Tissue oxygen tension measurements in the Shionogi model of prostate cancer using 19 F MRS and MRI
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Objectives: To investigate changes in tumour tissue oxygenation throughout the tumour growth–regression–relapse cycle in an androgen-dependent animal tumour model. Materials and methods: 19F T1 relaxometry of Perfluoro-15-Crown-5-Ether was used to measure in vivo partial oxygen pressure (pO2) of Shionogi tumours on a 2.35-T MR scanner. Perfluoro-15-Crown-5-Ether was administered as an emulsion injected intravenously or as a neat compound injected directly into the tumour. Non-localized, tumour 19F T1 measurements, made at multiple time points throughout the tumour cycle, were translated into pO2 levels. Results: No correlation between tumour size and pO2 values was found. Values of pO2 for growing tumours (50 ± 30 torr) were significantly lower than for regressing and relapsing tumours after 9 days post-castration (70 ± 10 torr, p<0.05). Maximum pO2 values (90 ± 30 torr) were reached between fifth and eighth day post-castration, when tumour pO2 was significantly higher than both pre-castration (p<0.001) and after 9 days post-castration (p<0.05). Conclusion: We demonstrate that longitudinal pO2 measurements in vivo are feasible. Values of pO2 for growing androgen-dependent tumours were significantly lower than for regressing and relapsing androgen-independent tumours. These results have potential clinical importance in optimizing the timing of chemotherapy and/or radiotherapy of hormone dependent tumours.
Keywords19F NMR pO2 measurements Shionogi tumour model Hormone sensitive tumours
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The authors thank Ms. Mary Bowden from the Prostate Centre at VGH for her excellent technical support. Generous help of Fresenius-Kabi, Clayton, NC, USA in the preparation of the PFC emulsion is gratefully acknowledged. This work was supported by research grants from Health Canada and Terry Fox Foundation.
- 3.De Jaeger K, Kavanagh MC, Hill RP (2001) Relationship of hypoxia to metastatic ability in rodent tumours. Br J Cancer 84:1280–1285Google Scholar
- 6.Minesita T, Yamaguchi K (1964) An androgen-dependent tumour derived from a hormone-independent spontaneous tumour of a female mouse. Steroids 4:815–829Google Scholar
- 8.Parhami P, Fung BM (1983) Fluorine-19 relaxation study of perfluoro chemicals as oxygen carriers. J Phys Chem 87:1928–1931Google Scholar
- 13.Hunjan S, Zhao D, Constantinescu A, Hahn EW, Antich PP, Mason RP (2001) Tumor oximetry: demonstration of an enhanced dynamic mapping procedure using fluorine-19 echo planar magnetic resonance imaging in the Dunning prostate R3327-AT1 rat tumor. Int J Radiat Oncol Biol Phys 49:1097–1108PubMedGoogle Scholar
- 18.Evelhoch JL, Ackerman JJH (1983) NMR T1 measurements in inhomogeneous B1 with surface coils. J Magn Reson 53:52–64Google Scholar
- 24.Kozlowski P, Wong J, Goldenberg SL. Serial tumour blood flow measurements in the androgen dependent and androgen independent shionogi tumour model. Br J Urol (in press)Google Scholar
- 30.Skov K, Adomat H, Bowden M, Dragowska W, Gleave ME, Koch CJ et al. (2004) Hypoxia in the androgen-dependent shionogi model for prostate cancer at three stages. Radiat Res (in press)Google Scholar