Severe Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) Following the Initiation of Valbenazine for Tardive Dyskinesia: A Case Report.

Hyponatremia, a common electrolyte disorder, usually has a benign clinical course. However, patients with the syndrome of inappropriate antidiuretic hormone secretion (SIADH) can suffer unfavorable outcomes, including mortality. Atypical antipsychotics, which are among the drugs associated with SIADH, also cause tardive dyskinesia, a condition that physicians can now effectively manage with the recently approved agent - valbenazine. We herein report a case of severe hyponatremia due to SIADH in a 58-year-old man who developed hyponatremia-induced generalized seizures six weeks after valbenazine was added to his regimen to mitigate olanzapine-associated tardive dyskinesia. His electrolyte derangement and clinical course improved following prompt recognition and treatment of SIADH. The temporal association between the commencement of valbenazine and the onset of SIADH suggests a possible but previously unreported link between valbenazine and the development of SIADH. Awareness of this uncommon association is relevant to patient safety.

Impact of compensation and willingness to keep same career path on burnout among long-term care workers in Japan.

BACKGROUND: This study examined the relationships between compensation, willingness to keep same career path, and burnout among long-term care workers in Japan. METHODS: Data were collected from 319 care workers at long-term care facilities in Japan. The study variables included data on demographics, compensation, willingness to keep same career path, and burnout. RESULTS: The study found that compensation and willingness to keep same career were significantly negatively associated with burnout levels among long-term care workers in Japan. Long-term care workers with high compensation levels were found to be more likely to have low burnout levels. In addition, care workers who expressed an intention to keep same career path were likely to have low burnout levels. In addition, compensation is associated with burnout as the mediating role of willingness to keep same career. CONCLUSIONS: These results highlight the importance of implementing policies and measures that reduce the risk of burnout among care workers to improve the quality of care. Strategies for improving working conditions include increasing wages, increasing compensation for experienced care workers, and reorganizing benefits.

Longitudinal Force Measurement and its Relationship to Technical Competence for Esophageal Anastomosis in a Thoracoscopic Esophageal Atresia/Tracheo-Esophageal Fistula Simulator.

PURPOSE: Thoracoscopic esophageal atresia with tracheo-esophageal fistula (EA/TEF) repair requires the gentle manipulation of delicate tissue. Force sensors were attached to the upper and lower esophagus of a 3D-printed EA/TEF simulator to explore force parameters as markers of performance. METHODS: Participants completed one intracorporeal suture between the anterior walls of upper and lower esophageal ends. Longitudinal force data were recorded at each end. A blinded pediatric surgeon marked attempt videos. Excessive force events, maximum tension, and force interquartile range (IQR) were measured. Data were reported as median (range) significance of p < 0.05. RESULTS: 17 participants of varying levels of experience performed the task. OSATS scores showed significant differences between experts and novices. Experts completed the task in a median time of 4 min. They used lower maximum tension, higher force IQR, and had fewer excess force events compared to the intermediate and novice groups. DISCUSSION: The application of force was dependent on expertise with more skilled participants having fewer excess force events. The higher expert force IQR likely reflects the consistent tension needed for task completion. Analysis of force data may be an indicator of competence, and trainees may benefit from a thoracoscopic simulator which provides force data feedback. LEVEL OF EVIDENCE: Not applicable.

Patterns of Progression in Patients With Newly Diagnosed Glioblastoma Treated With 5-mm Margins in a Phase 1/2 Trial of 5-Fraction Stereotactic Radiosurgery With Concurrent and Adjuvant Temozolomide.

