Ejaculatory Behavior and Seminal Vesicle Size During Radical Prostatectomy

NCT07243795 | Not Yet Recruiting

• 1 other identifier: 202507191RINA
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief 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. 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

Conditions

Prostate Cancer Patients Undergoing Radical Prostatectomy

Keywords

Prostate Cancer; Radical Prostatectomy; Seminal Vesicle; Ejaculation; Abstinence; Surgical Dissection

Outcome Measures

Primary Outcomes (1)

• 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.

  12-14 hours before surgery (afternoon prior to operation)

Secondary Outcomes (4)

• Dissection time of seminal vesicles during radical prostatectomy

  During surgery (intraoperative)

• Surgical difficulty score of seminal vesicle dissection

  Immediately after SV dissection during surgery

• Intraoperative visual clarity score of seminal vesicles

  During SV dissection, intraoperatively

• Seminal vesicle volume reported in postoperative pathology

  Within 7 days after surgery (postoperative pathology report)

Study Arms (2)

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.

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.

Behavioral: Preoperative Abstinence

Interventions

Recent Ejaculation BEHAVIORAL

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.

Also known as: Ejaculation within 36 hours before surgery

Recent Ejaculation Group

Preoperative Abstinence BEHAVIORAL

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.

Also known as: Ejaculatory Abstinence ≥72 hours

Abstinence Group

Eligibility Criteria

• Age: 18 Years+
• Sex: male
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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
• 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.)

Sponsors & Collaborators

• National Taiwan University Hospital: lead

Study Sites (1)

National Taiwan University Cancer Center

Taipei, Outside U.S./Canada, 106, Taiwan

Location

Related Publications (3)

• 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.

  PMID: 24495265 BACKGROUND

• Shin 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.

  PMID: 28986624 BACKGROUND

• Yuruk 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.

  PMID: 27660049 BACKGROUND

MeSH Terms

Conditions

Prostatic Neoplasms

Condition Hierarchy (Ancestors)

Genital Neoplasms, Male; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Genital Diseases, Male; Genital Diseases; Urogenital Diseases; Prostatic Diseases; Male Urogenital Diseases

Central Study Contacts

Yen Ho, M.D.

CONTACT

+886933092258; yenho.md@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: The operating surgeon was masked to the participant's group assignment. Group allocation was concealed until after surgery. Neither the participant nor the research investigator performing TRUS was masked.
• Purpose: HEALTH SERVICES RESEARCH
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Participants will be randomly assigned in a 1:1 ratio to either a recent ejaculation group or an abstinence group before radical prostatectomy.

Study Record Dates

• First Submitted: November 17, 2025
• First Posted: November 24, 2025
• Study Start: December 1, 2025
• Primary Completion (Estimated): August 1, 2026
• Study Completion (Estimated): October 9, 2026
• Last Updated: December 3, 2025

Record last verified: 2025-10

Data Sharing

• IPD Sharing: Will not share

Locations

TW (1)