRI) is a method of choice for follow-up of irradiated brain metastasis. It is difficult to differentiate local tumour recurrences from radiation induced-changes in case of suspicious contrast enhancement. New advanced MRI techniques (perfusion and spectrometry) and amino acid positron-emission tomography (PET) allow to be more accurate and could avoid a stereotactic biopsy for histological assessment, the only reliable but invasive method. We report the case of a patient who underwent surgery for a single, left frontal brain metastasis of a breast carcinoma, followed by adjuvant stereotactic radiotherapy in the operative bed. Seven months after, she presented a local change in the irradiated area on the perfusion-weighted MRI, for which the differentiation between a local tumour recurrence and radionecrosis was not possible. PET with 2-deoxy-(¹⁸F)-fluoro-D-glucose (FDG) revealed a hypermetabolic lesion. After surgical resection, the histological assessment has mainly recovered radionecrosis with few carcinoma cells. The multimodal MRI has greatly contributed to refine the differential diagnosis between tumour recurrence and radionecrosis, which remains difficult. The FDG PET is helpful, in favour of the diagnosis of local tumour recurrence when a hypermetabolic lesion is found. Others tracers (such as carbon 11 or a fluoride isotope) deserve interest but are not available in all centres. Stereotactic biopsy should be discussed if any doubt remains.     

Métastases cérébrales : rôle du pathologiste en 2012

Diagnosis of brain metastases should aim to identify anatomoclinical entities for which a specific treatment is more accurate. Growing numbers of targeted therapies have shown to be effective against specific cancers. Several studies have reported that targeted therapies are capable of reducing brain metastases in melanoma or non small cell lung cancer (NSCLC), sometimes with a high dramatic response. These results have clearly impacted routine neuropathological practice, leading to multidisciplinary strategy management of brain metastases tissues. In accordance with the recommendations of French National Cancer Institute (INCa), the pathologist develops appropriate strategies for molecular and immunohistochemical analysis, in order to provide results as soon as possible.     

La radiothérapie en conditions stéréotaxiques des métastases cérébrales en situation complexe

Stereotactic radiation therapy of brain metastases is a treatment recognized as effective, well tolerated, applicable for therapeutic indications codified and validated by national and international guidelines. However, the effectiveness of this irradiation, the evolution of patient care and the technical improvements enabling its implementation make it possible to consider it in more complex situations: proximity of brain metastases to organs at risk; large, cystic, haemorrhagic or multiple brain metastases, combination with targeted therapies and immunotherapy, stereotactic radiotherapy in patients with a pacemaker. This article aims to put forward the arguments available to date in the literature and those resulting from clinical practice to provide decision support for the radiation oncologists.     

Liposarcome rétropéritonéal géant récidivant: à propos d’un cas

The retroperitoneal liposarcoma is a malignant, primitive, and rare tumor. It has a long time asymptomatic evolution and a late diagnosis. It is generally single and consists of only one histological type. This tumor is characterized by the high risk of locoregional recurrence, and its prognosis is related to the possibilities of a complete exeresis and the histopronostic rank. The surgical resection extended to the surrounding organs constitutes the treatment of reference and this remains possible even in the event of recurrence. We report the observation of a retroperitoneal liposarcoma at multiple, synchronous localizations and which occurred twice, with the histological type of the liposarcoma differentiated well from the more aggressive liposarcoma myxoide. The surgical treatment was always a curative exeresis extended to the surrounding organs.     

Délinéation du lit opératoire des métastases cérébrales opérées traitées par irradiation en conditions stéréotaxiques adjuvante : revue de la littérature

Stereotactic radiotherapy of the surgical bed of brain metastases is a technique that comes supplant indications of adjuvant whole brain radiotherapy after surgery. After a growing number of retrospective studies, a phase III trial has been presented and validated this indication. However, several criteria such as the dose, the fractionation, the use of a margin and definition of volumes remain to be defined. Our study consisted in making a literature review in order to provide a guideline of delineation of surgical beds of brain metastases, as well as the different modalities of their implementation process.     