PURPOSE: In patients with newly diagnosed glioblastoma (GBM), tumor margins of at least 20 mm are the standard of care. We sought to determine the pattern of tumor progression in patients treated with 5-fraction stereotactic radiosurgery with 5-mm margins. METHODS AND MATERIALS: Thirty adult patients with newly diagnosed GBM were treated with 5-fraction stereotactic radiosurgery in escalated doses from 25 to 40 Gy with a 5-mm total treatment margin. Progression was scored as "in-field" if the recurrent tumor was within or contiguous with the 5-mm margin, "marginal" if between 5 and 20 mm, and "distant" if entirely occurring greater than 20 mm. As geometric patterns of progression do not reflect the biologic dose received, we calculated the minimum equi-effective dose in 2 Gy (EQD2) per day at the site of tumor recurrence. Progression was "dosimetrically in-field" if covered by a minimum EQD2 per day of 48 Gy10. RESULTS: From 2010 to 2016, 27 patients had progressed. Progression was in-field in 17 (63%), marginal in 3 (11%), and distant in 7 (26%) patients. In the 3 patients with marginal progression, the minimum EQD2 to recurrent tumor were 48 Gy10, 56 Gy10 (both considered dosimetrically in-field), and 7 Gy10 (ie, dosimetrically out-of-field). Median overall survival was 12.1 months for in-field (95% confidence interval [CI], 8.9-17.6), 15.1 months (95% CI, 10.1 to not achieved) for marginal, and 21.4 months (95% CI, 11.2-33.5) for distant progression. Patients with radiation necrosis were less likely to have in-field progression (1 of 7; 14%) compared with those without radiation necrosis (16 of 20; 80%; P = .003); those with necrosis had a median overall survival of 27.2 months (95% CI, 11.2-48.3) compared with 11.7 months (95% CI, 8.9-17.6) for patients with no necrosis (P = .077). CONCLUSIONS: In patients with newly diagnosed GBM treated with a 5-mm clinical target volume margin, 3 patients (11%) had marginal progression within 5 to 20 mm; only 1 patient (4%) may have dosimetrically benefitted from conventional 20-mm margins. Radiation necrosis was associated with in-field tumor control.

The role of motion tracking in assessing technical skill acquisition using a neonatal 3D-printed thoracoscopic esophageal atresia/tracheo-esophageal fistula simulator.

INTRODUCTION: Acquiring the technical skills required for thoracoscopic repair of esophageal atresia with tracheo-esophageal fistula (EA/TEF) is challenging. A high-fidelity 3D-printed pediatric thoracoscopic EA/TEF simulator has been developed to address this issue. This study explored motion-tracking as an assessment tool to distinguish between surgeons of different expertise using the simulator. METHODS: Participants performed a single intracorporeal suture between the esophageal ends in EA with TEF. Total relative path lengths of the right and left surgical instruments were recorded during the task. Each video-recorded attempt was assessed by a blinded pediatric surgeon using a modified Objective Structured Assessment of Technical Skills (OSATS) score. Data recorded as median (range) and statistical significance as p<0.05. RESULTS: The task was performed by 17 participants. The median OSATS scores identified a significant difference between experts and novices. A difference between left- and right-hands was only found in the mid-skill level group. Right-hand path length was greatest in novices and lowest in experts. Left-hand path length was greatest in novices and the mid-skill level group compared to experts. CONCLUSION: Experts had the lowest total path length for either hand, suggesting they had the greatest efficiency of movement. The similar high path lengths in both hands for novices indicate their relatively low level of skill with either hand. The difference between right- and left-hand path lengths in the mid-skill level group likely reflects the improved right-handed technical skills in contrast to the still developing left hand. Further focus on the left hand during simulation training may improve left-handed economy of movement.

Phase I/II Dose-Escalation Trial of 3-Fraction Stereotactic Radiosurgery for Resection Cavities From Large Brain Metastases: Health-related Quality of Life Outcomes.

OBJECTIVES: We investigated differences in quality of life (QoL) in patients enrolled on a phase I/II dose-escalation study of 3-fraction resection cavity stereotactic radiosurgery (SRS) for large brain metastases. METHODS: Eligible patients had 1 to 4 brain metastases, one of which was a resection cavity 4.2 to 33.5 cm3. European Organization for Research and Treatment of Cancer (EORTC) quality of life questionnaires core-30 (QLQ-30) and brain cancer specific module (QLQ-BN20) were obtained before SRS and at each follow-up. Nine scales were analyzed (global health status; physical, social, and emotional functioning; motor dysfunction, communication deficit, fatigue, insomnia, and future uncertainty). QoL was assessed with mixed effects models. Differences ≥10 points with q-value (adjusted P-value to account for multiplicity of testing) <0.10 were considered significant. RESULTS: Between 2009 and 2014, 50 enrolled patients completed 277 QoL questionnaires. Median questionnaire follow-up was 11.8 months. After SRS, insomnia demonstrated significant improvement (q=0.032, -17.7 points at 15 mo post-SRS), and future uncertainty demonstrated significant worsening (q=0.018, +9.9 points at 15 mo post-SRS). Following intracranial progression and salvage SRS, there were no significant QoL changes. The impact of salvage whole brain radiotherapy could not be assessed because of limited data (n=4 patients). In the 28% of patients that had adverse radiation effect, QoL had significant worsening in 3 metrics (physical functioning, q=0.024, emotional functioning q=0.001, and future uncertainty, q=0.004). CONCLUSIONS: For patients treated with 3-fraction SRS for large brain metastasis cavities, 8 of 9 QoL metrics were unchanged or improved after initial SRS. Intracranial tumor progression and salvage SRS did not impact QoL. Adverse radiation effect may be associated with at least short-term QoL impairments, but requires further investigation.

