NIMG-54. SPATIAL DISTRIBUTION ATLASES OF POST-TREATMENT MRI SCANS REVEAL DISTINCT HEMISPHERIC DISTRIBUTION OF GLIOBLASTOMA RECURRENCE FROM PSEUDO-PROGRESSION

Glioblastoma (GBM) is the most common adult glioma. Differentiating post-treatment effects such as pseudoprogression from true progression is paramount for treatment. Radiomics has been shown to predict overall survival and MGMT (methylguanine-DNA methyltransferase) promoter status in those with GBM. A potential application of radiomics is predicting pseudoprogression on pre-radiotherapy (RT) scans for patients with GBM. A retrospective review was performed with radiomic data analyzed using pre-RT MRI scans. Pseudoprogression was defined as post-treatment findings on imaging that resolved with steroids or spontaneously on subsequent imaging. Of the 72 patients identified for the study, 35 were able to be assessed for pseudoprogression, and 8 (22.9%) had pseudoprogression. A total of 841 radiomic features were examined along with clinical features. Receiver operating characteristic (ROC) analyses were performed to determine the AUC (area under ROC curve) of models of clinical features, radiomic features, and combining clinical and radiomic features. Two radiomic features were identified to be the optimal model combination. The ROC analysis found that the predictive ability of this combination was higher than using clinical features alone (mean AUC: 0.82 vs. 0.62). Additionally, combining the radiomic features with clinical factors did not improve predictive ability. Our results indicate that radiomics is potentially capable of predicting future development of pseudoprogression in patients with GBM using pre-RT MRIs.

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Quality of life and clinical results after endovascular sclerotherapy: A comparison between intra- and extramuscular low-flow venous malformations

Phlebology The Journal of Venous Disease ◽

10.1177/0268355520962920 ◽

2020 ◽

pp. 026835552096292

Author(s):

Annamaria Weitz-Tuoretmaa ◽

Leo Keski-Nisula ◽

Riitta Rautio ◽

Jussi Laranne

Keyword(s):

Quality Of Life ◽

Clinical Results ◽

Post Treatment ◽

Low Flow ◽

Subjective Symptoms ◽

Venous Malformations ◽

University Hospitals ◽

Mri Findings ◽

Mri Scans

Background Based on clinical observations we hypothesized that patients with intramuscular venous malformations (VMs) did worse or needed more sclerotherapy sessions than patients with extramuscular VMs. Purpose To evaluate the difference in treatment and quality of life (QOL) results after Polidocanol sclerotherapy of intra- and extramuscular low-flow VMs. Material and methods Forty-one patients with a VM were treated with Polidocanol in two university hospitals. The results were retrospectively analyzed. Pre- and post-treatment magnetic resonance imaging (MRI) scans were compared. All patients completed a self-evaluating form on symptoms as well as a QOL questionnaire. The results were compared between two groups: intra- and extramuscular VM’s. Results No statistically significant differences between intra- and extramuscular groups concerning QOL and specific dimensions pain, functional problems or cosmetic appearance were found. Radiological changes in MRI examinations did not correlate with any of the subjective symptoms. 56% of the patients benefitted from the treatment according to patient self-evaluation. Conclusion In this material intramuscular VM’s responded to the treatment comparably to extramuscular malformations. Post-treatment MRI findings do not correlate with subjective symptoms or QOL results and thus, a routine post-treatment examination seems to be unwarranted. Subjective symptoms and QOL results are the most important parameters in evaluating the effectiveness of sclerotherapy.

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Abnormal patterns of embryogenesis in Dirofilaria immitis treated with ivermectin

Journal of Helminthology ◽

10.1017/s0022149x00011482 ◽

1988 ◽

Vol 62 (3) ◽

pp. 175-180 ◽

Cited By ~ 16

Author(s):

J. B. Lok ◽

T. Harpaz ◽

D. H. Knight

Keyword(s):

Spatial Distribution ◽

Dirofilaria Immitis ◽

Distal Portion ◽

Post Treatment ◽

Body Region ◽

Percentage Composition ◽

Predominant Form ◽

Single Worm

ABSTRACTThe percentage composition and spatial distribution of embryogenic stages in the uteri of female Dirofilaria immitis were examined at various times after treatment with a microfilaricidal dose of ivermectin and compared to nontreated parasites. Worms sampled 42 days post-treatment (PT) exhibited an increased proportion of stretched microfilariae in the distal portion of the uterus. A decreased proportion of developed embryos was noted in the mid body region of worms sampled 42 days PT, and these forms were completely absent from the proximal area of the uterus. Relative numbers and spatial distribution of other stages remained virtually identical to controls. Radical changes in the composition and spatial distribution of embryogenic forms were noted in the uteri of a single worm sampled 80 days PT. Unlike nontreated parasites and worms sampled 42 days PT, stretched crofilariae constituted the predominant form in the distal uterus of this worm, and these stages were found in decreasing numbers throughout the proximal segments. Also, the intermediate embryogenic stages were either rare or absent.

