Time and dose dependency of radiation-induced changes in tumor microvascular characteristics using contrast-enhanced magnetic resonance imaging: Impact on the delivery of chemotherapeutic agents

1996 ◽  
Vol 3 ◽  
pp. S347-S348 ◽  
Author(s):  
Heidi C. Schmidt ◽  
Robert C. Brasch ◽  
Timothy P.L. Roberts ◽  
David M. Shames ◽  
Cornelis F. van Dijke ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Chemotherapeutic Agents ◽  
Resonance Imaging ◽  
Dose Dependency ◽  
Contrast Enhanced ◽  
Radiation Induced ◽  
Induced Changes

scholarly journals Repeat Gamma Knife Surgery for Incompletely Obliterated Cerebral Arteriovenous Malformations

Neurosurgery ◽  
2010 ◽  
Vol 67 (1) ◽  
pp. 55-64 ◽  
Author(s):  
Chun-Po Yen ◽  
Surbhi Jain ◽  
Iftikhar-ul Haq ◽  
Jay Jagannathan ◽  
David Schlesinger ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Gamma Knife ◽  
Arteriovenous Malformations ◽  
Gamma Knife Surgery ◽  
Neurological Deficits ◽  
Resonance Imaging ◽  
Cerebral Arteriovenous Malformations ◽  
Radiation Induced ◽  
Induced Changes

Abstract OBJECTIVE The causes of failure after an initial Gamma procedure were studied, along with imaging and clinical outcomes, in a series of 140 patients with cerebral arteriovenous malformations (AVMs) treated with repeat Gamma Knife surgery (GKS). METHODS Causes of initial treatment failure included inaccurate nidus definition in 14 patients, failure to fill part of the nidus as a result of hemodynamic factors in 16, recanalization of embolized AVM compartments in 6, and suboptimal dose (< 20 Gy) in 23. Nineteen patients had repeat GKS for subtotal obliteration of AVMs. In 62 patients, the AVM failed to obliterate despite correct target definition and adequate dose. At the time of retreatment, the nidus volume ranged from 0.1 to 6.9 cm3 (mean, 1.4 cm3), and the mean prescription dose was 20.3 Gy. RESULTS Repeat GKS yielded a total angiographic obliteration in 77 patients (55%) and subtotal obliteration in 9 (6.4%). In 38 patients (27.1%), the AVMs remained patent, and in 16 patients (11.4%), no flow voids were observed on magnetic resonance imaging. Clinically, 126 patients improved or remained stable, and 14 experienced deterioration (8 resulting from a rebleed, 2 caused by persistent arteriovenous shunting, and 4 related to radiation-induced changes). CONCLUSION By using repeat GKS, we achieved a 55% angiographic cure rate. Although radiation-induced changes as visualized on magnetic resonance imaging occurred in 48 patients (39%), only 4 patients (3.6%) developed permanent neurological deficits. These findings may be useful in deciding the management of AVMs in whom total obliteration after initial GKS was not achieved.

scholarly journals Dynamic contrast-enhanced magnetic resonance imaging may act as a biomarker for vascular damage in normal appearing brain tissue after radiotherapy in patients with glioblastoma

2018 ◽  
Vol 7 (11) ◽  
pp. 205846011880881 ◽  
Author(s):  
Markus Fahlström ◽  
Samuel Fransson ◽  
Erik Blomquist ◽  
Tufve Nyholm ◽  
Elna-Marie Larsson
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Radiation Dose ◽  
Brain Tissue ◽  
Tissue Type ◽  
Resonance Imaging ◽  
Dce Mri ◽  
Dynamic Contrast Enhanced ◽  
Contrast Enhanced ◽  
Radiation Induced

Background Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a promising perfusion method and may be useful in evaluating radiation-induced changes in normal-appearing brain tissue. Purpose To assess whether radiotherapy induces changes in vascular permeability (Ktrans) and the fractional volume of the extravascular extracellular space (Ve) derived from DCE-MRI in normal-appearing brain tissue and possible relationships to radiation dose given. Material and Methods Seventeen patients with glioblastoma treated with radiotherapy and chemotherapy were included; five were excluded because of inconsistencies in the radiotherapy protocol or early drop-out. DCE-MRI, contrast-enhanced three-dimensional (3D) T1-weighted (T1W) images and T2-weighted fluid attenuated inversion recovery (T2-FLAIR) images were acquired before and on average 3.3, 30.6, 101.6, and 185.7 days after radiotherapy. Pre-radiotherapy CE T1W and T2-FLAIR images were segmented into white and gray matter, excluding all non-healthy tissue. Ktrans and Ve were calculated using the extended Kety model with the Parker population-based arterial input function. Six radiation dose regions were created for each tissue type, based on each patient’s computed tomography-based dose plan. Mean Ktrans and Ve were calculated over each dose region and tissue type. Results Global Ktrans and Ve demonstrated mostly non-significant changes with mean values higher for post-radiotherapy examinations in both gray and white matter compared to pre-radiotherapy. No relationship to radiation dose was found. Conclusion Additional studies are needed to validate if Ktrans and Ve derived from DCE-MRI may act as potential biomarkers for acute and early-delayed radiation-induced vascular damages. No dose-response relationship was found.