A phase I/II trial of 5-fraction stereotactic radiosurgery with 5-mm margins with concurrent temozolomide in newly diagnosed glioblastoma: primary outcomes.

BACKGROUND: We sought to determine the maximum tolerated dose (MTD) of 5-fraction stereotactic radiosurgery (SRS) with 5-mm margins delivered with concurrent temozolomide in newly diagnosed glioblastoma (GBM). METHODS: We enrolled adult patients with newly diagnosed glioblastoma to 5 days of SRS in a 3 + 3 design on 4 escalating dose levels: 25, 30, 35, and 40 Gy. Dose limiting toxicity (DLT) was defined as Common Terminology Criteria for Adverse Events grades 3-5 acute or late CNS toxicity, including adverse radiation effect (ARE), the imaging correlate of radiation necrosis. RESULTS: From 2010 to 2015, thirty patients were enrolled. The median age was 66 years (range, 51-86 y). The median target volume was 60 cm3 (range, 14.7-137.3 cm3). DLT occurred in 2 patients: one for posttreatment cerebral edema and progressive disease at 3 weeks (grade 4, dose 40 Gy); another patient died 1.5 weeks following SRS from postoperative complications (grade 5, dose 40 Gy). Late grades 1-2 ARE occurred in 8 patients at a median of 7.6 months (range 3.2-12.6 mo). No grades 3-5 ARE occurred. With a median follow-up of 13.8 months (range 1.7-64.4 mo), the median survival times were: progression-free survival, 8.2 months (95% CI: 4.6-10.5); overall survival, 14.8 months (95% CI: 10.9-19.9); O6-methylguanine-DNA methyltransferase hypermethylated, 19.9 months (95% CI: 10.5-33.5) versus 11.3 months (95% CI: 8.9-17.6) for no/unknown hypermethylation (P = 0.03), and 27.2 months (95% CI: 11.2-48.3) if late ARE occurred versus 11.7 months (95% CI: 8.9-17.6) for no ARE (P = 0.08). CONCLUSIONS: The per-protocol MTD of 5-fraction SRS with 5-mm margins with concurrent temozolomide was 40 Gy in 5 fractions. ARE was limited to grades 1-2 and did not statistically impact survival.

Cavernous malformations are rare sequelae of stereotactic radiosurgery for brain metastases.

The development of cavernous malformations many years following conventionally fractionated brain irradiation is well recognized and commonly reported. However, cavernous malformation induction following stereotactic radiosurgery (SRS) is largely unreported. Herein, we describe two cases of cavernous malformation formation years following SRS for brain metastases. A 20-year-old woman with breast cancer brain metastases received treatment with whole brain radiotherapy (WBRT), then salvage SRS 1.4 years later for progression of a previously treated metastasis. This lesion treated with SRS had hemorrhagic enlargement 3.0 years after SRS. Resection revealed a cavernous malformation. A 25-year-old woman had SRS for a brain metastasis from papillary thyroid carcinoma. Resection of a progressive, hemorrhagic lesion within the SRS field 2 years later revealed both recurrent carcinoma as well as cavernous malformation. As patients with brain metastases live longer following SRS, our cases highlight that the differential diagnosis of an enlarging enhancing lesion within a previous SRS field includes not only cerebral necrosis and tumor progression but also cavernous malformation induction.

Vorinostat and Concurrent Stereotactic Radiosurgery for Non-Small Cell Lung Cancer Brain Metastases: A Phase 1 Dose Escalation Trial.

