Fractionated stereotactic conformal radiotherapy for large benign skull base meningiomas

<p>Abstract</p> <p>Purpose</p> <p>to assess the safety and efficacy of fractionated stereotactic radiotherapy (FSRT) for large skull base meningiomas.</p> <p>Methods and Materials</p> <p>Fifty-two patients with large skull base meningiomas aged 34-74 years (median age 56 years) were treated with FSRT between June 2004 and August 2009. All patients received FSRT for residual or progressive meningiomas more than 4 centimeters in greatest dimension. The median GTV was 35.4 cm³(range 24.1-94.9 cm³), and the median PTV was 47.6 cm³(range 33.5-142.7 cm³). Treatment volumes were achieved with 5-8 noncoplanar beams shaped using a micromultileaf collimator (MLC). Treatment was delivered in 30 daily fractions over 6 weeks to a total dose of 50 Gy using 6 MV photons. Outcome was assessed prospectively.</p> <p>Results</p> <p>At a median follow-up of 42 months (range 9-72 months) the 3-year and 5-year progression-free survival (PFS) rates were 96% and 93%, respectively, and survival was 100%. Three patients required further debulking surgery for progressive disease. Hypopituitarism was the most commonly reported late complication, with a new hormone pituitary deficit occurring in 10 (19%) of patients. Clinically significant late neurological toxicity was observed in 3 (5.5%) patients consisting of worsening of pre-existing cranial deficits.</p> <p>Conclusion</p> <p>FSRT as a high-precision technique of localized RT is suitable for the treatment of large skull base meningiomas. The local control is comparable to that reported following conventional external beam RT. Longer follow-up is required to assess long term efficacy and toxicity, particularly in terms of potential reduction of treatment-related late toxicity.</p

Stimulation of Subthalamic Nuclei Restores a Near Normal Planning Strategy in Parkinson’s Patients

<div><p>A fundamental function of the motor system is to gather key information from the environment in order to implement behavioral strategies appropriate to the context. Although several lines of evidence indicate that Parkinson’s disease affects the ability to modify behavior according to task requirements, it is currently unknown whether deep brain stimulation (DBS) of the subthalamic nucleus (STN) affects context-related planning. To explore this issue, we asked 12 Parkinson’s patients with bilateral STN DBS and 13 healthy subjects to execute similar arm reaching movements in two different paradigms: go-only and countermanding tasks. In the former task patients had to perform speeded reaching movements to a peripheral target. In contrast, in the countermanding task participants had to perform the same reaches unless an infrequent and unpredictable stop-signal was shown during the reaction time (RT) indicating that they should withhold the ongoing action. We compared the performance of Parkinson’s patients in different DBS conditions. We found that patients with both DBS-ON behaved similarly to healthy subjects, in that RTs of no-stop trial increased while movement times (MTs) decreased with respect to those of go-only-trials. However, when both DBS were off, both RTs and MTs were longer in no-stop trials than in go-only trials. These findings indicate that bilateral DBS of STN can partially restore the appropriate motor strategy according to the given cognitive contexts.</p></div

Exocrine pancreatic insufficiency in adults: A shared position statement of the Italian association for the study of the pancreas

This is a medical position statement developed by the Exocrine Pancreatic Insufficiency collaborative group which is a part of the Italian Association for the Study of the Pancreas (AISP). We covered the main diseases associated with exocrine pancreatic insufficiency (EPI) which are of common interest to internists/gastroenterologists, oncologists and surgeons, fully aware that EPI may also occur together with many other diseases, but less frequently. A preliminary manuscript based on an extended literature search (Medline/PubMed, Cochrane Library and Google Scholar) of published reports was prepared, and key recommendations were proposed. The evidence was discussed at a dedicated meeting in Bologna during the National Meeting of the Association in October 2012. Each of the proposed recommendations and algorithms was discussed and an initial consensus was reached. The final draft of the manuscript was then sent to the AISP Council for approval and/or modification. All concerned parties approved the final version of the manuscript in June 2013

For each patient the position of active electrodes, amplitude, pulse and frequency of stimulation are shown separately for the right (R) and the left (L) hemisphere.

