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BACKGROUND: The RxPONDER trial demonstrated that the 21-gene recurrence score can be used to guide adjuvant systemic therapy decisions in postmenopausal women with pN1 ER+/HER2- breast cancer. As such, a sentinel lymph node biopsy (SLNB) may not provide systemic treatment-altering information for many patients, and omission of SLNB in patients with low probability of pN2/N3 disease could be considered. METHODS: Postmenopausal women (aged ≥ 50 years) diagnosed with cN0cM0, ER+/HER- breast cancer from 2013 to 2017 were identified in the National Cancer Database. The primary outcome was the prevalence of pN2/N3 disease. RESULTS: Of 325,692 postmenopausal women with cN0 ER+/HER2- breast cancer, 7106 (2.2%) were pN2/N3. In total, 81.7% had cT1 tumors, 16.8% T2, 1.3% T3, and 0.2% T4. In patients with T1 tumors, the prevalence of pN2/N3 disease was 1.2% compared with 17.2% in patients with T3/T4 tumors. In multivariable models, cT stage was the strongest predictor of pN2/N3 disease (adjusted odds ratio [aOR] 14.9 [12.1-18.4]). Lobular histology (aOR 2.4 [2.3-2.6]), higher grade (aOR 2.9 [2.6-3.1]), and young age (aOR 1.5 [1.3-1.7]) were also associated with increased prevalence of pN2/N3. We created a model using histology, grade, and T stage that stratifies patients with low prevalence of pN2/3 disease (< 1%) and those at high risk (> 20%). CONCLUSIONS: In postmenopausal women with cN0 ER+/HER2- breast cancer, the prevalence of pN2/N3 disease is low, indicating a potential opportunity to use the results of RxPONDER to extend criteria to omit SLNB. Prospective study is needed to determine safety, including risk of nodal recurrence, of omission of SLNB in carefully selected patients.
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Neoplasias de la Mama , Axila/patología , Neoplasias de la Mama/cirugía , Terapia Combinada , Femenino , Humanos , Escisión del Ganglio Linfático , Estadificación de Neoplasias , Posmenopausia , Prevalencia , Biopsia del Ganglio Linfático CentinelaRESUMEN
The synchronization of coupled oscillators is a phenomenon found throughout nature. Mechanical oscillators are paradigmatic examples, but synchronizing their nanoscaled versions is challenging. We report synchronization of the mechanical dynamics of a pair of optomechanical crystal cavities that, in contrast to previous works performed in similar objects, are intercoupled with a mechanical link and support independent optical modes. In this regime they oscillate in antiphase, which is in agreement with the predictions of our numerical model that considers reactive coupling. We also show how to temporarily disable synchronization of the coupled system by actuating one of the cavities with a heating laser, so that both cavities oscillate independently. Our results can be upscaled to more than two cavities and pave the way towards realizing integrated networks of synchronized mechanical oscillators.
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OBJECTIVES: This study sought to assess facial emotion recognition deficit in children with Attention Deficit/Hyperactivity Disorder (ADHD) and to test the hypothesis that it is increased by comorbid features. METHOD: Forty children diagnosed with ADHD were compared with 40 typically developing children, all aged from 7 to 11years old, on a computerized facial emotion recognition task (based on the Pictures of Facial Affect). Data from parents' ratings of ADHD and comorbid symptoms (on the Conners' Revised Parent Rating Scale) were also collected. RESULTS: Children with ADHD had significantly fewer correct answer scores than typically developing controls on the emotional task while they performed similarly on the control task. Recognition of sadness was especially impaired in children with ADHD. While ADHD symptoms were slightly related to facial emotion recognition deficit, oppositional symptoms were related to a decrease in the number of correct answers on sadness and surprise recognition. CONCLUSION: Facial emotion recognition deficit in children with ADHD might be related to an impaired emotional process during childhood. Moreover, Oppositional Defiant Disorder seems to be a risk factor for difficulties in emotion recognition especially in children with ADHD.