PURPOSE: To determine the maximum tolerated dose (MTD) of vorinostat, a histone deacetylase inhibitor, given concurrently with stereotactic radiosurgery (SRS) to treat non-small cell lung cancer (NSCLC) brain metastases. Secondary objectives were to determine toxicity, local failure, distant intracranial failure, and overall survival rates. MATERIALS AND METHODS: In this multicenter study, patients with 1 to 4 NSCLC brain metastases, each ≤2 cm, were enrolled in a phase 1, 3 + 3 dose escalation trial. Vorinostat dose levels were 200, 300, and 400 mg orally once daily for 14 days. Single-fraction SRS was delivered on day 3. A dose-limiting toxicity (DLT) was defined as any Common Terminology Criteria for Adverse Events version 3.0 grade 3 to 5 acute nonhematologic adverse event related to vorinostat or SRS occurring within 30 days. RESULTS: From 2009 to 2014, 17 patients were enrolled and 12 patients completed study treatment. Because no DLTs were observed, the MTD was established as 400 mg. Acute adverse events were reported by 10 patients (59%). Five patients discontinued vorinostat early and withdrew from the study. The most common reasons for withdrawal were dyspnea (n=2), nausea (n=1), and fatigue (n=2). With a median follow-up of 12 months (range, 1-64 months), Kaplan-Meier overall survival was 13 months. There were no local failures. One patient (8%) at the 400-mg dose level with a 2.0-cm metastasis developed histologically confirmed grade 4 radiation necrosis 2 months after SRS. CONCLUSIONS: The MTD of vorinostat with concurrent SRS was established as 400 mg. Although no DLTs were observed, 5 patients withdrew before completing the treatment course, a result that emphasizes the need for supportive care during vorinostat administration. There were no local failures. A larger, randomized trial may evaluate both the tolerability and potential local control benefit of vorinostat concurrent with SRS for brain metastases.

Phase 1/2 Trial of 5-Fraction Stereotactic Radiosurgery With 5-mm Margins With Concurrent and Adjuvant Temozolomide in Newly Diagnosed Supratentorial Glioblastoma: Health-Related Quality of Life Results.

PURPOSE: We report a longitudinal assessment of health-related quality of life (HRQOL) in patients with glioblastoma (GBM) treated on a prospective dose escalation trial of 5-fraction stereotactic radiosurgery (25-40 Gy in 5 fractions) with concurrent and adjuvant temozolomide. METHODS: HRQOL was assessed using the European Organization for Research and Treatment of Cancer (EORTC) quality of life questionnaire core-30 (QLQ-C30) general, the EORTC quality of life questionnaire-brain cancer specific module (QLQ-BN20), and the M.D. Anderson Symptom Inventory-Brain Tumor (MDASI-BT). Questionnaires were completed at baseline and at every follow-up visit after completion of radiosurgery. Changes from baseline for 9 predefined HRQOL measures (global quality of life, physical functioning, social functioning, emotional functioning, motor dysfunction, communication deficit, fatigue, insomnia, and future uncertainty) were calculated at every time point. RESULTS: With a median follow-up time of 10.4 months (range, 0.4-52 months), 139 total HRQOL questionnaires were completed by the 30 patients on trial. Compliance with HRQOL assessment was 76% at 12 months. Communication deficit significantly worsened over time, with a decline of 1.7 points per month (P=.008). No significant changes over time were detected in the other 8 scales of our primary analysis, including global quality of life. Although 8 patients (27%) experienced adverse radiation effects (ARE) on this dose escalation trial, it was not associated with a statistically significant decline in any of the primary HRQOL scales. Disease progression was associated with communication deficit, with patients experiencing an average worsening of 13.9 points per month after progression compared with 0.7 points per month before progression (P=.01). CONCLUSION: On this 5-fraction dose escalation protocol for newly diagnosed GBM, overall HRQOL remained stable and appears similar to historical controls of 30 fractions of radiation therapy. Tumor recurrence was associated with worsening communication deficit, and ARE did not correlate with a decline in HRQOL.

Immunotherapy-induced sarcoidosis in patients with melanoma treated with PD-1 checkpoint inhibitors: Case series and immunophenotypic analysis.

