Prostate Cancer Patients Undergoing Radical ProstatectomyPreRP-EJACNCT07243795
Ejaculatory Behavior and Seminal Vesicle Size During Radical Prostatectomy
A study testing Recent Ejaculation and Preoperative Abstinence in people with Prostate Cancer Patients Undergoing Radical Prostatectomy, run by National Taiwan University Hospital at 1 site in Taiwan.
Trial summary
The goal of this clinical trial is to learn if recent ejaculation or abstinence before surgery affects seminal vesicle size and dissection-related surgical factors in adult men with prostate cancer undergoing radical prostatectomy. Read more about this study
- Who is it for?
- Ages 18 years and older, men only
- Conditions the study is for
- Prostate Cancer Patients Undergoing Radical Prostatectomy
- What is being tested?
- Recent Ejaculation and Preoperative Abstinence
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 1 siteTaiwan
- Study dates
- 1 Dec 2025to 9 Oct 2026
- 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
- Male patients aged 18 years or older
- Histologically confirmed prostate cancer
- Scheduled for radical prostatectomy
- Able and willing to comply with assigned ejaculation or abstinence protocol
- Willing to complete preoperative questionnaire
- Willing to undergo transrectal ultrasound (TRUS) 12-14 hours before surgery
- Able to understand and sign informed consent
Who cannot join
- Prior bilateral seminal vesicle resection or congenital absence of seminal vesicles
- Anatomical abnormalities preventing SV identification
- Hormone therapy within 6 months before surgery
- Inability to recall ejaculation history in the past 3 days
- Inability to follow behavioral instructions or TRUS protocol
- Severe anorectal disease or history of anorectal surgery preventing TRUS
Show all 10Show fewer
- Cognitive or psychiatric conditions impairing informed consent
- Incomplete data or poor-quality imaging
- Prior prostate cancer treatment
- Belonging to a vulnerable population (e.g., minors, prisoners, pregnant individuals, cognitively impaired, etc.)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Taiwan1 site
National Taiwan University Cancer Center
Taipei, Outside U.S./Canada, 106
Yen Ho, M.D., 886933092258, yenho.md@gmail.com
About this study
Official title: Impact of Preoperative Ejaculation or Abstinence on Seminal Vesicle Size and Intraoperative Dissection Parameters During Radical Prostatectomy: A Randomized Controlled Trial
The goal of this clinical trial is to learn if recent ejaculation or abstinence before surgery affects seminal vesicle size and dissection-related surgical factors in adult men with prostate cancer undergoing radical prostatectomy. The main questions it aims to answer are:
Does ejaculation within 36 hours before surgery reduce seminal vesicle size compared to abstinence of 72 hours or more?
Read more
Does seminal vesicle size affect the ease or difficulty of surgical dissection during radical prostatectomy?
Researchers will compare an ejaculation group to an abstinence group to see if seminal vesicle volume and intraoperative surgical parameters differ between them.
Participants will:
Follow specific instructions to either ejaculate or abstain before surgery
Undergo a transrectal ultrasound (TRUS) to measure seminal vesicle size after anesthesia but before surgery
Have their surgical dissection time and difficulty rated by the operating surgeon
Read the detailed description
Radical prostatectomy (RP) remains a cornerstone treatment for localized prostate cancer. During RP, the anatomical dissection of seminal vesicles (SVs) can be challenging, and SV volume may influence intraoperative visibility, dissection ease, and the risk of complications.
Recent imaging studies suggest that ejaculatory activity significantly affects SV size. In particular, abstinence has been associated with larger SV volumes on MRI and TRUS, while ejaculation may lead to temporary SV shrinkage. These physiological changes, though well-documented radiologically, have not been systematically studied in a surgical setting.
This trial aims to explore whether ejaculatory behavior in the days before RP alters the surgical anatomy and impacts dissection-related metrics. Forty adult male patients with biopsy-confirmed prostate cancer, scheduled for RP, will be randomized in a 1:1 ratio into two groups:
Ejaculation group: At least one ejaculation within 36 hours preoperatively.
Abstinence group: No ejaculation for ≥72 hours before surgery.
Under anesthesia and prior to surgery, transrectal ultrasound (TRUS) will be performed to measure bilateral SV dimensions. The average volume will serve as the primary endpoint. Intraoperative outcomes include dissection time, visual clarity, and perceived difficulty rated by the primary surgeon using a Likert scale. SV volume from final pathology reports will also be collected and compared.
This is a low-risk, behavior-based interventional study involving no experimental drug or device. The main purpose is to assess whether preoperative sexual behavior can be optimized to improve surgical planning and efficiency. Alpha-blocker usage and other potential confounders will be documented and adjusted for in the analysis.
