Vestibulární schwannom (VS) je intrakraniální benigní tumor vycházející ze Schwannových buněk vestibulární porce vestibulokochleárního nervu. Tento nádor tvoří 85 % tumorů mostomozečkového koutu. Vyrůstá v tzv. přechodové zóně vnitřního zvukovodu, odkud roste směrem k mozkovému kmeni a mozečku. Z toho lze vyvodit posloupnost příznaků, které se u pacienta rozvinou. Mezi jeho nejčastější projevy patří jednostranná porucha sluchu, ušní šelesty a poruchy rovnováhy. Ve většině případů je jeho růst pomalý. V naprosté většině případů (95 %) se jedná o sporadický typ nádoru, ve zbylých 5 % se pak jedná o dědičnou, autozomálně dominantní formu nádoru, která se vyskytuje především u neurofibromatózy 2. typu (NF2).

Vestibular schwannoma (VS) is a benign intracranial tumor derived from myelinating Schwann cells of the vestibular division of the vestibulocochlear nerve. Vestibular schwannomas account for approximately 85 % of cerebellopontine angle tumors. It grows in the so-called transition zone of the internal auditory canal, from which it extends toward the brainstem and cerebellum. From this knowledge, the sequence of symptoms the patient develops can be deduced. The most common manifestations include unilateral hearing loss, tinnitus, and balance disorders. In most cases, VS growth is slow. The vast majority of VS (95 %) occur as sporadic tumors, with the remaining 5 % occurring as part of an inherited, autosomal dominant form of VS, mainly found in patients with neurofibromatosis type 2 (NF2).

• MeSH
• Auditory Diseases, Central MeSH
• Diagnostic Techniques, Otological MeSH
• Humans MeSH
• Magnetic Resonance Imaging MeSH
• Microsurgery methods   MeSH
• Facial Nerve MeSH
• Radiosurgery MeSH
• Rehabilitation MeSH
• Evoked Potentials, Auditory, Brain Stem MeSH
• Neuroma, Acoustic * diagnosis   complications   therapy   MeSH
• Check Tag
• Humans MeSH

BACKGROUND AND OBJECTIVES: An international, multicenter, retrospective study was conducted to evaluate the long-term clinical outcomes and tumor control rates after stereotactic radiosurgery (SRS) for trigeminal schwannoma. METHODS: Patient data (N = 309) were collected from 14 international radiosurgery centers. The median patient age was 50 years (range 11-87 years). Sixty patients (19%) had prior resections. Abnormal facial sensation was the commonest complaint (49%). The anatomic locations were root (N = 40), ganglion (N = 141), or dumbbell type (N = 128). The median tumor volume was 4 cc (range, 0.2-30.1 cc), and median margin dose was 13 Gy (range, 10-20 Gy). Factors associated with tumor control, symptom improvement, and adverse radiation events were assessed. RESULTS: The median and mean time to last follow-up was 49 and 65 months (range 6-242 months). Greater than 5-year follow-up was available for 139 patients (45%), and 50 patients (16%) had longer than 10-year follow-up. The overall tumor control rate was 94.5%. Tumors regressed in 146 patients (47.2%), remained unchanged in 128 patients (41.4%), and stabilized after initial expansion in 20 patients (6.5%). Progression-free survival rates at 3 years, 5 years, and 10 years were 91%, 86%, and 80 %. Smaller tumor volume (less than 8 cc) was associated with significantly better progression-free survival ( P = .02). Seventeen patients with sustained growth underwent further intervention at a median of 27 months (3-144 months). Symptom improvement was noted in 140 patients (45%) at a median of 7 months. In multivariate analysis primary, SRS ( P = .003) and smaller tumor volume ( P = .01) were associated with better symptom improvement. Adverse radiation events were documented in 29 patients (9%). CONCLUSION: SRS was associated with long-term freedom (10 year) from additional management in 80% of patients. SRS proved to be a valuable salvage option after resection. When used as a primary management for smaller volume tumors, both clinical improvement and prevention of new deficits were optimized.