AIM: Sarcoidosis is a multisystem granulomatous disease. This condition has a documented association with the diagnosis of melanoma and can be induced in melanoma patients receiving anti-neoplastic therapy. We evaluated a case series of melanoma patients who developed immunotherapy-induced sarcoidosis. METHODS: Three patients with melanoma (n = 1 resected Stage III, n = 2 metastatic) treated with anti-programmed cell death (PD)-1 antibody therapy at two institutions developed biopsy-proven sarcoidosis. We used mass cytometry to determine expression of the relevant chemokine receptors (CR) by peripheral blood mononuclear cells for two of the three patients who developed sarcoidosis and 13 melanoma patients who did not. Blood samples were collected before receiving PD-1 checkpoint inhibitor therapy. RESULTS: Immunophenotypic analysis demonstrated abnormally high numbers of circulating Th17.1 (CCR6+ CCR4- CXCR3+ CCR10- ) cells prior to commencing PD-1 checkpoint inhibitor therapy in five of 15 melanoma patients, including both the patients who developed sarcoidosis during the course of therapy. CONCLUSION: Our findings support prior literature implicating Th17.1 cells in the pathogenesis of sarcoidosis. However, we demonstrate these findings in patients with melanoma prior to administration of checkpoint therapy and before the onset of clinically symptomatic sarcoidosis. The identification of elevated Th17.1 cells in melanoma patients who have not developed sarcoidosis may reflect the established association between melanoma and sarcoidosis. With some patients receiving these agents over a prolonged period, the clinical course of immunotherapy-induced sarcoidosis is uncertain.

Stereotactic radiosurgery for non-vestibular cranial nerve schwanommas.

Non-vestibular cranial nerve schwannomas (NVCNS) are rare lesions, representing <10 % of cranial nerve schwannomas. The optimal treatment for NVCNS is often derived from vestibular schwannomas experience. Surgical resection has been referred to as the first line treatment for those benign tumors, but significant complication rates are reported. Stereotactic radiosurgery (SRS) has arisen as a mainstay of treatment for many benign tumors, including schwanommas. We retrospectively reviewed the outcomes of NVCNS treated by SRS to characterize tumor control, symptom relief, toxicity, and the role of hypo-fractionation of SRS dose. Eighty-eight (88) patients, with ninety-five (95) NVCNS were treated with either single or multi-session SRS from 2001 to 2014. Local control was achieved in 94 % of patients treated (median follow-up of 33 months, range 1-155). Complications were seen in 7.4 % of cases treated with SRS. At 1-year, 57 % of patients had improvement or resolution of their symptoms, while 35 % were stable and 8 % had worsening or increased symptoms. While 42 % received only one session, results on local control were similar for one or multiple sessions (p = 0.424). SRS for NVCNS is a treatment modality that provides excellent local control with minimal complication risk compared to traditional neurosurgical techniques. Tumor control obtained with a multi-session treatment was not significantly different from single session treatment. Safety profile was also comparable for uni or multi-session treatments. We concluded that, as seen in VS treated with CK SRS, radiosurgery treatment can be safely delivered in cases of NVCNS.

CyberKnife Stereotactic Radiosurgery for Atypical and Malignant Meningiomas.

OBJECTIVE: Recurrent World Health Organization (WHO) grade II and III meningiomas have traditionally been treated by surgery alone, but early literature suggests that adjuvant stereotactic radiosurgery may greatly improve outcomes. We present the long-term tumor control and safety of a hypofractionated stereotactic radiosurgery regimen. METHODS: Prospectively collected data of 44 WHO grade II and 9 WHO grade III meningiomas treated by CyberKnife for adjuvant or salvage therapy were reviewed. Patient demographics, treatment parameters, local control, regional control, locoregional control, overall survival, radiation history, and complications were documented. RESULTS: For WHO grade II patients, recurrence occurred in 41%, with local, regional, and locoregional failure at 60 months recorded as 49%, 58%, and 36%. For WHO grade III patients, recurrence occurred in 66%, with local, regional, and locoregional failure at 12 months recorded as 57%, 100%, and 43%. The 60-month locoregional control rates for radiation naïve and experienced patients were 48% and 0% (P = 0.14). Overall, 7 of 44 grade II patients and 8 of 9 grade III patients had died at last follow-up. The 60-month and 12-month overall survival rates for grade II and III meningiomas were 87% and 50%, respectively. Serious complications occurred in 7.5% of patients. CONCLUSIONS: Stereotactic radiosurgery for adjuvant and salvage treatment of WHO grade II meningioma using a hypofractionated plan is a viable treatment strategy with acceptable long-term tumor control, overall survival, and complication rates. Future studies should focus on radiation-naïve patients and local management of malignant meningioma.

Dose-Response Modeling of the Visual Pathway Tolerance to Single-Fraction and Hypofractionated Stereotactic Radiosurgery.

