Multimodal target point assessment for stereotactic biopsy in children with diffuse bithalamic astrocytomas

Am, Messing-Jünger; Fw, Floeth; Pauleit, Dirk; Reifenberger, Guido; Willing, R. L.; Gärtner, Jutta; Hh, Coenen; Langen, Karl‐Josef

doi:10.1007/s00381-002-0644-6

Cited by 56 publications

(5 citation statements)

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“…An important FET-PET indication is in biopsy target planning with the identification of the biologically most aggressive component (“hot spots”) in heterogeneous glioma on MRI to optimize the diagnostic accuracy (Messing-Junger et al, 2002 ; Floeth et al, 2005 ; Ewelt et al, 2011 ; Kunz et al, 2011 ). The biopsy target is usually defined as the peak voxel of T MAX within the tumor.…”

Section: Methodsmentioning

confidence: 99%

RESOLUTE PET/MRI Attenuation Correction for O-(2-18F-fluoroethyl)-L-tyrosine (FET) in Brain Tumor Patients with Metal Implants

et al. 2017

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Aim: Positron emission tomography (PET) imaging is a useful tool for assisting in correct differentiation of tumor progression from reactive changes, and the radiolabeled amino acid analog tracer O-(2-18F-fluoroethyl)-L-tyrosine (FET)-PET is amongst the most frequently used. The FET-PET images need to be quantitatively correct in order to be used clinically, which require accurate attenuation correction (AC) in PET/MRI. The aim of this study was to evaluate the use of the subject-specific MR-derived AC method RESOLUTE in post-operative brain tumor patients.Methods: We analyzed 51 post-operative brain tumor patients (68 examinations, 200 MBq [18F]-FET) investigated in a PET/MRI scanner. MR-AC maps were acquired using: (1) the Dixon water fat separation sequence, (2) the ultra short echo time (UTE) sequences, (3) calculated using our new RESOLUTE methodology, and (4) a same day low-dose CT used as reference “gold standard.” For each subject and each AC method the tumor was delineated by isocontouring tracer uptake above a tumor(T)-to-brain background (B) activity ratio of 1.6. We measured B, tumor mean and maximal activity (TMEAN, TMAX), biological tumor volume (BTV), and calculated the clinical metrics TMEAN/B and TMAX/B.Results: When using RESOLUTE 5/68 studies did not meet our predefined acceptance criteria of TMAX/B difference to CT-AC < ±0.1 or 5%, TMEAN/B < ±0.05 or 5%, and BTV < ±2 mL or 10%. In total, 46/68 studies failed our acceptance criteria using Dixon, and 26/68 using UTE. The 95% limits of agreement for TMAX/B was for RESOLUTE (−3%; 4%), Dixon (−9%; 16%), and UTE (−7%; 10%). The absolute error when measuring BTV was 0.7 ± 1.9 mL (N.S) with RESOLUTE, 5.3 ± 10 mL using Dixon, and 1.7 ± 3.7 mL using UTE. RESOLUTE performed best in the identification of the location of peak activity and in brain tumor follow-up monitoring using clinical FET PET metrics.Conclusions: Overall, we found RESOLUTE to be the AC method that most robustly reproduced the CT-AC clinical metrics per se, during follow-up, and when interpreted into defined clinical use cut-off criteria and into the patient history. RESOLUTE is especially suitable for brain tumor patients, as these often present with distorted anatomy where other methods based on atlas/template information might fail.

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Section: Methodsmentioning

confidence: 99%

RESOLUTE PET/MRI Attenuation Correction for O-(2-18F-fluoroethyl)-L-tyrosine (FET) in Brain Tumor Patients with Metal Implants

et al. 2017

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“…In the last years many articles supported statement that 18 F-FET PET/CT is valuable modality for individual treatment decision in patients with low grade gliomas. 19 - 24 The T98G cells are the most radio resistant cell line available derived from a human glioblastoma multiform tumour. 25 T98G are arrested in G1 phase under stationary phase conditions, so they also exhibit the transformed characteristics of anchorage independence and immortality.…”

Section: Introductionmentioning

confidence: 99%

¹⁸F-FET and ¹⁸F-FCH uptake in human glioblastoma T98G cell lines

Persico

Buroni

Pasi

et al. 2016

Radiology and Oncology

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BackgroundDespite complex treatment of surgery, radiotherapy and chemotherapy, high grade gliomas often recur. Differentiation between post-treatment changes and recurrence is difficult. 18F-methyl-choline (18F-FCH) is frequently used in staging and detection of recurrent prostate cancer disease as well as some brain tumours; however accumulation in inflammatory tissue limits its specificity. The 18F-ethyl-tyrosine (18F-FET) shows a specific uptake in malignant cells, resulting from increased expression of amino acid transporters or diffusing through the disrupted blood-brain barrier. 18F-FET exhibits lower uptake in machrophages and other inflammatory cells. Aim of this study was to evaluate 18F-FCH and 18F-FET uptake by human glioblastoma T98G cells.Material and methodsHuman glioblastoma T98G or human dermal fibroblasts cells, seeded at a density to obtain 2 × 105 cells per flask when radioactive tracers were administered, grew adherent to the plastic surface at 37°C in 5% CO2 in complete medium. Equimolar amounts of radiopharmaceuticals were added to cells for different incubation times (20 to 120 minutes) for 18F-FCH and 18F-FET respectively. The cellular radiotracer uptake was determined with a gamma counter. All experiments were carried out in duplicate and repeated three times. The uptake measurements are expressed as the percentage of the administered dose of tracer per 2 × 105 cells. Data (expressed as mean values of % uptake of radiopharmaceuticals) were compared using parametric or non-parametric tests as appropriate. Differences were regarded as statistically significant when p<0.05.ResultsA significant uptake of 18F-FCH was seen in T98G cells at 60, 90 and 120 minutes. The percentage uptake of 18F-FET in comparison to 18F-FCH was lower by a factor of more than 3, with different kinetic curves.18F-FET showed a more rapid initial uptake up to 40 minutes and 18F-FCH showed a progressive rise reaching a maximum after 90 minutes.Conclusions18F-FCH and 18F-FET are candidates for neuro-oncological PET imaging. 18F-FET could be the most useful oncological PET marker in the presence of reparative changes after therapy, where the higher affinity of 18F-FCH to inflammatory cells makes it more difficult to discriminate between tumour persistence and non-neoplastic changes. Additional studies on the influence of inflammatory tissue and radionecrotic cellular components on radiopharmaceutical uptake are necessary.

