Gamma Knife: From single- fraction SRS to IG-HSRT

2016 ◽  
pp. 31-48
Author(s):  
Daniel Trifiletti ◽  
Jason Sheehan ◽  
David Schlesinger
Keyword(s):  
Gamma Knife ◽  
Single Fraction

Stereotactic radiosurgery versus stereotactic radiotherapy for patients with vestibular schwannoma: a Leksell Gamma Knife Society 2000 debate

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 90-92 ◽  
Author(s):  
Mark E. Linskey
Keyword(s):  
Gamma Knife ◽  
Stereotactic Radiotherapy ◽  
Three Dimensional ◽  
Late Recurrence ◽  
Vestibular Schwannomas ◽  
Tumor Control ◽  
Complication Rates ◽  
Content Type ◽  
Single Fraction ◽  
Fine Print

✓ By definition, the term “radiosurgery” refers to the delivery of a therapeutic radiation dose in a single fraction, not simply the use of stereotaxy. Multiple-fraction delivery is better termed “stereotactic radiotherapy.” There are compelling radiobiological principles supporting the biological superiority of single-fraction radiation for achieving an optimal therapeutic response for the slowly proliferating, late-responding, tissue of a schwannoma. It is axiomatic that complication avoidance requires precise three-dimensional conformality between treatment and tumor volumes. This degree of conformality can only be achieved through complex multiisocenter planning. Alternative radiosurgery devices are generally limited to delivering one to four isocenters in a single treatment session. Although they can reproduce dose plans similar in conformality to early gamma knife dose plans by using a similar number of isocenters, they cannot reproduce the conformality of modern gamma knife plans based on magnetic resonance image—targeted localization and five to 30 isocenters. A disturbing trend is developing in which institutions without nongamma knife radiosurgery (GKS) centers are championing and/or shifting to hypofractionated stereotactic radiotherapy for vestibular schwannomas. This trend appears to be driven by a desire to reduce complication rates to compete with modern GKS results by using complex multiisocenter planning. Aggressive advertising and marketing from some of these centers even paradoxically suggests biological superiority of hypofractionation approaches over single-dose radiosurgery for vestibular schwannomas. At the same time these centers continue to use the term radiosurgery to describe their hypofractionated radiotherapy approach in an apparent effort to benefit from a GKS “halo effect.” It must be reemphasized that as neurosurgeons our primary duty is to achieve permanent tumor control for our patients and not to eliminate complications at the expense of potential late recurrence. The answer to minimizing complications while maintaining maximum tumor control is improved conformality of radiosurgery dose planning and not resorting to homeopathic radiosurgery doses or hypofractionation radiotherapy schemes.

scholarly journals Intracranial Metastatic Neuroblastoma Treated with Gamma Knife Stereotactic Radiosurgery: Report of Two Novel Cases

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Nathan C. Rowland ◽  
Jennifer Andrews ◽  
Daxa Patel ◽  
David V. LaBorde ◽  
Adam Nowlan ◽  
...  
Keyword(s):  
Stereotactic Radiosurgery ◽  
Gamma Knife ◽  
Treatment Options ◽  
Tumor Burden ◽  
Poor Survival ◽  
Intracranial Metastasis ◽  
Temporary Reduction ◽  
Single Fraction ◽  
Curative Therapy ◽  
Gamma Knife Stereotactic Radiosurgery

Intracranial metastasis of neuroblastoma (IMN) is associated with poor survival. No curative therapy for the treatment of IMN currently exists. Unfractionated radiotherapy may be beneficial in the treatment of IMN given the known radiosensitivity of neuroblastoma as well as its proclivity to metastasize as discrete lesions. We present two patients with IMN treated with Gamma Knife stereotactic radiosurgery (SRS). Single-fraction radiotherapy yielded temporary reduction of tumor burden and stability of disease in both patients. SRS may be a useful palliative tool in the treatment of IMN and expands the overall treatment options for this disease.

scholarly journals 68. FRAMELESS, VAULT-FREE RADIOSURGERY: INITIAL CLINICAL EXPERIENCE WITH THE ZAP-X STEREOTACTIC SYSTEM

2020 ◽  
Vol 2 (Supplement_2) ◽  
pp. ii14-ii14
Author(s):  
Nicholas Flores ◽  
David Barranco ◽  
Leland Rogers ◽  
Stephen Sorensen ◽  
Shiv Srivastava ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Cost Effective ◽  
Response To Therapy ◽  
Single Fraction ◽  
Steroid Dependency ◽  
Frameless Radiosurgery ◽  
Stereotactic System ◽  
Dose Homogeneity ◽  
Cost Effective Alternative ◽  
San Carlos

