Long duration of immunotherapy before radiosurgery might improve intracranial control of melanoma brain metastases.

PURPOSE: Despite significant advances that have been made in management of metastatic melanoma with immune checkpoint therapy, optimal timing of combination immune checkpoint therapy and stereotactic radiosurgery is unknown. We have reported toxicity and efficiency outcomes of patients treated with concurrent immune checkpoint therapy and stereotactic radiosurgery. PATIENTS AND METHODS: From January 2014 to December 2016, we analyzed 62 consecutive patients presenting 296 melanoma brain metastases, treated with gamma-knife and receiving concurrent immune checkpoint therapy with anti-CTLA4 or anti-PD1 within the 12 weeks of SRS procedure. Median follow-up time was 18 months (mo) (13-22). Minimal median dose delivered was 18 gray (Gy), with a median volume per lesion of 0.219 cm3. RESULTS: The 1-year control rate per irradiated lesion was 89% (CI 95%: 80.41-98.97). Twenty-seven patients (43.5%) developed distant brain metastases after a median time of 7.6 months (CI 95% 1.8-13.3) after gamma-knife. In multivariate analysis, positive predictive factors for intracranial tumor control were: delay since the initiation of immunotherapy exceeding 2 months before gamma-knife procedure (P=0.003) and use of anti-PD1 (P=0.006). Median overall survival (OS) was 14 months (CI 95%: 11-NR). Total irradiated tumor volume<2.1 cm3 was a positive predictive factor for overall survival (P=0.003). Ten patients (16.13%) had adverse events following irradiation, with four grade≥3. Predictive factors of all grade toxicity were: female gender (P=0.001) and previous treatment with MAPK (P=0.05). CONCLUSION: A long duration of immune checkpoint therapy before stereotactic radiosurgery might improve intracranial tumor control, but this relationship and its ideal timing need to be assessed in prospective trials.

[Radiosurgery for brain arteriovenous malformations]. / 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.

[Dosimetric stereotactic radiosurgical accident: Study of 33 patients treated for brain metastases]. / Traitement des métastases cérébrales par radiochirurgie stéréotaxique : étude de 33 cas liés à un accident de "surexposition".

The consequences of a dosimetric radiosurgery accident are not the same as a conventional radiotherapy accident. The objective of this study was to estimate the clinical and radiological outcome of patients treated by radiosurgery for metastasis during the period of the overexposure accident that occurred in the Toulouse Radiosurgery Unit. Between April 2006 and March 2007, 33 patients with 57 metastases were treated in the Toulouse Radiosurgery Unit (Novalis(®), BrainLab). An initial error in the estimation of the scatter factors led to an overexposure to radiation. The median age was 55 years [range, 35-85]. Twenty-one patients (64%) harbored a single metastasis. The primary tumor location was lung (16 cases), kidney (nine cases), breast (four cases), and others (four cases). The mean tumoral volume was 3.2cm(3) [0.04-14.07]. The mean prescribed dose at the isocenter was 20 Gy [range, 10-23], the mean delivered dose was 31.5 Gy [range, 13-52], and the mean overdose was 61.2% [range, 5.6-226.8]. In order to evaluate the consequences of the overdose, three parameters were analyzed: a risk index using dose and volume, the volume of parenchyma that received more than 12 Gy, and the mean dose in a sphere of 20cm(3) surrounding the target volume. Median actuarial survival was 14.1 months, the survival rate was 79.4 % at six months, 59.1% at 12 months, and 27.2% at 24 months. The rate of tumor control was 80.7%. No morbidity was observed. There was no correlation between death and the parameters studied. The survival rates and times observed in our study of the patients treated for brain metastases by radiosurgery and overexposed were among the good results of the international literature. Deaths were not related to the overdose and no side effect was noted. This dosimetric accident has not had worse consequences in this population.

[Ventriculus terminalis dilatation in adults: A case report and review of the literature]. / Dilatation du ventriculus terminalis chez l'adulte : à propos d'un cas et revue de la littérature.

The ventriculus terminalis (VT) is a virtual cavity of the conus medullaris that appears during embryonic life. The occurrence of its dilatation is very rare in adulthood. Only 27 cases have been documented so far. We present the case of a 47-year-old woman who presented with hypoesthesia and dysesthesia of the lower limb, distal paresis, and urinary dysfunction evolving for the past 5 years. Electrophysiology confirmed radiculopathy. MRI revealed a cystic dilatation of the VT. Surgery consisted in laminectomy with myelotomy and fenestration. Histology showed a simple cubic ependymal epithelium. Progression has been favorable concerning the motor deficit and sphincter dysfunction but neuropathic pain has persisted for 6 months. The data are similar to those found in the literature. The sex ratio is 6:21, the mean age is 45. Symptoms appear on average over 2 years with lower limb pain (71%), sphincter dysfunction (71%), lumbago (64%), motor deficits (57%), and sensory disorders (47%). Imaging demonstrated cystic dilatation in the conus medullaris filled with cerebrospinal fluid without contrast enhancement. The histology analysis showed a simple ependymal epithelium with no tumoral process. The fenestration of the cyst allows complete recovery of symptoms in 52% of cases and partial recovery in 43%. The VT seems to be a whole nosologic entity in itself. Myelotomy with fenestration provides good results on motor and sphincter symptoms, whereas the benefit in terms of pain is subject to discussion.