If significant anatomical or procedural differences are observed, findings from this study may inform future multicenter research and guide preoperative patient counseling for RP.
- Being tested
- Recent Ejaculation, Preoperative Abstinence
- Keywords
- Prostate Cancer, Radical Prostatectomy, Seminal Vesicle, Ejaculation, Abstinence, Surgical Dissection
- Medical subject headings
- Prostatic Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Recent EjaculationBehavioural
Also called Ejaculation within 36 hours before surgery
Participants are instructed to ejaculate at least once within 36 hours prior to radical prostatectomy. This behavioral intervention is used to evaluate its effect on seminal vesicle volume and intraoperative dissection parameters.
Preoperative AbstinenceBehavioural
Also called Ejaculatory Abstinence ≥72 hours
Participants are instructed to abstain from ejaculation for at least 72 hours prior to radical prostatectomy. This behavioral intervention is used to assess whether prolonged seminal vesicle filling affects intraoperative anatomy and dissection.
| Study group | Role | What they receive |
|---|---|---|
| Recent Ejaculation Group | Experimental | Participants in this group will be instructed to have at least one ejaculation within 36 hours before surgery. Under anesthesia, they will undergo transrectal ultrasound (TRUS) to measure seminal vesicle volume prior to radical prostatectomy. Intraoperative dissection time, difficulty, and visual clarity will also be recorded. Receives: Behavioral: Recent Ejaculation |
| Abstinence Group | Active comparator | Participants in this group will be instructed to abstain from ejaculation for at least 72 hours before surgery. Under anesthesia, they will undergo transrectal ultrasound (TRUS) to measure seminal vesicle volume prior to radical prostatectomy. Intraoperative dissection time, difficulty, and visual clarity will also be recorded. Receives: Behavioral: Preoperative Abstinence |
What is being measured
The primary outcome is the main question the study is designed to answer.
Seminal vesicle volume measured by preoperative transrectal ultrasound (TRUS)
Seminal vesicle volume is measured by the research investigator using transrectal ultrasound (TRUS) in the outpatient ultrasound room approximately 12-14 hours before surgery. Both vesicles are measured in three dimensions (length × width × height), and the average volume is calculated using the ellipsoid formula (L × W × H × 0.52). The values will be compared between groups with recent ejaculation versus abstinence.
Measured: 12-14 hours before surgery (afternoon prior to operation)
Secondary outcomes (4)
Dissection time of seminal vesicles during radical prostatectomy
The time required for bilateral seminal vesicle dissection is recorded in minutes from surgical video or intraoperative notes.
Measured: During surgery (intraoperative)
Surgical difficulty score of seminal vesicle dissection
The primary surgeon rates the difficulty of SV dissection on a Likert scale from 1 (very easy) to 5 (very difficult), based on anatomical clarity and tissue handling.
Measured: Immediately after SV dissection during surgery
Intraoperative visual clarity score of seminal vesicles
The operating surgeon rates visual clarity of the surgical field (especially SV region) using a Likert scale from 1 (very poor) to 5 (excellent).
Measured: During SV dissection, intraoperatively
Seminal vesicle volume reported in postoperative pathology
Pathology reports include three-dimensional measurements of both SVs. Final volume is calculated using the same ellipsoid formula and compared with TRUS findings.
Measured: Within 7 days after surgery (postoperative pathology report)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Nov 2025
- Study start1 Dec 2025 (estimated)
- Primary completion1 Aug 2026 (estimated)
- Study completion9 Oct 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Prostate Cancer Patients Undergoing Radical ProstatectomyStudies of the same condition, open and under way.
- More trials run by National Taiwan University HospitalThe 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
- Health services research
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Participants will be randomly assigned in a 1:1 ratio to either a recent ejaculation group or an abstinence group before radical prostatectomy.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- National Taiwan University Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07243795
- Sponsor's protocol ID
- 202507191RINA
- Acronym
- PreRP-EJAC
- Status last verified
- Oct 2025
- First submitted
- 17 Nov 2025
- Last updated
- 3 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data (IPD) will not be shared due to institutional policies and IRB-approved protocols that limit data access to the research team. The dataset is small, single-center, and contains sensitive clinical and behavioral information. There is no current plan to develop a public repository or de-identified dataset for external use.
Publications
Medved M, Sammet S, Yousuf A, Oto A. MR imaging of the prostate and adjacent anatomic structures before, during, and after ejaculation: qualitative and quantitative evaluation. Radiology. 2014 May;271(2):452-60. doi: 10.1148/radiol.14131374. Epub 2014 Feb 1.
