Methyl-11C-L-methionine positron emission tomography for radiotherapy planning for recurrent malignant glioma (original) (raw)
Related papers
International Journal of Radiation Oncology*Biology*Physics, 2008
Purpose: To assess the importance of 11 C-methionine (MET)-positron emission tomography (PET) for clinical target volume (CTV) delineation. Methods and Materials: This retrospective study analyzed 16 patients with malignant glioma (4 patients, anaplastic astrocytoma; 12 patients, glioblastoma multiforme) treated with surgery and carbon ion radiotherapy from April 2002 to Nov 2005. The MET-PET target volume was compared with gross tumor volume and CTV, defined by using computed tomography/magnetic resonance imaging (MRI). Correlations with treatment results were evaluated between positive and negative extended volumes (EVs) of the MET-PET target for CTV. Results: Mean volumes of the MET-PET targets, CTV1 (defined by means of high-intensity volume on T2-weighted MRI), and CTV2 (defined by means of contrast-enhancement volume on T1-weighted MRI) were 6.35, 264.7, and 117.7 cm 3 , respectively. Mean EVs of MET-PET targets for CTV1 and CTV2 were 0.6 and 2.2 cm 3 , respectively. The MET-PET target volumes were included in CTV1 and CTV2 in 13 (81.3%) and 11 patients (68.8%), respectively. Patients with a negative EV for CTV1 had significantly greater survival rate (p = 0.0069), regional control (p = 0.0047), and distant control time (p = 0.0267) than those with a positive EV. Distant control time also was better in patients with a negative EV for CTV2 than those with a positive EV (p = 0.0401). Conclusions: For patients with malignant gliomas, MET-PET has a possibility to be a predictor of outcome in carbon ion radiotherapy. Direct use of MET-PET fused to planning computed tomography will be useful and yield favorable results for the therapy. Ó 2008 Elsevier Inc.
International Journal of Radiation Oncology*Biology*Physics, 2012
The purpose of this work was to define the optimal margins for gadolinium-enhanced T 1-weighted magnetic resonance imaging (Gd-MRI) and T 2-weighted MRI (T 2-MRI) for delineating target volumes in planning radiation therapy for postoperative patients with newly diagnosed glioblastoma multiforme (GBM) by comparison to carbon-11-labeled methionine positron emission tomography ([ 11 C]MET-PET) findings. Methods and Materials: Computed tomography (CT), MRI, and [ 11 C]MET-PET were separately performed for radiation therapy planning for 32 patients newly diagnosed with GBM within 2 weeks after undergoing surgery. The extent of Gd-MRI (Gd-enhanced clinical target volume [CTV-Gd]) uptake and that of T 2-MRI of the CTV (CTV-T 2) were compared with the extent of [ 11 C]MET-PET (CTV-[ 11 C]MET-PET) uptake by using CT-MRI or CT-[ 11 C]MET-PET fusion imaging. We defined CTV-Gd (x mm) and CTV-T 2 (x mm) as the x-mm margins (where x = 0, 2, 5, 10, and 20 mm) outside the CTV-Gd and the CTV-T 2 , respectively. We evaluated the relationship between CTV-Gd (x mm) and CTV-[ 11 C]MET-PET and the relationship between CTV-T 2 (x mm) and CTV-[ 11 C] MET-PET. Results: The sensitivity of CTV-Gd (20 mm) (86.4%) was significantly higher than that of the other CTV-Gd. The sensitivity of CTV-T 2 (20 mm) (96.4%) was significantly higher than that of the other CTV-T 2 (x = 0, 2, 5, 10 mm). The highest sensitivity and lowest specificity was found with CTV-T 2 (x = 20 mm). Conclusions: It is necessary to use a margin of at least 2 cm for CTV-T 2 for the initial target planning of radiation therapy. However, there is a limit to this setting in defining the optimal margin for Gd-MRI and T 2-MRI for the precise delineation of target volumes in radiation therapy planning for postoperative patients with GBM. Ó 2012 Elsevier Inc.
Ann Nucl Med, 2011
Objective 11 C-Methionine positron emission tomography (MET-PET) has been used to distinguish brain tumor recurrence from radiation necrosis. Because the spatial resolution of conventional PET scanners is low, partial volume effect (PVE) may decrease the detectability of small tumor recurrence. The aim of this study is to investigate the diagnostic value of MET-PET upon semiquantitative analyses in particular PVE-affected small lesions. Methods First, we performed a phantom experiment to investigate what size lesion is affected by PVE. This study included 29 patients (33 lesions) suspected of recurrent brain tumors by magnetic resonance imaging (MRI) after radiation therapy. All of them received MET-PET. Semiquantitative analysis was performed using maximum standardized uptake value (SUVmax) and lesion-versusnormal ratio (L/N ratio). ROC analysis was also assessed about the diagnostic value of MET-PET. Results From the result of the phantom experiment, lesions smaller than 20 mm in brain mode or smaller than 30 mm in whole-body mode were defined as PVE-affected lesions. Histological analysis or clinical follow-up confirmed the diagnosis of tumor recurrence in 22 lesions, and radiation necrosis in 11 lesions. L/N ratios of recurrence and necrosis for overall lesions were 1.98 ± 0.62 and 1.27 ± 0.28, respectively (p \ 0.01). In the PVE-affected lesions, L/N ratio for recurrence (1.72 ± 0.44) was also significantly higher than that for necrosis (1.20 ± 0.11) (p \ 0.01). On the ROC analysis for the PVE-affected lesions, the area under the curve for L/N ratio (0.897) was significantly higher than that for SUVmax (0.718) (p \ 0.05). These areas under the curve were almost equal to that of overall lesions for L/N ratio (0.886) and for SUVmax (0.738). Conclusions Semiquantitative analysis of MET provided high diagnostic value even for PVE-affected small lesions. MET-PET enables early diagnosis of recurrence of brain tumor in the follow-up after the radiation therapy.
