Cascades of Parametric Instabilities in the Tokamak Plasma Edge during Electron Cyclotron Resonance Heating.

We report observations of nonlinear two-plasmon decay instabilities (TPDIs) of a high-power microwave beam, a process similar to half-harmonic generation in optics, during electron cyclotron resonance heating in a tokamak. TPDIs are found to occur regularly in the plasma edge due to wave trapping in density fluctuations for various confinement modes, and the frequencies of both observed daughter waves agree with modeling. Emissions from a cascade of subsequent decays, which indicate a generation of ion Bernstein waves, are correlated with fast-ion generation. This emphasizes the limitations of standard linear microwave propagation models and possibly paves the way for novel microwave applications in plasmas.

Dysphagia in neurological diseases: a literature review.

Dysphagia is defined as an impairment of this complex and integrated sensorimotor system. It is estimated that 400,000 to 800,000 individuals worldwide develop neurogenic dysphagia per year. Neurogenic dysphagia is typically occurring in patients with neurological disease of different etiologies. A correct and early diagnosis and an appropriate management of dysphagia could be useful for improving patient's quality of life and may help to prevent or delay death. In the present review, we discuss thoroughly the anatomy and physiology of swallowing and also the pathophysiological mechanisms involved in impaired swallowing, as well as the diagnosis, management, and potential treatments of neurogenic dysphagia. Assessment of neurogenic dysphagia includes medical history, physical exam, and instrumental examinations (fiberoptic endoscopic evaluation of swallowing, videofluoroscopic swallowing study, electromyography). Pharmacological treatment of these problems includes oral anticholinergic drugs. Surgical myotomy of the cricopharyngeal muscle showed an important improvement of oropharyngeal dysphagia associated to upper esophageal sphincter hyperactivity. Chemical myotomy of the upper esophageal sphincter by local injections of botulinum toxin type A into the cricopharyngeal muscle has been proposed as an alternative less invasive and less unsafe than surgical myotomy.

Olfactory and rhinological evaluations in SARS-CoV-2 patients complaining of olfactory loss.

Since December 2019, a novel coronavirus SARS-CoV-2 (Covid-19) outbreak emerged in China and spread rapidly in several countries. As of April 5, 2020, 1.218.474 cases were confirmed with 65.884 deaths worldwide (1). The clinical manifestations of Covid-19 range from asymptomatic carrier status to severe pneumonia. In a study of 7,736 Covid-19 patients in China, of all the clinical symptoms, hyposmia was not reported in any patient(2). Anyway, it is now clear that olfactory dysfunction may also be present in these patients(3) as the only or prevalent manifestation(4).

The role of peak nasal and oral inspiratory flow in the evaluation of patients with sleep-related breathing disorders.

BACKGROUND: Sleep-related breathing disorders (SRBD) are common reported disorders in the adult population. The nose plays an important role in the development of SRBD; thus, the measurement of nasal respiratory function remains an important step in the management of these patients. Peak nasal inspiratory flow (PNIF) is a useful tool to assess nasal airflow and it has recently been studied together with peak oral inspiratory flow (POIF). OBJECTIVE: The aim of the present study was to evaluate the role of PNIF and POIF in an adult population of patients affected by SRBD. METHODOLOGY: Seventy consecutive adult patients with SRBD were included in the present study. All patients were evaluated with home-based sleep studies (type III), PNIF, POIF, SNOT-22 questionnaire, Epworth Sleepiness Scale test and VAS for nasal obstruction. RESULTS: Although PNIF and POIF showed to correlate with each other, no correlations were observed between Apnea Hypopnea index (AHI) and PNIF, POIF or NPI (PNIF/POIF). A further analysis showed a marginal correlation between SNOT- 22 and AHI and between SNOT-22 and POIF. Furthermore, in a multivariate analysis, also POIF marginally correlated with some of the sleep- related SNOT-22 items. CONCLUSIONS: In the present study neither PNIF nor POIF were found to be associated with OSAS severity. However, POIF values correlated better than PNIF with sleep related symptoms suggesting that POIF could be a more useful parameter for upper airway assessment in patients with SRBD. In addition, a correlation between OSAS severity, in terms of AHI, and SNOT-22 total score has been reported.

Development of the 174 GHz collective Thomson scattering diagnostics at Wendelstein 7-X.

