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Tracy Soanes, Anna Hampshire, Paul Vaughan, Christopher Brownett, Jeremy Rowe, Matthias Radatz, Andras Kemeny and Lee Walton

. In addition there was a slight reduction of available stereotactic space when the APS was used, especially in the x axis. In this paper we describe the methods adopted within our center to commission this new equipment and describe the routine quality assurance checks that were established to assess its ongoing performance. Materials and Methods It was believed to be important to verify independently the following aspects of the APS unit during our commissioning: 1) that the APS operates reliably; 2) that the APS achieves the specified target positions at

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Javad Rahimian, Joseph C. Chen, Ajay A. Rao, Michael R. Girvigian, Michael J. Miller and Hugh E. Greathouse

radiosurgery. 4 To deliver a precise target dose by means of stereotactic radiosurgery, comprehensive quality assurance is essential. The total spatial error is accumulated through the processes of target localization using medical imaging, image fusion, dose planning, mechanical errors, patient positioning, intraoperative movements, target positioning overlays, and radiation dose delivery system. There are numerous publications in which the spatial accuracy and quality assurance of the gamma knife unit7 and LINAC stereotactic radiosurgery systems have been assessed. 3, 9

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Roman Rodionov, Aidan O’Keeffe, Mark Nowell, Michele Rizzi, Vejay N. Vakharia, Victoria Wykes, Sofia H. Eriksson, Anna Miserocchi, Andrew W. McEvoy, Sebastien Ourselin and John S. Duncan

. Interpretations of reports of implantation accuracy are limited because 1) the published metrics do not separate the accuracy of implanting the guiding bolt from the accuracy of the electrode insertion, and 2) different surgical centers use electrode-related hardware (guiding bolt, stylet, electrode) that have different geometric and physical characteristics, which affect the observed deviation of the inserted electrode from the axis of the guiding bolt. We developed a quality assurance (QA) process to monitor and improve our frameless implantation techniques, 7 and

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Andreas Mack, Robert Wolff, Dirk Weltz, Günther Mack, Anja Jess, Bernd Heck, Heinz Czempiel, Hans-Jürg Kreiner, Berndt Wowra, Heinz Böttcher and Volker Seiffert

gamma knife stereotactic radiosurgery for treating intermediate intracranial lesions. Int J Radiat Oncol Biol Phys 45 : 1325 – 1330 , 1999 Ma L, Xia P, Verhey LJ, et al: A dosimetric comparison of fanbeam intensity modulated radiotherapy with gamma knife stereotactic radiosurgery for treating intermediate intracranial lesions. Int J Radiat Oncol Biol Phys 45: 1325–1330, 1999 7. Mack A , Czempiel H , Kreiner HJ , et al : Quality assurance in stereotactic space. A system test for verifying the accuracy of aim in

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Andreas Mack, Robert Wolff, Stefan Scheib, Marcus Rieker, Dirk Weltz, G. Mack, Hans-Jürg Kreiner, Ulrich Pilatus, Friedhelm E. Zanella, Heinz D. Böttcher and Volker Seifert

modification of the parameters, distortions due to chemical shift and susceptibility effects are analyzed with a head phantom leading to the final optimized parameters Fig. 2. Photograph of phantoms used for quality assurance in stereotactic radiosurgery. a: Precise cylinder phantom containing a grid of 145 rods. b: Known target phantom consisting of slabs with 21 embedded known targets (cross hairs with glass vials). c: Head phantom consisting of spheres and shells and a cubic clearance for inserts (slabs of different materials, detectors of all kinds

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Josef Novotný Jr., Josef Novotný, Václav Spĕvác˘ek, Pavel Dvor˘ák, Tomás˘ Cechák, Roman Lis˘c˘ák, Gustav Broz˘ek, Jaroslav Tintĕra and Josef Vymazal

stereotactic radiation techniques. Magnet Res Imag 18: 343–349, 2000 7. Flickinger JC , Lunsford D , Kondziolka D , et al : Potential human error in setting stereotactic coordinates for radiosurgery: implications for quality assurance. Int J Radiat Oncol Biol Phys 27 : 397 – 401 , 1993 Flickinger JC, Lunsford D, Kondziolka D, et al: Potential human error in setting stereotactic coordinates for radiosurgery: implications for quality assurance. Int J Radiat Oncol Biol Phys 27: 397–401, 1993 8. Ibbott GS

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The yin and yang of neurological surgery

The 1993 AANS presidential address

Merwyn Bagan

. Some may not be so obvious. Obvious or not, the changes have resulted in what I would call a dysfunctional state. It is what occurs when we are overcome by change, by decisions, and sometimes fail to adapt. Alvin Toffler described this in Future Shock , 5 when he analyzed our society. For neurological surgery the factors causing this problem are: 1) technological advances; 2) hospital-physician relationships; 3) medical liability; 4) quality assurance reviews; and 5) physician reimbursement. The field of neurological surgery is relatively young. It is only within

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Anil K. Roy, Jason Chu, Caroline Bozeman, Samir Sarda, Michael Sawvel and Joshua J. Chern


Various indicators are used to evaluate the quality of care delivered by surgical services, one of which is early reoperation rate. The indications and rate of reoperations within a 48-hour time period have not been previously reported for pediatric neurosurgery.


