Localizedin vivo1H NMR spectroscopy of murine tumours: effect of blood flow reduction

Nielsen, F. U.; Topp, Simon; Horsman, Michael R.; Overgaard, Jens; Stødkilde-Jørgensen, Hans; Maxwell, Ross J.

doi:10.1002/(sici)1099-1492(199906)12:4<175::aid-nbm552>3.0.co;2-f

Cited by 6 publications

(6 citation statements)

References 26 publications

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“…Both of the agents are commonly used in clinics. They have also been extensively investigated to modulate blood flow in animal experiments (22,26). …”

Section: Discussionmentioning

confidence: 99%

Radiofrequency Ablation

Exner

Krupka

et al. 2009

Academic Radiology

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Rationale and Objectives Inflammatory reaction surrounding the ablated area is a major confounding factor in the early detection of viable tumor after radiofrequency (RF) ablation. A difference in the responsiveness of normal and tumor blood vessels to vasoactive agents may be used to distinguish these regions in post-ablation follow-up. The goal of this study was to examine longitudinal perfusion changes in untreated viable tumor and the peripheral hyperemic rim of RF-ablated tumor in response to a vasoconstrictor (phenylephrine) or vasodilator (hydralazine) in a subcutaneous rat tumor model. Materials and Methods Bilateral subcutaneous shoulder tumors were inoculated in 24 BDIX rats and evenly divided into two groups (phenylephrine and hydralazine groups). One tumor in each animal was completely treated with RF ablation (at 90 ± 2°C for 3 minutes), and the other remained untreated. Computed tomographic perfusion scans before and after phenylephrine (10 μg/kg) or hydralazine (5 mg/kg) administration were performed 2, 7, and 14 days after ablation. Four rats per group were euthanized on each scan day, and pathologic evaluation was performed. The changes of blood flow in the peripheral rim of ablated tumor and untreated viable tumor in response to phenylephrine or hydralazine at each time point were compared. The diagnostic accuracy of viable tumor using the percentage change of blood flow in response to phenylephrine and hydralazine was compared using receiver-operating characteristic analysis. Results The peripheral rim of ablated tumor presented with a hyperemic reaction with dilated vessels and congestion on day 2 after ablation, numerous inflammatory vessels on day 7, and granulation tissue formation on day 14. Phenylephrine significantly decreased the blood flow in the peripheral hyperemic rim of ablated tumor on days 2, 7, and 14 by 16.3±9.7% (P = .001), 24.0±22.6% (P = .007), and 31.1±25.4% (P = .045), respectively. In untreated viable tumor, the change in blood flow after phenylephrine was irregular and insignificant. Hydralazine decreased the blood flow in the peripheral rim of both ablated tumor and untreated viable tumor. Receiver-operating characteristic analysis showed that reliable tumor diagnosis using the percentage change of blood flow in response to phenylephrine was noted on days 2 and 7, for which the areas under the curve were 0.82 (95% confidence interval, 0.64–1.00) and 0.81 (95% confidence interval, 0.56–1.00), respectively. However, tumor diagnosis using the blood flow change in response to hydralazine was unreliable. Conclusion Phenylephrine markedly decreased blood flow in the peripheral hyperemic rim of ablated tumor but had little effect on the untreated viable tumor. Computed tomographic perfusion with phenylephrine may be useful in the long-term treatment assessment of RF ablation.

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“…Both of the agents are commonly used in clinics. They have also been extensively investigated to modulate blood flow in animal experiments (22,26). …”

Section: Discussionmentioning

confidence: 99%

Radiofrequency Ablation

Exner

Krupka

et al. 2009

Academic Radiology

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“…These factors can be semi-quantitated and followed serially allowing the effects of therapeutic manipulations to be monitored. The technique has been used extensively in animal models looking at the effects of blood flow modifiers such as nicotinamide and carbogen (Robinson et al, 2000), hydralazine (Nielsen et al, 1999) and vascular occlusion (McCoy et al, 1995). One of the major problems of MRS is lack of sensitivity especially in deep-seated human tumours.…”

Section: Magnetic Resonance Spectroscopy (Mrs)mentioning

confidence: 99%

Measuring changes in human tumour vasculature in response to therapy using functional imaging techniques

et al. 2001

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Antiangiogenic and antivascular agents provide new approaches to treating tumours. These may avoid many of the problems experienced with current approaches such as inherent and acquired resistance to treatment. Tumours do not grow beyond 1–2 mm3in size without the development of new vessels (Folkman, 1971). Such neo-vascularization (angiogenesis) allows tumour cells to increase their nutrient supply, survive and proliferate despite the new vessels often having structural and functional differences compared to normal tissue vasculature. Treatments targeted at tumour vasculature have produced impressive results in animal models (Lindsay et al, 1996; Watson et al, 1996; O’Reilly, 1997; Horsman et al, 1998). These therapies are now entering clinical trials. However, the successful introduction of these therapies into clinical practice will require the development of reliable ways to assess angiogenesis and its modification or inhibition in vivo. Here we discuss some of the emerging imaging techniques that may be useful. © 2001 Cancer Research Campaign http://www.bjcancer.com

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“…Multiple signaling pathways and oncogenes can regulate glycolysis 54. Decreasing tumor oxygenation correlated with increasing glycolytic rate in a murine mammary carcinoma model in a study using volume localized 13 C MRS with 1 H- 13 C cross polarization to detect the conversion of [1- 13 C]-glucose to [3- 13 C]-lactate 63. Several studies showed that [1- 13 C]-labeled glucose is metabolized to lactate in poorly differentiated tumors 64–67.…”

Section: Metabolic Molecular and Functional Mrs Of Cancer Cells mentioning

confidence: 99%