Volume Of Seminal Vesicles Research Articles

912 POSTER Linac based helical intensity modulated total body irradiation

Purpose: To evaluate the image-guidance capabilities of megavoltage computed tomography (MVCT), this article compares the interobserver and intraobserver contouring uncertainty in kilovoltage computed tomography (KVCT) used for radiotherapy planning with MVCT acquired with helical tomotherapy.Methods and Materials: Five prostate-cancer patients were evaluated. Each patient underwent a KVCT and an MVCT study, a total of 10 CT studies. For interobserver variability analysis, four radiation oncologists, one physicist, and two radiation therapists (seven observers in total) contoured the prostate and seminal vesicles (SV) in the 10 studies. The intraobserver variability was assessed by asking all observers to repeat the contouring of 1 patient’s KVCT and MVCT studies. Quantitative analysis of contour variations was performed by use of volumes and radial distances.Results: The interobserver and intraobserver contouring uncertainty was larger in MVCT compared with KVCT. Observers consistently segmented larger volumes on MVCT where the ratio of average prostate and SV volumes was 1.1 and 1.2, respectively. On average (interobserver and intraobserver), the local delineation variability, in terms of standard deviations [Δσ = √(σ2MVCT − σ2KVCT)], increased by 0.32 cm from KVCT to MVCT.Conclusions: Although MVCT was inferior to KVCT for prostate delineation, the application of MVCT in prostate radiotherapy remains useful.

SU-FF-J-68: Dosimetric Comparison of Patient-Specific Margins Vs. Uniform Margins for Prostate IMRT Treatments

Purpose: To evaluate the dosimetric improvement of IMRT treatment plans generated with patient-specific margins compared to uniform margins for prostate cancer patients. Methods and Materials: For 13 prostate cancer patients who underwent IMRT treatment, daily cone-beam computed tomography (CBCT) scans were acquired during the first week, followed by weekly scans (total of 85 scans) for the remainder of the treatment. Both prostate and seminal vesicles were retrospectively segmented on all CBCTs. The patient-specific planning target volume (PTVPS) was defined based on a composite volume of both prostate and seminal vesicles from the first four daily CBCTs and the planning CT. A 3-mm margin was added around the composite volume to obtain PTVPS. As a comparison, we also generated a PTV in the planning CT with a uniform margin (PTVUni) of 10-mm in all directions, except 5-mm posteriorly, around the prostate and seminal vesicles. An IMRT plan for each PTV was generated for each patient. Evaluation plans based on each of weekly CBCT were generated to gauge the DVHs resulting from these IMRT plans to the patient volumes segmented on weekly CBCTs. Results: Evaluation plans generated with PTVPS in place of PTVUni resulted in average improvements of 1.4% and 2.8% for V95 of prostate and seminal vesicles, respectively, and average reduction of 7.0% and 4.7% for V50 of bladder and rectum, respectively. Out of 85 weekly CBCT evaluation plans for each PTV, 7.1% of cases showed improvement for V95 of prostate with PTVUni, 40.0% for V95 of seminal vesicles, 28.2% for V50 of bladder and 29.4% for V50 of rectum. Conclusions: Patient-specific margins, designed using multiple scans, appear to provide little dosimetric benefit with respect to target coverage over a standard uniform margin formulation; sparing critical structures is improved to a greater degree. “Partially supported by Varian Medical Systems”.

Is seminal vesicle implantation with permanent sources possible? A dose–volume histogram analysis in patients undergoing combined 103Pd implantation and external beam radiation for T3c prostate cancer

