Antivascular Effects of Neoadjuvant Androgen Deprivation for Prostate Cancer: An In Vivo Human Study Using Susceptibility and Relaxivity Dynamic MRI

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• 作者：Roberto Alonzi F.R.C.R. ; M.D.^* ; ^{robertoalonzi@btinternet.com"" rel=""nofollow} ; Anwar R. Padhani F.R.C.R. ; M.D.^† ; ; N. Jane Taylor Ph.D.^† ; ; David J. Collins B.A.^‡ ; ; James A. D'Arcy M.Phys.^‡ ; ; J. James Stirling M.Sc.^† ; ; Michele I. Saunders F.R.C.R. ; M.D.^* ; Peter J. Hoskin F.R.C.R. ; M.D.^*
• 刊名：International Journal of Radiation Oncology*Biology*Physics
• 出版年：2011
• 出版时间：1 July 2011
• 年：2011
• 卷：80
• 期：3
• 页码：721-727
• 全文大小：740 K

文摘

Purpose

The antivascular effects of androgen deprivation have been investigated in animal models; however, there has been minimal investigation in human prostate cancer. This study tested the hypothesis that androgen deprivation causes significant reductions in human prostate tumor blood flow and the induction of hypoxia at a magnitude and in a time scale relevant to the neoadjuvant setting before radiotherapy.

Methods and Materials

Twenty patients were examined, each with five multi-parameter magnetic resonance imaging scans: two scans before the commencement of androgen suppression, one scan after 1 month of hormone treatment, and two further scans after 3 months of therapy. Quantitative parametric maps of the prostate informing on relative blood flow (rBF), relative blood volume (rBV), vascular permeability (transfer constant [K^trans]), leakage space (v_e) and blood oxygenation (intrinsic relaxivity [R₂*]) were calculated.

Results

Tumor blood volume and blood flow decreased by 83 % and 79 % , respectively, in the first month (p < 0.0001), with 74 % of patients showing significant changes. The proportion of individual patients who achieved significant changes in T1 kinetic parameter values after 3 months of androgen deprivation for tumor measurements was 68 % for K^trans and 53 % for v_e By 3 months, significant increases in R₂* had occurred in prostate tumor, with a rise of 41.1 % (p < 0.0001).

Conclusions

Androgen deprivation induces profound vascular collapse within 1 month of starting treatment. Increased R₂* in regions of prostate cancer and a decrease in blood volume suggest a reduction in tumor oxygenation.