PubMed 24495265Shin T, Kaji Y, Shukuya T, Nozaki M, Soh S, Okada H. Significant changes of T2 value in the peripheral zone and seminal vesicles after ejaculation. Eur Radiol. 2018 Mar;28(3):1009-1015. doi: 10.1007/s00330-017-5077-4. Epub 2017 Oct 6.
PubMed 28986624Yuruk E, Pastuszak AW, Suggs JM 3rd, Colakerol A, Serefoglu EC. The association between seminal vesicle size and duration of abstinence from ejaculation. Andrologia. 2017 Sep;49(7):10.1111/and.12707. doi: 10.1111/and.12707. Epub 2016 Sep 23.
PubMed 27660049
Study at a glance
From the registry record, last updated by the sponsor on 3 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Impact of Preoperative Ejaculation or Abstinence on Seminal Vesicle Size and Intraoperative Dissection Parameters During Radical Prostatectomy: A Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07243795
- Acronym / sponsor ID
- PreRP-EJAC / 202507191RINA
- Keywords
- Prostate Cancer, Radical Prostatectomy, Seminal Vesicle, Ejaculation, Abstinence, Surgical Dissection
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- National Taiwan University HospitalUniversity, hospital or other
- Study start
- 1 Dec 2025 (estimated)
- Primary completion
- 1 Aug 2026 (estimated)
- Study completion
- 9 Oct 2026 (estimated)
- First posted
- 24 Nov 2025 (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.
The goal of this clinical trial is to learn if recent ejaculation or abstinence before surgery affects seminal vesicle size and dissection-related surgical factors in adult men with prostate cancer undergoing radical prostatectomy. The main questions it aims to answer are:
Does ejaculation within 36 hours before surgery reduce seminal vesicle size compared to abstinence of 72 hours or more?
Does seminal vesicle size affect the ease or difficulty of surgical dissection during radical prostatectomy?
Researchers will compare an ejaculation group to an abstinence group to see if seminal vesicle volume and intraoperative surgical parameters differ between them.
Participants will:
Follow specific instructions to either ejaculate or abstain before surgery
Undergo a transrectal ultrasound (TRUS) to measure seminal vesicle size after anesthesia but before surgery
Have their surgical dissection time and difficulty rated by the operating surgeon
Detailed description
Radical prostatectomy (RP) remains a cornerstone treatment for localized prostate cancer. During RP, the anatomical dissection of seminal vesicles (SVs) can be challenging, and SV volume may influence intraoperative visibility, dissection ease, and the risk of complications.
Recent imaging studies suggest that ejaculatory activity significantly affects SV size. In particular, abstinence has been associated with larger SV volumes on MRI and TRUS, while ejaculation may lead to temporary SV shrinkage. These physiological changes, though well-documented radiologically, have not been systematically studied in a surgical setting.
This trial aims to explore whether ejaculatory behavior in the days before RP alters the surgical anatomy and impacts dissection-related metrics. Forty adult male patients with biopsy-confirmed prostate cancer, scheduled for RP, will be randomized in a 1:1 ratio into two groups:
Ejaculation group: At least one ejaculation within 36 hours preoperatively.
Abstinence group: No ejaculation for ≥72 hours before surgery.
Under anesthesia and prior to surgery, transrectal ultrasound (TRUS) will be performed to measure bilateral SV dimensions. The average volume will serve as the primary endpoint. Intraoperative outcomes include dissection time, visual clarity, and perceived difficulty rated by the primary surgeon using a Likert scale. SV volume from final pathology reports will also be collected and compared.
This is a low-risk, behavior-based interventional study involving no experimental drug or device. The main purpose is to assess whether preoperative sexual behavior can be optimized to improve surgical planning and efficiency. Alpha-blocker usage and other potential confounders will be documented and adjusted for in the analysis.
If significant anatomical or procedural differences are observed, findings from this study may inform future multicenter research and guide preoperative patient counseling for RP.