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Trastorno por Déficit de Atención con Hiperactividad/epidemiología , Trastorno por Déficit de Atención con Hiperactividad/psicología , Emociones , Expresión Facial , Reconocimiento en Psicología/fisiología , Trastorno por Déficit de Atención con Hiperactividad/fisiopatología , Déficit de la Atención y Trastornos de Conducta Disruptiva/epidemiología , Déficit de la Atención y Trastornos de Conducta Disruptiva/psicología , Estudios de Casos y Controles , Niño , Comorbilidad , Femenino , Humanos , Masculino , Pruebas NeuropsicológicasRESUMEN
Silicon on insulator photonics has offered a versatile platform for the recent development of integrated optomechanical circuits. However, there are some constraints such as the high cost of the wafers and limitation to a single physical device level. In the present work we investigate nanocrystalline silicon as an alternative material for optomechanical devices. In particular, we demonstrate that optomechanical crystal cavities fabricated of nanocrystalline silicon have optical and mechanical properties enabling non-linear dynamical behaviour and effects such as thermo-optic/free-carrier-dispersion self-pulsing, phonon lasing and chaos, all at low input laser power and with typical frequencies as high as 0.3 GHz.
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Scanning Thermal Microscopy (SThM) has become an important measurement technique for characterizing the thermal properties of materials at the nanometer scale. This technique requires a SThM probe that combines an Atomic Force Microscopy (AFM) probe and a very sensitive resistive thermometer; the thermometer being located at the apex of the probe tip allows for the mapping of temperature or thermal properties of nanostructured materials with very high spatial resolution. The high interest of the SThM technique in the field of thermal nanoscience currently suffers from a low temperature sensitivity despite its high spatial resolution. To address this challenge, we developed a high vacuum-based AFM system hosting a highly sensitive niobium nitride (NbN) SThM probe to demonstrate its unique performance. As a proof of concept, we utilized this custom-built system to carry out thermal measurements using the 3ω method. By measuring the V3ω voltage on the NbN resistive thermometer under vacuum conditions, we were able to determine the SThM probe's thermal conductance and thermal time constant. The performance of the probe is demonstrated by performing thermal measurements in-contact with a sapphire sample.
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Contactless temperature field measurements in or at the surfaces of semitransparent media are a scientific challenge as classical thermography techniques based on proper material emission cannot be used. In this work, an alternative method using infrared thermotransmittance for contactless temperature imaging is proposed. To overcome the weakness of the measured signal, a lock-in acquisition chain is developed and an imaging demodulation technique is used to retrieve the phase and amplitude of the thermotransmitted signal. These measurements, combined with an analytical model, enable the estimation of the thermal diffusivity and conductivity of an infrared semitransparent insulator (wafer of Borofloat 33 glass) and the monochromatic thermotransmittance coefficient at 3.3 µm. The obtained temperature fields are in good agreement with the model, and a detection limit of ±2 °C is estimated with this method. The results of this work open new opportunities in the development of advanced thermal metrology for semitransparent media.
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PURPOSE: There is no consensus about the treatment of rectal tumour when there are synchronous metastases. The interest of radiotherapy is debated. PATIENTS AND METHODS: Thirty-seven patients with rectal tumour and synchronous metastases were treated with radiotherapy first between September 1994 and December 2004. We analysed the tolerance, local control, resecability, overall survival of such a therapeutic strategy. RESULTS: The mean follow-up was 30 months. Twenty-four tumors were resecable for both the primary site and the metastases. Thirteen were unresecable at the time of diagnosis. Thirty-three patients were treated with radiochemotherapy, ten with radiotherapy alone. Eighty-six decimal five percent of them had no pelvic symptom six weeks after the treatment. Twenty-one rectal tumours were finally resected. The disease progressed in six cases during the radiotherapy. Surgery of the metastases was possible for 12 patients with tumour initially resecable. CONCLUSION: Radiochemotherapy is a "tolerable" treatment, in spite of more frequent urinary or digestive side-effects. But, if there is no surgery, palliative effect of radiotherapy is limited.