• MeSH
• Child MeSH
• Progression-Free Survival MeSH
• Adult MeSH
• Cohort Studies MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Cranial Nerve Neoplasms * surgery   MeSH
• Follow-Up Studies MeSH
• Neurilemmoma * diagnostic imaging   radiotherapy   surgery   MeSH
• Radiosurgery * methods   MeSH
• Retrospective Studies MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Treatment Outcome MeSH
• Check Tag
• Child MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH

OBJECTIVE: Recent studies have suggested that biologically effective dose (BED) is an important correlate of pain relief and sensory dysfunction after Gamma Knife radiosurgery (GKRS) for trigeminal neuralgia (TN). The goal of this study was to determine if BED is superior to prescription dose in predicting outcomes in TN patients undergoing GKRS as a first procedure. METHODS: This was a retrospective study of 871 patients with type 1 TN from 13 GKRS centers. Patient demographics, pain characteristics, treatment parameters, and outcomes were reviewed. BED was compared with prescription dose and other dosimetric factors for their predictive value. RESULTS: The median age of the patients was 68 years, and 60% were female. Nearly 70% of patients experienced pain in the V2 and/or V3 dermatomes, predominantly on the right side (60%). Most patients had modified BNI Pain Intensity Scale grade IV or V pain (89.2%) and were taking 1 or 2 pain medications (74.1%). The median prescription dose was 80 Gy (range 62.5-95 Gy). The proximal trigeminal nerve was targeted in 77.9% of cases, and the median follow-up was 21 months (range 6-156 months). Initial pain relief (modified BNI Pain Intensity Scale grades I-IIIa) was noted in 81.8% of evaluable patients at a median of 30 days. Of 709 patients who achieved initial pain relief, 42.3% experienced at least one pain recurrence after GKRS at a median of 44 months, with 49.0% of these patients undergoing a second procedure. New-onset facial numbness occurred in 25.3% of patients after a median of 8 months. Age ≥ 63 years was associated with a higher probability of both initial pain relief and maintaining pain relief. A distal target location was associated with a higher probability of initial and long-term pain relief, but also a higher incidence of sensory dysfunction. BED ≥ 2100 Gy2.47 was predictive of pain relief at 30 days and 1 year for the distal target, whereas physical dose ≥ 85 Gy was significant for the proximal target, but the restricted range of BED values in this subgroup could be a confounding factor. A maximum brainstem point dose ≥ 29.5 Gy was associated with a higher probability of bothersome facial numbness. CONCLUSIONS: BED and physical dose were both predictive of pain relief and could be used as treatment planning goals for distal and proximal targets, respectively, while considering maximum brainstem point dose < 29.5 Gy as a potential constraint for bothersome numbness.

• MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Pain Measurement MeSH
• Follow-Up Studies MeSH
• Trigeminal Neuralgia * radiotherapy   surgery   MeSH
• Radiosurgery * adverse effects   MeSH
• Retrospective Studies MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Treatment Outcome MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH

INTRODUCTION: It is a normal procedure to avoid the application of ionizing radiation during pregnancy. In very rare occasions, treatment can be performed, but doses to the fetus must be evaluated and reported, and the patient must sign informed consent. There can occur two types of damage caused by ionizing radiation - deterministic and stochastic effects. Deterministic effects may occur after reaching a certain threshold (100 mGy for this study); meanwhile, stochastic effects have no limit and their probability rises with dose. This study focuses on deterministic effects. CASE PRESENTATIONS: This study compares the dose measured on phantom for the area of the pelvis and the dose measured on 3 patients with dosimeters positioned on the pelvis irradiated on Leksell Gamma Knife Perfexion/Icon. The mean dose for measurement on phantom for the pelvis was 0.73 ± 0.76 mGy, and for the patients, it was 1.28 mGy, 0.493 mGy, and 0.549 mGy which is 80 times lower, 200 times lower, and 180 times lower than the threshold for deterministic effects, respectively. CONCLUSION: The measurement carried on phantom served as the base for drafting informed consent and provided initial proof that treatment can be safely delivered. Measurements performed on patients only confirmed that irradiation of pregnant patients on Leksell Gamma Knife Perfexion/Icon is safe relative to the deterministic effects. Nevertheless, pregnant patients should be treated with ionizing radiation only in very extraordinary situations.