Patients with tumors adjacent to the optic nerves and chiasm are frequently not candidates for single-fraction stereotactic radiosurgery (SRS) due to concern for radiation-induced optic neuropathy. However, these patients have been successfully treated with hypofractionated SRS over 2-5 days, though dose constraints have not yet been well defined. We reviewed the literature on optic tolerance to radiation and constructed a dose-response model for visual pathway tolerance to SRS delivered in 1-5 fractions. We analyzed optic nerve and chiasm dose-volume histogram (DVH) data from perioptic tumors, defined as those within 3mm of the optic nerves or chiasm, treated with SRS from 2000-2013 at our institution. Tumors with subsequent local progression were excluded from the primary analysis of vision outcome. A total of 262 evaluable cases (26 with malignant and 236 with benign tumors) with visual field and clinical outcomes were analyzed. Median patient follow-up was 37 months (range: 2-142 months). The median number of fractions was 3 (1 fraction n = 47, 2 fraction n = 28, 3 fraction n = 111, 4 fraction n = 10, and 5 fraction n = 66); doses were converted to 3-fraction equivalent doses with the linear quadratic model using α/ß = 2Gy prior to modeling. Optic structure dose parameters analyzed included Dmin, Dmedian, Dmean, Dmax, V30Gy, V25Gy, V20Gy, V15Gy, V10Gy, V5Gy, D50%, D10%, D5%, D1%, D1cc, D0.50cc, D0.25cc, D0.20cc, D0.10cc, D0.05cc, D0.03cc. From the plan DVHs, a maximum-likelihood parameter fitting of the probit dose-response model was performed using DVH Evaluator software. The 68% CIs, corresponding to one standard deviation, were calculated using the profile likelihood method. Of the 262 analyzed, 2 (0.8%) patients experienced common terminology criteria for adverse events grade 4 vision loss in one eye, defined as vision of 20/200 or worse in the affected eye. One of these patients had received 2 previous courses of radiotherapy to the optic structures. Both cases were meningiomas treated with 25Gy in 5 fractions, with a 3-fraction equivalent optic nerve Dmax of 19.2 and 22.2Gy. Fitting these data to a probit dose-response model enabled risk estimates to be made for these previously unvalidated optic pathway constraints: the Dmax limits of 12Gy in 1 fraction from QUANTEC, 19.5Gy in 3 fractions from Timmerman 2008, and 25Gy in 5 fractions from AAPM Task Group 101 all had less than 1% risk. In 262 patients with perioptic tumors treated with SRS, we found a risk of optic complications of less than 1%. These data support previously unvalidated estimates as safe guidelines, which may in fact underestimate the tolerance of the optic structures, particularly in patients without prior radiation. Further investigation would refine the estimated normal tissue complication probability for SRS near the optic apparatus.

The Parotid Gland is an Underrecognized Organ at Risk for Craniospinal Irradiation.

PURPOSE: Current craniospinal irradiation (CSI) protocols do not include the parotid gland as an organ at risk, potentially leading to late effects of xerostomia and secondary parotid malignancies. We analyzed the effect of CSI treatment parameters on parotid dose. MATERIALS AND METHODS: We retrospectively reviewed 50 consecutive patients treated with CSI to an intracranial dose >26 Gy. Parotid dose was compared to a Radiation Therapy Oncology Group (RTOG) dose constraint (at least 1 parotid with mean dose <26 Gy). The effects of CSI dose (≤24 Gy vs 24 Gy), volumetric-modulated arc therapy (VMAT) versus 3-dimensional (3D) CSI technique, boost dose (≤24 Gy vs 24 Gy), supratentorial versus infratentorial boost location, intensity-modulated radiation therapy (IMRT)-based versus 3D boost technique, supine versus prone position, and age on parotid dose were analyzed using multivariate regression analysis. RESULTS: The RTOG parotid dose constraint was exceeded in 22 (44%) of 50 patients. On multivariate regression analysis, lower CSI dose and VMAT CSI technique were associated with reduced parotid dose for the CSI fields. For the boost fields, lower boost dose and supratentorial boost location were associated with lower parotid dose. All 5 patients who underwent VMAT CSI met dose constraints. Furthermore, for infratentorial lesions with a total (CSI plus boost) dose prescription dose >50 Gy (n = 24), 11 of 16 patients who received low-dose CSI (18-23.4 Gy) were able to meet dose constraints, when compared to only 2 of 8 patients who received high dose CSI (36 Gy). CONCLUSION: Given the large number of patients exceeding the parotid dose constraint, the parotid gland should be considered an organ at risk. CSI dose de-escalation and IMRT-based CSI techniques may minimize the risk of xerostomia.

