Prolate Ellipsoid Formula Research Articles

PROSTATIC CENTRAL ZONE VOLUME, LOWER URINARY TRACT SYMPTOM SEVERITY AND PEAK URINARY FLOW RATES IN COMMUNITY DWELLING MEN

Purpose Previous studies have suggested that central zone prostatic volume may be more strongly correlated with lower urinary tract symptom severity and peak urinary flow rates than total prostatic volume. We determine whether prostatic central zone volume and central zone index volume correlate better with these measures than total prostate volume in an age stratified, community based random sample of healthy white men. Materials and Methods A cohort of 474 men were randomly selected from the 2,115 community dwelling men, 40 to 79 years old, who participated in the Olmsted County study of urinary symptoms and health status among men. All men had undergone transrectal ultrasound of the prostate. The total prostate and hypoechoic central zone volumes were caliper measured by 1 operator on static ultrasounds from baseline. Volumes were calculated with the prolate ellipsoid formula. The operator was blinded to clinical information and outcome. The associations between total prostate volume and central zone index (central zone volume/total volume), and American Urological Association (AUA) symptom index and peak urinary flow rates, respectively, were quantified with the Spearman rank correlation coefficient and least squares regression models. Results There was a moderately strong correlation between patient age and central zone volume (r s 0.54, p <0.001), total prostate volume (r ( s) 0.45, p <0.001) and central zone index (r s 0.38, p <0.001). The AUA symptom index and peak flow rates correlated less strongly with central zone volume (r s 0.17, p = 0.001 and r s -0.20, p <0.001, respectively) and total volume (r s 0.16, p <0.001 and r s -0.16, p <0.001, respectively). Central zone index weakly correlated with AUA symptom index (r s 0.08, p = 0.103) and peak urinary flow rate (r s -0.08, p = 0.0823). In regression models predicting AUA symptom index and peak flow rates central zone volume added little information after accounting for age and total prostatic volume in predicting AUA symptom index (p = 0.55) and peak flow rate (p = 0.84). Conclusions Central zone volume measured from static images optimized for total prostate volume no more closely correlated with lower urinary tract symptom severity or peak urinary flow rates than total prostate volume. Thus, the potentially greater imprecision in measuring central zone volume may not be offset by gains in strength of association with lower urinary tract symptom severity or peak urinary flow rates.

TRANSITION ZONE PROSTATE SPECIFIC ANTIGEN DENSITY: LACK OF USE IN PREDICTION OF PROSTATIC CARCINOMA

Purpose Among the new approaches to enhance the performance of prostate specific antigen (PSA) testing in a biopsy population is the use of the free-to-total PSA as well as the transition zone density, which is calculated by dividing the PSA by the transition zone volume. We compare these manipulations of the PSA to PSA alone in a biopsy population. Materials and Methods We evaluated 917 consecutive men who underwent ultrasound guided biopsy for an elevation in serum PSA or abnormality on digital rectal examination. Total PSA was measured using the Tandem-E † or Tandem-R † method. Prostate gland volume and transition zone were measured with ultrasound and calculated using the prolate ellipsoid formula. Results In the overall PSA range 276 men had carcinoma (30.0% of the population), while in the PSA 4.0 to 10.0 ng./ml. range 141 of 477 had cancer (29.6%). Receiver operating characteristics analysis and analysis of variance were performed. In the overall PSA series the Tandem total PSA performed as well as any PSA index to predict carcinoma. In the restricted range of total PSA 4.0 to 10.0 ng./ml. total PSA density as well as transition zone density were more predictive than PSA alone. In both PSA ranges the volume of benign glands was significantly larger than in the prostates exhibiting carcinoma. There was no statistically significant difference in outcomes of analyses between different investigators or different sites of investigation (Veterans Affairs versus university based hospitals). Conclusions In this biopsy population transition zone PSA density did not add to the information available with total PSA and gland volume. Neither investigator nor site bias contributed to the failure of transition zone PSA density or PSA density to predict prostatic carcinoma.

Transvaginal Sonography as a Screening Method for the Detection of Early Ovarian Cancer