Molecular Imaging, 2012
The purpose of this positron emission tomography (PET) study was to compare the prognostic value of pretreatment volume of [ 11 C]methionine (MET) uptake and semiquantitative MET uptake ratio in patients with malignant glioma. The study population comprised 40 patients with malignant glioma. Pretreatment magnetic resonance imaging (MRI) and MET-PET imaging were performed before the initiation of glioma treatment in all patients. The pretreatment MET uptake ratios and volumes were assessed. To create prognostically homogeneous subgroups, patients' pretreatment prognostic factors were stratified according to the six classes of Radiation Therapy Oncology Group recursive partitioning analysis (RTOG RPA). Univariate and multivariate analyses were performed to determine significant prognostic factors. Survival analyses identified the pretreatment volume of MET uptake and a higher RTOG RPA class as significant predictors. In contrast, pretreatment maximum areas of contrast enhancement on MRI and semiquantitative MET uptake ratios could not be identified as significant prognostic factors. The patients' outcomes and Karnofsky Performance Scale scores were significantly correlated with pretreatment volume of MET uptake but not with semiquantitative MET uptake ratio. The data suggest that pretreatment volumetry of MET uptake but not the semiquantitative MET uptake ratio is a useful biologic prognostic marker in patients with malignant glioma.
Molecular Imaging, 2017
The value of combined L-(methyl-[ 11 C]) methionine positron-emitting tomography (MET-PET) and magnetic resonance imaging (MRI) with regard to tumor extent, entity prediction, and therapy effects in clinical routine in patients with suspicion of a brain tumor was investigated. In n ¼ 65 patients with histologically verified brain lesions n ¼ 70 MET-PET and MRI (T1-weighted gadolinium-enhanced [T1w-Gd] and fluid-attenuated inversion recovery or T2-weighted [FLAIR/T2w]) examinations were performed. The computer software ''visualization and analysis framework volume rendering engine (Voreen)'' was used for analysis of extent and intersection of tumor compartments. Binary logistic regression models were developed to differentiate between World Health Organization (WHO) tumor types/grades. Tumor sizes as defined by thresholding based on tumor-to-background ratios were significantly different as determined by MET-PET (21.6 + 36.8 cm 3), T1w-Gd-MRI (3.9 + 7.8 cm 3), and FLAIR/T2-MRI (64.8 + 60.4 cm 3 ; P < .001). The MET-PET visualized tumor activity where MRI parameters were negative: PET positive tumor volume without Gd enhancement was 19.8 + 35.0 cm 3 and without changes in FLAIR/T2 10.3 + 25.7 cm 3. FLAIR/T2-MRI visualized greatest tumor extent with differences to MET-PET being greater in posttherapy (64.6 + 62.7 cm 3) than in newly diagnosed patients (20.5 + 52.6 cm 3). The binary logistic regression model differentiated between WHO tumor types (fibrillary astrocytoma II n ¼ 10 from other gliomas n ¼ 16) with an accuracy of 80.8% in patients at primary diagnosis. Combined PET and MRI improve the evaluation of tumor activity, extent, type/grade prediction, and therapy-induced changes in patients with glioma and serve information highly relevant for diagnosis and management.
Radiotherapy and Oncology, 2014
To evaluate the impact of fluid-attenuated-inversion-recovery MRI (FLAIR/MRI) and Carbon-11-labeled-methionine PET (11C-MET-PET) on high grade glioma (HGG) tumor volume delineation for radiotherapy planning. Material and methods: Sixty-nine patients with HGG were evaluated. The clinical target volumes (CTV1, generated by adding a 10 mm margin to FLAIRMRI area, CTV2 by adding a 20 mm margin to enhanced T1MRI) and biological target volume (BTV) were delineated on pre-operative MRI images and 11CMETPET respectively. Results: The overlap between CTV1 and CTV2 showed a low correlation between the two volumes with CTV1 not always fully included into the CTV2. In all cases the whole BTV was included into the CTV1, while in 35/69 patients (50%) part of BTV was outside the CTV2 despite larger margins were added. In all cases recurrences were within the CTV1 volume and in 19/38 (50%) partially outside the CTV2. In all patients relapse corresponded to the BTV area. Conclusions: Our data suggest that the target volume definition using FLAIR-MRI is more adequate compared to enhanced T1MRI. 11C-METPET uptake could help identify microscopic residual areas.