Abstract The Zap-X is a novel self-contained and self-shielded dedicated radiosurgery system developed and manufactured by ZAP Surgical Systems, Inc. of San Carlos, California. Intended for the stereotactic radiosurgery (SRS) treatment of benign and malignant intracranial and cervical spine lesions, this gyroscopically stabilized 3 megavolt (MV) linear accelerator (LINAC) provides a unique radiosurgical alternative for selected patients. Beginning in January 2019, a total of 38 metastatic lesions in 24 patients were treated in our facility. Radiation prescription doses ranged from 1500–1900 cGy (single fraction) to 2500 cGy (five fractions), with treatment volumes ranging from .04 to 15.3 cc. Daily treatment times averaged 45 minutes or less. Target coverage, dose homogeneity, and conformality were comparable to the existing Gamma Knife, CyberKnife and LINAC-based radiosurgery treatment systems in daily use at our facility. As with other frameless radiosurgery platforms, the Zap-X proved particularly useful in situations where either surgery or single-fraction radiosurgery was considered a less desirable treatment option; or when fractionated radiosurgery was thought to be radiobiologically advantageous. All treatments were completed without complication. At two months post-treatment, all lesions showed a complete or partial response to therapy based on MRI scan. None of our patients experienced treatment-related skin reaction, cognitive deficit, fatigue or steroid dependency. Among patients who had previously undergone Gamma Knife treatment, there was a clear preference for frameless radiosurgery. In our experience, the Zap-X delivery system offers a high-precision, patient-friendly and cost-effective alternative to traditional dedicated radiosurgical platforms.

scholarly journals Stereotactic Gamma Knife Radiosurgery for Extracranial Arteriovenous Malformations

2020 ◽  
Vol 98 (6) ◽  
pp. 424-431
Author(s):  
Michaela Dedeciusova ◽  
Constantin Tuleasca ◽  
Steven David Hajdu ◽  
Luis Schiappacasse ◽  
David Patin ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Arteriovenous Malformations ◽  
Gamma Knife Radiosurgery ◽  
Treatment Method ◽  
Complication Rates ◽  
Historical Cohort ◽  
Single Fraction ◽  
First Case ◽  
Stereotactic Frame ◽  
Brain Avms

<b><i>Introduction:</i></b> Head and neck extracranial arteriovenous malformations (AVMs) are rare pathological conditions which pose diagnostic and reconstruction challenges. Stereotactic radiosurgery (SRS) is nowadays an established treatment method for brain AVMs, with high obliteration and low complication rates. Here we describe the first report of head extracranial AVMs successfully treated by Gamma Knife (GK) as a retrospective historical cohort. <b><i>Methods:</i></b> Over a 9-year period, 2 cases of extracranial AVMs were treated by GK Perfexion (Elekta Instruments AB, Stockholm, Sweden) at a single institution. A stereotactic frame and multimodal imaging, including digital subtraction angiography (DSA), were used. The prescribed dose was 24 Gy at the 50% isodose line. <b><i>Results:</i></b> The first case was of a patient with pulsating tinnitus and left superficial parotido-condylian AVM. Embolization achieved partial obliteration. Tinnitus disappeared during the following 6 months after GK. The second case was a patient with repetitive gingival hemorrhages and right superior maxillary AVM, fed by the right internal maxillary and facial arteries. Embolization achieved partial obliteration with recurrence of symptoms. GK was further performed. DSA confirmed complete obliteration in both patients. <b><i>Conclusions:</i></b> Single-fraction GK radiosurgery appears to be safe and effective for extracranial AVMs. We recommend prescribing doses that are comparable to the ones used for brain AVMs (i.e., 24 Gy). A stereotactic frame is an important tool to ensure higher accuracy in the context of these particular locations. However, in selected cases, a mask could be applied either for single fraction purposes (if in a non-mobile location) or for hypofractionation, in case of larger volumes. These findings should be validated in larger cohorts, inclusively in terms of dose prescription.

Single-fraction Stereotactic Radiosurgery Outcomes for Brain Metastases with Frameless Gamma Knife ICON Radiosurgery

2020 ◽  
Vol 108 (2) ◽  
pp. E29
Author(s):  
Elizabeth Buss ◽  
Horia Vulpe ◽  
Judith Jacobson ◽  
Akshay Save ◽  
Oscar Padilla ◽  
...  
Keyword(s):  
Brain Metastases ◽  
Stereotactic Radiosurgery ◽  
Gamma Knife ◽  
Single Fraction

In vitro biological dosimeter modeling of the glioblastoma response to radiation delivered by the Gamma Knife

2010 ◽  
Vol 113 (Special_Supplement) ◽  
pp. 222-227
Author(s):  
Ryan Smith ◽  
Kris A. Smith ◽  
Christopher A. Biggs ◽  
Adrienne C. Scheck
Keyword(s):  
Cell Line ◽  
Gamma Knife ◽  
Radiation Treatment ◽  
High Dose ◽  
Single Fraction ◽  
Fractionated Radiotherapy ◽  
Tissue Equivalent ◽  
Cell Subpopulations ◽  
Gamma Knife Perfexion