From December 1987 to December 1993, 6470 women underwent screening with transvaginal sonography (TVS) as part of the University of Kentucky Ovarian Cancer Screening Project. Two groups of women were eligible to participate in this investigation: (i) asymptomatic postmenopausal patients or patients >50 years of age, and (ii) asymptomatic women >30 years of age with a family history of ovarian cancer. Ovarian volume was calculated using the prolate ellipsoid formula (length x height x width x 0.523). An abnormal sonogram was defined by (1) an ovarian volume >10 cm3 in postmenopausal women or >20 cm3 in premenopausal women, and (2) a papillary or complex tissue projection into a cystic ovarian tumor. All women with an abnormal TVS had a repeat sonogram in 4-6 weeks. Patients with persistently abnormal scans had a serum CA-125 determination, tumor morphology indexing, and color Doppler sonography. Ninety patients (1.4%) with a persisting abnormality on TVS underwent exploratory laparotomy or laparoscopy for tumor removal. Thirty-seven patients had serous cystadenomas and six had primary ovarian cancers. Five patients had Stage IA ovarian cancer and one patient had Stage IIIB disease. Only one of the ovarian cancer patients had a palpable abnormality on pelvic examination, and none had an elevated (>35 u/ml) serum CA-125. All these patients are presently alive and well 1-5 years after conventional therapy. There was one false negative in this study, a 38-year-old white female who was noted to have a small ovarian cancer at the time of laparoscopic prophylactic oophorectomy 11 months after a normal scan. Over 17,000 screening years have been accrued and there have been no deaths from primary ovarian cancer in the screened population. A cost analysis of TVS screening is presented.

Transvaginal Sonography as a Screening Method for the Detection of Early Ovarian Cancer

From December 1987 to December 1993, 6470 women underwent screening with transvaginal sonography (TVS) as part of the University of Kentucky Ovarian Cancer Screening Project. Two groups of women were eligible to participate in this investigation: (i) asymptomatic postmenopausal patients or patients >50 years of age, and (ii) asymptomatic women >30 years of age with a family history of ovarian cancer. Ovarian volume was calculated using the prolate ellipsoid formula (length × height × width × 0.523). An abnormal sonogram was defined by (1) an ovarian volume >10 cm3in postmenopausal women or >20 cm3in premenopausal women, and (2) a papillary or complex tissue projection into a cystic ovarian tumor. All women with an abnormal TVS had a repeat sonogram in 4–6 weeks. Patients with persistently abnormal scans had a serum CA-125 determination, tumor morphology indexing, and color Doppler sonography. Ninety patients (1.4%) with a persisting abnormality on TVS underwent exploratory laparotomy or laparoscopy for tumor removal. Thirty-seven patients had serous cystadenomas and six had primary ovarian cancers. Five patients had Stage IA ovarian cancer and one patient had Stage IIIB disease. Only one of the ovarian cancer patients had a palpable abnormality on pelvic examination, and none had an elevated (>35 u/ml) serum CA-125. All these patients are presently alive and well 1–5 years after conventional therapy. There was one false negative in this study, a 38-year-old white female who was noted to have a small ovarian cancer at the time of laparoscopic prophylactic oophorectomy 11 months after a normal scan. Over 17,000 screening years have been accrued and there have been no deaths from primary ovarian cancer in the screened population. A cost analysis of TVS screening is presented.

Comparison of prostatic volume and dimensions by transrectal and transurethral ultrasonography.

To compare the volumes and dimensions of the prostate gland as measured by transrectal and transurethral ultrasonography (TRUS and TUUS) and to study the prostatic changes that occur in the presence of an urethral instrument. Twenty men (mean age 71 years, range 43-85) with symptoms of prostatic enlargement underwent TRUS and the dimensions and volumes of their prostates were obtained by the dimensional method and by step planimetry. Within 24 h, all the men were examined cystoscopically under sedoanalgesia and underwent TUUS. Their prostatic volumes and dimensions were again measured by the dimensional method and by step planimetry. Step planimetry was carried out using a specially designed indexer firmly attached to the examination couch or operating table. All the static images and planimetry slices were video recorded for later computer enhancement and to study the three-dimensional changes occurring in the prostate. The volumes and dimensions obtained by TRUS and TUUS were compared. Volumes obtained by transurethral step planimetry were 22% greater than those from transrectal planimetry. Although there was a good correlation (r = 0.984) between transurethral planimetry and the volumes derived using the transurethral dimensions with the prolate ellipsoid formula, the latter produced values 17% and 25% lower by the transurethral and transrectal routes, respectively. These volume estimates varied widely, indicating that the simple addition of a constant to the prolate ellipsoid formula would not correct the volume. Three-dimensional changes of the prostate occurred with TRUS and TUUS: with TUUS, the craniocaudal and anteroposterior diameters were significantly larger (by 7% and 18%, respectively) while the transverse diameter was smaller by 20%. The estimated volumes and dimensions of the prostate differed when measured by TRUS and TUUS and three-dimensional changes in the prostate occurred in the presence of an urethral instrument.

