Effects of B20 therapy on glioblastoma tumors.

<p>Tumor volume (mm³) for each individual tumor (<b>A</b>) and the average volume of the entire group (<b>B</b>), as a function of days post cell inoculation for control (black, n = 15) and B20 treated (blue, n = 6) mice. B20 showed only moderate effects on tumor growth kinetics. Comparison of the average diffusion (<b>C</b>) and HRI (<b>D</b>) values of tumors (blue; larger than 15 mm³) and the CLS (red) between control and B20 treated mice. Additionally, the HRI tumor values were also separated between borders (green) and the central area (purple). (<b>E</b>) Quantification of vessel count/HPF analyzed from 10 randomly selected HPF/tumor is based on the CD31 immunostaining. Tumor vascularity is significantly higher in the border (green) compared to the center (purple) in both groups. (<b>F</b>) Representative histological sections of control (left) and B20 treated (right) immunostained with Ki67 for proliferation (<b>top</b>) and TUNEL for apoptosis (<b>bottom</b>); Original magnification X40. *denotes statistical significance at P<0.05; **denotes statistical significance at P<0.01; ***denotes statistical significance at P<0.005.</p

Glioblastoma tumor imaging characteristics.

<p>Representative T₂W image (<b>A</b>), T₁W image obtained before Gd-DTPA injection (<b>B</b>); contrast enhanced T₁W image obtained 1 min after Gd-DTPA injection (<b>C</b>); DWI map (<b>D</b>) and HRI map (<b>E</b>) with the corresponding H&E stained histological slide (<b>F</b>) of control tumor obtained 30 days post Gl-261 murine glioma cells inoculation. T-tumor, E-edema; bar-1 cm.</p

HRI in the healthy brain.

<p>HRI maps were obtained without (<b>A, B, C, E, F, G</b>) or with (<b>I, J, K, M, N, O</b>) constant air flow above the head. HRI maps are presented for both positive and negative pixels (<b>A, I</b>) and the corresponding SI time course (<b>E, M</b>); only for positive pixels (<b>B, J</b>) and the corresponding SI time course (<b>F, N</b>) and only for negative pixels (<b>C, K</b>) and the corresponding SI time course (<b>G, O</b>). In the graphs the time-curse (TC, red line) is calculated only for active pixels in the brain ROI (marked in blue on the HRI maps) and the ROI time-course (RTC, blue line) is the TC multiplied by the ratio of the number of active pixels divided by the total number of pixels in the ROI. It can be seen that when airflow is used the negative response is significantly lower and randomly distributed (<b>K</b>) compared to maps acquired without airflow (<b>C</b>). The corresponding T₂W image is presented in (<b>D</b>) with the matching HRI superimposed on top (<b>H</b>). Note that the main blood vessels are clearly manifested on the HRI map. (<b>L</b>) The mean TC and RTC calculated from 44 HRI maps acquired with or without constant airflow are compared.</p

Glioblastoma imaging parameters progression over time.

<p>(<b>A</b>) Serial coronal FISP (first row) and T₂W (second row) images of a control tumor that were acquired on days 7, 14, 18 and 22. The corresponding DWI (third row) and HRI (fourth row) maps are also shown. ROIs delineating the tumor and contra-lateral healthy brain tissue are marked on the FISP and T₂W images (blue line). Increased HRI response during tumor progression can be seen both in the HRI maps and in the ROI-time-course (RTC) graphs (fifth row). The average diffusion values (<b>B</b>) and the HRI values (<b>C</b>) of the tumors (blue) and the contra-lateral side (CLS; red) are given as a function of time from cell inoculation. Note that the diffusion values are higher than the CLS throughout the entire period while tumor HRI increased over time. ***denotes statistical significance at P<0.005 compared to the CLS value.</p

Hemodynamic Response Imaging in the healthy brain.

<p>Representative HRI results obtained from a 29 year old healthy subject. (A) ΔS-O₂ map; (B) ΔS-CO₂ map; (C) the corresponding T₁-weighted (anatomical) image; (D) the gray and white matter masks (GM and WM, respectively); the mean time courses of the signal intensity change (%) during hyperoxic challenge (E) and hypecapnic (F) challenges, calculated from the GM VOI of this subject.</p

Patients' clinical information.

<p>y = years; M/F = male/female; RT = radiation therapy; Chemo = chemotherapy;</p

HRI and rCBV values calculated at the lesion and contra lateral side VOIs.

<p>ΔS = percent signal intensity changes; rCBV = relative cerebral blood volume; CLS = contralateral side.</p>1<p>Vascular reactivity index, number of voxels (in percentages) above the defined VRM threshold.</p>2<p>Lesion crosses brain midline, thus contralateral side VOI could not be defined.</p>3<p>DSC perfusion was not performed.</p

Means and standard deviations of HRI values calculated from all healthy subjects.

<p>ΔS = percent signal intensity changes; GM = gray matter; WM = white matter; VRM = vascular reactivity mismatch.</p

Negative

<p>Δ<b>S-O2 response.</b> Representative results obtained from a patient with recurrent GB (patient number 4), showing negative ΔS-O2 response during hyperoxic challenge observed distant from the tumor area. (A) ΔS-O₂ map; (B) T₁WI post contrast agent injection and (C) fluid attenuation inversion recovery (FLAIR) image. (D) The mean time courses of the signal intensity change (%) during hyperoxic challenge obtained from the area with negative response (VOI is marked by red rectangle on <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0049416#pone-0049416-g004" target="_blank">Figure 4A</a>).</p

Hemodynamic Response Imaging and pathological findings.

<p>Results obtained from a newly diagnosed patient with GB (patient number 2). Representative sagital (left), axial (center) and coronal (right) orientations taken through the tumor center of (A) T₁-weighted images; (B) ΔS-O₂ maps; (C) ΔS-CO₂ maps; (D) VRM maps (of the tumor area marked by white rectangle on <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0049416#pone-0049416-g003" target="_blank">figure 3B,C</a>) and (E) rCBV maps. The maps are superimposed on the anatomical images; color scales for all maps are located on the right side. Immunohistochemical staining of samples from the same tumor with: (F) Ki67 antibody for proliferation; (G) CD31 antibody for endothelial cells indicating vascularity and (H) SMA antibody for smooth muscle cells indicating vascular maturation.</p