Stereotactic MRI-guided Radiation Therapy for Localized prostatE Cancer (SMILE)

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.

Study Overview

• Status: Active, not recruiting
• Conditions: Prostate Cancer
• Intervention / Treatment: Radiation: MR-guided Radiotherapy

• Study Type: Interventional
• Enrollment (Estimated): 68
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Germany
  • Heidelberg, Germany, 69120
    • University Hospital of Heidelberg, Radiation Oncology

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: MR-guided Radiotherapy (5 x 7,5 Gy); 5 x 7,5 Gy prescribed on the PTV	Radiation: MR-guided Radiotherapy; Total Dose 37,5 Gy, Single Dose 7,5 Gy, 5 Fractions applied in 1-2 weeks

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Toxicity or Discontinuation of Therapy	One of the the following events are counted as an Event (Number of Participants affected): any urogenital or gastrointestinal grade ≥ 2 toxicity within one year after the start of RT (according to NCI CTCAE Version 5.0); Discontinuation of therapy, with a connection to the study treatment	Within 1 Year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mortality	Mortality due to study treatment or due to prostate Cancer (Number of Participants deceased)	Within 1 year and within 5 years
Number of Toxicities	Number and severity of urogenital or gastrointestinal toxicity	Within 1 year and within 5 years after start of radiotherapy
bPFS	biochemical progression free survival	from start of radiotherapy (day 1) until PSA-relapse according to Phoenix-Criteria (Prostate-specific antigen (PSA) nadir + 2 ng/mL after radiotherapy), assessed up to 5 years
Hormone therapy-free Survival	Hormone therapy-free Survival	from start of radiotherapy until start of hormon treatment; maximum 3 months neoadjuvant
OS	overall survival	from start of radiotherapy (day 1) until death or censoring assessed up to 5 years
Quality of life according to EORTC QLQ-C30	Quality of life according to EORTC QLQ-C30	from start of radiotherapy (day 1) until end of follow-up (up to 5 years)
Quality of life according to EORTC QLQ-PR25	Quality of life according to EORTC QLQ-PR25	from start of radiotherapy (day 1) until end of follow-up (up to 5 years)
Symptoms and Toxicity	Symptoms and Toxicity according to NCI CTCAE (Rate)	from start of radiotherapy (day 1) until end of follow-up (up to 5 years)

Collaborators and Investigators

• Sponsor: University Hospital Heidelberg
• Collaborators: Ludwig-Maximilians - University of Munich; University Hospital, Zürich

Study record dates

Study Major Dates

• Study Start (Actual): March 25, 2021
• Primary Completion (Actual): March 25, 2023
• Study Completion (Estimated): March 25, 2028

Study Registration Dates

• First Submitted: March 5, 2021
• First Submitted That Met QC Criteria: April 13, 2021
• First Posted (Actual): April 15, 2021

Study Record Updates

• Last Update Posted (Actual): March 10, 2026
• Last Update Submitted That Met QC Criteria: March 6, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Genital Neoplasms, Male; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Genital Diseases, Male; Prostatic Diseases; Male Urogenital Diseases; Prostatic Neoplasms
• Other Study ID Numbers: SMILE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No