Prostate CancerPAROSNCT04083937
Prostate Cancer Patients Treated With Alternative Radiation Oncology Strategies
A study testing Hypofractionated radiotherapy with photons, Hypofractionated radiotherapy with protons and Normofractionated radiotherapy with photons in people with Prostate Cancer, run by University Hospital Heidelberg at 1 site in Germany.
Trial summary
As the most common male carcinoma, prostate cancer is a major tumor entity in oncology. In addition to definitive radiotherapy, surgical procedure is considered to be an oncologically equivalent therapeutic alternative for non-metastatic malignancies in the primary setting. Read more about this study
- Who is it for?
- Ages 18 years and older, men only
- Conditions the study is for
- Prostate Cancer
- What is being tested?
- Hypofractionated radiotherapy with photons, Hypofractionated radiotherapy with protons and Normofractionated radiotherapy with photons
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 897 participants
- Where
- 1 siteGermany
- Study dates
- 12 Sep 2018to Jan 2029
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- Men only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- histology-proven prostate cancer with Gleason Score and PSA-value;
- indication for prostate bed irradiation (adjuvant/ salvage) after prostatectomy;
- Karnofsky-Index ≥ 70%
- age ≥ 18 years
Who cannot join
- androgen deprivation therapy
- lymphatic spread
- macroscopic tumor/ R2
- stage IV (M1)
- previous irradiation
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Germany1 site, 1 recruiting
- Recruiting
University Hospital Heidelberg
Heidelberg, 69120
Juergen Debus, 06221 56 8201, juergen.debus@med.uni-heidelberg.de
Adriane Hommertgen, 06221 56 8201, adriane.hommertgen@med.uni-heidelberg.de
About this study
As the most common male carcinoma, prostate cancer is a major tumor entity in oncology. In addition to definitive radiotherapy, surgical procedure is considered to be an oncologically equivalent therapeutic alternative for non-metastatic malignancies in the primary setting. However, a subsequent radiotherapy of the prostate bed is often necessary, which takes place as an "adjuvant" treatment immediately after surgery or in the course of a repeated increase in PSA and usually extends over several weeks. For the primary situation (without previous surgery), several randomized phase III clinical trials have shown that it is possible to shorten radiotherapy by increasing the single dose (called hypofractionation). In the context of two prospective Phase II studies, which were carried out in Heidelberg, it has since been shown that hypofractionation with both photons and protons is safe and feasible even in the postoperative situation.
The current, prospective and randomized PAROS study is now intended to demonstrate a multicentric phase III study as an improvement in the quality of life caused by rectum toxicity (primary endpoint) by the use of protons. The oncological non-inferiority of hypofractionated radiotherapy after surgery is a secondary endpoint.
- Conditions
- Prostate Cancer
- Being tested
- Hypofractionated radiotherapy with photons, Hypofractionated radiotherapy with protons, Normofractionated radiotherapy with photons
- Medical subject headings
- Prostatic Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Hypofractionated radiotherapy with photonsRadiation
hypofractionated radiotherapy with photons (total dose 57.0 Gray in 19 fractions)
Hypofractionated radiotherapy with protonsRadiation
hypofractionated radiotherapy with protons (total dose 57.0 Gray relative biological effectiveness (RBE) in 19 fractions)
Normofractionated radiotherapy with photonsRadiation
normofractionated radiotherapy with photons (total dose 70.0 Gray in 35 fractions)
| Study group | Role | What they receive |
|---|---|---|
| 70.0/ 2.0 Gray (RBE) | Active comparator | Normofractionated radiotherapy with photons (70.0/ 2.0 Gray) Receives: Radiation: Normofractionated radiotherapy with photons |
| 57.0/ 3.0 Gray (RBE) | Experimental | Hypofractionated radiotherapy with photons (57.0/ 3.0 Gray) Receives: Radiation: Hypofractionated radiotherapy with photons |
| 57.0/ 3.0 (RBE) | Experimental | Hypofractionated radiotherapy with protons (57.0/ 3.0 Gray relative biological effectiveness [RBE]). Receives: Radiation: Hypofractionated radiotherapy with protons |
What is being measured
The primary outcome is the main question the study is designed to answer.
Quality of life (prostate-associated, 12 weeks vs baseline)
The primary objective of the present trial is to show a Change in the bowel symptoms according to scores on the EORTC QLQ-PR25 questionaire after proton therapy compared to photon irradiation (week 12 vs. baseline).
Measured: 12 weeks
Secondary outcomes (5)
biochemical progression-free survival (bPFS)
non-inferiority of hypofractionated radiotherapy compared to normofractionated radiotherapy with regard to biochemical progression-free survival (bPFS)
Measured: 5 years after baseline
overall survival (OS)
non-inferiority of hypofractionated radiotherapy compared to normofractionated radiotherapy with regard to overall survival (OS)
Measured: 5 years after baseline
Toxicity acc. to NCI CTCAE V 5.0 after 2 and 5 years
non-inferiority of hypofractionated radiotherapy compared to normofractionated radiotherapy with regard to toxicity
Measured: 2 and 5 years after baseline
Quality of life (general and prostate-associated, 2 years and 5 years vs. baseline)
non-inferiority of hypofractionated radiotherapy compared to normofractionated radiotherapy with regard to changes in the scores of quality of life based on the EORTC QLQ-C30 questionaire
Measured: 2 and 5 years after baseline
Quality of life (general and prostate-associated, 2 years and 5 years vs. baseline)
non-inferiority of hypofractionated radiotherapy compared to normofractionated radiotherapy with regard to changes in the scores of quality of life based on the EORTC QLQ-PR25 questionaire
Measured: 2 and 5 years after baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Sep 2019
- Study start12 Sep 2018
- Primary completionApr 2028 (estimated)
- Study completionJan 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Prostate CancerStudies of the same condition, open and under way.
