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Journal of Applied Clinical Medical... Mar 2022The Leksell Gamma Knife Icon unit (IU) was introduced recently as an upgrade to the Perfexion unit (PU) at our Gamma Knife practice. In the current study, we sought...
PURPOSE
The Leksell Gamma Knife Icon unit (IU) was introduced recently as an upgrade to the Perfexion unit (PU) at our Gamma Knife practice. In the current study, we sought mainly to characterize dosimetry and targeting accuracy of the IU treatment deliveries using both invasive frame and frameless treatment workflows.
METHODS
Relative output factors were measured by delivering single-shot 4, 8 and 16 mm radiation profiles in the manufacturer's acrylonitrile butadiene styrene spherical phantom in coronal and sagittal planes using EBT3 film. Resultant dosimetry was compared with the manufacturer's dose calculation and derived output factors were compared with the manufacturer's published value. Geometric consistency of stereotactic coordinates based on cone-beam computed tomography (CBCT) versus the traditional conventional CT-based method was characterized using a rigid phantom containing nine fiducial indicators over four separate trials. End-to-end (E2E) testing using EBT3 film was designed to evaluate both dosimetric and geometric accuracy for hypothetical framed and frameless workflows.
RESULTS
Relative output factors as measured by the manufacturer were independently confirmed using EBT3 film measurements to within 2%. The mean 3D radial discrepancy in stereotactic space between CBCT and CT-based definition over the sampled locations in our rigid geometry phantom was demonstrated to be between 0.40 mm and 0.56 mm over the set of trials, larger than prior reported values. E2E performed in 2D demonstrates sub-mm (and typically < 0.5 mm) accuracy for framed and frameless workflows; geometric accuracy of framed treatments using CBCT-defined stereotactic coordinates was shown to be slightly improved in comparison with those defined using conventional CT. Furthermore, in phantom, frameless workflows exhibited better accuracy than framed workflows for fractionated treatments, despite large magnitudes of introduced interfraction setup error. Accuracy of dosimetric delivery was confirmed in terms of qualitative comparisons of dose profiles and in terms of 2D gamma pass rates based on 1%/1 mm criteria.
CONCLUSION
The IU was commissioned for clinical use of frameless and framed treatment protocols. The present study outlines an extensive E2E methodology for confirmation of dosimetric and geometric treatment accuracy.
Topics: Cone-Beam Computed Tomography; Humans; Imaging, Three-Dimensional; Phantoms, Imaging; Radiosurgery; Workflow
PubMed: 35064749
DOI: 10.1002/acm2.13475 -
PloS One 2022Cerebral arteriovenous malformations (AVMs) are challenging lesions, often requiring multimodal interventions; however, data on the efficacy of stereotactic radiosurgery...
BACKGROUND
Cerebral arteriovenous malformations (AVMs) are challenging lesions, often requiring multimodal interventions; however, data on the efficacy of stereotactic radiosurgery for cerebral AVMs are limited. This study aimed to evaluate the clinical and radiographic results following robotic radiosurgery, alone or in combination with endovascular treatment, and to investigate factors associated with obliteration and complications in patients with AVM.
METHODS
We retrospectively analyzed the clinical and imaging characteristics of 123 patients with AVMs of all Spetzler-Martin grades treated at two institutions by robotic radiosurgery in single-fraction doses (CyberKnife). Embolization was performed before radiosurgery in a subset of patients to attempt to downgrade the lesions. Factors associated with AVM obliteration and complications (toxicity) were identified via univariate and multivariate analyses.
RESULTS
The median follow-up time was 48.1 months (range, 3.6-123 months). Five patients were lost to follow-up. The obliteration rate in the 59 patients with a follow-up period exceeding four years was 72.8%. Complete obliteration and partial remission were achieved in 67 (56.8%) and 31 (26.3%) cases, respectively, whereas no change was observed in 20 cases (17.8%). Embolization was performed in 54/123 cases (43.9%). Complete and partial obliteration were achieved in 29 (55.7%) and 14 (26.9%) embolized patients, respectively. In the multivariate analysis, the factors associated with obliteration were age (p = .018) and the Spetzler-Martin grade (p = .041). Treatment-induced toxicity (radiation necrosis and/or edema) was observed in 15 cases (12.7%), rebleeding occurred in three cases (2.5%), and the rate of mortality associated with rebleeding was 1.7%.
