scholarly journals A Study of Dose Painting Radiotherapy Guided by Three-Dimensional Arterial Spin labeling Perfusion Magnetic Resonance  Imaging for Non-Enhancing Low-Grade Gliomas

2021 ◽  
Author(s):  
Zihong Zhu ◽  
Guanzhong Gong ◽  
Lizhen Wang ◽  
Ya Su ◽  
Xiaohang Qin ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Organs At Risk ◽  
Target Volume ◽  
Magnetic Resonance Images ◽  
Perfusion Magnetic Resonance Imaging ◽  
Low Grade ◽  
Dose Painting ◽  
Optic Chiasma ◽  
Low Grade Gliomas ◽  
Dose Constraint

Abstract Background: The purpose of this study was to investigate the feasibility and dosimetric characteristics of dose painting for non-enhancing low-grade gliomas (NE-LGGs) guided by three-dimensional arterial spin labeling (3D-ASL) perfusion magnetic resonance imaging.Methods: Eighteen patients with NE-LGGs were enrolled. 3D-ASL, T2 fluid attenuated inversion recovery (T2 FLAIR) and contrast-enhanced T1-weight magnetic resonance images were obtained. The gross tumor volume (GTV) was delineated on the T2 FLAIR. The hyper-perfusion region of the GTV (GTV-ASL) was determined by 3D-ASL, and the GTV-SUB was obtained by subtracting the GTV-ASL from the GTV. The planning target volume (PTV), PTV-ASL and PTV-SUB were developed by expanding the external margins of the GTV, GTV-ASL and GTV-SUB, respectively. Three plans were established for each patient: in plan 1, the traditional homogeneous prescription dose to the PTV was 45-60 Gy; in plan 2 and plan 3, the dose to the PTV-ASL increased by 10-20% based on plan 1, without the maximum dose constraint to the PTV-ASL in plan 3. The dosimetric differences among the three plans were compared.Results: Compared with plan 1, the dose to 2% (D2%), 98% (D98%) and 50% (Dmean) of PTV-ASL volumes increased by 14.67%, 16.17% and 14.31% in plan 2 and 19.84%, 15.52% and 14.27% in plan 3, respectively (P < 0.05); the D2% of the PTV, PTV-SUB increased by 11.89% and 8.34% in plan 2, 15.89% and 8.49% in plan 3, respectively (P< 0.05). The PTV coverages were comparable among the three plans (P > 0.05). In Plan 2 and plan 3, the conformity indexs decreased by 18.60% and 12.79%; while the homogeneity indexs increased by 1.43 and 2 times (P<0.05). Compared with plan 1, the D0.1cc of brain stem and Dmax of optic chiasma slightly increased in plan 2 and plan 3, but the absolute doses met the dose constraint. The other organs at risk were similar among the three plans (P > 0.05).Conclusions: The sub-volume with hyper-perfusion for NE-LGG radiotherapy can be segmented based on the perfusion difference guided by 3D-ASL. And the radiation dose to the hyper-perfusion area increased safely by 10-20% through dose painting.

scholarly journals Prediction of IDH Status Through MRI Features and Enlightened Reflection on the Delineation of Target Volume in Low-Grade Gliomas

2019 ◽  
Vol 18 ◽  
pp. 153303381987716 ◽  
Author(s):  
Haixia Ding ◽  
Yong Huang ◽  
Zhiqiang Li ◽  
Sirui Li ◽  
Qiongrong Chen ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Isocitrate Dehydrogenase ◽  
Target Volume ◽  
Low Grade ◽  
Creatinine Ratio ◽  
Wild Type ◽  
Resonance Imaging ◽  
Low Grade Gliomas ◽  
Mutational Status