In this paper, we present the design and commissioning results of the upgraded collective Thomson scattering diagnostic at the Wendelstein 7-X stellarator. The diagnostic has a new radiometer designed to operate between the second and third harmonics of the electron cyclotron emission from the plasma at 171-177 GHz, where the emission background has a minimum and is of order 10-100 eV. It allows us to receive the scattered electromagnetic field with a significantly improved signal-to-noise ratio and extends the set of possible scattering geometries compared to the case of the original instrument operated at 140 GHz. The elements of the diagnostic are a narrowband notch filter and a frequency stabilized probing gyrotron that will allow measuring scattered radiation spectra very close to the probing frequency. Here, we characterize the microwave components applied to the radiometer and demonstrate the performance of the complete system that was achieved during the latest experimental campaign, OP2.1.

Case report of cholesteatoma recurrence with Bezold's abscess presenting as a deep neck infection.

Cervical masses are a common clinical finding, but differential diagnosis is often challenging. Acute neck swellings are often due to deep cervical space infections that have originated at oral or oropharyngeal sites. Deep neck infections originating elsewhere are not rare; however, they are difficult to diagnose, and their origins remain obscure in 20% of cases. Neck swellings that originate in the middle ear are very rare, with only a few reported in the scientific literature. Here we report an atypical case of Bezold's abscess caused by the recurrence of a middle ear cholesteatoma. In patients with neck swelling and a history of primary cholesteatoma of the middle ear, otolaryngologists should consider regional recurrence of disease a possibility even several years after the primary surgery.

Tracking target position variability using intraprostatic fiducial markers and electronic portal imaging in prostate cancer radiotherapy.

PURPOSE: Modern radiotherapy has achieved substantial improvement in tumour control and toxicity rates by escalating the total dose to the target volume while sparing surrounding normal tissues. It has therefore become necessary to precisely track tumour position in order to minimise geometrical uncertainties due to setup errors and organ motion. We conducted this prospective evaluation of prostate cancer patients treated with image-guided conformal radiation therapy at our institution. We implanted three fiducial markers (gold seeds) within the prostatic gland in order to quantify daily target displacements and to generate specific margins around the clinical target volume (CTV) to create an appropriate planned target volume (PTV). MATERIALS AND METHODS: Between April and December 2009, ten patients affected with localised prostate cancer were transrectally implanted with three radio-opaque markers. Each patient underwent a computed tomography (CT) scan for planning purposes following proper bladder and rectum preparation. During treatment two orthogonal images were acquired daily and compared with previously generated digitally reconstructed radiographs. After manual localisation, comparison between the position of the gold seeds on the portal and reference images was carried out, and a set of extrapolated lateral-lateral (LL), anterior-posterior (AP) and cranial-caudal (CC) shift corrections was calculated and recorded. Couch corrections were applied with a threshold of 3 mm displacement. RESULTS: Systematic and random errors for each direction were calculated either as measured according to displacement of the gold seeds prior to any couch movement and after couch position correction according to the radio-opaque markers. For skin marks, mean systematic and random errors were 0.12+2.94 mm for LL, 1.04+3.37 mm for AP, -1.14+2.71 mm for CC, whereas for seed markers, mean and systematic errors were 0.6+1.5 mm for LL, 0.51+2.45 mm for AP and -0.25+2.51 mm for CC. A scatter plot generated on all measurements after couch repositioning according to gold-seed displacement suggested a confidence range of shift distributions within 5 mm for LL, 8 mm for CC, and 7 mm for AP. The total systematic and random components were then used to calculate proper PTV in patients receiving conventional treatment (7 mm for LL and 9 mm for both AP and CC). CONCLUSIONS: Prostate positional variability during a course of radiation treatment is strongly influenced by setup and organ motion. Organ tracking through fiducial markers and electronic portal imaging is able to reduce the spread of displacements, significantly contributing to improve the ballistic precision of radiation delivery.

Botulinum toxin improves dysphagia associated with multiple sclerosis.

OBJECTIVE: To evaluate the efficacy of botulinum neurotoxin type A (BoNT/A) for severe oro-pharyngeal dysphagia associated with multiple sclerosis (MS). PATIENTS AND METHODS: BoNT/A was injected percutaneously into the hyperactive cricopharyngeal muscle of 14 dysphagic MS patients under electromyographic control. Patients were evaluated by videofluoroscopic and electromyographic examinations and by the Penetration/Aspiration Scale (PAS), at week 1, 4, 12, 16, 18, and 24 after BoNT/A injection. RESULTS: All patients showed a significant improvement in all the swallowing outcome measures. CONCLUSION: No specific treatment for oro-pharyngeal dysphagia related to MS has been described to date. Our preliminary findings suggest a potential benefit from BoNT/A treatment in MS patients with dysphagia associated with upper esophageal sphincter hyperactivity.