Purpose Combined brachytherapy and external beam radiation therapy (EBRT) of the prostate and seminal vesicles (SVs) is evolving as a successful treatment option for high-risk prostate cancer. Dose–volume histogram (DVH) analysis of the SV was performed in patients with biopsy-positive SV who received implantation of the SV and prostate. Methods and materials Fifteen consecutive patients with high-risk features (prostate-specific antigen [PSA] ≥ 10 ng/mL, Gleason score ≥7, or clinical stage ≥T2b) and a positive SV biopsy were treated with a 103Pd implant of the prostate and SV followed by 45 Gy of EBRT. DVHs were generated for the prostate and total SV volume (SVT). In addition, the SV was divided into 3-mm-thick volumes identified as SV1, SV2, SV3, SV4, SV5, and SV6 starting from the junction of the prostate and SV and extending distally. Delivered dose was defined as the D 90 (dose delivered to 90% of the organ on DVH). Results The median number of seeds implanted into the prostate and the SVT was 59 (41–94) and 9 (4–21), respectively. The median D 90 values for the prostate, SVT, SV1, SV2, SV3, SV4, SV5, and SV6 were 103.2 (87.4–137.1), 46.2 (4.0–69.4), 76.0 (31.2–147), 63.4 (25.1–145.9), 49.7 (15.3–118), 27.4 (9.3–135.1), 14.2 (2.3–100.3), and 3.9 (0–61.5) Gy, respectively. Conclusions Implantation of the SV using a real-time intraoperative approach is technically feasible and results in higher doses to the SV than has been reported with implantation of the prostate alone. Although dose distribution in the SV can be variable and unpredictable, these doses, in combination with 45 Gy of EBRT, may be adequate to control disease spread in these organs.

Single Course IMRT Plan to Deliver 45 Gy to Seminal Vesicles and 81 Gy to Prostate in 45 Fractions

We treat prostate and seminal vesicles (SV) to 45 Gy in 25 fractions (course 1) and boost prostate to 81 Gy in 20 more fractions (course 2) with Intensity Modulated Radiation Therapy (IMRT). This two-course IMRT with 45 fractions delivered a non-uniform dose to SV and required two plans and two QA procedures. We used Linear Quadratic (LQ) model to develop a single course IMRT plan to treat SV to a uniform dose, which has the same biological effective dose (BED) as that of 45 Gy in 25 fractions and prostate to 81 Gy, in 45 fractions. Single course IMRT plans were compared with two-course IMRT plans, retrospectively for 14 patients. With two-course IMRT, prescription to prostate and SV was 45 Gy in 25 fractions and to prostate only was 36 Gy in 20 fractions, at 1.8 Gy/fraction. With 45-fraction single course IMRT plan, prescription to prostate was 81 Gy and to SV was 52 or 56 Gy for a alpha/beta of 1 and 3, respectively. 52 Gy delivered in 45 fractions has the same BED of 72 Gy3 as that of delivering 45 Gy in 25 fractions, and is called Matched Effective Dose (MED). LQ model was used to calculate the BED and MED to SV for alpha/beta values of 1-10. Comparison between two-course and single course IMRT plans was in terms of MUs, dose-max, and dose volume constraints (DVC). DVC were: 95% PTV to be covered by at least 95% of prescription dose; and 70, 50, and 30% of bladder and rectum should not receive more than 40, 60, and 70% of 81 Gy. SV Volumes ranged from 2.9-30 cc. With two-course IMRT plans, mean dose to SV was non-uniform and varied between patients by 48% (54 to 80 Gy). With single-course IMRT plan, mean dose to SV was more uniform and varied between patients by only 9.6% (58.2 to 63.8 Gy), to deliver MED of 56 Gy for alpha/beta - 1. Single course IMRT plan MUs were slightly larger than those for two-course IMRT plans, but within the range seen for two-course plans (549-959 MUs, n=51). Dose max for single-course plans were similar to two-course plans. Doses to PTV, rectum and bladder with single course plans were as per DVC and comparable to two-course plans. Single course IMRT plan reduces IMRT planning and QA time to half.