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Neoplasias del Recto/radioterapia , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Neoplasias del Recto/mortalidadRESUMEN
Adult gliomas (WHO grade II, III and IV) are heterogeneous primitive brain tumors. The prognosis of these tumors depends on multiple factors such as age at diagnosis, Karnofsky score, histopathology, biology and treatments. Radiotherapy (RT) plays an important role in the treatment strategy, after surgery. RT has been evaluated in terms of survival, median time to progression and toxicity. Techniques of RT have improved, during the last two decades: neuro-imaging (CT-scan, MRI and PET) and dedicated computers for dosimetry make it possible to deliver an homogeneous dose in the target volume while sparing normal tissues. Photons X are usually delivered with stereotactic or conformational noncoplanar techniques. Total doses delivered range from 50.4 to 60 Gy (1.8-2 Gy/fraction). Median survivals are different with regard to the tumor grade. However, genetic and biological factors also are important prognostic factors such as inactivation of the MGMT gene for glioblastomas and loss of heterozygosity (LOH) 1p/19q, usually associated with pure oligodendroglioma. During the 1990s, temozolomide (TMZ) was specifically developed as a chemotherapy agent against primary brain tumors. The current TMZ/RT regimen in newly diagnosed GBM has been proposed as a standard treatment. The optimal treatment strategy is not known. New clinical trials are needed to assess new techniques of RT; a further improvement in medical treatment requires novel agents.
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Neoplasias Encefálicas/radioterapia , Glioma/radioterapia , Radioterapia/tendencias , Adulto , Astrocitoma/radioterapia , Neoplasias Encefálicas/patología , Glioblastoma/radioterapia , Glioma/patología , Humanos , Oncología Médica/tendencias , Pronóstico , Radioterapia/efectos adversosRESUMEN
RATIONALE: Second-line chemotherapy is disappointing in recurrent high-grade gliomas. Dramatic responses in recurrent high-grade gliomas have been reported in a recent monocentric trial with a novel association combining bevacizumab (anti-VEGF monoclonal antibody agent) and irinitecan. OBJECTIVE: To report the experience of the ANOCEF group (French speaking neuro-oncology association) using the bevacizumab-irinotecan combination in recurrent high-grade gliomas. METHODS: Eight centers were involved in this retrospective multicenter study. Bevacizumab-irinotecan was delivered as previously described in a compassional setting to non-selected patients suffering from a high-grade glioma (WHO grade III and IV). Response rate at two months of the onset of the treatment was analyzed using the Macdonald criteria. The toxicity profile of the treatment was also investigated. RESULTS: From 2006 to 2007, 77 patients were treated (median age: 52 years; median Karnofsky score: 70) for a recurrent high-grade glioma (49 grade IV, 28 grade III). At two months, the response rates were objective response=36% (54% in grade III and 27% in grade IV); stable disease=39%; progressive disease=13%; patients not evaluable because of a rapid fatal clinical deterioration=12%. Improvement was noted in 49% of patients. Among the main toxicities, we noted; intratumoral hemorrage (n=5 with spontaneous regression in three) and thromboembolic complications including venous thrombophlebitis (n=4), pulmonary embolism (n=2), myocardial infarction (n=1), grade III-IV hematotoxicity (n=2), reversible leukoencephalopathy (n=1). CONCLUSION: This retrospective multicenter study adds further arguments in favor of the promising results of this new combination and its potential rapidity of action in recurrent high-grade gliomas. Antiangiogenic agents expose the patients to a well-known risk of thromboembolic and hemorragic complications, necessitating careful follow-up and patient selection in light of the cardiovascular contraindications.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Encefálicas/tratamiento farmacológico , Glioma/tratamiento farmacológico , Adulto , Anciano , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales Humanizados , Antineoplásicos Fitogénicos/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Bevacizumab , Neoplasias Encefálicas/patología , Camptotecina/administración & dosificación , Camptotecina/análogos & derivados , Preescolar , Femenino , Glioma/patología , Humanos , Irinotecán , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Estudios RetrospectivosRESUMEN
While the dispersion of nanomaterials is known to be effective in enhancing the thermal conductivity and specific heat capacity of fluids, the mechanisms behind this enhancement remain to be elucidated. Herein, we report on highly stable, surfactant-free graphene nanofluids, based on N,N-dimethylacetamide (DMAc) and N,N-dimethylformamide (DMF), with enhanced thermal properties. An increase of up to 48% in thermal conductivity and 18% in specific heat capacity was measured. The blue shift of several Raman bands with increasing graphene concentration in DMF indicates that there is a modification in the vibrational energy of the bonds associated with these modes, affecting all the molecules in the liquid. This result indicates that graphene has the ability to affect solvent molecules at long-range, in terms of vibrational energy. Density functional theory and molecular dynamics simulations were used to gather data on the interaction between graphene and solvent, and to investigate a possible order induced by graphene on the solvent. The simulations showed a parallel orientation of DMF towards graphene, favoring π-π stacking. Furthermore, a local order of DMF molecules around graphene was observed suggesting that both this special kind of interaction and the induced local order may contribute to the enhancement of the fluid's thermal properties.