Ovarian cancer screening

The three most extensively evaluated screening methods for ovarian cancer are pelvic examination, serum CA 125, and transvaginal sonography (TVS). The lack of sensitivity of pelvic examination and serum CA 125 has limited their use in ovarian cancer screening. Currently, the most effective screening method for ovarian cancer is TVS. Transvaginal sonography was performed with a standard ultrasound unit and a 5.0 MHz vaginal transducer. Each ovary was measured in three dimensions and ovarian volume was calculated using the prolate ellipsoid formula (L x H x W x 0.523). An ovarian volume greater than or equal to 20 cm3 in premenopausal women and greater than or equal to 10 cm3 in postmenopausal women was considered abnormal. Also, any internal papillary projection from the tumor wall was considered abnormal. A patient with an abnormal screen had a repeat TVS in 4-6 weeks. Women with a persisting abnormality on TVS underwent pelvic examination, serum CA 125 determination, Doppler flow sonography, and tumor morphologic indexing before operative tumor removal. Eighty-five hundred asymptomatic women underwent TVS screening. One hundred twenty-one of these women had a persisting abnormality and underwent tumor removal. Fifty-seven patients had serous cystadenomas and eight had primary ovarian cancers. Six patients had Stage IA ovarian cancer, one had Stage IIC ovarian cancer, and one had Stage IIIB ovarian cancer. Only one of these patients had palpable ovarian enlargement on clinical examination and one had an elevated serum CA 125. All patients are alive and well 4-61 months after conventional therapy. The direct cost of TVS screening was highest during the initial years of the program and fell progressively to $30/screen during the 4th year of the study. Worldwide, more than 14,000 women have been screened using ultrasonography, and 19 ovarian cancers have been detected. More than 20,000 patient-screening-years have been accrued, and there have been no deaths from primary ovarian cancer in the screened population. Transvaginal sonography screening causes a decrease in stage at detection and a decrease in case-specific mortality. Further study is needed to determine if annual TVS screening will significantly reduce ovarian cancer mortality. The cost for TVS screening is reasonable and is well within the range of that reported for other screening tests.

Ovarian Cancer Screening in Asymptomatic Postmenopausal Women

From 1987 to 1992, 3220 asymptomatic postmenopausal women underwent screening with transvaginal sonography (TVS) as part of the University of Kentucky Ovarian Cancer Screening Project. Ovarian volume was calculated using the prolate ellipsoid formula (length x height x width x 0.523). An abnormal sonogram was defined by (1) an ovarian volume > 10cm3 or (2) a papillary projection into a cystic ovarian tumor. All women with an abnormal TVS had a repeat sonogram in 4-6 weeks. If the repeat sonogram was abnormal, a morphology index score was assigned to each tumor, and a serum CA-125 was obtained. The patient then had a pelvic examination and an exploratory laparotomy. Forty-four patients (1.4%) with a persisting abnormality on TVS underwent exploratory laparotomy. Twenty-one patients had serous cystadenomas and 3 had primary ovarian cancers. Two patients with primary ovarian cancer had Stage IA disease and one had Stage IIIB disease. All patients with ovarian cancer had normal pelvic examinations and normal serum CA-125 levels, and are presently alive and well 32, 31, and 8 months after conventional therapy. Over 5000 screening years have been accumulated at this institution, and there have been no ovarian cancer deaths in the screened population. TVS screening has produced a decrease in stage at detection and case-specific mortality from ovarian cancer. A multi-institutional trial to test the efficacy of TVS as a screening method for ovarian cancer is indicated.

Ovarian Cancer Screening in Asymptomatic Postmenopausal Women

From 1987 to 1992, 3220 asymptomatic postmenopausal women underwent screening with transvaginal sonography (TVS) as part of the University of Kentucky Ovarian Cancer Screening Project. Ovarian volume was calculated using the prolate ellipsoid formula (length × height × width × 0.523). An abnormal sonogram was defined by (1) an ovarian volume >10cm 3 or (2) a papillary projection into a cystic ovarian tumor. All women with an abnormal TVS had a repeat sonogram in 4-6 weeks. If the repeat sonogram was abnormal, a morphology index score was assigned to each tumor, and a serum CA-125 was obtained. The patient then had a pelvic examination and an exploratory laparotomy. Forty-four patients (1.4%) with a persisting abnormality on TVS underwent exploratory laparotomy. Twenty-one patients had serous cystadenomas and 3 had primary ovarian cancers. Two patients with primary ovarian cancer had Stage IA disease and one had Stage IIIB disease. All patients with ovarian cancer had normal pelvic examinations and normal serum CA-125 levels, and are presently alive and well 32, 31, and 8 months after conventional therapy. Over 5000 screening years have been accumulated at this institution, and there have been no ovarian cancer deaths in the screened population. TVS screening has produced a decrease in stage at detection and case-specific mortality from ovarian cancer. A multi-institutional trial to test the efficacy of TVS as a screening method for ovarian cancer is indicated.