The upgraded TOMAS device: A toroidal plasma facility for wall conditioning, plasma production, and plasma-surface interaction studies.

The Toroidal Magnetized System device has been significantly upgraded to enable development of various wall conditioning techniques, including methods based on ion and electron cyclotron (IC/EC) range of frequency plasmas, and to complement plasma-wall interaction research in tokamaks and stellarators. The toroidal magnetic field generated by 16 coils can reach its maximum of 125 mT on the toroidal axis. The EC system is operated at 2.45 GHz with up to 6 kW forward power. The IC system can couple up to 6 kW in the frequency range of 10 MHz-50 MHz. The direct current glow discharge system is based on a graphite anode with a maximum voltage of 1.5 kV and a current of 6 A. A load-lock system with a vertical manipulator allows exposure of material samples. A number of diagnostics have been installed: single- and triple-pin Langmuir probes for radial plasma profiles, a time-of-flight neutral particle analyzer capable of detecting neutrals in the energy range of 10 eV-1000 eV, and a quadrupole mass spectrometer and video systems for plasma imaging. The majority of systems and diagnostics are controlled by the Siemens SIMATIC S7 system, which also provides safety interlocks.

Dosimetric predictors of acute hematologic toxicity during concurrent intensity-modulated radiotherapy and chemotherapy for anal cancer.

PURPOSE: This study aimed at investigating whether the irradiated volume of pelvic bone marrow (PBM) and specific subsites may predict the occurrence of acute hematologic toxicity (HT) in anal cancer patients undergoing concurrent chemo-radiation. METHODS: 50 patients, submitted to IMRT and concurrent chemotherapy, were analyzed. Several bony structures were defined on planning-CT: PBM and lumbar-sacral (LSBM), lower pelvis (LPBM) and iliac (IBM) bone marrow. On dose-volume histograms, dosimetric parameters were taken. Endpoints included white blood-cell-count (WBC), absolute-neutrophil-count (ANC), hemoglobin (Hb) and platelet nadirs and acute hematologic toxicity (HT) according to RTOG scoring scale. Generalized linear modeling was used to find correlations between dosimetric variables and blood cell nadirs, while logistic regression analysis was used to test correlation with ≥G3 HT. Receiver Operating Characteristic (ROC) curve analysis was used to evaluate the optimal cut-off points for predictive dosimetric variables with the Youden method. RESULTS: Maximum detected acute HT comprised 38 % of ≥G3 leukopenia and 32 % of ≥G3 neutropenia. Grade 2 anemia was observed in 4 % of patients and ≥G3 thrombocytopenia in 10 %. On multivariate analysis a higher PBM-V 20 was associated with lower WBC nadir. Increased LSBM-V 40 was correlated with a higher likelihood to develop ≥G3 HT. A cut-off point at 41 % for LSBM-V 40 was found. Patients with LSBM-V 40 ≥41 % were more likely to develop ≥G3 HT (55.3 vs. 32.4 %; p < 0.01). CONCLUSIONS: Increased low-dose to pelvic bony structures significantly predicted for WBC decrease. Medium-high dose to specific osseous subsites was associated with a higher probability of HT. LSBM-V 40 was a strong predictor of ≥G3 HT. A threshold at 41 % for LSBM-V 40 could be used to limit HT.

Botulinum toxin therapy: functional silencing of salivary disorders.

Botulinum toxin (BTX) is a neurotoxic protein produced by Clostridium botulinum, an anaerobic bacterium. BTX therapy is a safe and effective treatment when used for functional silencing of the salivary glands in disorders such as sialoceles and salivary fistulae that may have a post-traumatic or post-operative origin. BTX injections can be considered in sialoceles and salivary fistulae after the failure of or together with conservative treatments (e.g. antibiotics, pressure dressings, or serial aspirations). BTX treatment has a promising role in chronic sialadenitis. BTX therapy is highly successful in the treatment of gustatory sweating (Frey's syndrome), and could be considered the gold standard treatment for this neurological disorder.