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After a request for proposal initiated by National Institute against cancer (INCa) in 2005, three French centers in France started tomotherapy in the first semester of 2007. A national policy of evaluation was performed to study the feasibility of this innovative technique and to compare the interest of helicoidal tomotherapy with other modalities of conformal therapy. Common protocols have been designed to facilitate this evaluation. Description of dose, IMRT levels and constraints are achieved according to each selected indication as: sarcoma, head and neck tumors, lung cancer, mesothelioma, bone metastases, anal carcinoma and craniospinal irradiation.
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Neoplasias/radioterapia , Radioterapia Conformacional/métodos , Tomografía Computarizada Espiral/métodos , Adulto , Factores de Edad , Protocolos Clínicos , Irradiación Craneana/métodos , Estudios de Factibilidad , Femenino , Francia , Humanos , Masculino , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador , Radioterapia Conformacional/efectos adversos , Radioterapia de Intensidad Modulada/efectos adversos , Radioterapia de Intensidad Modulada/métodos , Factores de Riesgo , Factores Sexuales , Factores de TiempoRESUMEN
BACKGROUND: The amygdala has an important role in pain and pain modulation. We showed previously in animal studies that α2 -adrenoreceptor activation in the central nucleus of the amygdala (CeA) mediates hypoalgesia produced by restraint stress, and that direct application of an α2 -agonist in this region produces analgesia. AIMS: In the present animal experiments, we investigated the pathways through which α2 -sensitive systems in the CeA produce behavioural analgesia. The CeA has dense connections to a descending pain modulatory network, centred in the midbrain periaqueductal grey (PAG) and the rostral ventromedial medulla (RVM), which is implicated in various forms of stress-related hypoalgesia and which mediates the antinociceptive effect of morphine applied in the basolateral amygdala. We investigated whether this circuit mediates the hypoalgesic effects of α2 -adrenergic agonist administration into the CeA as well as the contribution of endogenous opioids and cannabinoids. We also tested the possibility that activation of α2 -receptors in the CeA produces antinociception by recruitment of noradrenergic pathways projecting to the spinal cord. RESULTS: Hypoalgesia resulting from bilateral application of the α2 -adrenergic agonist clonidine in the CeA was not reversed by chemical inactivation of the RVM or by systemic injections of naloxone (µ-opioid antagonist) or rimonabant (CB1 antagonist). By contrast, spinal α2 -receptor blockade (intrathecal idazoxan) completely prevented the hypoalgesic effect of clonidine in the CeA, and unmasked a small but significant hyperalgesia. CONCLUSION: In rats, adrenergic actions in the CeA mediating hypoalgesia require spinal adrenergic neurotransmission but not the PAG-RVM pain modulatory network, or opiate or cannabinoid systems.