• MeSH
• Phantoms, Imaging MeSH
• Humans MeSH
• Radiosurgery * methods   MeSH
• Pregnancy MeSH
• Check Tag
• Humans MeSH
• Pregnancy MeSH
• Female MeSH
• Publication type
• Case Reports MeSH

Východiska: Stereotaktická radioterapie (stereotactic body radiation therapy – SBRT) či stereotaktická ablativní radioterapie (stereotactic ablative radiotherapy – SABR) se stala standardem léčby u pacientů s časným stadiem nemalobuněčného karcinomu plic (early-stage non-small cell lung cancer – ES-NSCLC), kteří nejsou způsobilí k chirurgickému zákroku nebo operaci odmítají. SBRT je metoda zevní radioterapie, která přesně dodává vysokou dávku záření v jedné nebo několika léčebných frakcích. Režimy s biologicky ekvivalentní dávkou ≥ 100 Gy jsou spojeny s dobrou lokální kontrolou a celkovým přežitím, vyšším než u konvenčně frakcionované radioterapie. V indikaci SBRT stále existují sporné oblasti, kde jsou údaje omezené – indikace u starších a komorbidních pacientů, indikace léčby bez histologické verifikace, léčba centrálních/ultracentrálních lézí, indikace u tumorů větších než 5 cm, indikace u operabilních pacientů. Rovněž optimální postup při sledování pacientů po SBRT pro ES-NSCLC zůstává nejasný, vč. frekvence zobrazování, použití PET-CT a požadavků na biopsii. CT změny po SBRT se liší od změn po konvenční radioterapii a je obtížné je odlišit od recidivy nádoru. Vzhledem k vysoké míře lokální kontroly po SBRT plic jsou data o léčbě lokálního selhání nedostatečná. Cíl: Cílem sdělení je shrnout současné poznatky o významu SBRT v indikaci časného karcinomu plic nemalobuněčného typu.

Background: Stereotactic body radiation therapy (SBRT) is now a standard treatment option for patients with early-stage non-small cell lung cancer (ES-NSCLC) who are unfit for surgery or refuse to undergo an operation. SBRT is a method of external beam radiotherapy that accurately delivers a high dose of irradiation in one or few treatment fractions. Intensive regimens of biologically effective dose ≥ 100 Gy are associated with good local control and overall survival, higher than in conventionally fractionated radiotherapy. There are still controversial areas in the SBRT indication where data are limited – indications for elderly and comorbid patients, indications for treatment without histological verification, treatment of central/ultracentral lesions, indications for tumors larger than 5 cm, indications for operable patients. The optimal follow-up practice of these patients also remains unclear, including the frequency of imaging, the use of PET-CT, and requirements for biopsy. CT changes after SBRT differ from those following conventional radiotherapy and it is difficult to distinguish them from tumor recurrence. Due to the high local control achieved with lung SBRT, data on the treatment of local failure are insufficient. Purpose: The aim of the publication is to demonstrate the current information and the importance of SBRT for patients with ES-NSCLC.

• Keywords
• časné stadium nemalobuněčného karcinomu plic,
• MeSH
• Humans MeSH
• Carcinoma, Non-Small-Cell Lung * surgery   radiotherapy   MeSH
• Radiosurgery * methods   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Review MeSH