SU‐FF‐J‐99: MR Imaging for Improving IMRT Targeting of Prostate Cancer

Purpose: To evaluate the role of magnetic resonance imaging (MR) in improving prostate and seminal‐vesicles (SV) target localization as well as penile bulb (PB) tissue avoidance in IMRT for prostate cancer. Method and Materials: CT and MR planning data for 16 patients treated with IMRT were analyzed retrospectively. The prostate, SV, and PB volumes were delineated on both the CT and MR images while rectum, bladder, femurs and other normal tissue volumes were delineated only on CT images. CT and MR scans were acquired over a 4 hour interval and, the MR scans were registered with the 3D planning CT scans, and consequently the IMRT dose distributions. Dosimeteric parameters and DVHs for the prostate, SV, and PB volumes based on CT‐outlined and MR‐outlined contours were compared. Furthermore, the areas for potential geometric target underdosing based on MR information were calculated to evaluate the quality of the CT‐based plans. Results: Analysis revealed that the prostate MR‐delineated volumes were smaller than the CT‐delineated volumes by 10%–40%. The SV‐MR‐delineated volumes were larger than the SV‐CT‐delineated volumes by 25%–100% and, PB‐volumes in CT and MR varied up to +/−50%. The prostate mean‐dose for CT‐ and MR‐based volumes was within 3%. However, in 4 patients, the minimum‐dose to 4–10% of the MR prostate‐volume was lower by up to 15% when compared to the CT plan. In 3 of these patients, there was an anterior movement of the prostate because of rectal expansion. The SV‐CT‐volumes mean‐ and minimum‐dose were lower than the MR‐volumes by a maximum of 5%. The PB‐CT‐volume mean‐dose was higher than the PB‐MR‐volume by a maximum of 10%. Conclusion: The quality of the dose delivery can be improved by identifying patient‐specific margins based on the CT and MR imaging data thereby potentially allowing further gain in the therapeutic ratio for prostate cancer.

TU‐C‐ValB‐03: The Dosimetric Impact of Intrafractional Motion On IMRT Treatment of Prostate Cancer

Purpose: To quantify the dosimetric impact of intrafractional motion on reduced‐margin IMRT treatments of prostate cancer. Methods and Materials: CT images were acquired immediately before and after a daily treatment for 46 prostate cancer patients. These CT sets were registered to the bony anatomy of the patient using an in‐house 3D image registration software. To test the hypothesis that a 3‐mm isotropic target margin would adequately cover the target over the duration of the treatment, an 8‐field IMRT plan was designed on the pre‐treatment CT and subsequently copied and re‐calculated on the post‐treatment CT. For convenience of comparison, dose plans were designed to receive a full course of treatment (75.6Gy). Dosimetric impact was assessed with comparisons of prostate, seminal vesicle (SV), rectum, and bladder volumes receiving several dose levels as well as the minimum and maximum doses to 0.1cc of the prostate and SV. Anatomic variations were also quantified. Results: Over the duration of one treatment fraction (21.4+/−5.5 minutes), there were systematic reductions in the volumes of the prostate and SV receiving the prescription dose (1.8 and 7.2 % respectively, P<0.001) as well as the minimum dose to 0.1cc of their volumes (2.1 and 6.4Gy, P<0.001). Of the 46 patients, 4 patients' prostates (91%) and 8 patients' SVs (83%) did not maintain dose coverage above 70Gy. Rectal dose increased and dose to the percentage‐volume of the bladder decreased at all dose levels. Rectal volume filling was correlated with a decrease in percentage‐volume of the SV receiving 75.6, 70, and 60Gy (P<0.001, P<0.001, P=0.02). Conclusion: With a 3‐mm intrafractional margin, a considerable percent of patients will not receive full dose coverage. The rectal volume increase during a treatment fraction has significant dosimetric impact on SV dose coverage and rectal sparing. Proactive immobilization of the rectum during treatment may be warranted.

Prostate contouring uncertainty in megavoltage computed tomography images acquired with a helical tomotherapy unit during image-guided radiation therapy

To evaluate the image-guidance capabilities of megavoltage computed tomography (MVCT), this article compares the interobserver and intraobserver contouring uncertainty in kilovoltage computed tomography (KVCT) used for radiotherapy planning with MVCT acquired with helical tomotherapy. Five prostate-cancer patients were evaluated. Each patient underwent a KVCT and an MVCT study, a total of 10 CT studies. For interobserver variability analysis, four radiation oncologists, one physicist, and two radiation therapists (seven observers in total) contoured the prostate and seminal vesicles (SV) in the 10 studies. The intraobserver variability was assessed by asking all observers to repeat the contouring of 1 patient's KVCT and MVCT studies. Quantitative analysis of contour variations was performed by use of volumes and radial distances. The interobserver and intraobserver contouring uncertainty was larger in MVCT compared with KVCT. Observers consistently segmented larger volumes on MVCT where the ratio of average prostate and SV volumes was 1.1 and 1.2, respectively. On average (interobserver and intraobserver), the local delineation variability, in terms of standard deviations [Deltasigma = radical(sigma2MVCT-sigma2KVCT)], increased by 0.32 cm from KVCT to MVCT. Although MVCT was inferior to KVCT for prostate delineation, the application of MVCT in prostate radiotherapy remains useful.