Place de l’irradiation stéréotaxique hypofractionnée dans le traitement des métastases cérébrales

PurposeA survey of the literature has been performed to find arguments in order to help the choice between radiosurgery and hypofractionnated stereotactic radiotherapy in the treatment of brain metastases.Patients and methodsA comparison of two groups of brain metastases treated with hypofractionnated stereotactic radiotherapy or radiosurgery, with or without WBRT was performed. Hypofractionnated stereotactic radiotherapy: there were eight series including 448 patients published from 2000 to 2009; treated with 5–6 MV X-Rays, non invasive head immobilization, a margin 2 to 10 mm; 24 to 40 Gy in three to five fractions; a 5 to 8 days duration in six series and 15–16 days in two other series. WBRT (30%) ; radiosurgery: there were 12 series (1994 to 2005) including 2157 patients; an invasive head immobilization, no margin; doses from 10 to 25 Gy; six series over 12 had Gamma Knife radiosurgery and six had Linacs X-Rays. WBRT (30 Gy/10 F/12 days) associated to radiosurgery in several series. The following parameters were compared: median GTV, median survival, 1-year survival rate, local control rate, necrosis and WBRT rates.ResultsHypofractionnated stereotactic radiotherapy series: the parameters were respectively: 0,52–4,47 cm³ (median 2,8 cm³); 5–16 months (median 8,7 months); 68,2–93% (median 82,5%); necrosis rate 3,1%; associated WBRT 30%. Radiosurgery series: the parameters were respectively: 1,3 to 5,5 cm³ (median 2 cm³); 5,5 to 22 months (median 11 months); 71 to 95% (median 85%); 0,5 to 6% (median 2,4%); associated WBRT 58%. Results seem similar in the two groups: Hypofractionnated stereotactic radiotherapy with non invasive immobilization could theoretically treat all brain metastases sizes except lesions < 10 mm (500 mm³). In large volumes, > 4200 mm³ GTV, the toxicity of hypofractionnated stereotactic radiotherapy was not reported, thus it was difficult to compare its results with the published reports of radiosurgery toxicity. WBRT was a confusing parameter. Obviously, this initial survey has important limitations, specifically its methodology.ConclusionRadiosurgery and hypofractionnated stereotactic radiotherapy could be used to treat brain metastases with GTV > 500 mm³ and ≤ 4200 mm³ (Ø 20 mm); for GTV < 500 mm³ (Ø 10 mm) an invasive procedure with radiosurgery is necessary. For GTV > 4200 mm³ (Ø 20 mm), hypofractionnated stereotactic radiotherapy could be proposed, provided further studies, using 4 to 6 Gy fractions, a duration less or equal to 10–12 days and a margin of 2 mm will be performed.     

Mon réseau® cancer du sein,un réseau social de proximité

Mon réseau® cancer du sein is a social network launched in July 2014. It is dedicated to patients with breast cancer and their relatives. The website Mon réseau® cancer du sein was developed on the basis of personal experiences in the frame of the association Patients en réseau, which gather breast cancer patients and their relatives. The concrete daily needs of the patients during their treatment are at the heart of the project. Mon réseau® cancer du sein is a free and secured social website designed to encourage patients to share their experiences and to support exchanges between patients or between relatives. By providing access to professionals, associations, and care givers specific to their needs, patients benefit from a close network of information and practical, daily support. It acts as a facilitator to reduce the burden of disease.     

Évaluation de la réponse thérapeutique après radiothérapie stéréotaxique des lésions tumorales hépatiques

Stereotactic body radiation therapy takes more and more an important place in the therapeutic arsenal of primitive and secondary liver tumours. The administration of ablative radiation doses can result in specific changes to both the tumour and the healthy hepatic parenchyma, relative to conventional radiation therapy, making the assessment of local changes after stereotactic body radiation therapy, in terms of local control and reaction of healthy tissue, often difficult. It is mandatory to standardize and simplify our evaluation criteria to benefit from a better understanding of the effectiveness of this new treatment modality and allow better reproducibility of available imaging exams. This article presents a literature review of the various radiological changes observed after stereotactic body radiation therapy for liver tumours according to the multiple assessment methods used to determine local control. From the data available, we recommend using modified RECIST criteria proposed by the American Association for the Study of Liver Diseases (AASLD), as objective and relevant criteria of local control after stereotactic body radiation therapy for liver tumours.