Isocitrate dehydrogenase mutational status defines distinct biologic behavior and clinical outcomes in low-grade gliomas. We sought to determine magnetic resonance imaging characteristics associated with isocitrate dehydrogenase mutational status to evaluate the predictive roles of magnetic resonance imaging features in isocitrate dehydrogenase mutational status and therefore their potential impact on the determination of clinical target volume in radiotherapy. Forty-eight isocitrate dehydrogenase-mutant and 28 isocitrate dehydrogenase–wild-type low-grade gliomas were studied. Isocitrate dehydrogenase mutation was related to more frequency of cortical involvement compared to isocitrate dehydrogenase–wild-type group (34/46 vs 6/24, P = .0001). Peritumoral edema was less frequent in isocitrate dehydrogenase–mutant tumors (32.6% vs 58.3% for isocitrate dehydrogenase–wild-type tumors, P = .0381). Isocitrate dehydrogenase–wild-type tumors were more likely to have a nondefinable border, while isocitrate dehydrogenase–mutant tumors had well-defined borders (66.7% vs 39.1%, P = .0287). Only 8 (17.4%) of 46 of the isocitrate dehydrogenase–mutant tumors demonstrated marked enhancement, while this was 66.7% in isocitrate–wild-type tumors ( P < .0001). Choline–creatinine ratio for isocitrate dehydrogenase–wild-type tumors was significantly higher than that for isocitrate dehydrogenase–mutant tumors. In conclusion, frontal location, well-defined border, cortical involvement, less peritumoral edema, lack of enhancement, and low choline–creatinine ratio were predictive for the definition of isocitrate dehydrogenase–mutant low-grade gliomas. Magnetic resonance imaging can provide an advantage in the detection of isocitrate dehydrogenase status indirectly and indicate the need to explore new design for treatment planning in gliomas. Choline–creatinine ratio in magnetic resonance spectroscopy could be a potential more reasonable reference for the new design of delineation of target volume in low-grade gliomas.

MRI only in a patient with prostate cancer with bilateral metal hip prostheses: case study

2021 ◽  
pp. 030089162199754
Author(s):  
Marco Felisi ◽  
Angelo Filippo Monti ◽  
Domenico Lizio ◽  
Stefania Nici ◽  
Roberto Giuseppe Pellegrini ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Magnetic Resonance ◽  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Practical Method ◽  
Target Volume ◽  
Magnetic Resonance Images ◽  
Electron Densities ◽  
Hip Prostheses ◽  
Complete Arc

Objective: To outline a practical method of performing prostate cancer radiotherapy in patients with bilateral metal hip prostheses with the standard resources available in a modern general hospital. The proposed workflow is based exclusively on magnetic resonance imaging (MRI) to avoid computed tomography (CT) artifacts. Case description: This study concerns a 73-year-old man with bilateral hip prostheses with an elevated risk prostate cancer. Magnetic resonance images with assigned electron densities were used for planning purposes, generating a synthetic CT (sCT). Imaging acquisition was performed with an optimized Dixon sequence on a 1.5T MRI scanner. The images were contoured by autosegmentation software, based on an MRI database of 20 patients. The sCT was generated assigning averaged electron densities to each contour. Two volumetric modulated arc therapy plans, a complete arc and a partial one, where the beam entrances through the prostheses were avoided for about 50° on both sides, were compared. The feasibility of matching daily cone beam CT (CBCT) with MRI reference images was also tested by visual evaluations of different radiation oncologists. Conclusions: The use of magnetic resonance images improved accuracy in targets and organs at risk (OARs) contouring. The complete arc plan was chosen because of 10% lower mean and maximum doses to prostheses with the same planning target volume coverage and OAR sparing. The image quality of the match between performed CBCTs and MRI was considered acceptable. The proposed method seems promising to improve radiotherapy treatments for this complex category of patients.

scholarly journals Prognostic value of magnetic resonance imaging features in low-grade gliomas

2019 ◽  
Vol 39 (6) ◽  
Author(s):  
Liang Deng ◽  
Liangfang Shen ◽  
Lin Shen ◽  
Zhao Zhao ◽  
Yingpeng Peng ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Multivariate Analysis ◽  
Magnetic Resonance ◽  
Low Grade ◽  
Imaging Features ◽  
Resonance Imaging ◽  
Mr Images ◽  
Low Grade Gliomas ◽  
Kaplan Meier ◽  
Mri Features

AbstractIntroduction: The treatment strategy for low-grade gliomas (LGGs) is still controversial, and there are no standardized criteria to predict the prognosis of patients with LGGs. Magnetic resonance imaging (MRI) is a routine test for preoperative diagnosis for LGG and can reflect the destructive features for the tumor. In the present study, we aimed to explore the relationship between the MRI features and prognosis in patients with LGG.Methods: Clinical data of 80 patients with pathologically proved LGGs between January 2010 and December 2016 were analyzed retrospectively. MRI features were classified as contrast enhancement pattern (focal enhancement, diffuse enhancement and ring-like enhancement), necrosis and cysts based on the preoperative MR images. Kaplan–Meier method and multivariate analysis were performed on the data by SPSS software to explore the prognostic significance of MRI features.Results: Patients with cystic LGG had a significantly longer 5-year progression-free survival (PFS) than that with no cyst (90.9 ± 8.7 vs 65.7 ± 9.1%, P=0.045). Multivariate analysis further verified cyst as an independent prognosis factor for PFS (P=0.027, hazard ratio [HR] = 0.084). Additionally, patients with ring-like enhancement exhibited significantly longer 5-year PFS time in the Kaplan–Meier survival curves (100 vs 67.2 ± 7.7%, P=0.049). There was no significant difference in PFS and overall survival (OS) between patients with or without necrosis.Conclusion: Our study suggests that cyst formation and ring-like enhancement on preoperative MR images can be useful to predict a favorable prognosis in patients with LGGs.