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Amígdala del Cerebelo/efectos de los fármacos , Analgésicos Opioides/uso terapéutico , Norepinefrina/metabolismo , Dolor/tratamiento farmacológico , Amígdala del Cerebelo/metabolismo , Amígdala del Cerebelo/fisiopatología , Analgésicos Opioides/farmacología , Animales , Hiperalgesia/tratamiento farmacológico , Hiperalgesia/metabolismo , Hiperalgesia/fisiopatología , Masculino , Morfina/farmacología , Morfina/uso terapéutico , Naloxona/farmacología , Antagonistas de Narcóticos/farmacología , Dolor/metabolismo , Dolor/fisiopatología , Dimensión del Dolor/métodos , Sustancia Gris Periacueductal/efectos de los fármacos , Sustancia Gris Periacueductal/metabolismo , Ratas , Ratas Sprague-DawleyRESUMEN
PURPOSE/OBJECTIVES: To assess feasibility and toxicity of Helical TomoTherapy for treating anal cancer patients. METHODS: From 2007 to 2011, 64 patients were consecutively treated with TomoTherapy in three centres for locally advanced squamous-cell anal carcinoma (T2 > 4 cm or N positive). Prescribed doses were 45 Gy to the pelvis including inguinal nodes and 59.4 Gy to the primary site and involved nodes with fractions of 1.8 Gy, five days a week. A positional Megavoltage Computed Tomography was performed before each treatment session. All acute and late toxicities were graded according to Common Terminology Criteria for Adverse Events version 3.0. Survival analysis was performed using the Kaplan-Meier method. RESULTS: Median follow-up was 22.9 months. Fifty-four women and 10 men were treated (median age: 62 years). Nineteen patients (29.7%) had T2, 16 patients (25.0%) T3, and 27 patients (42.2%) T4 tumours. Thirty-nine patients (60.9%) had nodal involvement. Median tumour size was 45 mm (range, 10-110 mm). Seven patients had a colostomy before treatment initiation. Fifty-seven patients received concomitant chemotherapy (5-FU/cisplatin or 5-FU/mitomycin-based therapy). Forty-seven patients (73.4 %) experienced a complete response, 13 a partial response or local recurrence, and 11 had salvage surgery; among these, six became complete responders, three experienced metastatic failure, and two local failure. At least four patients experienced metastatic recurrence (concomitant to a local failure for one patient). The two-year overall survival was 85.6% (95 %CI [71.1%-93.0%]), and the one-year disease-free survival, and colostomy-free survival were 68.7% (95 %CI [54.4%-79.4]), and 75.5% (95 %CI [60.7%-85.3%]) respectively. Overall survival, disease-free survival and colostomy free-survival were significantly better for women than men (p = 0.002, p = 0.004, and p = 0.002 respectively). Acute grade ≥3 toxicity included dermatologic (46.9% of patients), gastrointestinal (20.3%), and hematologic (17.2%) toxicity. Acute grade 4 hematologic toxicity occurred in one patient. No grade 5 event was observed. CONCLUSIONS: TomoTherapy for locally advanced anal cancer is feasible. In our three centres of expertise, this technique appeared to produce few acute gastrointestinal toxicities. However, high rates of dermatologic toxicity were observed. The therapeutic efficacy was within the range of expectations and similar to previous studies in accordance with the high rates of locally advanced tumours and nodal involvement.
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Neoplasias del Ano/radioterapia , Carcinoma de Células Escamosas/radioterapia , Radioterapia de Intensidad Modulada/métodos , Adulto , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Neoplasias del Ano/tratamiento farmacológico , Neoplasias del Ano/mortalidad , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/mortalidad , Quimioradioterapia/efectos adversos , Quimioradioterapia/métodos , Cisplatino/administración & dosificación , Supervivencia sin Enfermedad , Femenino , Fluorouracilo/administración & dosificación , Francia , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Dosis de Radiación , Radioterapia de Intensidad Modulada/efectos adversosRESUMEN
From 1980 to 1984, forty-five patients suffering gastric cancer were irradiated with curative intent. Twenty-three were considered at high risk of recurrence after complete surgical resection (invasion of the serosa, lymph nodes and/or surgical margins); eleven were treated after partial resection, and for eleven others, the local extension precluded surgery. Radiotherapy combined two lateral fields (usually with wedge filters) and an anterior field. The planned dose was 40 to 50 Gy, according to the amount of residual disease and doses delivered to the major part of the liver and the right and left kidneys did not exceed 30, 5, and 18 Gy, respectively. For patients aged less than 71 and whose general condition was acceptable, one cycle of chemotherapy (FAM for 20 patients and 5-FU for 10) preceded irradiation, followed if possible by 6 other cycles. Adverse effects, essentially anorexia, vomiting, and weight loss, led to definitively stopping irradiation in 8 cases, and were present in 21 other patients. Mean weight loss was 2.5 kg. Apart from one patient who developed a subphrenic abcess and died after reoperation, there was neither chronic complication, nor radiation hepatitis or nephritis. For 34 patients, the observation time was superior to 3 years: 23 died of their cancer, 1 of a subphrenic abcess, and 2 of an intercurrent disease. Eight were disease-free at 3 years (three of these were irradiated for macroscopic disease). For the overall series, the 4-year survival rate is 23%. There is a significant survival advantage for females versus males (p less than 0.01), a non-significant tendency in favor of microscopic residual disease versus macroscopic, and no advantage for the combination with FAM compared with no chemotherapy (non-randomized). This technique appears feasible with an acceptable tolerance and can control local tumor in a few cases. The planned dose of 40 Gy was probably too small and we are now testing 45 Gy delivered over the large initial volume, and boosts of 10-15 Gy to residual disease.