Ovarian cancer screening in asymptomatic postmenopausal women by transvaginal sonography

From November 1987 to January 1991, 1300 postmenopausal women underwent screening with transvaginal sonography (TVS). Women eligible for screening were all asymptomatic with no known ovarian tumors. Ovarian volume was calculated using the prolate ellipsoid formula, and a value in excess of 8.0 cm3 was considered abnormal. Ovarian abnormalities were detected in 33 women (2.5%), and 27 underwent exploratory laparotomy. Ovarian tumors were noted in all 27 patients, including 2 primary carcinomas and 14 serous cystadenomas. The two women with ovarian carcinomas had normal results of pelvic examinations and normal serum CA-125 levels. Both women had Stage I disease, and are alive and well after conventional therapy. TVS was time efficient, easy to perform, and well-accepted by patients. Currently, there are more than 3000 patient years of follow-up in the screened population, and there have been no deaths due to ovarian cancer. A multi-institutional trial to determine the efficacy of TVS as a screening method for ovarian cancer is indicated.

Interobserver variation in ovarian measurements using transvaginal sonography

Ultrasound examination of ovarian size and morphology has been proposed as a screening method for ovarian carcinoma. A screening test must give consistent results when performed by different examiners to reliably determine the sensitivity and specificity of the test. This study was designed to evaluate interobserver variation in ovarian size measurements using transvaginal sonography. Two examiners independently measured 86 ovaries in three planes and ovarian volumes were calculated using the prolate ellipsoid formula. The correlation coefficient between the ovarian volume measurements made by each examiner was 0.960. These results indicate that interobserver variation in ovarian volume measurements is extremely low as determined by transvaginal sonography.

Transvaginal sonography as a screening method for ovarian cancer a report of the first 1000 cases screened

From November 1987 to April 1989, 1000 women 40 years or older underwent screening vaginal sonography at the University of Kentucky Medical Center (Lexington, KY). Patients included in this investigation were all asymptomatic and had no known pelvic abnormalities. Each ovary was measured in three planes and ovarian volume was calculated using the prolate ellipsoid formula. The upper limit of normal for ovarian volume was 18 cm3 in premenopausal women and 8 cm3 in postmenopausal women. In patients with normal scans, mean ovarian volumes decreased from 6.8 cm3 to 3.0 cm3 with menopause. Thirty-one patients (3.1%) had abnormal vaginal sonograms and 24 underwent exploratory laparotomy. All patients undergoing surgery had ovarian or fallopian tube tumors with dimensions identical to those predicted by ultrasound. Histologic diagnoses of these tumors included the following: adenocarcinoma, one, serous cystadenoma, eight; endometrioma, six; and cystic teratomas, two. Vaginal sonography was performed easily and without complications, and was well accepted by patients. All patients with normal sonograms have been rescreened annually and none have subsequently developed ovarian cancer. Further clinical trials to determine the efficacy of vaginal sonography as a screening method for ovarian cancer are indicated.

Ultrasound of the normal nongravid uterus: Correlation with gross and histopathology

Accurate assessment of uterine size and significance of uterine enlargement are common clinical problems. We examined 156 patients by sonography prior to scheduled hysterectomy. Uterine volumes from normal-sized uteri were calculated from the sonograms using the equation of a prolate ellipsoid formula, and these calculated volumes were highly correlated with actual measured uterine volumes. Mean values and normal ranges of uterine weight were determined. These values are of particular value in postmenopausal patients in whom subjective evaluation of uterine enlargement is often difficult. When a sonographically enlarged, but otherwise normal uterus is discovered, it may contain a leiomyoma or other pathology not morphologically detectable by ultrasound.

Transvaginal sonography as a screening method for ovarian cancer

From November 1, 1987, to July 1, 1988, 506 asymptomatic patients 40 years or older underwent screening vaginal sonography at the University of Kentucky Medical Center. Eligibility requirements included no known pelvic symptoms or clinical abnormalities, no history of pelvic radiation, and no history of ovarian cancer. Each ovary was measured in three planes and ovarian volume was calculated using the prolate ellipsoid formula. Ovarian morphology was classified as uniformly hypoechogenic, cystic, solid, or complex. The upper limit of normal for ovarian volume was 18 cm 3 in premenopausal women and 8 cm 3 in post-menopausal women. With respect to these criteria, 12 patients (2.4%) were noted to have abnormal sonograms, and 10 agreed to surgery. All 10 patients had ovarian tumors with dimensions equal to those predicted by ultrasound. These tumors included four serous cystadenomas, three endometriomas, two cystic teratomas, and one adenocarcinoma. Vaginal sonography is a relatively simple test that can detect subtle changes in ovarian size and morphology. Further evaluation of this test as a screening method for ovarian cancer should be performed in the setting of controlled clinical trials that emphasize cost control and strict patient follow-up.