Stereotactic irradiation for treatment of acoustic neuromas

Stereotactic cerebral irradiation is a radiotherapeutic technique for precise delivery of ionizing irradiation to an intracranial target with simultaneous sparing of adjacent parenchyma. Treatment can be administered by a multi-source cobalt-60 device (gamma knife) or a dedicated linear accelerator.The target dose can be delivered in a large, single fraction (stereotactic radiosurgery SRS) or in multiple, daily increments (stereotactic radiotherapy SRT). The latter approach combines the physical dose localization advantages of SRS with the radiobiologic benefits of dose fractionation. This literature review will present the rationale and clinical results of SRS and SRT for the treatment of acoustic neuromas. Emphasis will be placed on tumor control, imaging outcome and cranial nerve preservation. The findings demonstrate that SRS and SRT represent reasonable therapeutic options for patients with acoustic neuromas.

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Cranial Nerve Preservation in Surgery for Large Acoustic Neuromas

Skull Base ◽

10.1055/s-2004-828699 ◽

2004 ◽

Vol 14 (2) ◽

pp. 85-90 ◽

Cited By ~ 17

Author(s):

J. Thomas Roland ◽

Andrew J Fishman ◽

John G Golfinos ◽

Noel Cohen ◽

George Alexiades ◽

...

Keyword(s):

Cranial Nerve ◽

Nerve Preservation ◽

Acoustic Neuromas ◽

Cranial Nerve Preservation

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Cranial Nerve Preservation and Outcomes after Stereotactic Radiosurgery for Jugular Foramen Schwannomas

Neurosurgery ◽

10.1227/01.neu.0000279726.90650.6d ◽

2007 ◽

Vol 61 (1) ◽

pp. 76-81 ◽

Cited By ~ 37

Author(s):

Juan J. Martin ◽

Douglas Kondziolka ◽

John C. Flickinger ◽

David Mathieu ◽

Ajay Niranjan ◽

...

Keyword(s):

Stereotactic Radiosurgery ◽

Cranial Nerve ◽

Gamma Knife Radiosurgery ◽

Jugular Foramen ◽

Tumor Control ◽

Lower Cranial Nerve ◽

Nerve Preservation ◽

Cranial Nerve Function ◽

Cranial Neuropathies ◽

Cranial Nerve Preservation

Abstract OBJECTIVE Jugular foramen region schwannomas are rare intracranial tumors that usually present with multiple lower cranial nerve deficits. For some patients, complete surgical resection is possible but may be associated with significant morbidity. Stereotactic radiosurgery is a minimally invasive alternative or adjunct to microsurgery for such tumors. We reviewed our clinical and imaging outcomes after patients underwent gamma knife radiosurgery for management of jugular foramen schwannomas. METHODS Thirty-four patients with 35 tumors (one patient had bilateral tumors) underwent radiosurgery between May 1990 and December 2005. Twenty-two patients had previous microsurgical resection and all patients experienced various cranial neuropathies. A median of six isocenters were used. Median marginal and maximum doses were 14 and 28 Gy, respectively. RESULTS None of the patients were lost to evaluation and the mean duration of follow-up was 83 months. Tumors regressed in 17 patients, remained stable in 16, and progressed in two. Five- and 10-year actuarial control rates were 97 and 94%, respectively. Preexisting cranial neuropathies improved in 20% and remained stable in 77% after radiosurgery. One patient worsened. The function of all previous intact nerves was preserved after radiosurgery. CONCLUSION Stereotactic radiosurgery proved to be a safe and effective management for newly diagnosed or residual jugular foramen schwannomas. Long-term tumor control rates and stability or improvement in cranial nerve function was confirmed.

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Hypofractionated Robotic Stereotactic Radiosurgery for Vagal Paragangliomas: A Novel Treatment Strategy for Cranial Nerve Preservation

Otolaryngology ◽

10.1177/0194599820910150 ◽

2020 ◽

Vol 162 (6) ◽

pp. 897-904

Author(s):

Anne K. Maxwell ◽

Gautam U. Mehta ◽

Thomas Muelleman ◽

Zachary R. Barnard ◽

Thomas Hartwick ◽

...