Prostate Position Variability and Dose-Volume-Histograms in Radiotherapy for Prostate Cancer with Full and Empty Bladder

Purpose/Objective: Evaluation of prostate position variability and dose-volume-histograms in prostate cancer radiotherapy with a full bladder (FB) compared to an empty bladder (EB). Materials/Methods: Thirty patients underwent planning CT scans in supine treatment position and a slice thickness of 5mm with a full and an empty bladder before the beginning (CT1-FB/CT2-EB), after four weeks (CT3-FB/CT4-EB) and eight weeks (CT5-FB/CT6-EB) of radiation therapy. The data was transferred to a commercially available stereotactic planning system (Brainlab®, Heimstetten, Germany). Prostate, seminal vesicles, bladder, rectum, and bowel loops were contoured. The scans were matched by alignment of the pelvic bones. Displacements of the prostate/seminal vesicles centres of mass and organ borders were compared. Treatment plans were calculated using a six-field technique for CT1 (full bladder) and CT2 (empty bladder) and dose-volume-histograms for the organs at risk (rectum, rectum wall, bladder, bladder wall, bowel loops) compared for the primary and consecutive scans. Planning target volume (PTV) was defined as the prostate with seminal vesicles plus a 10mm margin, the posterior margin reduced to 5mm. Results: The prostate+seminal vesicle volume did not change during the course of radiotherapy (61±21cm3 vs. 60±20cm3; CT1/2 vs. CT5/6; mean±standard deviation), neither the ability of the patient to fill (203±132cm3 vs. 201±105cm3; CT1 vs. CT5) or empty the bladder (75±35cm3 vs. 79±38cm3; CT2 vs. CT6). The rectal volume decreased significantly (82±38cm3 vs.67±21cm3; CT1/2 vs. CT5/6; p<0.01). Compared to the primary scan, the volume of the full bladder for each patient varied more (9±106cm3) than the volume of the empty bladder (5±47cm3). However, the prostate/seminal vesicle center of mass (see table) and organ borders position variability was the same. Rectum volume variability was similar (−17±39cm3 with FB vs. −8±36cm3 with EB). A rectal volume >100cm3 in the planning CT scan was associated with a higher probability of prostate/seminal vesicle posterior displacement in the later course of radiotherapy (30% vs. 10% posterior displacement >5mm in the following CT scans with a primary rectal volume >100cm3 vs. ≤100cm3; p<0.01). With 192±44cm3 vs. 188±43cm3 the PTV was similar for the treatment plan with a full and empty bladder. The bladder volume treated with 90% of the prescription dose was significantly larger with an empty bladder (39±14% vs. 22±10%; p<0.01). Bowel loops received a maximum dose of >90% of the prescription dose in 37% (3% with full bladder; p<0.01). Dose-volume-histograms for the rectum were the same with a full or empty bladder. Histograms for the contours of the organs and the organ walls hardly differed. Conclusions: In spite of the larger variability of the bladder filling, prostate position stability is the same with a full compared to an empty bladder. The rectum volume has a major influence on the prostate position. An increased amount of bladder volume in the high dose region and a higher dose to bowel loops result in treatment plans with an empty bladder. Tabled 1Prostate displacement with full vs. empty bladder* mean ± standard deviation * mean ± standard deviation

Interobserver Delineation Variation Using CT versus Combined CT + MRI in Intensity–Modulated Radiotherapy for Prostate Cancer

To quantify interobserver variation of prostate and seminal vesicle delineations using CT only versus CT + MRI in consensus reading with a radiologist. The prostate and seminal vesicles of 13 patients treated with intensity-modulated radiotherapy for prostatic adenocarcinoma were retrospectively delineated by three radiation oncologists on CT only and on CT + MRI in consensus reading with a radiologist. The volumes and margin positions were calculated and intermodality and interobserver variations were assessed for the clinical target volume (CTV), seminal vesicles, prostate and three prostatic subdivisions (apical, middle and basal third). Using CT + MRI as compared to CT alone, the mean CTV, prostate and seminal vesicle volumes significantly decreased by 6.54%, 5.21% and 10.47%, respectively. More importantly, their standard deviations significantly decreased by 63.06%, 62.65% and 44.83%, respectively. The highest level of variation was found at the prostatic apex, followed by the prostatic base and seminal vesicles. Addition of MRI to CT in consensus reading with a radiologist results in a moderate decrease of the CTV, but an important decrease of the interobserver delineation variation, especially at the prostatic apex.

