CT cisternography to visualize epidermoid tumors for stereotactic radiosurgery treatment planning

2021 ◽  
Vol 89 ◽  
pp. 91-96
Author(s):  
Leslie A. Nussbaum ◽  
Camille A. Schwarzrock ◽  
Elizabeth M. Burke ◽  
Collin M. Torok ◽  
Eric S. Nussbaum
Keyword(s):  
Stereotactic Radiosurgery ◽  
Treatment Planning ◽  
Ct Cisternography

scholarly journals Stereotactic diffusion tensor imaging tractography for Gamma Knife radiosurgery

2016 ◽  
Vol 125 (Supplement_1) ◽  
pp. 139-146 ◽  
Author(s):  
Cormac G. Gavin ◽  
H. Ian Sabin
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Stereotactic Radiosurgery ◽  
Treatment Planning ◽  
Vestibular Schwannoma ◽  
Diffusion Tensor ◽  
Gamma Knife Radiosurgery ◽  
Optic Radiation ◽  
Arcuate Fasciculus ◽  
Stereotactic Frame

OBJECTIVEThe integration of modern neuroimaging into treatment planning has increased the therapeutic potential and safety of stereotactic radiosurgery. The authors report their method of integrating stereotactic diffusion tensor imaging (DTI) tractography into conventional treatment planning for Gamma Knife radiosurgery (GKRS). The aim of this study was to demonstrate the feasibility of this technique and to address some of the technical limitations of previously reported techniques.METHODSTwenty patients who underwent GKRS composed the study cohort. They consisted of 1 initial test case (a patient with a vestibular schwannoma), 5 patients with arteriovenous malformations, 9 patients with cerebral metastases, 1 patient with parasagittal meningioma, and 4 patients with vestibular schwannoma. DT images were obtained at the time of standard GKRS protocol MRI (T1 and T2 weighted) for treatment, with the patient's head secured by a Leksell stereotactic frame. All studies were performed using a 1.5-T magnet with a single-channel head coil. DTI was performed with diffusion gradients in 32 directions and coregistered with the volumetric T1-weighted study. DTI postprocessing by means of commercially available software allowed tensor computation and the creation of directionally encoded color–, apparent diffusion coefficient–, and fractional anisotropy–mapped sequences. In addition, the software allowed visualized critical tracts to be exported as a structural volume and integrated into GammaPlan as an “organ at risk” during shot planning. Combined images were transferred to GammaPlan and integrated into treatment planning.RESULTSStereotactic DT images were successfully acquired in all patients, with generation of correct directionally encoded color images. Tract generation with the software was straightforward and reproducible, particularly for axial tracts such as the optic radiation and the arcuate fasciculus. Corticospinal tract visualization was hampered by some artifacts from the base of the stereotactic frame, but this was overcome by a combination of frame/MRI volume adjustment and DTI seeding parameters. Coregistration of the DTI series with the T1-weighted treatment volume at the time of imaging was essential for the generation of correct tensor data. All patients with the exception of the vestibular schwannoma cases had treatment pathology in the vicinity of eloquent tracts and/or the cortex. No new neurological deficits due to radiation were recorded at the short-term follow-up.CONCLUSIONSRecent reports in the medical literature have suggested that white matter tracts (particularly the optic radiation and arcuate fasciculus) are more vulnerable to radiation during stereotactic radiosurgery than previously thought. Integration of stereotactic tractography into GKRS represents a promising tool for preventing GKRS complications by reduction in radiation doses to functional organs at risk, including critical cortical areas and subcortical white matter tracts.

Assessment of sequence dependent geometric distortion in contrast-enhanced MR images employed in stereotactic radiosurgery treatment planning

2018 ◽  
Vol 63 (13) ◽  
pp. 135006 ◽  
Author(s):  
Eleftherios P Pappas ◽  
Ioannis Seimenis ◽  
Dimitrios Dellios ◽  
Georgios Kollias ◽  
Kostas I Lampropoulos ◽  
...  
Keyword(s):  
Stereotactic Radiosurgery ◽  
Treatment Planning ◽  
Geometric Distortion ◽  
Mr Images ◽  
Sequence Dependent ◽  
Contrast Enhanced

Identification of occult brain metastases amenable to stereotactic radiosurgery by motexafin gadolinium (MGd) based treatment planning MRI: Results of a phase II trial of MGd and whole brain radiotherapy (WBRT) with stereotactic radiosurgery (SRS)

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 2037-2037
Author(s):  
M. P. Mehta ◽  
A. Dagnault ◽  
P. Chabot ◽  
J. Suh ◽  
E. Chang ◽  
...  
Keyword(s):  
Brain Metastases ◽  
Stereotactic Radiosurgery ◽  
Treatment Planning ◽  
Phase Ii ◽  
Phase Ii Trial ◽  
Whole Brain Radiotherapy ◽  
Gadolinium Contrast ◽  
Motexafin Gadolinium ◽  
Occult Lesion ◽  
Grade 3

2037 Background: Motexafin gadolinium (MGd) is a novel anti-cancer agent that selectively localizes in tumors and is detectable by MRI. Previous studies of patients (pts) with brain metastases (BM) demonstrated the detection of occult lesions after MGd administration not visible with gadolinium MRI contrast. The purpose of this study was to evaluate if MRI scanning after MGd improves SRS treatment-planning and treatment outcome by identifying and better defining lesions that can be treated with the SRS boost. Methods: Pts with 1–4 BM (< 4 cm diameter, or, if multiple, < 3cm) received WBRT (37.5 Gy) and MGd, 5 mg/kg/day during weeks 2–3 of WBRT, plus MGd, 5 mg/kg prior to treatment planning MRI and prior to SRS (21 Gy for lesions = 2 cm, 18 Gy for lesions 2.1–3.0 cm, and 15 Gy for lesions 3.1–4.0 cm). MRI was obtained within 4 weeks prior to enrollment with standard contrast, and after WBRT for SRS treatment planning with MGd and standard contrast. Patients were followed for neurologic progression and survival. Results: 45 patients with either lung cancer (76%), breast cancer (11%), melanoma (7%), or other cancers (7%), a median age of 58 years (range 42–74), and a median of 2 BM (range 1–4) were evaluable. In 9 of 42 patients (21%) with MRI data available, the MGd-based treatment planning MRI demonstrated at least one occult lesion not visualized on the screening MRI. The MGd-based treatment planning MRI detected 1 occult lesion in 6 pts, 2 occult lesions in 1 patient, and 3 occult lesions in 2 patients. Median survival for evaluable pts is 10 months; median time to neurologic progression or radiologic progresssion is not reached at 15 months. Grade 3+ neurotoxicity was limited to 1 pt with tumor necrosis and 1 pt with motor weakness. Most common Grade 3+ adverse events were pneumonia (9%) and DVT (9%). Conclusions: MGd-based treatment planning MRI for SRS identified occult BM that are amenable to SRS and are undetected with standard gadolinium contrast agents in 21% of the pts enrolled in this phase II trial. Treatment with MGd, WBRT and SRS to all lesions visualized resulted in improved survival and local control compared with historical results. [Table: see text]

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