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Neoplasias Gástricas/radioterapia , Adulto , Terapia Combinada , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radioterapia/efectos adversos , Dosificación Radioterapéutica , Neoplasias Gástricas/tratamiento farmacológico , Neoplasias Gástricas/patologíaRESUMEN
From January 1986 to March 1989, 20 patients with stage III and IV cerebello-pontine angle neurinomas were treated with external fractionated radiation therapy; seven patients had phacomatosis. Indications for radiation therapy were as follows: (a) poor general condition or old age contraindicating surgery, 10 patients; (b) hearing preservation in bilateral neurinomas after contralateral tumor removal, 5 patients; (c) partial resection or high risk of recurrence after subsequent surgery for relapse, 4 patients; (d) non-surgical relapse, 1 patient. Most patients were irradiated with a 9 MV linear accelerator. A 3 to 4-field technique with 5 x 5 cm portals was used. Doses were calculated on a 95% isodose and were given 5 days a week for a mean total dose of 5140 cGy (180 cGy/fraction). Median follow-up from radiation therapy was 30 months (7 to 46); 4 patients died, 2 with progressive disease. Two patients underwent total tumor removal after radiation therapy (1 stable and 1 growing tumor). On the whole, 14 tumors remained stable, 3 decreased in size, and 3 progressed. CT scan or NMR tumor changes consistent with partial tumor necrosis appeared in four cases. Hearing preservation was obtained in 3/5 hearing patients with phacomatosis. When surgery is not indicated or incomplete, fractionated radiation therapy appears to be an effective and well-tolerated treatment for stage III and IV neurinomas. Hearing can be preserved.
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Neoplasias Cerebelosas/radioterapia , Ángulo Pontocerebeloso , Neurilemoma/radioterapia , Neurofibromatosis 1/radioterapia , Neuroma Acústico/radioterapia , Adulto , Anciano , Neoplasias Cerebelosas/epidemiología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Neurilemoma/epidemiología , Neurofibromatosis 1/epidemiología , Neuroma Acústico/epidemiología , Estudios RetrospectivosRESUMEN
PURPOSE: To reevaluate long-term results of fractionated radiation therapy (RT) in a previously published series of cerebello-pontine angle neurinomas (CPA). METHODS AND MATERIALS: From January 1986 to May 1992, 24 patients with Stage III and IV CPA neurinomas were treated with external fractionated RT; 7 patients had phacomatosis. One patient was irradiated on both sides and indications for radiotherapy were as follows: (a) poor general condition or old age contraindicating surgery, 14 cases; (b) hearing preservation in bilateral neurinomas after contralateral tumor removal, 5 cases; (c) partial resection or high risk of recurrence after subsequent surgery for relapse, 4 cases; (d) nonsurgical relapse, 2 cases. Most patients were irradiated with 9 MV photons. A three- to four-field technique with coned-down portals was used. Doses were calculated on a 95% isodose and were given 5 days a week for a mean total dose of 51 Gy (1.80 Gy/fraction). RESULTS: Median follow-up from RT was 60 months (7 to 84); five patients died, two with progressive disease. Two patients underwent total tumor removal after RT (one stable and one growing tumor). On the whole, tumor shrinkage was observed in 9 patients (36%), stable disease in 13 (52%), and tumor progression in 3. Hearing was maintained in 3 out of 5 hearing patients with phacomatosis. CONCLUSION: Fractionated RT appears to be an effective and well-tolerated treatment for Stage III and IV CPA neurinomas. Hearing can be preserved for a long time.