Repeat Courses of Stereotactic Radiosurgery (SRS), Deferring Whole-Brain Irradiation, for New Brain Metastases After Initial SRS.

PURPOSE: To report the outcomes of repeat stereotactic radiosurgery (SRS), deferring whole-brain radiation therapy (WBRT), for distant intracranial recurrences and identify factors associated with prolonged overall survival (OS). PATIENTS AND METHODS: We retrospectively identified 652 metastases in 95 patients treated with 2 or more courses of SRS for brain metastases, deferring WBRT. Cox regression analyzed factors predictive for OS. RESULTS: Patients had a median of 2 metastases (range, 1-14) treated per course, with a median of 2 courses (range, 2-14) of SRS per patient. With a median follow-up after first SRS of 15 months (range, 3-98 months), the median OS from the time of the first and second course of SRS was 18 (95% confidence interval [CI] 15-24) and 11 months (95% CI 6-17), respectively. On multivariate analysis, histology, graded prognostic assessment score, aggregate tumor volume (but not number of metastases), and performance status correlated with OS. The 1-year cumulative incidence, with death as a competing risk, of local failure was 5% (95% CI 4-8%). Eighteen (24%) of 75 deaths were from neurologic causes. Nineteen patients (20%) eventually received WBRT. Adverse radiation events developed in 2% of SRS sites. CONCLUSION: Multiple courses of SRS, deferring WBRT, for distant brain metastases after initial SRS, seem to be a safe and effective approach. The graded prognostic assessment score, updated at each course, and aggregate tumor volume may help select patients in whom the deferral of WBRT might be most beneficial.

Risk of leptomeningeal disease in patients treated with stereotactic radiosurgery targeting the postoperative resection cavity for brain metastases.

PURPOSE: We sought to determine the risk of leptomeningeal disease (LMD) in patients treated with stereotactic radiosurgery (SRS) targeting the postsurgical resection cavity of a brain metastasis, deferring whole-brain radiation therapy (WBRT) in all patients. METHODS AND MATERIALS: We retrospectively reviewed 175 brain metastasis resection cavities in 165 patients treated from 1998 to 2011 with postoperative SRS. The cumulative incidence rates, with death as a competing risk, of LMD, local failure (LF), and distant brain parenchymal failure (DF) were estimated. Variables associated with LMD were evaluated, including LF, DF, posterior fossa location, resection type (en-bloc vs piecemeal or unknown), and histology (lung, colon, breast, melanoma, gynecologic, other). RESULTS: With a median follow-up of 12 months (range, 1-157 months), median overall survival was 17 months. Twenty-one of 165 patients (13%) developed LMD at a median of 5 months (range, 2-33 months) following SRS. The 1-year cumulative incidence rates, with death as a competing risk, were 10% (95% confidence interval [CI], 6%-15%) for developing LF, 54% (95% CI, 46%-61%) for DF, and 11% (95% CI, 7%-17%) for LMD. On univariate analysis, only breast cancer histology (hazard ratio, 2.96) was associated with an increased risk of LMD. The 1-year cumulative incidence of LMD was 24% (95% CI, 9%-41%) for breast cancer compared to 9% (95% CI, 5%-14%) for non-breast histology (P=.004). CONCLUSIONS: In patients treated with SRS targeting the postoperative cavity following resection, those with breast cancer histology were at higher risk of LMD. It is unknown whether the inclusion of whole-brain irradiation or novel strategies such as preresection SRS would improve this risk or if the rate of LMD is inherently higher with breast histology.

Cochlea radiation dose correlates with hearing loss after stereotactic radiosurgery of vestibular schwannoma.