Treatment of complications of parotid gland surgery.

Although several reports in the literature have documented the surgical technique, and the oncological outcome achieved with parotidectomy, only a few articles have described the complications of parotid gland surgery and their management. Several complications have been reported in parotid surgery. We re-classified the complications of parotidectomy in intra-operative and post-operative (early and late). The commonest complications after parotidectomy are temporary or permanent facial palsy and Frey's syndrome.

Outcome predictors of treatment effectiveness for fungal malignant external otitis: a systematic review.

The aim of this review is to summarise literature data on clinical aspects and traditional management of fungal malignant external otitis (FMEO), and to identify potential predictive factors of positive treatment outcome. Articles were initially selected based on their titles or abstracts. Full articles were then retrieved and further scrutinised according to predetermined criteria. Reference lists of selected articles were searched for any missed publications. The selected articles were methodologically evaluated. Of an initial 143 references, 14 were selected that focalised on the management of FMEO. The majority of studies demonstrated a correlation between treatment effectiveness, assessed as symptom resolution, and clinical and management variables: abstention from surgical debridement, absence of facial palsy, Aspergillus spp. as causative pathogen and absence of imaging findings at diagnosis and follow-up. The effectiveness of FMEO treatment depends on the assessment of cranial nerve state, the causative pathogen and imaging findings. Above all, absence of facial nerve palsy, Aspergillus spp. and absence of radiological signs at diagnosis and during follow-up correlate with symptom resolution. The fact that conservative treatment may be associated with a better outcome than surgical debridement could purely reflect that patients with more aggressive and advanced illness required debridement, whereas milder disease was treated conservatively. Thus, caution should be advised in the interpretation of data due to the need for further trials on the topic.

Improvement of diabetic autonomic gustatory sweating by botulinum toxin type A.

Fourteen diabetic subjects with gustatory sweating were treated by intracutaneous injections of botulinum toxin type A into the affected facial skin areas. In all subjects, sweating (measured by Minor starch iodine test) ceased within 4 days, with the maximal follow-up time lasting 24 weeks. This therapeutic approach, which could be used to reduce the severity of diabetic gustatory sweating, appears to be long lasting, adverse effect free, and minimally invasive.

Technique, dosimetry and results of total body irradiation in preparation to ABMT in Torino.

Twenty-five patients with haematologic malignancies received total body irradiation (TBI) as part of their conditioning regimen prior to autologous bone marrow transplantation (ABMT). TBI was delivered with an 18 MeV photon beam through AP-PA ports; the total dose was 13.2 Gy/8 fractions over 4 days; shields were used to limit the total dose to the lung to 8-10 Gy. Five relapses were observed; among 14 patients with ALL or advanced lymphoblastic lymphoma, 10 patients are currently alive and free of disease. Acute and late morbidity of TBI were low.

Results of hypofractionated stereotactic re-irradiation on 13 locally recurrent nasopharyngeal carcinomas.

Thirteen patients with locally recurrent, previously-irradiated nasopharyngeal carcinoma were treated with linac-based hypofractionated stereotactic radiotherapy (24 Gy in two or four fractions). One- and 3-year overall survival were 54 and 31%. Three patients were free of disease at 30, 34 and 65 months. No severe acute or late complications were seen.

Can Ki67 immunostaining predict response to radiotherapy in oral squamous cell carcinoma?

AIMS: To determine whether immunohistochemical evaluation of the abatement of proliferating cells after a first course of radiotherapy could predict the final response to treatment in oral squamous cell carcinoma (SCC). METHODS: Frozen sections from 31 cases of histologically confirmed oral SCC were stained with the monoclonal antibody Ki67 at diagnosis and after 10 Gy of radiotherapy. The percentage difference of Ki67 positive cells among the biopsy specimens taken at the beginning and after 10 Gy was correlated with the clinical response obtained at the end of the treatment and its significance determined. RESULTS: The percentage of Ki67 positive cells at diagnosis had no significant correlation with the final therapeutic result of radiotherapy. By contrast, the 32% difference of proliferating cells after 10 Gy of radiotherapy significantly differentiated responders from non-responders (p < 0.05). Furthermore, the abatement of the growth fraction after 10 Gy of radiotherapy was significantly correlated with the complete response (p < 0.01). CONCLUSIONS: These data show that the immunohistochemical evaluation of the abatement of Ki67 positive cells after 10 Gy of radiotherapy provides an independent variable of responsiveness to radiotherapy, allowing a reliable prediction of the final therapeutic result to be made.

