TY - JOUR
T1 - Rapid in vivo monitoring of chemotherapeutic response using weighted sodium magnetic resonance imaging
AU - Kline, Richard P.
AU - Wu, Ed X.
AU - Petrylak, Daniel P.
AU - Szabolcs, Matthias
AU - Alderson, Philip O.
AU - Weisfeldt, Myron L.
AU - Cannon, Paul
AU - Katz, Jose
PY - 2000/6
Y1 - 2000/6
N2 - A novel pulse sequence strategy uses sodium magnetic resonance imaging to monitor the response to chemotherapy of mouse xenograft tumors propagated from human prostate cancer cell lines. An inversion pulse suppresses sodium with long longitudinal relaxation times, weighting the image toward intracellular sodium nuclei. Comparing these weighted sodium images before and 24 h after administration of antineoplastics, we measured a 36 ± 4% (P < 0.001; n = 16) increase in signal intensity. Experiments with these same drugs and cells, treated in culture, detected a significant intracellular sodium elevation (10-20 mM) using a ratiometric fluorescent dye. Flow cytometry studies showed that this elevation preceded cell death by apoptosis, as determined by fluorescent end-labeling of apoptotic nuclei or Annexin V binding. Histopathology on formalin-fixed sections of explanted tumors confirmed that drug administration reduces proliferation (2.2 versus 8.6 mitotic figures per high power field; P < 0.0001), an effect that inversely correlates with the sodium magnetic resonance image response on a tumor-to-tumor basis (P < 0.02; n = 10). Morphological features, such as central zones of nonviable cells, rims of active apoptosis, and areas of viable tumor, could be distinguished by comparing weighted and unweighted images. Advantages of this sodium imaging technique include rapid determination of drug efficacy, improved diagnosis of lesions, ease of coregistration with high resolution proton magnetic resonance imaging, and absence of costly or toxic reagents.
AB - A novel pulse sequence strategy uses sodium magnetic resonance imaging to monitor the response to chemotherapy of mouse xenograft tumors propagated from human prostate cancer cell lines. An inversion pulse suppresses sodium with long longitudinal relaxation times, weighting the image toward intracellular sodium nuclei. Comparing these weighted sodium images before and 24 h after administration of antineoplastics, we measured a 36 ± 4% (P < 0.001; n = 16) increase in signal intensity. Experiments with these same drugs and cells, treated in culture, detected a significant intracellular sodium elevation (10-20 mM) using a ratiometric fluorescent dye. Flow cytometry studies showed that this elevation preceded cell death by apoptosis, as determined by fluorescent end-labeling of apoptotic nuclei or Annexin V binding. Histopathology on formalin-fixed sections of explanted tumors confirmed that drug administration reduces proliferation (2.2 versus 8.6 mitotic figures per high power field; P < 0.0001), an effect that inversely correlates with the sodium magnetic resonance image response on a tumor-to-tumor basis (P < 0.02; n = 10). Morphological features, such as central zones of nonviable cells, rims of active apoptosis, and areas of viable tumor, could be distinguished by comparing weighted and unweighted images. Advantages of this sodium imaging technique include rapid determination of drug efficacy, improved diagnosis of lesions, ease of coregistration with high resolution proton magnetic resonance imaging, and absence of costly or toxic reagents.
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M3 - Article
C2 - 10873063
AN - SCOPUS:0034125873
SN - 1078-0432
VL - 6
SP - 2146
EP - 2156
JO - Clinical Cancer Research
JF - Clinical Cancer Research
IS - 6
ER -