ISRN Oncology, 2014
We investigated the sensitivity and specificity of [ 11 C]-methionine positron emission tomography ([ 11 C]-MET PET) in the management of glioma patients. We retrospectively analysed data from 53 patients with primary gliomas (16 low grade astrocytomas, 15 anaplastic astrocytomas and 22 glioblastomas) and Karnofsky Performance Status (KPS) > 70. Patients underwent [ 11 C]-MET PET scans ( = 249) and parallel contrast-enhanced MRI ( = 193) and/or CT ( = 113) controls. In low grade glioma patients, MRI or CT findings associated with [ 11 C]-MET PET additional data allowed discrimination residual disease from postsurgical changes in 96.22% of these cases. [ 11 C]-MET PET early allowed detection of malignant progression from low grade to anaplastic astrocytoma with high sensitivity (91.56%) and specificity (95.18%). In anaplastic astrocytomas, we registered high sensitivity (93.97%) and specificity (95.18%) in the postoperative imaging and during the followup of these patients. In GBM patients, CT and/or MRI scans with additional [ 11 C]-MET PET data registered a sensitivity of 96.92% in the postsurgical evaluation and in the tumour assessment during temozolomide therapy. A significant correlation was found between [ 11 C]-MET mean uptake index and histologic grading ( < 0.001). These findings support the notion that complementary information derived from [ 11 C]-MET PET may be helpful in postoperative and successive tumor assessment of glioma patients.
Objective: [ 11 C] methionine (MET) positron-emission tomography (PET) is a useful diagnostic and therapeutic tool in neuro-oncology. The aim of this study was to evaluate the relationship between MET uptake and the histopathological grade in both primary brain tumours and brain metastases. A secondary goal was to assess the relationship between MET uptake and patients' survival after surgery. Methods: We reviewed a consecutive series of 43 PET studies performed at our institution. Out of the 43 patients studied, 35 harboured primary brain tumours (3 grade I, 12 grade II, 7 grade III and 13 grade IV) and 8 patients had brain metastases. We measured the tumour/cortex ratio (T/C ratio) on each PET study and we investigated the correlations among the tracer uptake, tumour grade, tumour type, MRI parameters and outcome. Results: The mean T/C ratio was 1.8 ± 0.9 for benign lesions and low grade gliomas (grade I and II) and 2.7 ± 1 for high grade gliomas (grade III and IV). In brain metastases it was 2.5 ± 0.7, with a significant difference in MET uptake between low and high grades gliomas (P = 0.03). There was no statistically significant difference among all different histologic types. We found that both contrast enhancement and perfusion studies correlate with MET uptake in brain tumours. Moreover, in Kaplan–Meier curves, the T/C ratio adversely affects long term survival in patients with brain tumours (P = 0.01). Conclusions: MET PET appears to be useful in diagnosis and evaluation of potential malignancy in brain tumours. MET uptake is also related with the overall survival in patients with brain tumours. Nevertheless, further studies are needed in order to define its possible clinical implications in identifying patients at high risk of tumour progression or resistance to therapy.
ACT-07 Clinical Trials of 11C-Methionine PET for brain tumors
Neuro-Oncology Advances, 2020
Background: Although 11C-Methionine (MET) PET has widely used, 11C-MET tracer has not been approved in Japan. We conducted multi-center prospective clinical trials using MET for drug approval in diagnosis of brain tumors[Methods] Two trials using 11C-MET PET were performed in Hokkaido University, Osaka University and Fukushima Medical University; 1) Diagnostic accuracy in differentiating tumor recurrence from radiation injury after radiotherapy in brain tumors, 2) The diagnostic efficacy in newly-diagnosed gliomas. 1) The patients with suspected brain tumor recurrence underwent MET and 18F-Fluorodeoxyglucose (FDG) PET. When the target lesion showed MET and/or FDG uptake, the patients underwent target resection for pathological confirmation. Positive prediction values of each tracer uptake were assessed as primary outcome measure, and the sensitivities and specificities of each PET exams were also assessed. 2) The patients with suspected gliomas underwent MET PET. Tissue samplings we...
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 2002
The use of (18)F-FDG PET for brain tumors has been shown to be accurate in identifying areas of active disease. Radiation dose escalation in the treatment of glioblastoma multiforme (GBM) may lead to improved disease control. On the basis of these premises, we initiated a pilot study to investigate the use of (18)F-FDG PET for the guidance of radiation dose escalation in the treatment of GBM. Patients were considered eligible to participate in the study if they had a diagnosis of GBM, were at least 18 y old, and had a score of at least 60 on the Karnofsky Scale. Patients were treated with standard conformal fractionated radiotherapy (1.8 Gy per fraction, to 59.4 Gy), with volumes defined by MRI. At a dose of 45-50.4 Gy, patients underwent (18)F-FDG PET for boost target delineation. Final noncoplanar fields (3-4) were designed to treat the volume of abnormal (18)F-FDG uptake plus a 0.5-cm margin for an additional 20 Gy (2 Gy per fraction), to a total dose of 79.4 Gy. If no abnormal (...