<p>Active electrodes indicated by a star have a bipolar configuration, with cathode (+) and anode (−); all other electrodes have a monopolar configuration. Abbreviations: SNr, Substantia Nigra pars reticulata; STNd, dorsal subthalamic nucleus; STNv, ventral subthalamic nucleus; Zi, zona incerta.</p

Results of the two-way ANOVAs on the RTs and MTs with group (control subjects, CTRL, versus PD patients in each DBS state) and trial type (go-only versus no-stop trials) as factors.

<p><i>F-</i>values, degrees of freedom (df) and significance value (Sig.) are reported for both main factors and interactions.</p

Clinical data of PD patients with bilateral implantation of DBS participating in the experiment.

<p>For each patient sex, age, years since diagnosis, years since the implantation of the second DBS electrode, Hoehn & Yahr scores (indicating the relative level of disability due to PD disease) in the “ON” phase, L-dopa equivalents/kg, side of onset of symptoms and the Unified Parkinson’s Disease Rating Scale part 3 (UPDRS3, indicating the patient’s motor symptoms) in each DBS condition and without medications, rated by a neurologist (NM) before starting the task, are given.</p

Summary of behavioral measurements for Parkinson’s patients in each DBS condition and for healthy controls in no-stop trials and in go-only trials.

<p>In all cases the average values ±SEM are reported. Accuracy was computed as the percentage of correct responses with respect to the sum of correct plus incorrect responses. Incorrect trials were either those in which subjects touched the target outside the tolerance window or those whose RTs exceeded the upper RT (overreach trials). The percentage of overreach trials was computed with respect to the sum of correct plus incorrect responses.</p

Temporal sequence of the visual displays for no-stop and stop trials in the countermanding reaching task.

<p>Temporal sequence of the visual displays for each task. All trials began with the appearance of a central stimulus. The subject had to reach and hold it with the index of the right (dominant) hand for a variable period of 500–800 ms. In the go-only task and in the no-stop trials of the countermanding task, the central stimulus disappeared and, simultaneously, a target appeared to the right, acting as a go-signal. Subjects were instructed to perform a speeded reaching movement toward the peripheral target. Randomly, in the 33% of trials of the countermanding task (stop trials), the central stimulus (stop signal) reappeared at variable delays after the go signal (SSDs), indicating that the subject should cancel the pending movement. If subjects executed the reaching movement the trial was scored as a stop-failure trial (not shown). The dotted circle (which was not visible to the subjects) indicates the size of the tolerance window for the touches (3.5 cm diameter).</p

Results of the two-way ANOVAs on the accuracy with group (control subjects, CTRL, versus PD patients in each DBS state) and trial type (go-only versus no-stop trials) as factors.

<p><i>F-</i>values, degrees of freedom (df) and significance value (Sig.) are reported for both main factors and interactions.</p

Reaction times (RTs) and movement times (MTs) for reaching movements across the populations of Parkinson’s patients and control subjects.

<p>A. Cumulative distribution of RTs (solid lines) and MTs (dotted lines) of healthy subjects (n = 13) for go-only (grey) and no-stop trials (black). B. Cumulative distributions of RTs (solid lines) and MTs (dotted lines) of DBS patients (n = 12) in DBS-ON and DBF-OFF conditions for both go-only (grey lines) and no-stop (black lines) trials. For each condition the p-value of Kolmogorov-Smirnov test is given, both for RTs and for MTs. C. Histograms of average RTs of no-stop and go-only trials in DBS-ON and DBF-OFF conditions. Bars represent the standard error of the mean. D. Histograms of average MTs of no-stop and go-only trials in each DBS-ON and DBF-OFF conditions. Bars represent the standard error of the mean.</p