PSA-recurrence prostate carcinoma is associated with two general problems.

1. Localisation of PSA-recurrence is unconfident. In many cases it's not clear if a local, locoregional oder systemic relapse is available.
2. There is no standard therapy proved by randomised clinical trials. Recommended radiotherapy starting with PSA-value < 0.5 ng/ml according to german S3 guidelines is based on retrospective data.

These difficulties may lead to a therapy potentially not adapted to patients situation of disease.This study aims to randomised examine if an instant radiotherapy of prostate PSA-recurrence (PSA-value between 0.2 - 0.99 ng/ml) or a delayed radiotherapy with additional imaging (PSA value >= 1 ng/ml) including PET/CT and bone scintigraphy for reliable information about tumor location and expansion is beneficial regarding therapy efficiency, quality of life and social economic aspects.

Inclusion Criteria:

• postoperative, biochemical recurrent prostate carcinoma with PSA value between 0.2 to 0.99 ng/ml
• prior irradiation
• comprehension of study protocol content and signed informed consent form
• minimum age 18 years

Exclusion Criteria:

• primary therapy of prostate carcinoma
• PSA value >= 1 ng/ml
• diagnosed distant metastases before randomisation (osseous or systemic)
• performed PET/CT before randomisation
• malignant slave tumor
• potent men that are not willing or are unable to apply consequent contraception
• ongoing drug- and/or alcohol abuse
• patients that are not willing or able to cooperate according to protocol
• patients in care
• patients that are not able to understand German language