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
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 Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
HEALTH_SERVICES_RESEARCH
Masking
SINGLE
Enrollment
40
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.
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.
National Taiwan University Cancer Center
Taipei, Outside U.S./Canada, Taiwan
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.
Time frame: 12-14 hours before surgery (afternoon prior to operation)
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.
Time frame: 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.
Time frame: 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).
Time frame: 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.
Time frame: Within 7 days after surgery (postoperative pathology report)
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