Intravoxel incoherent motion magnetic resonance imaging of the normal-appearing parotid glands in patients with differentiated thyroid cancer after radioiodine therapy

2017 ◽  
Vol 59 (2) ◽  
pp. 204-211 ◽  
Author(s):  
Jie Shen ◽  
Xiao-Quan Xu ◽  
Guo-Yi Su ◽  
Hao Hu ◽  
Hai-Bin Shi ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Thyroid Cancer ◽  
Magnetic Resonance ◽  
Differentiated Thyroid Cancer ◽  
Radioiodine Therapy ◽  
Resonance Imaging ◽  
Parotid Glands ◽  
Intermediate Group ◽  
Radiation Induced ◽  
Induced Changes

Background Radiation damage to the salivary gland is a common complication of radioiodine therapy (RIT) in the patients with differentiated thyroid cancer (DTC). Purpose To investigate the feasibility of using intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI) to detect radiation-induced changes of normal-appearing parotid glands in the patients after RIT for DTC. Material and Methods We prospectively enrolled 20 patients with RIT-induced sialoadenitis and 20 healthy control (HC) participants. The patients were divided into intermediate and late groups, and a questionnaire was used to assess the related symptoms. IVIM MRI was scanned using nine b-values (0, 50, 100, 150, 200, 400, 600, 800, and 1000 s/mm2). Quantitative parameters (pseudodiffusion coefficient, D*; perfusion fraction, f; tissue diffusivity, D) were obtained using a biexponential model and compared among different groups using one-way analysis of variance (ANOVA) test. Correlations between significant parameters and symptom score were assessed using Spearman’s correlation analysis. Results The f and D value differed significantly (f, P = 0.016; D, P = 0.006) among different groups. Post hoc analysis showed that f and D value of intermediate group were significantly higher than those of HC group (f, P = 0.012; D, P = 0.004), while no significant differences between late group and HC group (f, P = 0.852; D, P = 0.707). Significant positive correlation was found between f value and the total symptom score of the patients in intermediate group ( P = 0.028, r = 0.762). Conclusion The IVIM MRI might be feasible to detect the radiation-induced changes of parotid glands in the patients after RIT for DTC.

Early Draining Vein Occlusion After Gamma Knife Surgery for Arteriovenous Malformations

Neurosurgery ◽  
2010 ◽  
Vol 67 (5) ◽  
pp. 1293-1302 ◽  
Author(s):  
Chun-Po Yen ◽  
Mohamad A Khaled ◽  
Lucia Schwyzer ◽  
Matjaz Vorsic ◽  
Aaron S Dumont ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Brain Edema ◽  
Arteriovenous Malformations ◽  
Venous Occlusion ◽  
Neurological Deficits ◽  
Resonance Imaging ◽  
Vein Occlusion ◽  
Radiation Induced ◽  
Induced Changes

Abstract BACKGROUND: Increased signals on T2-weighted magnetic resonance imaging usually interpreted as radiation-induced changes or brain edema is a common short- to mid-term complication after Gamma Knife surgery (GKS) for intracranial arteriovenous malformations (AVMs), although its nature remains to be clarified. Early draining vein occlusion with resultant brain edema or hemorrhage, although well established in surgical series, was not described in radiosurgical literature until recently. OBJECTIVE: To outline the incidence, clinical manifestations, and outcomes of this unusual complication in our series of 1256 AVM patients treated with GKS. METHODS: From 1989 to 2008, 1400 patients underwent GKS for cerebral AVMs or dural arteriovenous fistulae at the University of Virginia. In 1256 patients, magnetic resonance imaging after GKS was available for analysis of radiation-induced changes and early draining vein occlusion. RESULTS: After GKS, 456 patients (36%) developed radiation-induced changes surrounding the treated nidi. Among these patients, 12 had early thrombosis of the draining vein accompanied by radiation-induced changes. Venous thrombosis occurred 6 to 25 months (median 11.6 months) after GKS. Three patients were asymptomatic on the image findings of venous occlusion and brain edema, 3 experienced headache, 1 had seizure and headache, and neurological deficits developed in 5. Patients with neurological deficits were treated with corticosteroids; 2 of the patients recovered completely, 1 still had slight hemiparesis, 1 had short-term memory deficits, and 1 died of massive intracerebral hemorrhage. CONCLUSION: Although venous structures are considered more radioresistant, endothelial damage accompanied by venous flow stasis might cause early venous thrombosis and premature venous occlusion after radiosurgery for AVMs. In our series, all patients had a favorable outcome except 1 with a fatal hemorrhage.

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