Between May 1, 2009, and December 30, 2014, 7942 surgeries were performed by the pediatric neurosurgery service in the operating rooms at a single institution. Demographic, socioeconomic, and clinical characteristics associated with each of the operations were prospectively collected. The procedures were grouped into 31 categories based on the nature of the procedure and underlying diseases. Reoperations within 48 hours at the conclusion of the index surgery were reviewed to determine whether the reoperation was planned or unplanned. Multivariate logistic regression was employed to analyze risk factors associated with unplanned reoperations.


Cerebrospinal fluid shunt–and hydrocephalus-related surgeries accounted for 3245 (40.8%) of the 7942 procedures. Spinal procedures, craniotomy for tumor resections, craniotomy for traumatic injury, and craniofacial reconstructions accounted for an additional 8.7%, 6.8%, 4.5%, and 4.5% of surgical volume. There were 221 reoperations within 48 hours of the index surgery, yielding an overall incidence of 2.78%; 159 of the reoperation were unplanned. Of these 159 unplanned reoperations, 121 followed index operations involving shunt manipulations. Using unplanned reoperations as the dependent variable (n = 159), index operations with a starting time after 3 pm and admission through the emergency department (ED) were associated with a two- to threefold increase in the likelihood of reoperations (after-hour surgery, odds ratio [OR] 2.01 [95% CI 1.43–2.83, p < 0.001]; ED admission, OR 1.97 (95% CI 1.32–2.96, p < 0.05]).


Approximately 25% of the reoperations within 48 hours of a pediatric neurosurgical procedure were planned. When reoperations were unplanned, contributing factors could be both surgeon related and system related. Further study is required to determine the extent to which these reoperations are preventable. The utility of unplanned reoperation as a quality indicator is dependent on proper definition, analysis, and calculation.

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Samir Sarda, Markus Bookland, Jason Chu, Mohammadali M. Shoja, Matthew P. Miller, Stephen B. Reisner, Philip H. Yun and Joshua J. Chern


Hospital readmission after discharge is a commonly used quality measure. In a previous study, the authors had documented the rate of readmission and reoperation after pediatric CSF shunt surgery. This study documents the rate of readmission and reoperation after pediatric neurosurgical procedures excluding those related to CSF shunts.


Between May 1, 2009, and April 30, 2013, 3098 non-shunt surgeries during 2924 index admissions were performed at a single institution. Demographic, socioeconomic, and clinical characteristics were prospectively collected in the administrative, business, and clinical databases. Clinical events within the 30 days following discharge were reviewed and analyzed. The following events of interest were analyzed for risk factor associations using multivariate logistic regression: return to the emergency department (ED), all-cause readmission, readmission to the neurosurgical service, and reoperation.


The number of all-cause readmissions within 30 days of discharge was 304 (10.4%, 304/2924). Admission sources consisted of the ED (n = 173), hospital transfers (n = 47), and others (n = 84). One hundred eighty of the 304 readmissions were associated with an operation, but only 153 were performed by the neurosurgical service (reoperation rate = 5.2%). These procedures included wound revisions (n = 30) and first-time shunt insertions (n = 35). The remaining 124 readmissions were nonsurgical, and only 54 were admitted to the neurosurgical service for issues related to the index non-shunt surgery. Thus, the rate of related readmission was 7.1% ([153 + 54]/2924). A longer length of stay and admission to the neonatal intensive care unit during the index admission were associated with an increased likelihood of return to the ED and readmission. Certain procedures, such as baclofen pump insertion and intracranial pressure monitor placement, were also found to be associated with adverse clinical events in the 30-day period. Lastly, patients were more likely to a undergo reoperation if the index procedure had started after 3 p.m.


The all-cause readmission rate within 30 days of discharge after a pediatric neurosurgical procedure was 10.4%, and the rate of related readmission was 7.1%. Whether these readmissions are preventable and to what extent they are preventable requires further study.

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Peter C. Gerszten, Josef Novotny Jr., Mubina Quader, Valerie C. Dewald and John C. Flickinger

the radiation is directed precisely to the target. The study cohort consisted of 47 men and 61 women ranging in age from 23 to 87 years (mean age 56 years). These patients' cases were prospectively evaluated as part of a quality assurance program for the implementation of this new technology at our institution. Table 1 lists the characteristics of the treatment group. With respect to location, there were 28 cervical, 69 thoracic, 48 lumbar, and 21 sacral lesions. The most common primary histological types for the metastatic lesions (136 cases total) included 33