Choix des contraintes et amélioration dosimétrique d’une radiothérapie conformationnelle du cancer de la prostate modulée en intensité pendant une partie du traitement

Intensity modulated radiation therapy (IMRT) is based on a methodology called inverse planning. Starting from dosimetric objectives, constraints of optimization are fixed and given to the inverse planning system, which in turn calculates the modulated intensity to apply to each beam. Since the algorithms allow the constraints to be violated, the results of optimization may differ from the initial dosimetric objectives. Consequently, the user is compelled to adapt the choice of the constraints according to the type of modulation and until satisfactory results are found. The purpose of this work is to present our experience in the choice of these constraints for prostate cancer treatments, as we moved from conformal radiotherapy to IMRT. Treatments were performed with a Varian 23EX linac and calculations were realized with the Varian CadPlan-Helios planning system. The approach used for the first 12 patients treated at institut Curie with IMRT from June 2002 was analysed. The treatment always consisted of a combination of conformal radiotherapy with and without intensity modulation. Results showed that, a larger fraction of the treatment performed with IMRT induced a better sparing of the organs at risk for the same homogeneous dose distribution to the target volume. Apart from the dose-volume constraint for the rectum, a fixed set of constraints, slightly more restrictive than the dosimetric objectives, could be used for all patients. Compared with conformal radiotherapy, the conformation factor for IMRT increased up to 16%. A specific study was undertaken in view of treatments completely performed with IMRT. The optimal technique consisted in performing separated IMRT plans for the two target volumes, the prostate volume and the prostate plus seminal vesicles volume respectively. Another satisfactory possibility was to define new constraints on two separated planning target volumes, prostate and seminal vesicles. This last approach is now routinely implemented for our IMRT patients.

Target-volume and critical-organ delineation for conformal radiotherapy of prostate cancer: experience of French dose-escalation trials

The delineation of target volume and organs at risk depends on the organs definition, and on the modalities for the CT-scan acquisition. Inter-observer variability in the delineation may be large, especially when patient's anatomy is unusual. During the two french multicentric studies of conformal radiotherapy for localized prostate cancer, it was made an effort to harmonize the delineation of the target volumes and organs at risk. Two cases were proposed for delineation during two workshops. In the first case, the mean prostate volume was 46.5 mL (extreme: 31.7-61.3), the mean prostate and seminal vesicles volume was 74.7 mL (extreme: 59.6-80.3), the rectal and bladder walls varied respectively in proportion from 1 to 1.45 and from 1 to 1.16; in the second case, the mean prostate volume was 53.1 mL (extreme: 40.8-73.1), the volume of prostate plus seminal vesicles was 65.1 mL (extreme: 53.2-89), the rectal wall varied proportionally from 1 to 1, 24 and the vesical wall varied from 1 to 1.67. For participating centers to the french studies of dose escalation, a quality control of contours was performed to decrease the inter-observer variability. The ways to reduce the discrepancies of volumes delineation, between different observers, are discussed. A better quality of the CT images, use of urethral opacification, and consensual definition of clinical target volumes and organs at risk may contribute to that improvement.

Does prostate brachytherapy treat the seminal vesicles? A dose–volume histogram analysis of seminal vesicles in patients undergoing combined PD-103 prostate implantation and external beam irradiation