CONCLUSIONS
CyberKnife radiosurgery is a valid approach for treating AVMs of all Spetzler-Martin-grades, with satisfactory obliteration rates, low toxicity, and a relatively rare incidence of rebleeding.
Topics: Follow-Up Studies; Humans; Intracranial Arteriovenous Malformations; Radiosurgery; Retrospective Studies; Robotic Surgical Procedures; Treatment Outcome
PubMed: 36137082
DOI: 10.1371/journal.pone.0266744 -
Technology in Cancer Research &... Feb 2012
Topics: Brain; Humans; Radiosurgery; Spinal Cord
PubMed: 22181325
DOI: 10.7785/tcrt.2012.500228 -
Technology in Cancer Research &... Jan 2018In recent years, the concept of oligometastases has become accepted and reports on stereotactic body radiotherapy as a treatment method have been published. Lesions in... (Review)
Review
In recent years, the concept of oligometastases has become accepted and reports on stereotactic body radiotherapy as a treatment method have been published. Lesions in the brain, lung, and liver have been reported as target lesions. However, lymph node oligometastases could be a good candidate for stereotactic body radiotherapy as well. In this study, the usability of stereotactic body radiotherapy for oligometastases to lymph nodes is assessed by researching for each primary site. As a result, we could consider that stereotactic body radiotherapy could be almost well applied for lymph node oligometastases from the breast, gynecological organs, and prostate. However, doubts remain concerning the usefulness of stereotactic body radiotherapy for cervical node metastases from head and neck cancer or for mediastinal node metastases from lung or esophageal cancer since late toxicities have occurred with a large radiation dose at hypofractionation to major vessels or the central respiratory tract, especially in patients with irradiation histories. In addition, high-dose irradiation is required to control lymph node metastases from colorectal cancer due to its radioresistance, and severe late adverse events would therefore occur in adjacent organs such as the gastrointestinal tract. In cases of lymph node oligometastases with a primary tumor in the stomach or esophagus, stereotactic body radiotherapy should be used limitedly at present because this patient population is not so large and these metastases are often located close to organs at risk. Because of the varied status of recurrence and varied conditions of patients, it is difficult to determine the optimal dose for tumor control. It might be reasonable to determine the treatment dose individually based on dose constraints of adjacent organs. The oligometastatic state is becoming more frequently identified with more sensitive methods of detecting such oligometastases. In addition, there seems to be another type of oligometastases, so-called induced oligometastases, following successful systemic treatment. To determine the optimal indication of stereotactic body radiotherapy for lymph node oligometastases, further investigation about the mechanisms of oligometastases and further clinical studies including a phase III study are needed.
Topics: Clinical Trials as Topic; Diagnostic Imaging; Humans; Lymph Nodes; Lymphatic Metastasis; Neoplasms; Radiosurgery; Radiotherapy Planning, Computer-Assisted; Treatment Outcome
PubMed: 30352542
DOI: 10.1177/1533033818803597 -
Journal of Cancer Research and Clinical... Jan 2023Meningioma is a common type of benign tumor that can be managed in several ways, ranging from close observation, surgical resection, and various types of radiation. We... (Review)
Review
PURPOSE
Meningioma is a common type of benign tumor that can be managed in several ways, ranging from close observation, surgical resection, and various types of radiation. We present here results from a 10 year experience treating meningiomas with a hypofractionated approach.
MATERIALS AND METHODS
To define the rate of tumor control and factors associated with the relief of symptoms and radiation-related complications after radiosurgery and hypofractionated radiosurgery for patients with imaging-defined intracranial meningiomas. We reviewed the charts of 48 patients treated with stereotactic radiosurgery (SRS) or hypofractionated stereotactic radiotherapy (SRT) from 2002 to 2018. A total of 37 (82%) patients had WHO Grade 1 disease, and 11 (22%) had Grade 2. Outcomes that were analyzed included local control rates and the rate and grade of any reported toxicity.
RESULTS
Only 36 patients with 38 lesions, who underwent the follow-up regime, were enrolled in the retrospective analysis. The follow-up mean was 40 months (12-120 months). 25/34 patients had surgery before the radiotherapy. Sixteen underwent SRS with a median dose of 13, 5, and 20 received hypofractionated SBRT with a median dose of 26.9 (22-45 Gy) in median six fractions (5-13 fractions). Local control at 2 and 5 years for all patients was 90 and 70%, respectively. No patient suffered from toxicity > 2 CTC. 21/36 patients showed stable disease, while 8/36 patients showed partial Remission. 7/36 developed recurrent meningioma (five in-field), only one patient with grade 1 meningioma, in a median of 22 months (13-48 months).
CONCLUSION
SFRT was superior to SRS for local control in our analysis of Grade I meningiomas. This might be due to a tendency for higher EQD2 in the PTV with SFRT compared to SRS, which was reduced to avoid brain necrosis in large PTVs. Therefore, SFRT appears preferable for typical meningioma PTVs.
Topics: Humans; Meningioma; Radiosurgery; Meningeal Neoplasms; Retrospective Studies; Radiation Dose Hypofractionation; Follow-Up Studies; Neoplasm Recurrence, Local; Particle Accelerators; Treatment Outcome
PubMed: 36307558
DOI: 10.1007/s00432-022-04450-y -
Chinese Clinical Oncology Apr 2022The management of metastatic disease has been greatly influenced by molecular-based tumor classification and associated therapeutic targets, leading to a significant... (Review)
Review
BACKGROUND AND OBJECTIVE
The management of metastatic disease has been greatly influenced by molecular-based tumor classification and associated therapeutic targets, leading to a significant improvement in survival in many cases. This improvement, in both progression free survival and overall survival, has led to an increased incidence of brain metastases (BM) in a population with systemically well controlled disease or patients with promising therapeutic options available. Within this review, we discuss the paradigm of treatment for 5 to 15 BM, and how the treatment has evolved away from short-term palliation towards providing long term intracranial control.
METHODS
A review of literature pertaining to treatment of multiple BM was performed. We searched in PubMed to identify literature on treatment of multiple brain metastases. Only English literature published until February 1st, 2022 was reviewed.
KEY CONTENT AND FINDINGS
The management of 5-15 BM include multi-modality treatment pathways that are tailored towards each individual's primary cancer and burden of disease. Surgical resection of a dominant metastasis is still reserved for large symptomatic lesions, and is combined with post-operative local disease control. Overall, there is a shift away from whole brain radiation therapy (WBRT) due to side effect profile towards stereotactic radiosurgery (SRS). However, advances in WBRT continue to be studied, as well as the use of immunotherapy, targetable mutations, and synergistic effects between SRS and targeted therapies.
CONCLUSIONS
The use of SRS to treat 5 to 15 BM is an increasingly acceptable and well-regarded practice, along with a combinatorial approach taking into account systemic options during all treatment timepoints.
Topics: Brain Neoplasms; Combined Modality Therapy; Cranial Irradiation; Humans; Radiosurgery
PubMed: 35534795
DOI: 10.21037/cco-22-15 -
Journal of Cancer Research and... 2018As a radiosurgical tool, Gamma Knife has the best and widespread name recognition. Gamma Knife is a noninvasive intracranial technique invented and developed by Swedish... (Review)
Review
As a radiosurgical tool, Gamma Knife has the best and widespread name recognition. Gamma Knife is a noninvasive intracranial technique invented and developed by Swedish neurosurgeon Lars Leksell. The first commercial Leksell Gamma Knife entered the therapeutic armamentarium at the University of Pittsburgh in the United States on August 1987. Since that time, different generation of Gamma Knife developed. In this study, the technical points and dosimetric parameters including full width at half maximum and penumbra on different generation of Gamma Knife will be reviewed and compared. The results of this review study show that the rotating gamma system provides a better dose conformity.
Topics: Humans; Neoplasms; Radiometry; Radiosurgery
PubMed: 29516905
DOI: 10.4103/0973-1482.189248 -
Radiation Oncology (London, England) Oct 2016Stereotactic radiosurgery (SRS) delivered as either single-fraction or multi-fraction SRS (2-5 fractions) is frequently employed in patients with residual or recurrent... (Review)
Review
Stereotactic radiosurgery (SRS) delivered as either single-fraction or multi-fraction SRS (2-5 fractions) is frequently employed in patients with residual or recurrent pituitary adenoma. The most common delivery systems used for SRS include the cobalt-60 system Gamma Knife, the CyberKnife (CK) robotic radiosurgery system, or a modified conventional radiotherapy machine (linear accelerator, LINAC). Tumor control and normalization of hormone hypersecretion have been reported in 75-100 % and 25-80 % of patients, respectively. Hypopituitarism is the most commonly reported late complication of radiation treatment, whereas other toxicities occur less frequently. We have provided an overview of the recent available literature on SRS in patients with a pituitary adenoma. Critical aspects of pituitary irradiation, including target delineation and doses to organs at risk, optimal radiation dose, as well as the long-term efficacy and toxicity of SRS for either nonfunctioning or secreting pituitary adenomas are discussed. Single-fraction SRS represents an effective treatment for patients with a pituitary adenoma; however, caution should be used for lesions > 2.5-3 cm in size and/or involving the anterior optic pathway. Future studies will be necessary to optimize target doses and critical organ dose constrains in order to reduce the long-term toxicity of treatments while maintaining high efficacy.
Topics: Adenoma; Brain Stem; Hippocampus; Humans; Hypopituitarism; Optic Nerve Diseases; Pituitary ACTH Hypersecretion; Pituitary Neoplasms; Radiosurgery; Radiotherapy Dosage
PubMed: 27729088
DOI: 10.1186/s13014-016-0710-y -
Seminars in Radiation Oncology Apr 2022For patients with oligometastatic cancer, radiotherapy presents a promising avenue for achieving meaningful symptom relief and durable disease control. Data from... (Review)
Review
For patients with oligometastatic cancer, radiotherapy presents a promising avenue for achieving meaningful symptom relief and durable disease control. Data from recently published and ongoing randomized studies are helping to define the appropriate contexts for effective intervention with stereotactic ablative body radiotherapy (SABR) in the oligometastatic setting. Importantly, older adults represent a significant portion of patients with oligometastatic disease, yet often comprise a minority of patients in clinical trials. Moreover, older adults of the same chronologic age may have variable degrees of fitness and frailty. In this review, we highlight the specific challenges and considerations for the use of radiotherapy for older adults with oligometastatic disease-noting the importance of geriatric assessments in clinical decision-making about the appropriateness of SABR and other metastasis-directed therapies in this population. We then review data from existing trials, including a subset analysis of adverse events and survival estimates among older adults enrolled in the landmark SABR-COMET trial. Finally, we discuss future directions for research, including the need for focused clinical trials in older adult cohorts. Ultimately, a multidisciplinary approach is critical when carefully balancing the potential risks and benefits of this emerging treatment paradigm in the older adult population.
Topics: Aged; Humans; Neoplasms; Radiosurgery
PubMed: 35307115
DOI: 10.1016/j.semradonc.2021.11.009 -
Deutsches Arzteblatt International Feb 2009Radiosurgery is a special treatment method that employs highly focused radiation to destroy tumors with high precision in a single session. A broad base of scientific... (Review)
Review
BACKGROUND
Radiosurgery is a special treatment method that employs highly focused radiation to destroy tumors with high precision in a single session. A broad base of scientific evidence already exists for the radiosurgical treatment of brain metastases. Recent advances in medical technology now allow radiosurgery to be extended to the spine as well.
METHODS
Selective literature review based on a PubMed search using the search terms stereotaxis, radiosurgery, stereotactic radiotherapy, accuracy, quality assurance, spine, spine metastasis, pain, Novalis, CyberKnife, Synergy, and robotics. We also present and analyze our own data as an illustration of the application of spinal radiosurgery.
RESULTS
The literature search identified 20 scientific original publications and one recent review. The data indicate that, within the specific constraints of the method, radiosurgery can arrest the growth of up to 96% of spinal metastases. Durable pain relief can be achieved in patients with tumor-associated pain syndromes. The morbidity of spinal radiosurgery is low, with a less than 1% risk of myelopathy.
CONCLUSIONS
Spinal radiosurgery is an independent, essentially noninvasive method of treatment. Different types of radiosurgical treatment apparatus are available. For properly selected patients, radiosurgery offers a good chance of therapeutic success with relatively rare complications.
Topics: Humans; Neoplasms; Radiosurgery; Surgery, Computer-Assisted
PubMed: 19562022
DOI: 10.3238/arztebl.2009.0106