OBJECTIVE: For multisession radiosurgery, no published data relate the volume and dose of cochlear irradiation to quantified risk of hearing loss. We conducted a retrospective, dosimetric study to evaluate the relationship between hearing loss after stereotactic radiosurgery (SRS) and the dose-volume of irradiated cochlea. METHODS: Cochlear dose data were retrospectively collected on consecutive patients who underwent SRS (18 Gy in 3 sessions) for vestibular schwannoma between 1999 and 2005 at Stanford University Hospital. Inclusion criteria included Gardner-Robertson (GR) grade I or II hearing prior to radiosurgical treatment, complete audiograms, and magnetic resonance imaging (MRI) follow-up. A cochlea dose-volume histogram was generated for each of the 94 patients who qualified for this study. RESULTS: GR grade I-II hearing posttreatment was maintained in 74% of patients (70/94). Median time to last follow-up audiogram was 2.4 years (range 0.4-8.9) and to last MRI was 3.6 years (range 0.5-9.4). Each higher level of cochlear irradiation was associated with increased risk of hearing loss. Larger cochlear volume was associated with lower risk of hearing loss. Controlling for differences in cochlear volume among subjects, each additional mm(3) of cochlea receiving 10 to 16 Gy (single session equivalent doses of 6.6-10.1 Gy3) significantly increased the odds of hearing loss by approximately 5%. CONCLUSIONS: Larger cochlear volume is associated with lower risk of hearing loss following trisession SRS for vestibular schwannoma. Controlling for this phenomenon, higher radiation dose and larger irradiated cochlear volume are significantly associated with higher risk of hearing loss. This study confirms and quantifies the risk of hearing loss following trisession SRS for vestibular schwannoma.

Cavity volume dynamics after resection of brain metastases and timing of postresection cavity stereotactic radiosurgery.

BACKGROUND: An alternative treatment option to whole-brain irradiation after surgical resection of brain metastases is resection cavity stereotactic radiosurgery (SRS). OBJECTIVE: To review the dynamics of cavity volume change after surgical resection with the goal of determining the optimal timing for cavity SRS. METHODS: Preresection tumor, postresection/pre-SRS cavity, and post-SRS cavity volumes were measured for 68 cavities in 63 patients treated with surgery and postresection cavity SRS. Percent differences between volumes were calculated and correlation analyses were performed to assess volume changes before and after SRS. RESULTS: For the majority of tumors, the postresection cavity volume was smaller than the preresection tumor volume by a median percent volume change of -29% (range, -82% to 1258%), with larger preresection tumors resulting in greater cavity shrinkage (P < .001). To determine the optimal timing for cavity SRS, we examined cavity volume dynamics by comparing the early postresection (postoperative days 0-3) and treatment planning magnetic resonance imaging scans (median time to magnetic resonance imaging, 20 days; range, 9-33 days) and found no association between the postresection day number and volume change (P = .75). The volume decrease resulting from tumor resection was offset by the addition of a 2-mm clinical target volume margin, which is our current technique. CONCLUSION: The greatest volume change occurs immediately after surgery (postoperative days 0-3) with no statistically significant volume change occurring up to 33 days after surgery for most patients. Therefore, there is no benefit of cavity shrinkage in waiting longer than the first 1 to 2 weeks to perform cavity SRS.

Stereotactic radiosurgery as the primary treatment for new and recurrent paragangliomas: is open surgical resection still the treatment of choice?

OBJECTIVE: Paragangliomas (PGs) or glomus tumors are rare, and publications comparing treatment alternatives are few. We sought to analyze our experience with stereotactic radiosurgery (SRS), review the literature, and develop treatment guidelines. METHODS: We retrospectively examined the outcomes of 41 PGs in 36 patients treated with SRS at Stanford. Our data from medical records, telephone interviews, and imaging studies were combined with previously reported SRS data and compared to results following other treatments. RESULTS: With a median clinical follow-up of 4.8 years (3.9 years radiographic), local control was 100%. Complications included increase in preexistent vertigo in one patient and transient cranial neuropathies in two patients. Published surgical series describe a lower local control rate as well as more frequent and severe complications. Published radiation therapy (RT) series document a slightly lower local control rate than SRS, but SRS can be delivered more quickly and conveniently. Open surgery and other combinations of treatments appear to be required for several subpopulations of PG patients. CONCLUSIONS: We feel that SRS should be the primary treatment for most new and recurrent PGs. Even some very large PGs are appropriate for SRS. RT remains an appropriate option in some centers, especially those where SRS is not available. PGs occurring in the youngest patients, catecholamine secreting PGs, and PGs causing rapidly progressing neurologic deficits may be more appropriate for open resection. Metastatic PGs may benefit from combinations of chemotherapy and SRS or RT. Treatment guidelines are proposed.