Purpose: Combined brachytherapy of the prostate and external beam irradiation (EBRT) of the prostate and seminal vesicles (SV) is becoming a popular treatment for high-risk prostate cancer. Dose–volume histogram (DVH) analysis of the SV in patients undergoing this treatment was performed to determine the dose distribution to the SV and the adequacy of this treatment in patients with potential SV involvement.Methods and Materials: Twenty-five consecutive patients were treated with a Pd-103 implant of the prostate alone and 45 Gy of EBRT to the prostate and SV. Attempts were not made to implant the SV but seeds were routinely placed at the junction of the prostate and SV. All patients underwent CT-based postimplant dosimetric analysis 1 month after implantation. As part of this analysis, DVH were generated for the prostate and total SV volume (SVT). In addition, the SV was divided into 6-mm-thick volumes identified as SV1, SV2, SV3, SV4, and SV5 starting from the junction of the prostate and SV and extending distally. DVH were also generated for these structures. Delivered dose was defined as the D90 (dose delivered to 90% of the organ on DVH).Results: The median volumes in cc of the prostate, SVT, SV1, SV2, SV3, SV4, and SV5 were 34.33, 9.75, 2.7, 3.48, 2.92, 3.18, and 1.96 respectively. The SVT contained from 0–9 seeds (median 2). There was little dose delivered to the SVT and SV volumes from the implanted prostate. The median D90 values for the prostate, SVT, SV1, SV2, SV3, SV4, and SV5 were 8615 cGy, 675 cGy, 3100 cGy, 1329 cGy, 553 cGy, 246 cGy, and 67 cGy, respectively. The dose delivered to the prostate covered small percentages of SV. The percents of SV volumes covered by the prostate D90 were 11, 35, 3.3, 0, 0, and 0 for SVT, SV1, SV2, SV3, SV4, and SV5, respectively.Conclusions: DVH analysis of the SV reveals that dose generated from an implanted prostate contributes little to the SV. Those patients at high risk for SV involvement may be undertreated with combined EBRT to prophylactic doses and prostate implantation.

Significant changes in volume of seminal vesicles as determined by transrectal sonography in relation to age and benign prostatic hyperplasia.

We evaluated the changes in volume of the seminal vesicles as determined by transrectal sonography in terms of the possible relationship with aging, lower urinary tract symptoms and benign prostatic hyperplasia (BPH) in community based populations in Japan. In 641 men (55-86 year, mean 67) on a mass screening program for prostatic diseases, the maximum horizontal area of the seminal vesicles (MHA) was compared with age, American Urological Association (AUA) symptom index scores and transrectal ultrasonic parameters of the prostate including prostatic volume, transition zone (TZ) volume, TZ index and presumed circle area ratio (PCAR). Simple regression analyses demonstrated that MHA correlated significantly with age, prostatic volume, TZ volume, TZ index and PCAR, but not with AUA symptom index scores. Multiple regression analysis revealed age, prostatic volume and PCAR to be independent determinants of MHA. There was a difference in MHA between subjects with BPH (7.1+/-2.5 cm2) and those with a normal prostate (5.6+/-2.1 cm2) with a statistical significance. In the morphological evaluation of the seminal vesicles, the significant influence of age and BPH has to be taken into account.

Evaluation of changes in the size and location of the prostate, seminal vesicles, bladder, and rectum during a course of external beam radiation therapy

To document the size and location of the prostate, seminal vesicles, bladder, and rectum throughout the course of external beam radiotherapy. The frequency and range of motion of these organs are quantified. Ten patients with localized carcinoma of the prostate had conventional simulation followed immediately by a treatment planning computed tomography scan (TPCT0). Once treatment was initiated, each patient had a weekly CT (TPCT1-N) before or after his daily treatment. Anatomical structures from CT were delineated on a computer workstation for analysis. The serial CT sets were spatially registered to the initial scan using image correlation software that brings into congruence the bony pelvis of the different scans. The location of the prostate, seminal vesicles, bladder, and rectum on subsequent scans were compared to TPCT0, as well as to each other. Prostate volumes were observed to vary by an average of +/- 10% during the course of radiation therapy, while the seminal vesicle volumes varied by as much as 100%. Bladder and rectal volumes varied by +/- 30%. Compared to TPCT0, movement of the prostate was demonstrated in all patients. Quantitation of the center-of-mass (CM) showed motion of less than 1 mm in the left-right direction, while motion ranging from 0 to +/- 1 cm was observed in the anterior-posterior and superior-inferior directions. The individual standard deviations of these motions varied from approximately 1-5 mm. These variations were correlated to changes in the dimensions of the bladder and rectum. Changes in the location of the prostate, seminal vesicles, and normal tissue volumes during the course of radiation therapy occur and have dosimetric consequences that may impact tumor control and normal tissue complication probabilities. Conformal therapy for prostate cancer will require the incorporation of knowledge of the anatomic relationships of these structures as a function of time. Therefore, these uncertainties must be taken into account when designing treatment plans and in considering dose escalation trials.

