Yukihisa Takayama MD, Presenter: Research Grant, FUJIFILM Holdings Corporation

Akihiro Nishie MD, Abstract Co-Author: Nothing to Disclose

Masaaki Sugimoto, Abstract Co-Author: Nothing to Disclose

Osamu Togao MD, PhD, Abstract Co-Author: Nothing to Disclose

Yoshiki Asayama MD, Abstract Co-Author: Nothing to Disclose

Hiroshi Honda MD, Abstract Co-Author: Nothing to Disclose

Jochen Keupp PhD, Abstract Co-Author: Employee, Koninklijke Philips NV

Yasuhiro Ushijima MD, Abstract Co-Author: Nothing to Disclose

Daisuke Okamoto MD, Abstract Co-Author: Nothing to Disclose

Nobuhiro Fujita MD, PhD, Abstract Co-Author: Nothing to Disclose

Koichiro Morita, Abstract Co-Author: Nothing to Disclose

To evaluate a clinical utility of amide proton transfer magnetic resonance imaging (APT-MRI) in assessing prostate cancer (Pca) aggressiveness

A total of 105 patients (age = 68.4 ± 7.0 years) with biopsy proved Pca were enrolled. In addition to conventional MRI, such as T2WI and DWI, APT-MRI was scanned on a 3T MR system. The areas of Pca, noncancerous peripheral and transitional zones, and the Gleason score (GS) of each Pca were defined by referring to the needle biopsy results. The MR parameters of APT-MRI were as follows: 2D-TSE sequence with driven equilibrium refocusing, TR/TR = 5 s/6 ms, FOV = 2302 mm2, resolution = 1.8×1.8×5 mm3, 25 saturation frequency offsets = -6 to 6 ppm (step 0.5 ppm) and ω0 = -160 ppm. Saturation pulse length = 0.5 s, B1rms = 2.0 μT. δB0 maps were acquired separately for a δB0 correction. The APT signal intensity (APTSI) was defined as: MTRasym = {S[-3.5ppm] - S[+3.5ppm])/S0}×100 (%). We assessed MRI-detectable 66 cancers about Pca aggressiveness after categorizing into 4 groups: GS of 6 (GS = 3 + 3, n = 23); GS of 7 (GS = 3 + 4 or 4 + 3, n = 18); GS of 8 (GS = 4 + 4, n = 11) and GS of 9 (GS = 4 + 5 or 5 + 4, n = 14). Mean ± SDs of the APTSI of each group were calculated after drawing regions-of-interest on the APT-MRI. The mean APTSIs among 4 groups were compared one-way analysis of variance with Tukey’s HSD post hoc test.

Mean ± SDs of the APTSI (%) of each group were; GS of 6, 2.48 ± 0.59; GS of 7, 5.17 ± 0.66; GS of 8, 2.56 ± 0.85; and GS of 9, 1.96 ± 0.75, respectively. There was a significant difference in APTSIs between GS of 6 and GS of 7, and GS of 7 and GS of 9, (p<.05), but no significant differences in APTSI between GS of 6 and GS of 8, GS of 6 and GS of 9, and GS of 7 and GS of 8. The increase and decrease in APTSIs relating to the progression of Pca aggressiveness might reflect the changes of cellularity, cell proliferation and protein synthesis of Pca.

The APTSI in GS of 7 was the highest. The APT-MRI has a possibility as a new biomarker of Pca aggressiveness.

The APT-MRI can be useful to predict prostate cancer aggressiveness alone or in combination with other modalities and MR sequences.

Takayama, Y, Nishie, A, Sugimoto, M, Togao, O, Asayama, Y, Honda, H, Keupp, J, Ushijima, Y, Okamoto, D, Fujita, N, Morita, K, Amide Proton Transfer Magnetic Resonance Imaging of Prostate Cancer: A New Biomarker of Prostate Cancer Aggressiveness.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045519.html