scholarly journals The Utility of Diffusion and Perfusion Magnetic Resonance Imaging in Target Delineation of High-Grade Gliomas

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Qian Fei ◽  
Lu-Xi Qian ◽  
Yu-Jie Zhang ◽  
Wen-Jie Guo ◽  
Xiu-Hua Bian ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Overall Survival ◽  
Magnetic Resonance ◽  
Target Volume ◽  
Perfusion Magnetic Resonance Imaging ◽  
Target Area ◽  
High Grade ◽  
Resonance Imaging ◽  
Failure Patterns ◽  
Selection Of

Background. The tumor volume of high-grade glioma (HGG) after surgery is usually determined by contrast-enhanced MRI (CE-MRI), but the clinical target volume remains controversial. Functional magnetic resonance imaging (multimodality MRI) techniques such as magnetic resonance perfusion-weighted imaging (PWI) and diffusion-tensor imaging (DTI) can make up for CE-MRI. This study explored the survival outcomes and failure patterns of patients with HGG by comparing the combination of multimodality MRI and CE-MRI imaging with CE-MRI alone. Methods. 102 patients with postoperative HGG between 2012 and 2016 were included. 50 were delineated based on multimodality MRI (PWI, DTI) and CE-MRI (enhanced T1), and the other 52 were delineated based on CE-MRI as control. Results. The median survival benefit was 6 months. The 2-year overall survival, progression-free survival, and local–regional control rates were 48% vs. 25%, 42% vs. 13.46%, and 40% vs. 13.46% for the multimodality MRI and CE-MRI cohorts, respectively. The two cohorts had similar rates of disease progression and recurrence but different proportions of failure patterns. The univariate analysis shows that characteristics of patients such as combined with epilepsy, the dose of radiotherapy, the selection of MRI were significant influence factors for 2-year overall survival. However, in multivariate analyses, only the selection of MRI was an independent significant predictor of overall survival. Conclusions. This study was the first to explore the clinical value of multimodality MRI in the delineation of radiotherapy target volume for HGG. The conclusions of the study have positive reference significance to the combination of multimodality MRI and CE-MRI in guiding the delineation of the radiotherapy target area for HGG patients.

Very Late Frontal Relapse of Medulloblastoma Mimicking a Meningioma in an Adult: Usefulness of 1H Magnetic Resonance Spectroscopy and Diffusion-perfusion Magnetic Resonance Imaging for Preoperative Diagnosis: Case Report

Neurosurgery ◽  
2006 ◽  
Vol 58 (4) ◽  
pp. E789-E789 ◽  
Author(s):  
Emmanuel Jouanneau ◽  
Rafael Alfonso Guzman Tovar ◽  
Claude Desuzinges ◽  
Didier Frappaz ◽  
Guy Louis-Tisserand ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Diffusion Imaging ◽  
Magnetic Resonance Images ◽  
Perfusion Magnetic Resonance Imaging ◽  
Metabolic Imaging ◽  
Resonance Spectroscopy ◽  
Resonance Imaging ◽  
Apparent Diffusion Coefficient Value