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Radiographic evaluation of recurrent glioblastoma multiforme (GBM) in patients treated with bevacizumab and irinotecan

Journal of Clinical Oncology ◽

10.1200/jco.2007.25.18_suppl.12512 ◽

2007 ◽

Vol 25 (18_suppl) ◽

pp. 12512-12512

Author(s):

J. Andre ◽

K. Spearman ◽

S. Lu ◽

S. Hwang ◽

L. Dorsett ◽

...

Keyword(s):

Spin Echo ◽

Brain Mri ◽

Recurrent Glioblastoma ◽

Post Treatment ◽

Radiographic Evaluation ◽

Recurrent Glioblastoma Multiforme ◽

Post Contrast ◽

Chemotherapeutic Regimen ◽

Mri Scans ◽

Recurrent Gbm

12512 Background: Recurrent GBM carries a poor prognosis after first-line therapies have been exhausted, even in the setting of gross total resection. Bevacizumab and Irinotecan have shown promising results in patients with recurrent GBM (Stark-Vance, et al. Neuro- Oncol, 2005). We sought to retrospectively document the short-term effects of this chemotherapeutic regimen on recurrent GBM, as evidenced by comparative MRI brain scans obtained prior to, and one-month following initiation of treatment. Methods: We collected brain MRI data from August 2005 to December 2006, in which post-contrast spin-echo T1-weighted images demonstrated measurable enhancement and/or GBM tumor mass. Having failed temozolomide and radiation therapy, 14 consecutive patients’ MRI scans were available for review at this institution by a neuro-radiologist, in which both pre- and post-treatment hard and/or soft copy MR images were available for direct measurement. Each was treated with Bevacizumab 5 mg/kg IV and Irinotecan 125 mg/m2 IV infusion every 2 weeks until disease progression, or development of unacceptable toxicity. We measured pre- and post-treatment recurrent GBM bulk tumor in anteroposterior, transverse, and cranio-caudad dimensions, and calculated volumetric data, assuming an ellipsoid tumor configuration. Results: Pre-treatment MRI scans were performed 2 weeks prior to initiation of therapy (Mean: 13 days; Median: 10 days). Post-treatment scans were performed at approximately one month following initial treatment (Mean: 30 days; Median: 28 days). All patients witnessed significant decrease in tumor bulk volume ranging from 15.3 to 89.8%, having received an average of two cycles of chemotherapy. We observed a mean decrease in tumor volume of 46.6% (SD = 22.6%; SEM = 6.0%; 95% CI = 33.6 - 60.0 % decrease). Conclusions: We report 46.6% mean reduction in recurrent GBM tumor bulk at an average of 1-month post-treatment in patients treated with an average of two cycles of Bevacizumab and Irinotecan therapy. These promising initial results necessitate further long-term prospective evaluation of this chemotherapy. No significant financial relationships to disclose.

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NIMG-16. FEASIBLITY OF FLUORINE-18 FLUCICLOVINE PET-CT AND MRI FOR MONITORING OF CHEMO-RADIATION IN GLIOBLASTOMA: INITIAL RESULTS FROM A PILOT STUDY

Neuro-Oncology ◽

10.1093/neuonc/noz175.688 ◽

2019 ◽

Vol 21 (Supplement_6) ◽

pp. vi164-vi165

Author(s):

Susan C Short ◽

Russell Frood ◽

David Broadbent ◽

Sharon Fernandez ◽

Garry McDermott ◽

...

