As the most common carcinoma in men, prostate cancer is a significant tumor entity in oncology. In addition to the surgical approach, definitive radiotherapy is an equivalent therapy alternative in the non-metastatic primary situation. However, radiotherapy usually stretches over a period of several weeks (7 to 8 weeks) during which the patient receives irradiation on a daily basis. For this reason and for radiobiological considerations the total treatment time is increasingly shortened. It has been shown in several randomized phase III studies that shorting radiotherapy to about 4 weeks by increasing the single dose (so-called hypofractionation) is possible. Meanwhile there is also more data on extreme hypofractionation (max. 10 radiation sessions) available, however often times, extensive preparations are necessary (such as the invasive introduction of markers into the prostate). The current, prospective, non-randomized, multicentric, Phase II SMILE study is now testing whether the MRI-guided radiotherapy with a greatly shortened radiotherapy of the prostate over 5 radiation sessions is possible and safe.

Inclusion Criteria:

• Histologically confirmed prostate carcinoma with tissue classification according to Gleason score and PSA
• low- or intermediate-risk carcinoma according to d'Amico criteria or early high-risk Carcinoma (cT3a and / or GS ≤ 8 and / or PSA ≤ 20ng / ml)
• IPSS (International Prostate Symptom Score) max. 12
• Prostate volume <80cm³
• Karnofsky index ≥ 70%
• Age ≥ 18 years
• Patient information provided and written consent
• Ability of the patient to give consent

Exclusion Criteria:

• Previous radiotherapy in the pelvis
• Previous local therapy of the prostate
• lymphogenic metastasis
• Stage IV (distant metastases)
• Contraindication to MRI
• Simultaneous participation in another clinical study which could influence results of either of the respective study