Search

Background: Stereotactic radiosurgery (SRS) alone is an increasingly accepted treatment for brain metastases, but it requires adherence to frequently scheduled follow-up neuroimaging because of the risk of distant brain metastasis. The effect of disparities in access to follow-up care on outcomes after SRS alone is unknown.Methods: This retrospective study included 153 brain metastasis patients treated consecutively with SRS alone from 2010 through 2016 at an academic medical center and a safety-net hospital (SNH) located in Los Angeles, California. Outcomes included neurologic symptoms, hospitalization, steroid use and dependency, salvage SRS, salvage whole-brain radiotherapy, salvage neurosurgery, and overall survival.Results: Ninety-three of the 153 patients were private hospital (PH) patients, and 60 were SNH patients. The median follow-up time was 7.7 months. SNH patients received fewer follow-up neuroimaging studies (1.5 vs 3; P = .008). In a multivariate analysis, the SNH setting was a significant risk factor for salvage neurosurgery (hazard ratio [HR], 13.65; P < .001), neurologic symptoms (HR, 3.74; P = .002), and hospitalization due to brain metastases (HR, 6.25; P < .001). More clinical visits were protective against hospitalizations due to brain metastases (HR, 0.75; P = .002), whereas more neuroimaging studies were protective against death (HR, 0.65; P < .001).Conclusions: SNH patients with brain metastases treated with SRS alone had fewer follow-up neuroimaging studies and were at higher risk for neurologic symptoms, hospitalization for brain metastases, and salvage neurosurgery in comparison with PH patients. Clinicians should consider the practice setting and patient access to follow-up care when they are deciding on the optimal strategy for the treatment of brain metastases. Cancer 2018;124:167-75. © 2017 American Cancer Society. [ABSTRACT FROM AUTHOR]

Trigeminal Neuralgia (TN) is a rare, non-malignant central nervous system condition affecting one or more branches of the fifth cranial nerve, the trigeminal nerve. The occurrence of TN is extremely rare. TN is primarily unilateral; however, there are rare cases of bilateral TN. Pain is the predominant presenting symptom, consisting of sudden, stabbing, burning, aching sensations which can become debilitating. TN is a progressive condition initially presenting with periodic attacks lasting for brief periods followed by asymptomatic periods. As TN progresses the gap between occurrences may become shorter, and the pain intensifies. Unfortunately, pain medications only provide minimal relief, if any. Stereotactic radiosurgery is an effective treatment modality for TN; however, a cisternogram is necessary for planning treatment. The CT-cisternogram examines the cisternal portion of the trigeminal nerve, which is the treatment target. Radiation oncology is seeing an increase in TN cases. Stereotactic radiosurgery offers pain relief with minimal side effects for these patients. It was determined that nurse and patient education needed to be reviewed in order to provide excellent nursing care to this increasing patient population. One radiation oncology nurse, with a background in neurology, conducted informal educational sessions for the newer nurses unfamiliar with TN. Once this education was complete, a standardized way of educating the patient was discussed. Educational sessions with the patient include the process of obtaining a CT-cisternogram to be used for treatment planning; the immobilization device the patient would wear during treatment, and the radiation treatment itself. Pain assessments occurred during each patient appointment utilizing the 0-10 Numerical Pain Rating Scale. This assessment included pain level, location, type, interventions performed and result, assessment of known triggers, and a neurological exam. Data reviewed from 2016-2021, demonstrated an increasing number of these patients receiving stereotactic radio surgery for TN, one presenting with bilateral TN. Prior to initiation of treatment, pain scores averaged 8/10. One-month post-treatment pain scores averaged 1/10, and patients described shorter episodes with longer intervals between pain occurrences. Radiation oncology nurses are integral in the care of patients with trigeminal neuralgia. Patients rely on nursing expertise to guide them from consult through to post-treatment care. The nurses continually reinforce their knowledge of TN to improve patient understanding of the entire radiation process. [ABSTRACT FROM AUTHOR]