Object The goal of this study was to develop an assay that makes possible the assessment of the glioma cell response to single-fraction high-dose Gamma Knife surgery. In this assay, the isolation of radioresistant cell subpopulations facilitates mechanistic studies of radioresistance. Methods A tissue-equivalent paraffin phantom with an aperture capable of holding an Opticell cell culture cassette was developed for treatment with the Leksell Gamma Knife model C. A second apparatus, which the authors also created, uses the manufacturer-supplied polystyrene phantom, thereby allowing this assay to be performed in the Leksell Gamma Knife Perfexion. After treatment, the cells were morphologically assessed to determine their response to radiation treatment. Two specific parameters were used to determine radiosensitivity: 1) the diameter of the clearing zone, defined as the central region of cell death; and 2) the number of surviving colonies within this central high-dose clearing zone. Results Radioresistance was compared in 2 different cell lines from glioblastomas. The first cell line, ME, was established from a primary tumor before its treatment, and the second cell line, DIV, was established from a tumor that recurred after treatment with chemotherapy and fractionated radiotherapy. The ME cell line had the most robust response to radiosurgery, as characterized by a consistently larger clearing zone (28.33 ± 1.1 mm). In contrast, the clearing zone produced when the DIV cell line was used was 24.0 ± 1 mm, indicating an approximate response difference of 5 Gy. The mean number of surviving colonies within the clearing zone for the ME cell line was 1.33 ± 1 compared with that for the DIV cell line, which was 66.67 ± 2. Conclusions The authors developed a biological dosimeter to model the response of cells from glioblastomas to single-fraction high-dose radiation. This system also allows the identification and isolation of radioresistant cells.

scholarly journals A Rare Event: Pituitary Apoplexy 6 Weeks After Gamma Knife Radiosurgery for a Non-Functioning Pituitary Macroadenoma

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A568-A569
Author(s):  
Gabrielle Sach ◽  
Yu-Fang Wu ◽  
John Fuller ◽  
Andrew Davidson ◽  
Bernard Champion ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Cranial Nerve ◽  
Nerve Palsy ◽  
Pituitary Apoplexy ◽  
Hormone Replacement ◽  
Gamma Knife Radiosurgery ◽  
Pituitary Macroadenoma ◽  
Single Fraction ◽  
Third Nerve Palsy ◽  
Third Nerve

Abstract Background: Pituitary apoplexy is a very uncommon side effect of gamma-knife radiosurgery, with only one other case to our knowledge. We report an acute presentation of pituitary apoplexy within 6 weeks of single fraction gamma-knife stereotactic radiosurgery for a non-functioning pituitary macroadenoma. Clinical Case: An 84-year-old male presented initially to his GP with lethargy. He was found to have a non-functioning pituitary macroadenoma 23Tx17APx12CC mm, with right cavernous sinus invasion causing cranial nerve IV palsy and panhypopituitarism. He declined transsphenoidal surgery. He was managed with pituitary hormone replacement therapy, including full anterior hormone replacement. Approximately 6 months after his initial diagnosis, he underwent single fraction stereotactic gamma knife radiosurgery aimed at local control. One month after single fraction gamma knife radiosurgery the patient presented to another hospital with a new two-day history of nausea, vomiting and persistent bilateral retro-orbital headache. On examination, he was afebrile and alert, with a new third nerve palsy of the right eye. The initial diagnosis was presumed steroid-underdosing by the non-treating team. An MRI of the brain and pituitary gland was performed. Review by the patient’s usual multidisciplinary pituitary care team confirmed acute pituitary apoplexy, with new haemorrhage on imaging in the gland post-gamma knife radiosurgery, with the additional clinical relevant development of a right cranial nerve III palsy. Review of the biochemistry showed to the patient to have a cortisol of &lt;28nmol/L (despite Cortate ingestion), TSH &lt;0.005mIU/L (RI: 0.40-5.00), T4 10.6 pmol/L (RI: 10.0-20.0) and T3 4.1 pmol/L (RI: 2.3-5.7). The patient was commenced on dexamethasone to aid reduction of swelling in the pituitary fossa, and there was resolution of the third nerve palsy. Pituitary apoplexy usually occurs spontaneously without any known precipitant. It has been reported to occur in association with other conditions including fractionated radiotherapy, head trauma, estrogen, anticoagulants1. Gamma knife radiosurgery is a form of stereotactic radiosurgery for intracerebral lesions, with lower overall dose and usually complications. Conclusion: To our knowledge, this is the second case of gamma-knife associated pituitary apoplexy. It raises the importance of recognising an acute clinical deterioration in our patients. References: 1. Briet C, Salenave S, Bonneville JF, Laws ER, Chanson P. Pituitary apoplexy. Endocrine reviews. 2015 Dec 1;36(6):622-45.

Incidence of radiation retinopathy after high-dosage single-fraction gamma knife radiosurgery for choroidal melanoma

Ophthalmology ◽  
2002 ◽  
Vol 109 (5) ◽  
pp. 909-913 ◽  
Author(s):  
Anton Haas ◽  
Oliver Pinter ◽  
Georg Papaefthymiou ◽  
Martin Weger ◽  
Andrea Berghold ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Gamma Knife Radiosurgery ◽  
Choroidal Melanoma ◽  
Radiation Retinopathy ◽  
Single Fraction
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