High prognostic impact of growth fraction parameters in advanced stage laryngeal squamous cell carcinoma.

One hundred and two cases of laryngeal squamous cell carcinoma, all treated in the same center with total or supraglottic laryngectomy, bilateral neck dissection and postoperative radiotherapy, were investigated with both Ki67 and MIB-1 monoclonal antibodies. The aim was to determine the prognostic impact of growth fraction markers in a homogeneous series of patients. All samples were stained with Ki67 monoclonal antibody on frozen sections, and with MIB-1 monoclonal antibody on paraffin sections, using the ABC immunoperoxidase method. The percentage of positive cells was compared in each case with the overall and disease-free survival, pathologic stage and histologic grading. The values obtained from Ki67 and MIB-1 counts were similar and highly correlated (r=0.90). Two groups of cases with low and high proliferation rate (59 and 43 respectively) were obtained by splitting up the whole series, on the basis of the median value; 84. 6% of the patients with high proliferation relapsed and/or died due to the tumor within two years from diagnosis whereas, at time of writing, 94% of the patients with low proliferation are alive and well (p<0.00001). No relation was found between growth fraction and histologic grading, pathologic stage (pT and pN) and site of the tumor. Only lymph node involvement was correlated with disease-free survival. Our results indicate that Ki67/MIB-1 index represents an independent variable to determine long-term prognosis in laryngeal squamous cell carcinomas. We recommend its use in diagnostic protocols, to distinguish high risk subsets of patients who might benefit from more aggressive treatments.

Angiogenesis: prognostic significance in laryngeal cancer.

The aim of this study was to evaluate the role of angiogenesis in the progression of laryngeal squamous cell carcinoma (LSCC). We correlated disease-free survival with microvessel count (MC) in the hot spot areas of 97 randomly selected caucasian males with LSCC followed for 60 to 90 months after surgery with or without radiotherapy. The results obtained indicate that: a) MC higher than 130 microvessels/mm2 is a cut-off value that distinguished patients who relapsed during the follow up period; b) multivariated analysis indicates that MC (p < 0.00001) is an independent predictor of disease free-survival; c) multivariated analysis selectively done on cases with relapse demonstrates that MC correlates with the presence of metastasis (or/and M) with local relapse (T). We suggest that MC is useful in the assessment of prognosis in LSCC and probably will permit selection of patients that could benefit from anti-angiogenic therapy associated with chemotherapy and/or radiotherapy.

Dosimetry of 169 Yb seed model X1267.

Unlike previous brachytherapy sources a number of published studies have been addressed to the dosimetry of 169 Yb seeds, manufactured in several prototypes, before widespread clinical use has been made. Discrepancies seen in the dosimetry obtained for ytterbium seed prototypes appear to be related to inconsistency and non-reproducibility in the vendor's calibration procedure to determine contained activity. Av. The comparison of 169 Yb seed dosimetries demonstrates a need for more accurate implementation of calibration procedures to determine the air kerma rate for the definitive 169 Yb seed design. This paper reports an experimental procedure to determine the reference air kerma rate, Kr (mu Gy h-1), defined as the kerma rate at 1 m along the source transverse axis in free space for the new 169 Yb seed, model X1267. A mean value of the ratio Kr/Av = 1.53 mu Gy h-1 mCi-1 was obtained from determining the Kr value of eleven seeds. Since this ratio is only 3% less than the air kerma rate constant for the 169 Yb point source, (gamma delta)k = 1.58 mu Gy h-1 m2 mCi-1, this means that the Av is closer to an apparent activity than a contained activity, Ac. A Monte Carlo simulation to determine the ratio between reference air kerma rate and the contained activity gave Kr/Ac = 1.33 mu Gy h-1 mCi-1. For the dose rate constant in water we obtained DKr (1, pi/2) = 1.20 +/- 0.05 cGy h-1 (mu Gy h-1)-1, using calibrated thermoluminescent dosimeters (TLDs) and DKr (1, pi/2) = 1.21 +/- 0.03 cGy h-1 (mu Gy h-1)-1 by Monte Carlo simulation. TLDs were used both to determine the radial dose distribution along the seed transverse axis and to calibrate GAFChromic films to obtain the two-dimensional dose distribution around the seed.