Study design
- Primary purpose
- Health services research
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- Participants will be randomly assigned in a 1:1 ratio to either a recent ejaculation group or an abstinence group before radical prostatectomy.
| Arm | Type | Receives |
|---|---|---|
| Recent Ejaculation Group | Experimental | Behavioral: Recent EjaculationParticipants in this group will be instructed to have at least one ejaculation within 36 hours before surgery. Under anesthesia, they will undergo transrectal ultrasound (TRUS) to measure seminal vesicle volume prior to radical prostatectomy. Intraoperative dissection time, difficulty, and visual clarity will also be recorded. |
| Abstinence Group | Active comparator | Behavioral: Preoperative AbstinenceParticipants in this group will be instructed to abstain from ejaculation for at least 72 hours before surgery. Under anesthesia, they will undergo transrectal ultrasound (TRUS) to measure seminal vesicle volume prior to radical prostatectomy. Intraoperative dissection time, difficulty, and visual clarity will also be recorded. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- Male patients aged 18 years or older
- Histologically confirmed prostate cancer
- Scheduled for radical prostatectomy
- Able and willing to comply with assigned ejaculation or abstinence protocol
- Willing to complete preoperative questionnaire
Key exclusion criteria (10 listed)
- Prior bilateral seminal vesicle resection or congenital absence of seminal vesicles
- Anatomical abnormalities preventing SV identification
- Hormone therapy within 6 months before surgery
- Inability to recall ejaculation history in the past 3 days
- Inability to follow behavioral instructions or TRUS protocol
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 |
|---|---|---|
| Recent EjaculationAlso: Ejaculation within 36 hours before surgeryParticipants are instructed to ejaculate at least once within 36 hours prior to radical prostatectomy. This behavioral intervention is used to evaluate its effect on seminal vesicle volume and intraoperative dissection parameters. | Behavioural | Recent Ejaculation Group |
| Preoperative AbstinenceAlso: Ejaculatory Abstinence ≥72 hoursParticipants are instructed to abstain from ejaculation for at least 72 hours prior to radical prostatectomy. This behavioral intervention is used to assess whether prolonged seminal vesicle filling affects intraoperative anatomy and dissection. | Behavioural | Abstinence Group |
Primary outcome
Seminal vesicle volume measured by preoperative transrectal ultrasound (TRUS)
Time frame: 12-14 hours before surgery (afternoon prior to operation)
Seminal vesicle volume is measured by the research investigator using transrectal ultrasound (TRUS) in the outpatient ultrasound room approximately 12-14 hours before surgery. Both vesicles are measured in three dimensions (length × width × height), and the average volume is calculated using the ellipsoid formula (L × W × H × 0.52). The values will be compared between groups with recent ejaculation versus abstinence.
4 secondary outcomes
Dissection time of seminal vesicles during radical prostatectomy
Time frame: During surgery (intraoperative)
Surgical difficulty score of seminal vesicle dissection
Time frame: Immediately after SV dissection during surgery
Intraoperative visual clarity score of seminal vesicles
Time frame: During SV dissection, intraoperatively
Seminal vesicle volume reported in postoperative pathology
Time frame: Within 7 days after surgery (postoperative pathology report)
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 3 Dec 2025.
- Background: PubMed 24495265Medved M, Sammet S, Yousuf A, Oto A. MR imaging of the prostate and adjacent anatomic structures before, during, and after ejaculation: qualitative and quantitative evaluation. Radiology. 2014 May;271(2):452-60. doi: 10.1148/radiol.14131374. Epub 2014 Feb 1.
- Background: PubMed 28986624Shin T, Kaji Y, Shukuya T, Nozaki M, Soh S, Okada H. Significant changes of T2 value in the peripheral zone and seminal vesicles after ejaculation. Eur Radiol. 2018 Mar;28(3):1009-1015. doi: 10.1007/s00330-017-5077-4. Epub 2017 Oct 6.
- Background: PubMed 27660049Yuruk E, Pastuszak AW, Suggs JM 3rd, Colakerol A, Serefoglu EC. The association between seminal vesicle size and duration of abstinence from ejaculation. Andrologia. 2017 Sep;49(7):10.1111/and.12707. doi: 10.1111/and.12707. Epub 2016 Sep 23.
- Individual participant dataSharing planned: No. Individual participant data (IPD) will not be shared due to institutional policies and IRB-approved protocols that limit data access to the research team. The dataset is small, single-center, and contains sensitive clinical and behavioral information. There is no current plan to develop a public repository or de-identified dataset for external use.
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Recent Ejaculation and Preoperative Abstinence in people with Prostate Cancer Patients Undergoing Radical Prostatectomy, run by National Taiwan University Hospital at 1 site in Taiwan.
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 7 inclusion and 10 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: opening soon, as of the sponsor's last update on 3 Dec 2025. 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 Taiwan. 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 Yen Ho, M.D. (+886933092258, yenho.md@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Seminal vesicle volume measured by preoperative transrectal ultrasound (TRUS) (time frame: 12-14 hours before surgery (afternoon prior to operation)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07243795, which also lists 3 linked publications.
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 3 Dec 2025; AzTrials last refreshed its copy on 30 Oct 2026.