Radioterapie je jedným ze základních složek léčby pacientů s intrakraniálními metastázami. Součástí nechirurgické léčby mozkových metastáz jsou celomozkové ozáření (whole brain radiotherapy – WBRT) a také stereotaktická radiochirurgie. V éře pokroku onkologické léčby s implikacemi pro dlouhodobé přežití pacientů je diskutovaným tématem toxicita těchto léčebných postupů, u které nemůžeme přehlédnout kognitivní poruchy. Mechanizmů, na jejichž základě kognitivní poruchy vznikají, je několik a jsou stále předmětem výzkumu. Zaměřujeme se na patofyziologické elementy, které se podílí na kognitivních poruchách, a na strategie, jakými jsou hipokampus šetřící (hippocampal avoidance; HA) WBRT pro kandidáty na cílenou léčbu s různými histologickými typy nádorů, která přechází hematoencefalickou bariéru. I když je léčba HA-WBRT plus memantinem jakožto standard stále předmětem diskuzí, v případech mnohočetných mozkových metastáz nebo metastáz, u kterých není vhodná cílená radioterapie, a u pacientů s očekávaným přežitím > 4 měsíce je nutné aplikovat strategii pro prevence poruch kognitivních funkcí. V budoucnu musí být do analýz a studií zařazeny nové studie, které zhodnotí kognitivní funkce u pacientů s dlouhodobým přežitím, ale také další faktory, jako je počet a objem mozkových metastáz, jejich intrakraniální a extrakraniální lokalizace a efekt moderních onkologických terapií.

Radiotherapy is one of the cornerstones for treatment of patients with intracranial metastases. Whole brain radiotherapy (WBRT) as well as stereotactic radiosurgery are part of the non-surgical treatment for brain metastases. The toxicities associated with the treatment, among which we cannot neglect cognitive impairment, represent a current topic in an era marked by advances in oncological treatments with implications for the long-term survival of these patients. The mechanisms that involve the onset of cognitive decline are multiple and are still the subject of research. We propose to highlight the pathophysiological elements involved in cognitive impairment as well as strategies including hippocampal avoidance (HA) WBRT for different histological cancer type candidates for target therapies that cross the blood-brain barrier. Even if the implementation of HA-WBRT plus memantine as standard is still a subject for debate, for cases with multiple brain metastases or metastases unsuitable for targeted radiotherapy and a life expectancy > 4 months, it is necessary to apply a preventive strategy for the impairment of cognitive function. New studies to evaluate cognitive function for long term survivals, but also an evaluation of other factors including the number and volume of brain metastases, their intracranial and extracranial localization and the effect of modern oncological therapies must be included in future analyzes and studies.

• MeSH
• Molecular Targeted Therapy methods   MeSH
• Radiation Dosage MeSH
• Cognition Disorders * chemically induced   physiopathology   prevention & control   MeSH
• Combined Modality Therapy methods   MeSH
• Humans MeSH
• Memantine pharmacology   therapeutic use   MeSH
• Brain Neoplasms drug therapy   complications   radiotherapy   MeSH
• Antineoplastic Agents classification   therapeutic use   MeSH
• Radiosurgery methods   MeSH
• Radiotherapy * methods   adverse effects   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Review MeSH

Úvod: Stereotaktická radioterapie (SBRT) je moderní metodou v zevní radioterapii. Přináší možnost aplikovat vysokou dávku záření s vyšší biologickou účinností do malého cílového objemu. Zabývali jsme se pacienty s karcinomem štítné žlázy indikovaných k této terapii. Pacienti a metody: Retrospektivně jsme zhodnotili soubor pacientů s diferencovaným karcinomem štítné žlázy z období let 2011 až 2019 indikovaných k této léčbě pro přetrvávající reziduum. Výsledky: V daném období 9 let podstoupilo terapii z důvodu přetrvávajícího rezidua 14 pacientů, 10 žen, 4 muži. Radiojód akumulující reziduum bylo před terapií přítomno u 9 pacientů, 5 pacientů bylo indikováno na základě elevované hladiny tyreoglobulinu (Tg) a rezidua přítomného na jiných zobrazovacích metodách. Po terapii došlo k plné nebo parciální regresi radiojód akumulujícího rezidua ve šech 9 případech. U 5 pacientů bez radiojód akumulujícího rezidua nedošlo k progresi ložiska na zobrazovacích metodách, odpověď ve sledované hladině Tg byla variabilní. Závěr: Radioterapie pomocí robotického systému CyberKnife představuje další léčebnou modalitu u pacientů s diferencovaným karcinomem štítné žlázy, umožňující lokální kontrolu nemoci.

