Noninvasive imaging of the functional effects of anti-VEGF therapy on tumor cell extravasation and regional blood volume in an experimental brain metastasis model

SummaryThe technique of blood pool scanning was used to examine 15 hemophilic subjects. Employing an in vivo method for erythrocyte labeling with Technetium-99 m, a dynamic perfusion sequence is obtained using a scintillation camera positioned over the area to be examined. This demonstrates the vascularity of the tissue. Subsequently, equilibrium blood pool images of the area are obtained and analyzed with a densitometer to assess relative regional blood volume. In patients who were not bleeding but had chronic arthropathy, vascularity was not increased, and the blood volume of comparable joints was similar. By contrast, marked increases in vascularity and image density were observed in studies of acutely bleeding joints. Chronic hemarthroses were associated with persistent, but less marked increases in joint perfusion. Transient increases in joint vascularity were demonstrated after insertion of knee prostheses. In a patient with a thigh hematoma, the dimensions of the hemorrhage were clearly delineated. Since only a tracer dose of nuclide is infused intravenously, there are no allergic reactions or other side effects of the procedure. Blood pool scanning is a safe, non-invasive technique that augments clinical and radiographic evaluations, and provides a new dimension in the assessment of the hemophilic patient.

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Measurement of Blood—Brain Hexose Transport with Dynamic PET: Comparison of [18F]2-Fluoro-2-Deoxyglucose and [11C]O-Methylglucose

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.1989.14 ◽

1989 ◽

Vol 9 (1) ◽

pp. 104-110 ◽

Cited By ~ 8

Author(s):

K. Herholz ◽

K. Wienhard ◽

U. Pietrzyk ◽

G. Pawlik ◽

W.-D. Heiss

Keyword(s):

Blood Volume ◽

Rate Constants ◽

Regional Analysis ◽

Close Correlation ◽

Transport Rate ◽

Hexose Transport ◽

Tracer Transport ◽

Parametric Images ◽

Positron Emission ◽

Regional Blood Volume

Blood-to-tissue transport of [18F]2-fluoro-2-deoxyglucose (FDG) and [11C]O-methylglucose (CMG) was compared by dynamic positron emission tomography in four patients with recent ischemic infarcts and in three patients with intracerebral tumors. Local blood volume, tracer transport from tissue to blood, and FDG phosphorylation rates were also determined. A regional analysis of parametric images showed a close correlation of FDG and CMG transport rate constants in pathological tissue. Transport rates of FDG and CMG showed correspondingly less asymmetric remote effects than FDG phosphorylation rates. Transport rate constants were consistently higher for FDG than for CMG in pathological and normal tissue, in accordance with the higher affinity of carrier enzymes to FDG. There was a significant correlation between fitted regional blood volume values and correspondence of average absolute values with both tracers. It is concluded that dynamic FDG PET for measurement of cerebral glucose metabolism is also useful to measure alterations of hexose transport and local blood volume in pathological tissue.

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Heterogeneity in malignant gliomas: a magnetic resonance analysis of spatial distribution of metabolite changes and regional blood volume

Journal of Neuro-Oncology ◽

10.1007/s11060-010-0443-y ◽

2010 ◽

Vol 103 (3) ◽

pp. 663-672 ◽

Cited By ~ 13

Author(s):

Marlies Wagner ◽

Reinhold Nafe ◽

Alina Jurcoane ◽

Ulrich Pilatus ◽

Kea Franz ◽

...

Keyword(s):

Spatial Distribution ◽

Magnetic Resonance ◽

Blood Volume ◽

Malignant Gliomas ◽

Resonance Analysis ◽

Regional Blood Volume

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OTHR-07. Systematic Review and Meta-analysis of Lung Cancer Brain Metastasis and Primary Tumor PD-L1 Expression Discordance

Neuro-Oncology Advances ◽

10.1093/noajnl/vdab071.062 ◽

2021 ◽

Vol 3 (Supplement_3) ◽

pp. iii15-iii16

Author(s):

Raees Tonse ◽

Muni Rubens ◽

Haley Appel ◽

Martin C Tom ◽

Matthew D Hall ◽

...

Keyword(s):

Lung Cancer ◽

Systematic Review ◽

Brain Metastasis ◽

Tumor Cell ◽

Small Cell Lung Cancer ◽

Cell Lung Cancer ◽

Primary Tumor ◽

Small Cell ◽

Receptor Expression ◽

Small Cell Lung

Abstract Background Novel immunotherapeutic strategies, such as those targeting the PD-1/PD-L1 axis, are promising in patients with metastatic lung cancer and are often administered when tumors show PD-L1 positivity. The objective of this study was to analyze PD-L1 receptor discordance in tumor cell between the primary tumor and lung cancer brain metastasis (LCBM). Methods A systematic review of series published prior to April 2021 obtained from the Medline database of biopsied or resected LCBM evaluating PD-L1 discordance was performed using PRISMA guidelines. Weighted random effects models were used to calculate pooled estimates. Results Six full-text articles (n=247 patients) with a median of 32 patients in each study (range: 24–73 patients) reported PD-L1 receptor expression analyses of both primary lung tumors and brain metastases. The majority of patients (81%) were smokers, with 67% non-small cell lung cancer and 33% small cell lung cancer. The pooled estimate for overall PD-LI receptor concordance between primary and LCBM was 76% (95% CI: 52%-90). The positivity rate varied when analyzed by various cutoff levels of PD-L1 expression; for <1% expression, it was 41% (95% CI: 22%-62%) for primary vs. 58% (95% CI: 35%-78%) for LCBM; for PD-L1 expression of 1–50%, it was 24% (95% CI: 13%-40%) vs. 19% (95% CI: 10%-33%); and for PD-L1 >50% it was 12% (95% CI: 4%-33%) vs. 21% (95% CI: 14%-29%) (p=0.425). The pooled estimate for overall PD-LI receptor discordance between primary and LCBM was 17% (95% CI: 10%-27%). Meta-regression analysis showed that age, sex, smoking status, and histology were not associated with PD-LI receptor discordance. Conclusions PD-L1 status discordance in tumor cell occurs in approximately 20% of LCBM, with the greatest discordance in the <1% expression category. Awareness of this discordance is important for the selection of immune checkpoint inhibitor therapy as well as in the analysis of patterns of failures.

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