Keyword(s):

Side Effects ◽

Stereotactic Radiosurgery ◽

Cranial Nerve ◽

Tumor Resection ◽

Tumor Control ◽

Subtotal Resection ◽

Lower Cranial Nerve ◽

Nerve Preservation ◽

Cranial Nerve Preservation ◽

Vagal Function

Objective To provide the first description of hypofractionated stereotactic radiosurgery (SRS) and evaluate tumor control and safety for vagal paragangliomas (VPs), which begin at the skull base but often have significant extracranial extension. Study Design Retrospective chart review. Setting Tertiary-referral neurotology and neurosurgery practice. Subjects and Methods Five VPs in 4 patients (all male, ages 15-56 years) underwent SRS between 2010 and 2018. Outcome measures included tumor dimensions on serial imaging, cranial nerve function, and radiation side effects. Results CyberKnife hypofractionated SRS was performed. The prescription dose was 24 or 27 Gy (maximum dose 33.4 Gy; range, 29.3-35.5 Gy) delivered in 3 equal fractions. The mean isodose line was 79% (range, 76%-82%). Four VPs were treated primarily, and 1 tumor underwent SRS to treat regrowth 2 years after microsurgical subtotal resection via the modified infratemporal fossa approach. The treatment volume ranged from 8.81 to 86.3 cm3 (mean, 35.7 cm3). All demonstrated stable size (n = 3) or regression (n = 2) at last follow-up, 63 to 85 months after SRS (mean, 76 months). One patient had stable premorbid vocal fold paralysis from a prior ipsilateral glomus jugulare tumor resection. All others demonstrated normal vagal function following SRS. Treatment-related side effects, including dysgeusia (n = 1), mucositis (n = 1), and neck soft-tissue edema (n = 2), were self-limited. Conclusions Hypofractionated SRS appears to be both safe and effective for treating VPs, including large-volume and predominantly extracranial tumors, while preserving vagal function. SRS should be considered as a cranial nerve preservation option, especially in settings of contralateral lower cranial nerve deficits or in those with multiple paragangliomas risking both vagal nerves.

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Quality of life following acoustic neuroma surgery

Neurosurgical FOCUS ◽

10.3171/foc.1998.5.3.7 ◽

1998 ◽

Vol 5 (3) ◽

pp. E6 ◽

Cited By ~ 10

Author(s):

Marc S. Schwartz ◽

Seth A. Riddle ◽

Johnny B. Delashaw ◽

Michael A. Horgan ◽

Jordi X. Kellogg ◽

...

Keyword(s):

Quality Of Life ◽

Acoustic Neuroma ◽

Age Groups ◽

Well Being ◽

Activity Level ◽

Nerve Preservation ◽

Acoustic Neuromas ◽

Acoustic Neuroma Surgery ◽

Cranial Nerve Preservation

In the treatment of acoustic neuroma, operative results have improved greatly during recent years, with high rates of functional cranial nerve preservation. Because of this, it has become more important to consider issues of patient satisfaction and quality of life (QOL) following treatment for these lesions. The authors have developed a novel questionnaire designed to measure QOL in patients with acoustic neuromas, and they administered it to 50 consecutive patients at least 6 months after acoustic neuroma surgery. Overall QOL was judged to be good but with definite minor difficulties, including some problems with hearing, facial nerve function, headache, tinnitus, dizziness, activity level, enjoyment of life, and emotional well-being. No significant differences were found between age groups and different operative approaches, and only minor differences were found in relation to tumor size. Patients with intracanalicular tumors fared no better than those with cerebellopontine angle tumors. Analysis of the data suggests an overall good outcome from acoustic neuroma surgery; however, when discussing the possible effects on postoperative QOL, even the potential minor problems should not be minimized, especially in patients undergoing operation for small or intracanalicular tumors.

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Stereotactic radiotherapy for the treatment of acoustic neuromas

Journal of Neurosurgery ◽

10.3171/sup.2004.101.supplement3.0362 ◽

2004 ◽

Vol 101 (Supplement3) ◽

pp. 362-372 ◽

Cited By ~ 38

Author(s):

Michael T. Selch ◽

Alessandro Pedroso ◽

Steve P. Lee ◽

Timothy D. Solberg ◽

Nzhde Agazaryan ◽

...