Introduction: Stereotactic body radiation therapy (SBRT) is a modern method in external radiation therapy. It offers an option to use a high dose of radiation with a higher biological effect in a small target volume. We assessed the patients with the thyroid cancer indicated to this type of therapeutic approach. Patients and methods: We evaluated a group of patients with the differentiated thyroid cancer retrospectively, indicated to SBRT for the persisting residuals on the neck, from the time interval 2011–2019. Results: During the nine years interval, 14 patients (10 female, 4 male), underwent this type of therapy. Radioiodine accumulating remnants were present before SBRT in 9 patients, higher thyroglobulin (Tg) levels or residuals diagnosed by other imaging modalities were indications in 5 patients. The radioiodine accumulating residuals regressed fully or partially in all 9 cases. In the later 5 patients there was not observed any progression on the imaging examinations, response according to the thyroglobulin levels was variable. Conclusion: SBRT with the robotic CyberKnife system represents another therapeutic modality for patients with differentiated thyroid cancer, allowing local control of the disease.

• MeSH
• Humans MeSH
• Thyroid Neoplasms * radiotherapy   MeSH
• Radiosurgery methods   MeSH
• Retrospective Studies MeSH
• Check Tag
• Humans MeSH

BACKGROUND: Vestibular schwannomas (VSs) related to neurofibromatosis type 2 (NF2) are challenging tumors. The increasing use of stereotactic radiosurgery (SRS) necessitates further investigations of its role and safety. OBJECTIVE: To evaluate tumor control, freedom from additional treatment (FFAT), serviceable hearing preservation, and radiation-related risks of patients with NF2 after SRS for VS. METHODS: We performed a retrospective study of 267 patients with NF2 (328 VSs) who underwent single-session SRS at 12 centers participating in the International Radiosurgery Research Foundation. The median patient age was 31 years (IQR, 21-45 years), and 52% were male. RESULTS: A total of 328 tumors underwent SRS during a median follow-up time of 59 months (IQR, 23-112 months). At 10 and 15 years, the tumor control rates were 77% (95% CI: 69%-84%) and 52% (95% CI: 40%-64%), respectively, and the FFAT rate were 85% (95% CI: 79%-90%) and 75% (95% CI: 65%-86%), respectively. At 5 and 10 years, the serviceable hearing preservation rates were 64% (95% CI: 55%-75%) and 35% (95% CI: 25%-54%), respectively. In the multivariate analysis, age (hazards ratio: 1.03 [95% CI: 1.01-1.05]; P = .02) and bilateral VSs (hazards ratio: 4.56 [95% CI: 1.05-19.78]; P = .04) were predictors for serviceable hearing loss. Neither radiation-induced tumors nor malignant transformation were encountered in this cohort. CONCLUSION: Although the absolute volumetric tumor progression rate was 48% at 15 years, the rate of FFAT related to VS was 75% at 15 years after SRS. None of the patients with NF2-related VS developed a new radiation-related neoplasm or malignant transformation after SRS.

• MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Cell Transformation, Neoplastic MeSH
• Follow-Up Studies MeSH
• Hearing Loss * surgery   MeSH
• Neurofibromatosis 2 * complications   surgery   MeSH
• Radiosurgery * adverse effects   MeSH
• Retrospective Studies MeSH
• Neuroma, Acoustic * complications   radiotherapy   surgery   MeSH
• Treatment Outcome MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH

K nádorům centrální nervové soustavy (CNS) patří nádory primární, intraaxiální – vyrůstající z buněk mozkové a míšní tkáně (neuroepitelové nádory) nebo extraaxiální, které rostou z okolních struktur (mozkových a míšních plen, nervových obalů, cévních struktur, lymfatické tkáně, zárodečných buněk, malformací, hypofýzy). Mnohem častěji se v nitrolebním prostoru vyskytuje solitární nebo vícečetný metastatický rozsev malignity původem z jiného orgánu, např. maligního tumoru plíce, prsu, metastáza maligního melanomu, Grawitzova tumoru. Výskyt metastáz solidních nádorů je pak v oblasti intraaxiální či extraaxiální, leptomeningeální nebo durální. I nádory morfologicky benigní se svým výskytem v uzavřeném kompartmentu CNS mohou projevovat maligně a způsobovat závažné pomalu se rozvíjející, až akutně vzniklé neurologické symptomy, včetně nitrolební hypertenze. Primární nádory centrálního nervového systému tvoří 1-2 % všech zhoubných nádorů, s častějším výskytem u dospělých po 60. roce věku, s mírnou převahou výskytu u mužů, s vyšší mortalitou u mužů než u žen. Kolem 5 % CNS nádorů je podmíněno dědičně (např. Li-Fraumeni syndrom, neurofibromatóza typ I, II). Příčiny vzniku většiny nádorů mozku a míchy jsou nejasné, jednoznačně prokázán byl vliv radioaktivního záření, zvýšené riziko je u pacientů po transplantaci a nemocných AIDS (Acquired Immune Deficiency Syndrome), nejisté jsou potenciační účinky některých chemikálií a virů na vznik CNS neoplasií. Účinnost léčby nádorů mozku a míchy je ovlivněna existencí tzv. hematoencephalické bariéry, která chrání mozek před průnikem toxických látek, ale zároveň znemožňuje průnik většiny cytostatik k nádorovému cíli. Další překážkou může být lokalizace nádoru v oblastech obtížně přístupných histologické verifikaci (mozkový kmen, optické chiasma) pro vysoké riziko komplikací i po stereotaktické biopsii. V některých případech, ve snaze nezpůsobit ireverzibilní neurologický deficit nešetrným odběrem tkáně, se pak může stát vzorek histologického materiálu nevýtěžný, to znamená, že nejsou zachyceny nádorové buňky. Limitující je v neposlední řadě i radiosenzitivita některých mozkových struktur, která znemožňuje aplikovat vyšší dávku ionizujícího záření do nádoru postihujícího senzitivní tkáně CNS nebo nacházejícího se v blízkosti těchto senzitivních tkání. Prudký rozvoj metod imunohistochemické (IHC) a molekulárně-genetické analýzy výrazně zpřesnil diagnostiku a tím teoreticky usnadňuje volbu optimálního léčebného postupu pro individuálního pacienta. Zatímco pokrok v moderní technice konformní fotonové, částicové (v současné době nejčastěji protonové) radioterapie, stereotaktické radiochirurgie umožnil přesné cílené ozáření nádorového ložiska CNS se šetřením rizikových mozkových struktur a tím výrazně snížil riziko akutní a pozdní neurotoxicity, možnosti farmakoterapie jsou stále limitované. Právě molekulárně-genetické poznatky nám již nyní poskytují prediktivní a prognostické informace. Do budoucna by měly stále více stratifikovat pacienty k cílené terapii.