- More trials run by University Hospital HeidelbergThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 897 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Hospital Heidelberg
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Juergen Debus, University Hospital Heidelberg
- Investigators
- Juergen Debus, Principal investigator, University Hospital Heidelberg
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04083937
- Sponsor's protocol ID
- PAROS
- Acronym
- PAROS
- Status last verified
- Mar 2026
- First submitted
- 7 Jan 2019
- Last updated
- 9 Mar 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 9 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prostate Cancer Patients Treated With Alternative Radiation Oncology Strategies
- ClinicalTrials.gov ID
- NCT04083937
- Acronym / sponsor ID
- PAROS / PAROS
- Conditions
- Prostate Cancer
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 897 participants (estimated)
- Lead sponsor
- University Hospital HeidelbergUniversity, hospital or other
- Study start
- 12 Sep 2018 (actual)
- Primary completion
- Apr 2028 (estimated)
- Study completion
- Jan 2029 (estimated)
- First posted
- 10 Sep 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
As the most common male carcinoma, prostate cancer is a major tumor entity in oncology. In addition to definitive radiotherapy, surgical procedure is considered to be an oncologically equivalent therapeutic alternative for non-metastatic malignancies in the primary setting. However, a subsequent radiotherapy of the prostate bed is often necessary, which takes place as an "adjuvant" treatment immediately after surgery or in the course of a repeated increase in PSA and usually extends over several weeks. For the primary situation (without previous surgery), several randomized phase III clinical trials have shown that it is possible to shorten radiotherapy by increasing the single dose (called hypofractionation). In the context of two prospective Phase II studies, which were carried out in Heidelberg, it has since been shown that hypofractionation with both photons and protons is safe and feasible even in the postoperative situation.
The current, prospective and randomized PAROS study is now intended to demonstrate a multicentric phase III study as an improvement in the quality of life caused by rectum toxicity (primary endpoint) by the use of protons. The oncological non-inferiority of hypofractionated radiotherapy after surgery is a secondary endpoint.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| 70.0/ 2.0 Gray (RBE) | Active comparator | Radiation: Normofractionated radiotherapy with photonsNormofractionated radiotherapy with photons (70.0/ 2.0 Gray) |
| 57.0/ 3.0 Gray (RBE) | Experimental | Radiation: Hypofractionated radiotherapy with photonsHypofractionated radiotherapy with photons (57.0/ 3.0 Gray) |
| 57.0/ 3.0 (RBE) | Experimental | Radiation: Hypofractionated radiotherapy with protonsHypofractionated radiotherapy with protons (57.0/ 3.0 Gray relative biological effectiveness [RBE]). |
Who may qualify
- Ages
- 18 years and older
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- histology-proven prostate cancer with Gleason Score and PSA-value;
- indication for prostate bed irradiation (adjuvant/ salvage) after prostatectomy;
- Karnofsky-Index ≥ 70%
- age ≥ 18 years
Key exclusion criteria (5 listed)
- androgen deprivation therapy
- lymphatic spread
- macroscopic tumor/ R2
- stage IV (M1)
- previous irradiation
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Hypofractionated radiotherapy with photonshypofractionated radiotherapy with photons (total dose 57.0 Gray in 19 fractions) | Radiation | 57.0/ 3.0 Gray (RBE) |
| Hypofractionated radiotherapy with protonshypofractionated radiotherapy with protons (total dose 57.0 Gray relative biological effectiveness (RBE) in 19 fractions) | Radiation | 57.0/ 3.0 (RBE) |
| Normofractionated radiotherapy with photonsnormofractionated radiotherapy with photons (total dose 70.0 Gray in 35 fractions) | Radiation | 70.0/ 2.0 Gray (RBE) |
Primary outcome
Quality of life (prostate-associated, 12 weeks vs baseline)
Time frame: 12 weeks
The primary objective of the present trial is to show a Change in the bowel symptoms according to scores on the EORTC QLQ-PR25 questionaire after proton therapy compared to photon irradiation (week 12 vs. baseline).
5 secondary outcomes
biochemical progression-free survival (bPFS)
Time frame: 5 years after baseline
overall survival (OS)
Time frame: 5 years after baseline
Toxicity acc. to NCI CTCAE V 5.0 after 2 and 5 years
Time frame: 2 and 5 years after baseline
Quality of life (general and prostate-associated, 2 years and 5 years vs. baseline)
Time frame: 2 and 5 years after baseline
Quality of life (general and prostate-associated, 2 years and 5 years vs. baseline)
Time frame: 2 and 5 years after baseline
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Mar 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Juergen Debus principal investigator
University Hospital Heidelberg
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Hypofractionated radiotherapy with photons, Hypofractionated radiotherapy with protons and Normofractionated radiotherapy with photons in people with Prostate Cancer, run by University Hospital Heidelberg at 1 site in Germany.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 9 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Germany. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Juergen Debus (06221 56 8201, juergen.debus@med.uni-heidelberg.de), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Quality of life (prostate-associated, 12 weeks vs baseline) (time frame: 12 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Mar 2026.