Keyword(s):

Stereotactic Radiotherapy ◽

Tumor Size ◽

Cranial Nerve ◽

Target Volume ◽

Tumor Control ◽

Content Type ◽

Seventh Cranial Nerve ◽

Acoustic Neuromas ◽

Fine Print

Object. The authors sought to assess the safety and efficacy of stereotactic radiotherapy when using a linear accelerator equipped with a micromultileaf collimator for the treatment of patients with acoustic neuromas. Methods. Fifty patients harboring acoustic neuromas were treated with stereotactic radiotherapy between September 1997 and June 2003. Two patients were lost to follow-up review. Patient age ranged from 20 to 76 years (median 59 years), and none had neurofibromatosis. Forty-two patients had useful hearing prior to stereotactic radiotherapy. The fifth and seventh cranial nerve functions were normal in 44 and 46 patients, respectively. Tumor volume ranged from 0.3 to 19.25 ml (median 2.51 ml). The largest tumor dimension varied from 0.6 to 4 cm (median 2.2 cm). Treatment planning in all patients included computerized tomography and magnetic resonance image fusion and beam shaping by using a micromultileaf collimator. The planning target volume included the contrast-enhancing tumor mass and a margin of normal tissue varying from 1 to 3 mm (median 2 mm). All tumors were treated with 6-MV photons and received 54 Gy prescribed at the 90% isodose line encompassing the planning target volume. A sustained increase greater than 2 mm in any tumor dimension was defined as local relapse. The follow-up duration varied from 6 to 74 months (median 36 months). The local tumor control rate in the 48 patients available for follow up was 100%. Central tumor hypodensity occurred in 32 patients (67%) at a median of 6 months following stereotactic radiotherapy. In 12 patients (25%), tumor size increased 1 to 2 mm at a median of 6 months following stereotactic radiotherapy. Increased tumor size in six of these patients was transient. In 13 patients (27%), tumor size decreased 1 to 14 mm at a median of 6 months after treatment. Useful hearing was preserved in 39 patients (93%). New facial numbness occurred in one patient (2.2%) with normal fifth cranial nerve function prior to stereotactic radiotherapy. New facial palsy occurred in one patient (2.1%) with normal seventh cranial nerve function prior to treatment. No patient's pretreatment dysfunction of the fifth or seventh cranial nerve worsened after stereotactic radiotherapy. Tinnitus improved in six patients and worsened in two. Conclusions. Stereotactic radiotherapy using field shaping for the treatment of acoustic neuromas achieves high rates of tumor control and preservation of useful hearing. The technique produces low rates of damage to the fifth and seventh cranial nerves. Long-term follow-up studies are necessary to confirm these findings.

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Advanced Imaging Techniques for Radiotherapy Planning of Gliomas

Cancers ◽

10.3390/cancers13051063 ◽

2021 ◽

Vol 13 (5) ◽

pp. 1063

Author(s):

Antonella Castellano ◽

Michele Bailo ◽

Francesco Cicone ◽

Luciano Carideo ◽

Natale Quartuccio ◽

...

Keyword(s):

Radiation Treatment ◽

Imaging Modality ◽

Imaging Techniques ◽

Clinical Results ◽

Target Volume ◽

Radiotherapy Planning ◽

Tumor Control ◽

Current Standard ◽

Volume Delineation ◽

Hemodynamic Information

The accuracy of target delineation in radiation treatment (RT) planning of cerebral gliomas is crucial to achieve high tumor control, while minimizing treatment-related toxicity. Conventional magnetic resonance imaging (MRI), including contrast-enhanced T1-weighted and fluid-attenuated inversion recovery (FLAIR) sequences, represents the current standard imaging modality for target volume delineation of gliomas. However, conventional sequences have limited capability to discriminate treatment-related changes from viable tumors, owing to the low specificity of increased blood-brain barrier permeability and peritumoral edema. Advanced physiology-based MRI techniques, such as MR spectroscopy, diffusion MRI and perfusion MRI, have been developed for the biological characterization of gliomas and may circumvent these limitations, providing additional metabolic, structural, and hemodynamic information for treatment planning and monitoring. Radionuclide imaging techniques, such as positron emission tomography (PET) with amino acid radiopharmaceuticals, are also increasingly used in the workup of primary brain tumors, and their integration in RT planning is being evaluated in specialized centers. This review focuses on the basic principles and clinical results of advanced MRI and PET imaging techniques that have promise as a complement to RT planning of gliomas.

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RADT-19. EFFECTS OF RADIATION DOSE-RATE AND TUMOR CHARACTERISTICS ON LOCAL CONTROL AND TOXICITY AFTER RADIOSURGERY FOR ACOUSTIC NEUROMAS

Neuro-Oncology ◽

10.1093/neuonc/noaa215.772 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii185-ii185

Author(s):

Conrad Josef Villafuerte ◽

Fred Gentili ◽

David Shultz ◽

Alejandro Berlin ◽

Robert Heaton ◽

...