Keyword(s):

Disease Progression ◽

Standard Of Care ◽

Response Assessment ◽

Early Response ◽

Post Treatment ◽

Residual Tumour ◽

Post Surgery ◽

Pet Ct ◽

Mri Scans ◽

Ct And Mri

Abstract BACKGROUND Glioblastoma has a poor prognosis despite treatment with surgery and chemo-radiotherapy (CRT). Monitoring early response to CRT is challenging and conventional imaging is sub-optimal for stratifying poorly responding patients for novel agents. Also, imaging is not routinely performed during CRT and consequently, personalised treatment through individualised radiation dose adaption is not possible. AIMS: To evalutate the feasibility of Fluorine-18 Fluciclovine PET-CT for early response assessment during and post-treatment in patients with glioblastoma undergoing standard-of-care CRT. METHODS Patients with confirmed glioblastoma and macroscopic residual tumour post-surgery were consented for PET-CT and MRI prior to CRT (scan 1), after completing 2 weeks (10 fractions) of CRT (scan 2) and 6 weeks after completing treatment (scan 3). For each scan, patients were immobilised in a radiotherapy treatment mask. PET-CT and MRI scans were performed at each timepoint within a few days of each other. Patients were treated and followed up according to local guidelines. RESULTS 6 patients were recruited to the study between June 2018 and May 2019. All patients tolerated the additional imaging without problems. 2 patients were unable to attend their post-treatment PET-CT scan due to clinical deterioration. Fluciclovine PET-CT highlighted potentially active disease beyond the surgical cavity pre-radiotherapy (scan 1) in 3 patients. In 4/6, PET signal persisted after 2 weeks of radiotherapy with stable MRI appearances (scan 2). Frank disease progression was seen in 1 patient on both MRI and PET-CT mid-treatment. 3/4 patients with persistent activity at scan 2, showed disease progression post-treatment on both PET-CT and MRI (scan 3). Another had progressive changes on MRI but stable PET-CT appearances possibly representing pseudoprogression. CONCLUSION These preliminary results suggest that Fluciclovine PET-CT could help in monitoring treatment and further work to assess the ability to guide individualised treatment planning in glioblastoma is warranted.

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Predicting response to radiotherapy of intracranial metastases with hyperpolarized $$^{13}$$C MRI

Journal of Neuro-Oncology ◽

10.1007/s11060-021-03725-7 ◽

2021 ◽

Vol 152 (3) ◽

pp. 551-557

Author(s):

Casey Y. Lee ◽

Hany Soliman ◽

Nadia D. Bragagnolo ◽

Arjun Sahgal ◽

Benjamin J. Geraghty ◽

...

Keyword(s):

Stereotactic Radiosurgery ◽

Post Treatment ◽

Local Progression ◽

Intracranial Metastases ◽

The Status ◽

Mri Scans ◽

Cancer Types ◽

Pre Treatment ◽

Risk Of Treatment

Abstract Background Stereotactic radiosurgery (SRS) is used to manage intracranial metastases in a significant fraction of patients. Local progression after SRS can often only be detected with increased volume of enhancement on serial MRI scans which may lag true progression by weeks or months. Methods Patients with intracranial metastases (N = 11) were scanned using hyperpolarized $$^{13}$$ 13 C MRI prior to treatment with stereotactic radiosurgery (SRS). The status of each lesion was then recorded at six months post-treatment follow-up (or at the time of death). Results The positive predictive value of $$^{13}$$ 13 C-lactate signal, measured pre-treatment, for prediction of progression of intracranial metastases at six months post-treatment with SRS was 0.8 $$p < 0.05$$ p < 0.05 , and the AUC from an ROC analysis was 0.77 $$p < 0.05$$ p < 0.05 . The distribution of $$^{13}$$ 13 C-lactate z-scores was different for intracranial metastases from different primary cancer types (F = 2.46, $$p = 0.1$$ p = 0.1 ). Conclusions Hyperpolarized $$^{13}$$ 13 C imaging has potential as a method for improving outcomes for patients with intracranial metastases, by identifying patients at high risk of treatment failure with SRS and considering other therapeutic options such as surgery.

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Predicting Response to Radiotherapy of Intracranial Metastases with Hyperpolarized 13C MRI

10.1101/2020.11.06.20227298 ◽

2020 ◽

Author(s):

Casey Y. Lee ◽

Hany Soliman ◽

Nadia D. Bragagnolo ◽

Arjun Sahgal ◽

Benjamin J. Geraghty ◽

...

Keyword(s):

Stereotactic Radiosurgery ◽

Post Treatment ◽

Hyperpolarized 13C ◽

Local Progression ◽

Intracranial Metastases ◽

The Status ◽

Mri Scans ◽

Cancer Types ◽

Pre Treatment

AbstractPurposeStereotactic radiosurgery (SRS) is used to manage intracranial metastases in a significant fraction of patients. Local progression after SRS can often only be detected with increased volume of enhancement on serial MRI scans which may lag true progression by weeks or months.Experimental DesignPatients with intracranial metastases (N = 11) were scanned using hyperpolarized 13C MRI prior to treatment with stereotactic radiosurgery (SRS). The status of each lesion was then recorded at six months post-treatment follow-up (or at the time of death).ResultsThe positive predictive value of 13C-lactate signal, measured pre-treatment, for prediction of progression of intracranial metastases at six months post-treatment with SRS was 0.8 p < 0.05, and the AUC from an ROC analysis was 0.77 p < 0.05. The distribution of 13C-lactate z-scores was different for intracranial metastases from different primary cancer types (F = 2.46, p = 0.1).ConclusionsHyperpolarized 13C imaging has potential as a method for improving outcomes for patients with intracranial metastases, by identifying patients at high risk of treatment failure with SRS and considering other therapeutic options such as surgery.