Seminal vesicle volume as a sonographicpredictor of prostate cancer stage

Objectives Accurate clinical staging of prostate cancer continues to challengethe urologist, with understaging a common problem. Preoperative identification of men with capsular penetration or seminal vesicle invasion would allow deferment of radical surgery unlikely to cure the patient. We investigated the ability of seminal vesicle volume as determined by transrectal ultrasound (TRUS) to predict the stage of prostate carcinoma. Methods Forty-seven consecutive men undergoing radical prostatectomy had preoperative determination of the seminal vesicle volume by TRUE. The volume was determined for each individual seminal vesicle as well as the total seminal vesicle volume. Asymmetry was defined as one seminal vesicle having twice the volume of the other. Results Average total seminal vesicle volume was statistically greater for patients withStage C disease as opposed to those with organ-confined tumors. Seminal vesicle asymmetry was also present statistically more often in Stage C patients than Stage B men. The combination of total seminal vesicle volume less than 15 cc and symmetrical seminal vesicles yielded a possibility of only 18% of extraprostatic extension of tumor. Conclusions We believe that seminal vesicle volume as determined by TRUS can aid in the staging of adenocarcinoma of the prostate and should be considered along with other parameters, such as prostate-specific antigen, acid phosphatase, and Gleason score, when planning therapy for this disease.

Accuracy of in-vivo assessment of prostatic volume by MRI and transrectal ultrasonography.

More accurate noninvasive estimation of prostate size is important in therapeutic trials for benign prostatic hyperplasia. The accuracy of MRI and transrectal ultrasound (TRUS) in assessing prostate weight was evaluated in 48 patients who underwent radical prostatectomy for stage A or B cancer. The volume derived from the wet weight of the freshly excised specimen was used as a reference. We compared that volume with volume estimates derived from the three-axis linear dimension measurement by MRI and TRUS using a tissue density of 1.05 g/cc and the standard formula for an ellipsoid object. Prostate and seminal vesicle volumes were also computed by contouring T2-weighted 5 mm thick contiguous MR images using a semiautomatic edge detection program and pixel summation. Three-axis volume MRI method versus volume from wet weight has slightly less scatter than TRUS three-axis method (r = 0.85 vs r = 0.81). Contoured MR volume method has the least scatter r = 0.93, statistically better than the linear axis method. Contoured MRI volumetric analysis appears superior to linear MRI or TRUS methods in estimating true prostate volume.

Testosterone Replacement Therapy and Prostate/Seminal Vesicle Volume in Klinefelter's Syndrome

Volume of prostate and seminal vesicles was measured in patients with Klinefelter's syndrome by means of transrectal ultrasonography before and after testosterone replacement therapy. Continuous suppression of plasma gonadotropin levels was not observed, and plasma levels of testosterone did not maintain the normal range. However, volume of prostate (p less than 0.001) and seminal vesicles (p less than 0.05) increased significantly after testosterone replacement therapy. Volume determination of prostate and seminal vesicles by means of transrectal ultrasonography is an available parameter for evaluating the adequacy of testosterone replacement therapy in Klinefelter's syndrome.

Relationship of seminal vesicle size and measures of libido in yearling beef bulls

Ninety-five yearling beef bulls were given routine Breeding Soundness Examinations, two libido tests and palpated rectally for internal genital disease and measurement of seminal vesicle size. Finger tips were premeasured, and then used as “glandometers”. The bulls were examined at the end of a 140-day performance test. Sixteen lines of breeding were examined including 13 Hereford, 2 Angus and 1 Red Angus. Average age was 384 days and average weight was 961 lbs. Line and breed differences (P<.05) were observed for scrotal circumference, scrotal circumference score and second libido test. Similar differences were observed for SV length (P<.01), depth and volume both (P<.05). There were no significant correlations between seminal vesicle (SV) size and libido scores. There were, however, significant correlations between SV size and scrotal circumference (P<.05), BSE score (P<.01), body weight (P<.01), and semen morphology score (P<.05). Proximal droplets and midpiece abnormalities, respectively, were the most common spermatozoal abnormalities observed in semen from this group of bulls.