Keyword(s):

Dose Rate ◽

Proportional Hazards Model ◽

Multivariable Analysis ◽

Tumor Resection ◽

Local Failure ◽

Tumor Control ◽

Tumor Diameter ◽

Radiation Dose Rate ◽

Acoustic Neuromas

Abstract INTRODUCTION The effect of stereotactic radiosurgery (SRS) dose-rate on tumor control for acoustic neuroma (AN, or vestibular schwannoma) is unclear. METHODS This was a retrospective study of all patients treated for AN with frame-based cobalt-60 SRS at the Toronto Western Hospital between 2005-2019. Dose rates on the day of SRS were calculated from the calibration dose-rate while accounting for the cobalt-60 half-life of 5.2713 years. Local failure was defined as continued tumor growth >36 months post-SRS, tumor resection for LF, or use of any repeat SRS for LF. Cumulative incidence of LF was reported after accounting for competing risks of death, on a per-lesion basis. Comparisons of actuarial LF were made using Gray’s test. Multivariable analysis of LF was performed using a proportional hazards model. RESULTS A total of 607 patients were treated for 617 acoustic neuromas. Median follow-up was 5.0 years. 158 tumors (26%) were cystic. 71 tumors (12%) had previous resection. Nine patients received 10-11 Gy due to large tumor size; all remaining patients received 12 Gy to approximately the 50% isodose line. Median dose rate was 2.4 Gy/min (range, 1.3-3.7). There was no association between dose rate and LF (≥ 2.4 Gy/min vs. < 2.4 Gy/min, 6.07% vs. 6.12% at 5-year follow-up, p = 0.75). The adjusted local failure-specific hazard ratio (HR) for dose rate (per Gy/min) was 1.2 (95% CI 0.69-2.1, p = 0.52). Patients with previous surgery had higher LF, with a HR of 3.6 (95% CI 1.7-7.8, p = 0.0012), after adjusting for presence of cysts (HR 0.27, p = 0.034) and maximum tumor diameter (HR 1.055 per cm, p = 0.071). CONCLUSIONS In a large cohort of patients with acoustic neuromas, radiosurgery dose-rate was not associated with tumor control. Previous resection was a strong risk factor for local failure after SRS.

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The Changing Paradigm for the Surgical Treatment of Large Vestibular Schwannomas

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0038-1668540 ◽

2018 ◽

Vol 79 (S 04) ◽

pp. S362-S370 ◽

Cited By ~ 5

Author(s):

Constantin Tuleasca ◽

Alda Rocca ◽

Mercy George ◽

Etienne Pralong ◽

Luis Schiappacasse ◽

...

Keyword(s):

Functional Outcome ◽

Residual Tumor ◽

University Hospital ◽

Tumor Control ◽

Subtotal Resection ◽

Consecutive Series ◽

Cochlear Function ◽

Nerve Preservation ◽

The Past

Objective Planned subtotal resection followed by Gamma Knife surgery (GKS) in patients with large vestibular schwannoma (VS) has emerged during the past decade, with the aim of a better functional outcome for facial and cochlear function. Methods We prospectively collected patient data, surgical, and dosimetric parameters of a consecutive series of patients treated by this method at Lausanne University Hospital during the past 8 years. Results A consecutive series of 47 patients were treated between July 2010 and January 2018. The mean follow-up after surgery was 37.5 months (median: 36, range: 0.5–96). Mean presurgical tumor volume was 11.8 mL (1.47–34.9). Postoperative status showed normal facial nerve function (House–Brackmann I) in all patients. In a subgroup of 28 patients, with serviceable hearing before surgery and in which cochlear nerve preservation was attempted at surgery, 26 (92.8%) retained serviceable hearing. Nineteen had good or excellent hearing (Gardner–Robertson class 1) before surgery, and 16 (84.2%) retained it after surgery. Mean duration between surgery and GKS was 6 months (median: 5, range: 3–13.9). Mean residual volume as compared with the preoperative one at GKS was 31%. Mean marginal dose was 12 Gy (11–12). Mean follow-up after GKS was 34.4 months (6–84). Conclusion Our data show excellent results in large VS management with a combined approach of microsurgical subtotal resection and GKS on the residual tumor, with regard to the functional outcome and tumor control. Longer term follow-up is necessary to fully evaluate this approach, especially regarding tumor control.

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