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Lithography below 100 nm

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100074367 ◽

1983 ◽

Vol 41 ◽

pp. 96-99

Author(s):

L. D. Jackel

Keyword(s):

Spatial Distribution ◽

Electron Beam ◽

Electron Scattering ◽

Electron Beam Lithography ◽

Substrate Material ◽

Local Electron ◽

Electron Dose ◽

Positive Resist ◽

Exposure Process

Most production electron beam lithography systems can pattern minimum features a few tenths of a micron across. Linewidth in these systems is usually limited by the quality of the exposing beam and by electron scattering in the resist and substrate. By using a smaller spot along with exposure techniques that minimize scattering and its effects, laboratory e-beam lithography systems can now make features hundredths of a micron wide on standard substrate material. This talk will outline sane of these high- resolution e-beam lithography techniques.We first consider parameters of the exposure process that limit resolution in organic resists. For concreteness suppose that we have a “positive” resist in which exposing electrons break bonds in the resist molecules thus increasing the exposed resist's solubility in a developer. Ihe attainable resolution is obviously limited by the overall width of the exposing beam, but the spatial distribution of the beam intensity, the beam “profile” , also contributes to the resolution. Depending on the local electron dose, more or less resist bonds are broken resulting in slower or faster dissolution in the developer.

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An emerging technology: Nuclear magnetic resonance microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010010706x ◽

1988 ◽

Vol 46 ◽

pp. 1000-1001

Author(s):

M.J. Hennessy ◽

E. Kwok

Keyword(s):

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Relaxation Times ◽

Basic Research ◽

Local Environment ◽

Magnetic Resonance Images ◽

Nmr Microscopy ◽

Mri Scans ◽

Temperature Relaxation ◽

Nuclear Magnetic

Much progress in nuclear magnetic resonance microscope has been made in the last few years as a result of improved instrumentation and techniques being made available through basic research in magnetic resonance imaging (MRI) technologies for medicine. Nuclear magnetic resonance (NMR) was first observed in the hydrogen nucleus in water by Bloch, Purcell and Pound over 40 years ago. Today, in medicine, virtually all commercial MRI scans are made of water bound in tissue. This is also true for NMR microscopy, which has focussed mainly on biological applications. The reason water is the favored molecule for NMR is because water is,the most abundant molecule in biology. It is also the most NMR sensitive having the largest nuclear magnetic moment and having reasonable room temperature relaxation times (from 10 ms to 3 sec). The contrast seen in magnetic resonance images is due mostly to distribution of water relaxation times in sample which are extremely sensitive to the local environment.

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SEM evaluation of the TEM cold-stage double-film specimen

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100111471 ◽

1984 ◽

Vol 42 ◽

pp. 272-273

Author(s):

Jayesh Bellare

Keyword(s):

Spatial Distribution ◽

Sample Preparation ◽

Sample Thickness ◽

Specimen Preparation ◽

Preparation Technique ◽

Liquid Sample ◽

Thin Specimen ◽

Sample Preparation Technique ◽

Cold Stage ◽

Film Specimen

Seeing is believing, but only after the sample preparation technique has received a systematic study and a full record is made of the treatment the sample gets.For microstructured liquids and suspensions, fast-freeze thermal fixation and cold-stage microscopy is perhaps the least artifact-laden technique. In the double-film specimen preparation technique, a layer of liquid sample is trapped between 100- and 400-mesh polymer (polyimide, PI) coated grids. Blotting against filter paper drains excess liquid and provides a thin specimen, which is fast-frozen by plunging into liquid nitrogen. This frozen sandwich (Fig. 1) is mounted in a cooling holder and viewed in TEM.Though extremely promising for visualization of liquid microstructures, this double-film technique suffers from a) ireproducibility and nonuniformity of sample thickness, b) low yield of imageable grid squares and c) nonuniform spatial distribution of particulates, which results in fewer being imaged.

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