Background Cerebral arteriovenous malformations (CAVMs) may be treated with microsurgery, radiosurgery, endovascular surgery, or a combination of these modalities. Grading scales are available to aid the assessment of curative risk for microsurgery and radiosurgery. No grading system has been developed to assess the curative risk of endovascular surgery. Objective To report our retrospective application of the AVM embocure score to patients treated at our institution between 2005 and 2011 Methods We performed a retrospective review of 39 patients with CAVM treated at our institution between 2005 and 2011 with the primary aim of achieving a curative embolization. After reviewing all the different variables associated with the conventional Onyx embolization technique for CAVMs, we identified the following as the most relevant characteristics influencing the chances for complete angiographic embolization and complication risk: the number of arterial pedicles and draining veins, size of AVM nidus, and vascular eloquence. We sought to develop a scoring system to assess the complication risk for a curative embolization of CAVM with liquid embolic Onyx (Covidien, Irvine, California, USA). We developed the AVM embocure score (AVMES). This scoring system ranges from 3 to 10 and is the arithmetic sum of the number of arterial pedicles feeding the AVM (<3, 4-6, >6), the number of draining veins (<3, 4-6, >6), the size of the AVM nidus in centimeters (<3, 4-6, >6), and the vascular eloquence (0-1). We applied AVMES to the same cohort of patients and validated the predictability of complete angiographic embolization and expected clinical risk of complication. Results In lesions with an AVMES of 3 (n=8), there was a 100% rate of complete AVM obliteration and 0% rate of major complications. In AVMES 4 (n=12) lesions, there was 75% complete obliteration rate, with 8% major morbidity. In AVMES 5 (n=9) lesions, there was 78% complete obliteration and 11% major morbidity. In AVMES >5 (n=10) there was 20% complete obliteration and 30% major morbidity. Receiver-operator curve analysis showed that this scoring system was robust in its discriminative ability, with an area under the curve (AUC) of 0.8356 for complete obliteration without complication, AUC=0.8240 for complete obliteration regardless of the presence of major morbidity, and AUC=0.7529 for major morbidity. Conclusions The AVMES complements existing scoring systems for microsurgery and radiosurgery. It provides a valuable tool for risk assessment during the complex decision-making process in treating AVMs that accounts for angioarchitectural features of particular relevance to endovascular surgeons. [ABSTRACT FROM AUTHOR]

Robotic radiosurgery using more than one circular collimator can improve treatment plan quality and reduce total monitor units (MU). The rationale for an iris collimator that allows the field size to be varied during treatment delivery is to enable the benefits of multiple-field-size treatments to be realized with no increase in treatment time due to collimator exchange or multiple traversals of the robotic manipulator by allowing each beam to be delivered with any desired field size during a single traversal. This paper describes the Iris variable aperture collimator (Accuray Incorporated, Sunnyvale, CA, USA), which incorporates 12 tungsten-copper alloy segments in two banks of six. The banks are rotated by 30deg with respect to each other, which limits the radiation leakage between the collimator segments and produces a 12-sided polygonal treatment beam. The beam is approximately circular, with a root-mean-square (rms) deviation in the 50% dose radius of <0.8% (corresponding to <0.25 mm at the 60 mm field size) and an rms variation in the 20-80% penumbra width of about 0.1 mm at the 5 mm field size increasing to about 0.5 mm at 60 mm. The maximum measured collimator leakage dose rate was 0.07%. A commissioning method is described by which the average dose profile can be obtained from four profile measurements at each depth based on the periodicity of the isodose line variations with azimuthal angle. The penumbra of averaged profiles increased with field size and was typically 0.2-0.6 mm larger than that of an equivalent fixed circular collimator. The aperture reproducibility is [?] 0.1 mm at the lower bank, diverging to [?] 0.2 mm at a nominal treatment distance of 800 mm from the beam focus. Output factors (OFs) and tissue-phantom-ratio data are identical to those used for fixed collimators, except the OFs for the two smallest field sizes (5 and 7.5 mm) are considerably lower for the Iris Collimator. If average collimator profiles are used, the assumption of circular symmetry results in dose calculation errors that are <1 mm or <1% for single beams across the full range of field sizes; errors for multiple non-coplanar beam treatment plans are expected to be smaller. Treatment plans were generated for 19 cases using the Iris Collimator (12 field sizes) and also using one and three fixed collimators. The results of the treatment planning study demonstrate that the use of multiple field sizes achieves multiple plan quality improvements, including reduction of total MU, increase of target volume coverage and improvements in conformality and homogeneity compared with using a single field size for a large proportion of the cases studied. The Iris Collimator offers the potential to greatly increase the clinical application of multiple field sizes for robotic radiosurgery. [ABSTRACT FROM AUTHOR]