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Neoplasias Cerebelosas/radioterapia , Ángulo Pontocerebeloso , Neurilemoma/radioterapia , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Cerebelosas/diagnóstico por imagen , Neoplasias Cerebelosas/patología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Neurilemoma/diagnóstico por imagen , Neurilemoma/patología , Dosificación Radioterapéutica , Tomografía Computarizada por Rayos XRESUMEN
Since recent treatment planning systems calculate volumetric dose distribution, an objective evaluation of potential toxicity in the main critical organs may be helpful in treatment optimization. Modeling the toxicity of radiotherapy must at least account for: (a) specific risks in every critical organ; (b) total dose and dose per fraction; (c) partial irradiation of critical organs; (d) heterogeneous dose distribution. The Radiation Damage Factor formula is aimed at estimating the delayed toxicity of a given treatment plan on every critical organ concerned. The formulation uses a double exponential function: RDF = 100 e-Ke-(a+bd)DVc, where: D is the total dose, and d the dose per fraction; a and b are coefficients representing the radiosensitivity of the critical organ, according to the linear-quadratic model, with a/b = alpha/beta. K represents the theoretical critical unit content of the organ, these critical units being groups of functionally related stem cells. The avoidance of a complication depends on the ability of surviving critical units to preserve organ function. V is the ratio:irradiated volume/total volume of the organ. Exponent c accounts for tissue organization: c is equal to or near 1 in "parallel organs" like the liver or the lung, where localized hot spots are tolerated; c is lower in "series organs" like the spinal cord where hot spots, even in a small portion, are dangerous. Heterogeneous irradiation, summarized by dose cumulative-volume histograms, is accounted for by calculating step by step the dose D' considered as having an equivalent effect when given in the largest irradiated volume ratio. Preliminary calibration of the RDF formula is attempted for radiation myelitis and radiation hepatitis.
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Planificación de la Radioterapia Asistida por Computador , Radioterapia/efectos adversos , Femenino , Hepatitis/etiología , Humanos , Masculino , Matemática , Modelos Teóricos , Mielitis/etiología , Dosificación RadioterapéuticaRESUMEN
PURPOSE: To evaluate efficacy and tolerance of external fractionated radiation therapy (RT) in the treatment of intracranial meningiomas. METHODS AND MATERIALS: From January 1981 to September 1993, 91 patients with intracranial meningiomas were treated with fractionated RT. Indications were as follows: (a) incomplete surgical resection, 29 patients; (b) tumor recurrences without considering the amount of the second resection, if performed, 14 patients; (c) completely excised angioblastic, aggressive benign, and anaplastic tumors, 8 patients; (d) medically inoperable and basilar tumors where operation would involve considerable danger or permanent neurological damage, 44 patients. Most patients were irradiated with 6 to 9 MV photon beams. A three- to four-field technique with coned-down portals was used. Doses were calculated on the 95% isodose and were given 5 days a week for a median total dose of 52 Gy (1.80 Gy/fraction). RESULTS: Median follow-up from radiation therapy was 40 months. Acute tolerance was excellent, but there were six late delayed injuries. Tumor recurrences occurred in six cases. Six patients died from their tumor or RT complications, 19 from nontumoral reasons. Three, 5- and 10-year survival rates were 82, 71, and 40%, respectively. The most significant prognostic factor was age: 5-year survival rate was 86% for patients less than 65 years and 37% for patients more than 65. However, there were no differences in recurrence-free survival rates between patients younger than 65 and the oldest ones. Of 60 symptomatic patients with neurological deficits, 43 had neurological improvement (72%), beginning in some cases within 15 to 20 days after starting RT. CONCLUSION: These results reassess the role of fractionated RT in the treatment of meningiomas, and stress on its efficacy, especially on cranial nerves palsies, without severe toxicity in most cases.