Tumors of the central nervous system (CNS) include primary tumors - itraaxial, growing from brain and spinal cord cells (neuroepithelial tumors) or extraaxial, growing from surrounding structures (brain and spinal cord, nerve sheaths, vascular structures, lymphatic tissue, germ cells, malformations, pituitary glands). Much more often they are located in the intracranial space a solitary or multiple metastatic spread of malignancy originating from another organ (eg lung, breast, malignant melanoma, Grawitz’s tumor). The occurrence of metastases of solid tumors is then in the intraaxial or extraaxial region, leptomeningeal or dural. Even morphologically benign tumors with their occurrence in a closed CNS compartment can have malignant behaviour and cause severe slowly developing to acute neurological symptoms, including intracranial hypertension. Primary tumors of the central nervous system present 1-2% of all cancers, with a higher incidence in adults after the age of 60, with a slight predominance in men, with higher mortality in men than in women. About 5% of CNS tumors are hereditary (e.g., Li-Fraumeni syndrome, neurofibromatosis type I, II). The causes of most brain and spinal cord tumors are unclear, the effect of radiation has been definitely demonstrated, there is an increased risk in transplant patients and AIDS (Acquired Immune Deficiency Syndrome) patients, and the potentiating effects of some chemicals and viruses on the development of CNS neoplasms are uncertain. The effectiveness of treatment of brain and spinal cord tumors is influenced by the existence of the so-called hematoencephalic barrier, which protects the brain from the penetration of toxic substances, but at the same time prevents the penetration of most cytostatics to the tumor target. Another obstacle may be the localization of the tumor in areas difficult to access for histological verification (brain stem, optical chiasma) due to the high risk of complications even after stereotactic biopsy. In some cases, in an effort not to cause an irreversible neurological deficit by inconsiderate tissue collection, the sample of histological material can then become inconclusive to tumor cells, i.e., tumor cells are not captured. Last but not least, the radiosensitivity of some brain structures is also limiting, which makes it impossible to apply a higher dose of ionizing radiation to a tumor affecting sensitive tissues or located near of these sensitive tissues. The rapid development of immunohistochemical (IHC) and molecular genetic analysis methods has significantly refined diagnostics and thus theoretically facilitates the choice of the optimal treatment procedure for the individual patient. While advances in modern conformal photon and particle (currently the most frequently proton) radiotherapy, stereotactic radiosurgery has enabled accurately targeted irradiation of the CNS tumor site and at the same time spare the high-risk brain structures, thereby significantly reduce the risk of acute and late neurotoxicity, pharmacotherapy options are still limited. Just molecular-genetic knowledge already provides us with predictive and prognostic information. They should increasingly stratify patients for targeted therapy.

• MeSH
• Glioma diagnosis   genetics   classification   MeSH
• Immunohistochemistry MeSH
• Humans MeSH
• Mutation genetics   MeSH
• Central Nervous System Neoplasms * diagnosis   MeSH
• Spinal Cord Neoplasms secondary   MeSH
• Radiosurgery methods   adverse effects   MeSH
• Check Tag
• Humans MeSH

OBJECTIVE: The management of neurofibromatosis type 2 (NF2)-associated meningiomas is challenging. The role of Gamma Knife radiosurgery (GKRS) in the treatment of these tumors remains to be fully defined. In this study, the authors aimed to examine the role of GKRS in the treatment of NF2-associated meningiomas and to evaluate the outcomes and complications after treatment. METHODS: Seven international medical centers contributed data for this retrospective cohort. Tumor progression was defined as a ≥ 20% increase from the baseline value. The clinical features, treatment details, outcomes, and complications were studied. The median follow-up was 8.5 years (range 0.6-25.5 years) from the time of initial GKRS. Shared frailty Cox regression was used for analysis. RESULTS: A total of 204 meningiomas in 39 patients treated with GKRS were analyzed. Cox regression analysis showed that increasing the maximum dose (p = 0.02; HR 12.2, 95% CI 1.287-116.7) and a lower number of meningiomas at presentation (p = 0.03; HR 0.9, 95% CI 0.821-0.990) were predictive of better tumor control in both univariable and multivariable settings. Age at onset, sex, margin dose, location, and presence of neurological deficit were not predictive of tumor progression. The cumulative 10-year progression-free survival was 94.8%. Radiation-induced adverse effects were noted in 4 patients (10%); these were transient and managed medically. No post-GKRS malignant transformation was noted in 287 person-years of follow-up. CONCLUSIONS: GKRS achieved effective tumor control with a low and generally acceptable rate of complications in NF2-associated meningiomas. There did not appear to be an appreciable risk of post-GKRS-induced malignancy in patients with NF2-treated meningiomas.

• MeSH
• Child MeSH
• Adult MeSH
• Cohort Studies MeSH
• Middle Aged MeSH
• Humans MeSH
• Meningioma etiology   surgery   MeSH
• Adolescent MeSH
• Young Adult MeSH
• Brain Neoplasms etiology   surgery   MeSH
• Follow-Up Studies MeSH
• Nervous System Diseases etiology   MeSH
• Neurofibromatosis 2 complications   MeSH
• Disease Progression MeSH
• Radiosurgery adverse effects   methods   MeSH
• Retrospective Studies MeSH
• Risk Factors MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Age of Onset MeSH
• Treatment Outcome MeSH
• Check Tag
• Child MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH