scholarly journals Multimodality Imaging for Radiosurgical Management of Arteriovenous Malformations

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Ferrat Dincoglan ◽  
Omer Sager ◽  
Seluck Demiral ◽  
Murat Beyzadeoglu
Keyword(s):  
Treatment Planning ◽  
Arteriovenous Malformations ◽  
Multimodality Imaging ◽  
Target Volume ◽  
Endovascular Embolization ◽  
Volume Determination ◽  
Target Definition ◽  
Target Volumes ◽  
Magnetic Resonance Imaging Mri ◽  
Consensus Decision

Background: Cerebral arteriovenous malformations (AVMs) are rarely seen congenital vascular anomalies. AVMs may lead to intracranial hemorrages due to disorganized tangle of vessels. Lifetime risk of bleeding from AVMs may be significant given the diagnosis at typically earlier ages of the lifespan, and complications associated with hemorrhage may lead to substantial morbidity or mortality. Management of AVMs aims at eliminating or reducing the risk of subsequent bleeding. In this context, microvascular surgical resection, endovascular embolization and radiosurgical treatment may be used for management of AVMs.Objective: In this study, we assessed the incorporation of Magnetic Resonance Imaging (MRI) in treatment planning for AVM radiosurgery. Methods: We identified 25 patients receiving radiosurgery for AVMs at our institution. Radiosurgery target volumes generated by using CT-only based imaging and CT-MR fusion based imaging for each patient were evaluated.Results: Twenty five patients undergoing SRS for AVMs were evaluated for target volume determination in this study. Mean target volume was 4.9 cc (range: 1.3-15.9 cc) on CT-only imaging, 5.7 cc (range: 1.4-16.7 cc) on CT-MR fusion based imaging, and 5.9 cc (range: 1.4-16.9 cc) on consensus decision of all treating physicians with colleague peer review. Target definition based on CT-MR fusion based imaging was identical to the consensus decision of all treating physicians in majority of patients.Conclusions: Treatment planning for AVM radiosurgery may be improved by incorporating CT-MR fusion based imaging, which clearly should be supplemented with additional data from angiography. There is need for additional studies to establish a consensus on optimal target definition by multimodality imaging for SRS of AVMs.

scholarly journals Determination of Radiosurgery Treatment Volume for Intracranial Germ Cell Tumors (GCTS)

2020 ◽  
Vol 8 (3) ◽  
Author(s):  
Murat Beyzadeoglu ◽  
Ferrat Dincoglan ◽  
Omer Sager ◽  
Selcuk Demiral
Keyword(s):  
Germ Cell ◽  
Background Radiation ◽  
Germ Cell Tumors ◽  
Target Volume ◽  
Whole Brain Irradiation ◽  
Volume Determination ◽  
Radiation Oncologists ◽  
Intracranial Germ Cell Tumors ◽  
Target Definition ◽  
Treatment Volume

Background: Radiation therapy (RT) volumes for intracranial germ cell tumors (GCTs) may include focal treatment volumes, whole ventricle irradiation, whole brain irradiation, or irradiation of the entire neuroaxis. RT doses and volumes for management of primary intracranial GCTs have been an area of active research over the years. Improved sparing of critical organs by use of less extensive RT volumes and lower doses has been investigated for avoiding excessive morbidity of treatment. Herein, we assess intracranial GCT treatment volume determination. Methods: Treatment volume definition for intracranial GCT by incorporation of Magnetic Resonance Imaging (MRI) was comparatively assessed in our study. Reference volume for comparison purposes was defined after thorough assessment and collaboration of the board certified radiation oncologists. Definition of radiosurgery target volume was based solely on CT images or fusion of CT with MRI. Comparative evaluation of treatment volume determination was performed. Results: Ground truth target volume defined after thorough evaluation and collaboration of the board certified radiation oncologists was similar with treatment volume definition based on CT-MR fusion based imaging. Conclusions: In conclusion, radiosurgery treatment planning for intracranial GCTs may be improved by incorporation of MRI into target definition process. Clearly, further studies are warranted to draw firm conclusions on optimal target definition for intracranial GCT radiosurgery.  

scholarly journals Gamma Knife radiosurgery for the treatment of intracranial dural arteriovenous fistulas

2016 ◽  
Vol 23 (2) ◽  
pp. 211-220 ◽  
Author(s):  
Adam A Dmytriw ◽  
Michael L Schwartz ◽  
Michael D Cusimano ◽  
Vitor Mendes Pereira ◽  
Timo Krings ◽  
...  
Keyword(s):  
Gamma Knife ◽  
De Novo ◽  
Gamma Knife Radiosurgery ◽  
Target Volume ◽  
Endovascular Embolization ◽  
Arteriovenous Fistulas ◽  
Alternative Treatment Option ◽  
Target Volumes ◽  
One Year ◽  
Symptom Palliation

Background Intracranial dural arteriovenous fistulae (DAVF) may present a treatment challenge. Endovascular embolization is in most cases the first line of treatment but does not always achieve cure. Gamma Knife (GK) radiosurgery represents an alternative treatment option, and the purpose of this study was to further evaluate its utility. Methods We reviewed all cases of DAVF treated between 2009 and 2016 at our institution with GK radiosurgery independently, or following failed/refused endovascular or surgical management. Patients’ clinical files, radiological images, catheter angiograms, and surgical DAVF disconnection reports were retrospectively reviewed. Results Sixteen DAVF (14 patients) treated by GK radiosurgery were identified. Eleven fistulae were aggressive and five were benign. Marginal doses ranged from 15 to 25 Gy. Target volumes ranged from 0.04 to 4.47 cm3. In all symptomatic patients, GK treatment resulted in symptom palliation. In 13/15 lesions, cure of symptoms (86.0%) was reported. One lesion was asymptomatic. Angiographic cure was achieved in eight cases (50%), small residual DAVF occurred in four, and four were unchanged. One patient developed headache that resolved at one year. No hemorrhage occurred during the follow-up period. There was no significant association between Borden type and cure rate. Prior failed endovascular treatment and small target volume were associated with lower rates of cure. Conclusions Stereotactic radiosurgery is viable treatment for DAVF. It is very effective in palliating symptoms as a de novo approach or adjunctive to endovascular therapy. In our experience it is only somewhat effective in achieving complete angiographic cure.

Stereotactic Radiosurgery for Motor Cortex Region Arteriovenous Malformations

Neurosurgery ◽  
2001 ◽  
Vol 48 (1) ◽  
pp. 70-77 ◽  
Author(s):  
Constantinos G. Hadjipanayis ◽  
Elad I. Levy ◽  
Ajay Niranjan ◽  
Andrew D. Firlik ◽  
Douglas Kondziolka ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Stereotactic Radiosurgery ◽  
Arteriovenous Malformations ◽  
Target Volume ◽  
Complete Obliteration ◽  
Target Volumes ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Abstract OBJECTIVE The optimal management of arteriovenous malformations (AVMs) in critical brain locations remains controversial. To reduce the risk of an AVM hemorrhage and to enhance the possibility of preserving neurological function, stereotactic radiosurgery was performed in 33 patients with newly diagnosed or residual AVMs located within the motor cortex. The role of embolization also was examined. METHODS During a 9-year study period, 33 patients with AVMs located primarily in the motor cortex region were treated with stereotactic radiosurgery. These patients were followed up radiographically for a minimum of 36 months, or less if obliteration was documented before 36 months had elapsed. Of the 33 patients, 9 underwent embolization and 1 underwent microsurgery before radiosurgery. Nine patients required a second radiosurgery. The mean AVM target volume was 4.35 cc, and the average radiation dose to the AVM margin was 20 Gy. The median follow-up was 36 months (range, 10–91 mo), and angiographic follow-up of eligible patients was performed 24 or 36 months after radiosurgery. RESULTS Results were stratified by radiosurgical target volumes: less than 3 cc (Group 1), 3 to 10 cc (Group 2), and greater than 10 cc (Group 3). Overall (including second radiosurgery), 13 (87%) of 15 patients in Group 1 had complete obliteration confirmed by angiography. Nine (64%) of 14 patients in Group 2 exhibited nidus obliteration, and one (25%) of four patients in Group 3 demonstrated obliteration on a magnetic resonance imaging scan. Eight patients (24%) underwent second-stage radiosurgery after angiography revealed a persistent AVM nidus; three patients demonstrated complete obliteration on follow-up angiography. The obliteration rate was higher (87%) for AVMs with less than 3 cc target volume and lower (56%) for those with target volumes larger than 3 cc. One patient experienced worsening neurological function after radiosurgery, and one died from delayed AVM hemorrhage during the latency period. No patient bled after angiographically confirmed AVM obliteration. CONCLUSION Stereotactic radiosurgery is a successful and safe management option for patients with motor cortex AVMs. The obliteration of AVMs and the attendant low morbidity rates indicate a primary role for radiosurgery in these patients. Staged radiosurgery may be necessary to increase obliteration rates for larger AVMs or for those that are not obliterated after the first procedure.

SPECIAL ASPECTS OF DIAGNOSTIC IMAGING FOR RADIOSURGERY OF ARTERIOVENOUS MALFORMATIONS

Neurosurgery ◽  
2008 ◽  
Vol 62 (suppl_5) ◽  
pp. A44-A52 ◽  
Author(s):  
Klaus D. Hamm ◽  
Joachim Klisch ◽  
Gunnar Surber ◽  
Gabriele Kleinert ◽  
Cornelia Eger ◽  
...  
Keyword(s):  
Image Fusion ◽  
Treatment Planning ◽  
Arteriovenous Malformations ◽  
Target Volume ◽  
Quantitative Comparison ◽  
Wilcoxon Test ◽  
Data Sets ◽  
Fusion Algorithm ◽  
Follow Up Studies

ABSTRACT OBJECTIVE Radiosurgery can be considered a well-established option for the treatment of arteriovenous malformations (AVMs). The exact application of the therapeutic dose is based on the availability of imaging data sets with superior image quality that can be superimposed using an image fusion algorithm. For follow-up studies, the quantitative comparison of the respective image data sets also plays an important role. Until now, digital subtraction angiography (DSA) has been a mandatory tool for treatment planning and follow-up procedures. The aim of this study was to investigate whether a suitable computed tomographic (CT) and/or magnetic resonance (MR) angiography procedure can replace DSA and, if so, in which cases. METHODS For 34 AVM patients, various MR data sets were used together with the stereotactically localized CT and DSA data sets for treatment planning. To define the AVM nidus precisely, all available MR data sets were fused onto the CT data set by the use of an automatic image fusion algorithm. The nidus was outlined in both localized DSA projections, resulting in the DSA target volume. Subsequently, the DSA target volume was adapted by inclusion of the available CT/MR data sets (localized and/or fused, slice by slice), resulting in the final target volume. Finally, both volumes were compared and analyzed. For precise comparison purposes, all available digital follow-up studies were fused. RESULTS In all cases, the thin-slice MR data sets (1-mm slice width) that included T1-weighted series and time of flight angiographies have been precisely fused onto the stereotactically localized treatment planning CT. The final target volume was compared with the DSA target volume as follows. In 19 cases, the final target volume was larger than the DSA target volume; in six cases, it was smaller; and in five cases, it was approximately equal. The difference was significant (Wilcoxon test, difference <0.0001; t test, t = 3.01; P > 0.005). In four cases, outlining the AVM was not possible without DSA. In five patients, a two- or three-vessel DSA was needed because there were different AVM compartments. In cases in which a previous partial embolization had been undergone by the patient, the use of superimposed CT sets with and without contrast medium was important to define the completely embolized partial volumes that were not subject to treatment. The inclusion of the DSA images enabled a better identification of those arterialized veins that did not belong to the nidus. In six cases, the follow-up MR studies showed contrast enhancements overlapping the AVM nidus as a result of brain-blood barrier disturbances (T1-weighted series with contrast). In seven cases, perifocal reactions were primarily observed (T2-weighted series) 12 months after treatment with rather low clinical relevance. CONCLUSION By integrating all available imaging modalities, the exact three-dimensional definition of the AVM nidus was safely realized for all patients. Stereotactic DSA data acquisition remains a crucial tool for safe nidus definition in radiosurgery treatment planning and cannot, therefore, be discarded at present. It is recommended that a quantitative comparison of all MR follow-up studies be established.

scholarly journals Impact of 68Ga-DOTATOC PET/MRI on robotic radiosurgery treatment planning in meningioma patients: first experiences in a single institution

2019 ◽  
Vol 46 (6) ◽  
pp. E9 ◽  
Author(s):  
Güliz Acker ◽  
Anne Kluge ◽  
Mathias Lukas ◽  
Alfredo Conti ◽  
Diana Pasemann ◽  
...  
Keyword(s):  
Treatment Planning ◽  
Organs At Risk ◽  
Target Volume ◽  
Data Sets ◽  
Robotic Radiosurgery ◽  
Volume Delineation ◽  
Complex Shapes ◽  
Target Volumes ◽  
Skull Base Lesions ◽  
The Impact

OBJECTIVEFor stereotactic radiosurgery (SRS) planning, precise contouring of tumor boundaries and organs at risk is of utmost importance. Correct interpretation of standard neuroimaging (i.e., CT and MRI) can be challenging after previous surgeries or in cases of skull base lesions with complex shapes. The aim of this study was to evaluate the impact of 68Ga-DOTATOC PET/MRI on treatment planning for image-guided SRS by CyberKnife.METHODSThe authors retrospectively identified 11 meningioma treatments in 10 patients who received a 68Ga-DOTATOC PET/MRI prior to SRS. The planning target volume (PTV) used for the patients’ treatment was defined as the reference standard. This was contoured by a treating radiosurgeon (RS0) using fused planning CT and PET/MRI data sets. The same tumors were then contoured by another experienced radiosurgeon (RS1) and by a less-experienced radiosurgeon (RS2), both blinded to PET data sets. A comparison of target volumes with focus on volume-based metrics and distance to critical structures was performed. RS1 and RS2 also filled in a questionnaire analyzing the confidence level and the subjective need for the implementation of PET data sets for contouring.RESULTSAnalysis showed a subjective personal preference for PET/MRI in all cases for both radiosurgeons, particularly in proximity to critical structures. The analysis of the planning volumes per physician showed significantly smaller RS2-PTV in comparison to RS1-PTV and to RS0-PTV, whereas the median volumes were comparable between RS1-PTV and RS2-PTV (median: RS0: 4.3 cm3 [IQR 3.4–6.5 cm3] and RS1: 4.5 cm3 [IQR 2.7–6 cm3] vs RS2: 2.6 cm3 [IQR 2–5 cm3]; p = 0.003). This was also reflected in the best spatial congruency between the 2 experienced physicians (RS0 and RS1). The percentage of the left-out volume contoured by RS1 and RS2 compared to RS0 with PET/MRI demonstrated a relevant left-out-volume portion in both cases with greater extent for the less-experienced radiosurgeon (RS2) (RS1: 19.1% [IQR 8.5%–22%] vs RS2: 40.2% [IQR 34.2%–53%]). No significant differences were detected regarding investigated critical structures.CONCLUSIONSThis study demonstrated a relevant impact of PET/MRI on target volume delineation of meningiomas. The extent was highly dependent on the experience of the treating physician. This preliminary study supports the relevance of 68Ga-DOTATOC PET/MRI as a tool for radiosurgical treatment planning of meningiomas.

The integration of metabolic imaging in stereotactic procedures including radiosurgery: a review

2002 ◽  
Vol 97 ◽  
pp. 542-550 ◽  
Author(s):  
Marc Levivier ◽  
David Wikler ◽  
Nicolas Massager ◽  
Philippe David ◽  
Daniel Devriendt ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Brain Tumors ◽  
Treatment Planning ◽  
Target Volume ◽  
Emission Tomography ◽  
Low Grade ◽  
Content Type ◽  
Positron Emission ◽  
Pet Scanning ◽  
Fine Print

Object. The authors review their experience with the clinical development and routine use of positron emission tomography (PET) during stereotactic procedures, including the use of PET-guided gamma knife radiosurgery (GKS). Methods. Techniques have been developed for the routine use of stereotactic PET, and accumulated experience using PET-guided stereotactic procedures over the past 10 years includes more than 150 stereotactic biopsies, 43 neuronavigation procedures, and 34 cases treated with GKS. Positron emission tomography—guided GKS was performed in 24 patients with primary brain tumors (four pilocytic astrocytomas, five low-grade astrocytomas or oligodendrogliomas, seven anaplastic astrocytomas or ependymomas, five glioblastomas, and three neurocytomas), five patients with metastases (single or multiple lesions), and five patients with pituitary adenomas. Conclusions. Data obtained with PET scanning can be integrated with GKS treatment planning, enabling access to metabolic information with high spatial accuracy. Positron emission tomography data can be successfully combined with magnetic resonance imaging data to provide specific information for defining the target volume for the radiosurgical treatment in patients with recurrent brain tumors, such as glioma, metastasis, and pituitary adenoma. This approach is particularly useful for optimizing target selection for infiltrating or ill-defined brain lesions. The use of PET scanning contributed data in 31 cases (93%) and information that was specifically utilized to adapt the target volume in 25 cases (74%). It would seem that the integration of PET data into GKS treatment planning may represent an important step toward further developments in radiosurgery: this approach provides additional information that may open new perspectives for the optimization of the treatment of brain tumors.

A comprehensive evaluation of the quality and complexity of prostate IMRT and VMAT plans generated by an automated inverse planning tool

2021 ◽  
pp. 1-7
Author(s):  
Dean Wilkinson ◽  
Kelly Mackie ◽  
Dean Novy ◽  
Frances Beaven ◽  
Joanne McNamara ◽  
...  
Keyword(s):  
Dose Level ◽  
Comprehensive Evaluation ◽  
Volumetric Modulated Arc Therapy ◽  
Intensity Modulated Radiotherapy ◽  
Target Volume ◽  
Planning Tool ◽  
Inverse Planning ◽  
Dose Planning ◽  
Target Volumes ◽  
Lymph Node Irradiation

Abstract Introduction: The Pinnacle3 Auto-Planning (AP) package is an automated inverse planning tool employing a multi-sequence optimisation algorithm. The nature of the optimisation aims to improve the overall quality of radiotherapy plans but at the same time may produce higher modulation, increasing plan complexity and challenging linear accelerator delivery capability. Methods and materials: Thirty patients previously treated with intensity-modulated radiotherapy (IMRT) to the prostate with or without pelvic lymph node irradiation were replanned with locally developed AP techniques for step-and-shoot IMRT (AP-IMRT) and volumetric-modulated arc therapy (AP-VMAT). Each case was also planned with VMAT using conventional inverse planning. The patient cohort was separated into two groups, those with a single primary target volume (PTV) and those with dual PTVs of differing prescription dose levels. Plan complexity was assessed using the modulation complexity score. Results: Plans produced with AP provided equivalent or better dose coverage to target volumes whilst effectively reducing organ at risk (OAR) doses. For IMRT plans, the use of AP resulted in a mean reduction in bladder V50Gy by 4·2 and 4·7 % (p ≤ 0·01) and V40Gy by 4·8 and 11·3 % (p < 0·01) in the single and dual dose level cohorts, respectively. For the rectum, V70Gy, V60Gy and V40Gy were all reduced in the dual dose level AP-VMAT plans by an average of 2·0, 2·7 and 7·3 % (p < 0·01), respectively. A small increase in plan complexity was observed only in dual dose level AP plans. Findings: The automated nature of AP led to high quality treatment plans with improvement in OAR sparing and minimised the variation in achievable dose planning metrics when compared to the conventional inverse planning approach.

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