Evaluation of Hypoxia by PET With F-Miso in Radiation Therapy of Prostate Cancer (HYPOXProstat)

Poitiers University Hospital, IASON Gmbh, Feldkirchner strasse 4, 8054 Graz-Seiesberg AUSTRIA, Cyclopharma

With functional imaging development, it becomes possible to increase radiation dose to radioresistant areas (located inside tumor volume) using radiotherapy dose-painting. This strategy is particularly suitable for prostate cancer where tumor hypoxia plays a major role in the resistance of these tumors to radiation. In order to develop intratumoral hypoxia targeting by radiotherapy dose-painting areas, we should characterize changes in hypoxia before treatment and during radiotherapy. If hypoxia does not change during radiotherapy, radiotherapy dose-painting strategy by an "integrated" boost is performed. If hypoxia varied (increasing or incomplete regression), a "final" boost strategy of radiotherapy dose-painting(IMRT, stereotactic brachytherapy or high dose rate) after a first fractionated IMRT could be considered. This study should show that PET imaging with fluoromisonidazole (18F-MISO) is an available tool to physicians in assessing tumor hypoxia.

To characterize changes in tumor hypoxia (PET with 18F-MISO) during radiation therapy of prostate cancer.

First PET-scan with 18-F-Miso done before radiation Second PET-scan with 18-F-Miso done 3 to 4 weeks after the beginning of radiation therapy.

To compare hypoxia imaging (PET with 18F-MISO) with anatomical imaging (PET with 18F-choline) to study the feasibility of a tailored treatment.

Images obtained with PET Choline and MRI (anatomical location) will be merge with images obtained by 18F-MISO PET to search hypoxia on these anatomical areas.

Inclusion Criteria: histologically proven prostate adenocarcinoma Absence of metastases (lymph node or bone) One or more tumor nodules seen on MRI and PET Choline. Intermediate Risk : Gleason 7 and PSA (prostate specific antigen)<20 ng / ml, T <T2c or Gleason 6 and PSA 10-20 ng / ml, T <T2c No concomitant hormonal treatment. (NB: the introduction of hormone therapy during radiotherapy before the second 18F-MISO is a criterion to study exit) Indication of radiotherapy up to a total dose> 70 Gy and 2 Gy/day fractions Signed Informed consent Social Insurance Exclusion Criteria: Age < 18 years old Patient protected by law

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