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“…The location of the TBRmax, which is usually used for biopsy target planning as it identifies the biologically most aggressive component ("hot spots") in heterogeneous glioma (Messing-Junger et al, 2002;Floeth et al, 2005;Ewelt et al, 2011;Kunz et al, 2011), were compared for each method. Our criterion was set at < 10 mm from the location at our reference PET with CT-AC, as this corresponds to the approximate size of an average stereotactic biopsy.…”

Section: Pet Evaluation Metricsmentioning

confidence: 99%

DeepDixon synthetic CT for [18F]FET PET/MRI attenuation correction of post-surgery glioma patients with metal implants

Ladefoged

Andersen

et al. 2023

Front. Neurosci.

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PurposeConventional magnetic resonance imaging (MRI) can for glioma assessment be supplemented by positron emission tomography (PET) imaging with radiolabeled amino acids such as O-(2-[18F]fluoroethyl)-L-tyrosine ([18F]FET), which provides additional information on metabolic properties. In neuro-oncology, patients often undergo brain and skull altering treatment, which is known to challenge MRI-based attenuation correction (MR-AC) methods and thereby impact the simplified semi-quantitative measures such as tumor-to-brain ratio (TBR) used in clinical routine. The aim of the present study was to examine the applicability of our deep learning method, DeepDixon, for MR-AC in [18F]FET PET/MRI scans of a post-surgery glioma cohort with metal implants.MethodsThe MR-AC maps were assessed for all 194 included post-surgery glioma patients (318 studies). The subgroup of 147 patients (222 studies, 200 MBq [18F]FET PET/MRI) with tracer uptake above 1 ml were subsequently reconstructed with DeepDixon, vendor-default atlas-based method, and a low-dose computed tomography (CT) used as reference. The biological tumor volume (BTV) was delineated on each patient by isocontouring tracer uptake above a TBR threshold of 1.6. We evaluated the MR-AC methods using the recommended clinical metrics BTV and mean and maximum TBR on a patient-by-patient basis against the reference with CT-AC.ResultsNinety-seven percent of the studies (310/318) did not have any major artifacts using DeepDixon, which resulted in a Dice coefficient of 0.89/0.83 for tissue/bone, respectively, compared to 0.84/0.57 when using atlas. The average difference between DeepDixon and CT-AC was within 0.2% across all clinical metrics, and no statistically significant difference was found. When using DeepDixon, only 3 out of 222 studies (1%) exceeded our acceptance criteria compared to 72 of the 222 studies (32%) with the atlas method.ConclusionWe evaluated the performance of a state-of-the-art MR-AC method on the largest post-surgical glioma patient cohort to date. We found that DeepDixon could overcome most of the issues arising from irregular anatomy and metal artifacts present in the cohort resulting in clinical metrics within acceptable limits of the reference CT-AC in almost all cases. This is a significant improvement over the vendor-provided atlas method and of particular importance in response assessment.

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Multimodal target point assessment for stereotactic biopsy in children with diffuse bithalamic astrocytomas

Abstract: Stereotactic biopsy using metabolic imaging and image fusion can enhance the diagnostic yield in cases of diffuse pediatric gliomas disclosing unexpected 'hot spots'.

Cited by 56 publications

References 6 publications

RESOLUTE PET/MRI Attenuation Correction for O-(2-18F-fluoroethyl)-L-tyrosine (FET) in Brain Tumor Patients with Metal Implants

RESOLUTE PET/MRI Attenuation Correction for O-(2-18F-fluoroethyl)-L-tyrosine (FET) in Brain Tumor Patients with Metal Implants

¹⁸F-FET and ¹⁸F-FCH uptake in human glioblastoma T98G cell lines

DeepDixon synthetic CT for [18F]FET PET/MRI attenuation correction of post-surgery glioma patients with metal implants

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Multimodal target point assessment for stereotactic biopsy in children with diffuse bithalamic astrocytomas

Abstract: Stereotactic biopsy using metabolic imaging and image fusion can enhance the diagnostic yield in cases of diffuse pediatric gliomas disclosing unexpected 'hot spots'.

Cited by 56 publications

References 6 publications

RESOLUTE PET/MRI Attenuation Correction for O-(2-18F-fluoroethyl)-L-tyrosine (FET) in Brain Tumor Patients with Metal Implants

RESOLUTE PET/MRI Attenuation Correction for O-(2-18F-fluoroethyl)-L-tyrosine (FET) in Brain Tumor Patients with Metal Implants

18F-FET and 18F-FCH uptake in human glioblastoma T98G cell lines

DeepDixon synthetic CT for [18F]FET PET/MRI attenuation correction of post-surgery glioma patients with metal implants

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¹⁸F-FET and ¹⁸F-FCH uptake in human glioblastoma T98G cell lines