Abstract OBJECTIVE AND IMPORTANCE: We present a rare case of very long-term medulloblastoma relapse in an adult patient and discuss the pattern of recurrence and metabolic imaging of the tumor. CLINICAL PRESENTATION: A 45-year-old man was referred for evaluation of a frontobasal midline tumor 21 years after treatment of a cerebellar medulloblastoma by surgery followed by chemotherapy and craniospinal radiotherapy. Magnetic resonance images were suggestive of a meningioma. Several hypotheses were discussed, such as other radio-induced tumors, sarcomas, high-grade gliomas, or lymphomas (previous chemotherapy) and even recurrence of medulloblastoma. Preoperative exploration included 1H magnetic resonance single-voxel spectroscopy (35 and 135 ms echo time), diffusion imaging, and perfusion magnetic resonance imaging. INTERVENTION: On magnetic resonance spectroscopy, N-acetyl-aspartate and an elevated choline/creatine ratio were retrieved, with a huge unidentified peak at 1.27 parts per million (ppm). Myoinositol signal was present at both echo times. On diffusion imaging, the tumor appeared hyperintense, with a low apparent diffusion coefficient value of 0.689. In the perfusion study, the maximal relative cerebral blood volume was 2. Metabolic imaging favored the diagnosis of medulloblastoma over the initially suspected diagnosis of meningioma. The patient underwent complete removal of the tumor that was confirmed to be a metastasis of his primary medulloblastoma. The postoperative course was uneventful, and complementary courses of radiotherapy and chemotherapy were planned. CONCLUSION: Late relapse should be considered, even after several decades, on occurrence of a second intracranial tumor in this context. Our observation validates the clinical interest of preoperative metabolic imaging for brain tumors with distinctive pattern.

Surgical treatment of low-grade gliomas in the intraoperative magnetic resonance imager

1998 ◽  
Vol 4 (4) ◽  
pp. E10 ◽  
Author(s):  
Claudia Martin ◽  
Eben Alexander ◽  
Terry Wong ◽  
Richard Schwartz ◽  
Ferenc Jolesz ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Image Guidance ◽  
Intraoperative Imaging ◽  
Radical Resection ◽  
Low Grade ◽  
Term Outcome ◽  
Long Term Outcome ◽  
Low Grade Gliomas ◽  
Surgical Field

Radical resection of low-grade gliomas can decrease the incidence of recurrence, the time to tumor progression, and the incidence of malignant transformation. The authors present a series of 25 patients who underwent craniotomy and resection of low-grade tumor in an intraoperative magnetic resonance (MR) imager. This is an open configuration 0.5-tesla imager developed by The Brigham and Women's Hospital and General Electric, in which a patient can be placed to undergo surgery. Gross-total removal was accomplished under real-time image guidance. These intraoperative images allow definitive localization and targeting of the lesions and accommodate anatomical changes that may occur during surgery. The authors consistently found that the extent of abnormality seen on the intraoperatively obtained films of resection was larger than that apparent in the surgical field of view alone. Intraoperative imaging made accurate surgical identification of these abnormal areas and subsequent resection possible. Patients with tumors adjacent to or within motor or language cortex underwent resection while awake, with monitoring of neurological function. In these cases, an aggressive resection without increased neurological morbidity was accomplished using the image guidance in conjunction with serial testing. A 1-month postoperative MR image was obtained in all patients. These correlated with the final intraoperative images obtained after the resection was completed. Only one patient had a mild postoperative deficit that remained at the 1-month follow-up examination. As the long-term outcome in patients with low-grade gliomas has been shown to correspond to the degree of resection, surgical resection in which intraoperative MR imaging guidance is used can be an invaluable modality in the treatment of these tumors.

Imaging-based stereotaxic serial biopsies in untreated intracranial glial neoplasms

1987 ◽  
Vol 66 (6) ◽  
pp. 865-874 ◽  
Author(s):  
Patrick J. Kelly ◽  
Catherine Daumas-Duport ◽  
David B. Kispert ◽  
Bruce A. Kall ◽  
Bernd W. Scheithauer ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Contrast Enhancement ◽  
Tumor Tissue ◽  
Magnetic Resonance Images ◽  
Low Grade ◽  
Content Type ◽  
Mri Scans ◽  
Isolated Tumor Cell ◽  
Magnetic Resonance Imaging Mri ◽  
Ct And Mri

✓ Forty patients with previously untreated intracranial glial neoplasms underwent stereotaxic serial biopsies assisted by computerized tomography (CT) and magnetic resonance imaging (MRI). Tumor volumes defined by computer reconstruction of contrast enhancement and low-attenuation boundaries on CT and T1 and T2 prolongation on MRI revealed that tumor volumes defined by T2-weighted MRI scans were larger than those defined by low-attenuation or contrast enhancement on CT scans. Histological analysis of 195 biopsy specimens obtained from various locations within the volumes defined by CT and MRI revealed that: 1) contrast enhancement most often corresponded to tumor tissue without intervening parenchyma; 2) hypodensity corresponded to parenchyma infiltrated by isolated tumor cells or in some instances to tumor tissue in low-grade gliomas or to simple edema; and 3) isolated tumor cell infiltration extended at least as far as T2 prolongation on magnetic resonance images. This information may be useful in planning surgical procedures and radiation therapy in patients with intracranial glial neoplasms.

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