Purpose: Volumetric modulated arc therapy (RapidArc [RA]; Varian Medical Systems, Palo Alto, CA) allows for the generation of intensity-modulated dose distributions by use of a single gantry rotation. We used RA to plan and deliver whole-brain radiotherapy (WBRT) with a simultaneous integrated boost in patients with multiple brain metastases. Methods and Materials: Composite RA plans were generated for 8 patients, consisting of WBRT (20 Gy in 5 fractions) with an integrated boost, also 20 Gy in 5 fractions, to the brain metastases, and clinically delivered in 3 patients. Summated gross tumor volumes were 1.0 to 37.5 cm3. RA plans were measured in a solid water phantom by use of Gafchromic films (International Specialty Products, Wayne, NJ). Results: Composite RA plans could be generated within 1 hour. Two arcs were needed to deliver the mean of 1,600 monitor units with a mean “beam-on” time of 180 seconds. RA plans showed excellent coverage of planning target volume for WBRT and planning target volume for the boost, with mean volumes receiving at least 95% of the prescribed dose of 100% and 99.8%, respectively. The mean conformity index was 1.36. Composite plans showed much steeper dose gradients outside the brain metastases than plans with a conventional summation of WBRT and radiosurgery. Comparison of calculated and measured doses showed a mean gamma for double-arc plans of 0.30, and the area with a gamma larger than 1 was 2%. In-room times for clinical RA sessions were approximately 20 minutes for each patient. Conclusions: RA treatment planning and delivery of integrated plans of WBRT and boosts to multiple brain metastases is a rapid and accurate technique that has a higher conformity index than conventional summation of WBRT and radiosurgery boost. [Copyright &y& Elsevier]

Stereotactic radiosurgery using charged-particle beams has been the subject of biomedical research and clinical development for more than 50 years. Charged particles of proton mass or greater manifest unique physical properties that can be used to place a high dose of radiation preferentially within the boundaries of a deeply located intracranial target volume. Since 1954, nearly 10000 patients have been treated using this technique. Treated disorders include pituitary tumors, vascular malformations, primary and metastatic brain tumors, and subfoveal neovascularization. Charged-particle radiosurgery is particularly advantageous for the conformal treatment of large and/or irregularly shaped lesions, or for the treatment of lesions located in front of or adjacent to sensitive brain structures. [ABSTRACT FROM AUTHOR]

Abstract: The authors report their experience of using the CyberKnife® system (Accuray Incorporated, Sunnyvale, California, USA), a new radiosurgical device, as a treatment option for squamous cell carcinoma (SCC) of the maxillary sinus. A 66-year-old man with SCC stage T4 was treated using the CyberKnife system. [Copyright &y& Elsevier]

The article presents information on the Ask the Expert Luncheons to be held at the San Diego Convention Center in California and Evening Sessions at the CVC West in October 2006. A registration fee of $39 per session is required for the luncheons which includes a special lunch. Among the topics to be discussed at the Evening Sessions are radiosurgery and alternative medicine.

Object: Stereotactic radiosurgery for arteriovenous malformations (AVMs) is an accepted treatment option, but few reports have been published on the results of this treatment in children. In this study the authors describe a series of pediatric patients with a minimum follow-up duration of 36 months., Methods: From 1991 to 1997, 40 children (26 boys and 14 girls) with AVMs were treated with radiosurgery at the University of California at San Francisco (UCSF). Follow-up information was available for 31 children (20 boys and 11 girls) in whom the median age at initial treatment was 11.2 years (range 3.4-17.5 years). The median follow-up duration was 60 months (range 6-99 months). Sixteen percent of the AVMs were Spetzler-Martin Grade II; 68%, Grade III; 10%, Grade IV; and 6%, Grade V. The mean volume of the AVMs was 5.37 cm3 and the median volume was 1.6 cm3. The mean marginal dose of radiation was 16.7 Gy and the median dose was 18 Gy (range 12-19 Gy). Angiography performed in 26 children confirmed obliteration of the AVM nidus in nine patients (35%), partial response in 16 patients (62%), and no response in one patient (4%). In five patients who refused angiography, magnetic resonance (MR) imaging revealed obliteration in two patients and partial response in three patients, bringing the overall obliteration rate associated with initial radiosurgery to 35%. Logistic regression analysis confirmed a significant correlation between marginal dose prescription and response (p = 0.025); in AVMs that received at least 18 Gy there was a 10-fold increase in the obliteration rate (63%) over AVMs that received a lower dose. Lesions smaller than 3 cm3 were associated with a six-fold increased obliteration rate (53%) over lesions larger than 3 cm3 (8%), but AVM volume was not a statistically significant predictor of response (p = 0.09). Twelve patients have since undergone repeated radiosurgery and are currently being followed up with serial MR imaging studies (in five cases, the AVM is now obliterated). During the follow-up period (1918 patient-months) there were eight hemorrhages in five patients, with a cumulative posttreatment hemorrhage rate of 3.2%/patient/year in the 1st year and a rate of 4.3%/patient/year over the first 3 years. There were two permanent neurological complications (6%) and no deaths in this study., Conclusions: The lower overall obliteration rate reported in this series is most likely due to the larger mean AVM volumes treated at UCSF as well as conservative dose-volume prescriptions delivered to children. Significantly higher obliteration rates were observed when a marginal radiation dose of at least 18 Gy was delivered. The permanent complication rate is low and should encourage those treating children to use doses similar to those used in adults.