Search PubMed⌕ Search

Biomedical subjects

R Oyen

Publications and source records attributed to R Oyen.

At least 73 records · Page 4Linked to original sources
PubMed1995

[The significance of focal hypoechoic lesions in the peripheral zone of the prostate].

Hypoechoic lesions in the peripheral zone of the prostate gland are one of the commonest abnormalities at transrectal ultrasonography (TRUS). 90% of all carcinomas originating in the peripheral zone present as a hypoechoic lesion. Hypoechogenicity though is not specific, as many benign lesions are also hypoechoic. In this retrospective study, based on TRUS alone 57% of the hypoechoic lesions showed carcinoma in the biopsy core (43% of the biopsy cores were benign). The number of positive biopsies increased up to 75% when the hypoechoic lesion was palpable at digital rectal examination. 5.2% of the hypoechoic cancers would have been missed when non-palpable lesions would not have had a biopsy. When the hypoechoic lesion was associated with increased serum concentration of prostate specific antigen (PSA > 4 ng/ml) 74% of the biopsies were positive. 20% to 25% of all hypoechoic cancers would not have had a biopsy. The positive predictive value was 85% when the hypoechoic lesion was palpable at digital rectal examination and the PSA-concentration was > 4 ng/ml (and 90% when volume-adjusted PSA-parameter would have been applied).

Adenocarcinoma↗
PubMed1994

Accuracy of combined computerized tomography and fine needle aspiration cytology in lymph node staging of localized prostatic carcinoma.

The sensitivity and accuracy rate of computerized tomography (CT) in lymph node staging of localized prostatic carcinoma is commonly considered to be low. Fine needle aspiration cytology of pathological lymph nodes seen on radiological staging can enhance this low accuracy rate. We prospectively investigated the accuracy of CT and fine needle aspiration cytology in lymph node evaluation of 285 patients with clinically locally confined prostatic carcinoma. The sensitivity, specificity and accuracy rates of this combined method were 77.8%, 100% and 96.5%, respectively. False-negative staging results were found in only 10 patients with minimal nodal disease. Although in contrast with previous reports, combined CT and fine needle aspiration cytology in our hands seems to be a highly efficient staging method for lymph node involvement. This method could be considered as an alternative to surgical lymphadenectomy in the preoperative evaluation of the nodal status of patients with localized prostatic carcinoma who are scheduled for radical prostatectomy or curative radiotherapy.

Aged↗
PubMed1994

Primary lymphoma of the uterine cervix.

A case of primary non-Hodgkin lymphoma of the uterine cervix is reported. The ultrasonographic and computed tomographic findings are described as well as the MRI appearance of this peculiar cervical mass. The best tumor delineation was achieved by T2-predominant and contrast-enhanced T1-weighted images. The lesion was treated successfully with external radiotherapy.

Adult↗
PubMed1994

[Hormone therapy before radical prostatectomy. Effects on surgical method and resection margins. Belgian Uro-Oncological Study Group (B.U.O.S.)].

127 patients with a clinical stage T2b and T3 prostate cancer were randomized in order to undergo either a radical prostatectomy alone or a radical prostatectomy after hormonal treatment (560 mg of estramustine phosphate daily for 6 weeks) in a prospective multi-center study. The clinical or radiological evaluation of an eventual downstaging being extremely difficult, the authors compared in the 2 groups the influence on the surgical act and the number of positive surgical margins at pathological examination of the resected specimen. There was no significant difference between the 2 groups concerning the surgery (duration of the procedure, blood transfusion, degree of difficulty). For clinical T2 prostate tumors the number of positive surgical margins was significantly lower in the group that had preoperative hormonal treatment. In the group with clinical T3 prostate cancer this difference was not found. The influence of positive margins on the later development of local or systemic recurrence and on survival still has to be awaited. At this moment one could conclude that only patients with a T2 prostate cancer benefit of a preoperative hormonal treatment.

Estramustine↗
PubMed1993

In vitro analysis of urinary calculi: type differentiation using computed tomography and bone densitometry.

Thirty-six urinary stones were studied by computed tomography and bone densitometry in order to find a correlation between the chemical composition of the stones and the densitometric data. In vitro, the more common cases of lithiasis can be divided into 3 main groups: uric acid, cystine and the calcium salts, e.g. calcium oxalate monohydrate, calcium oxalate dihydrate and calcium phosphate. Struvite stones fall between the second and third groups. Computed tomography and bone densitometry can differentiate between the groups, provided that the value of the "stone mineral or calcium content" is correlated with the true calculated volume of the stone (resulting in the specific stone density) instead of the projection area (resulting in the area density). This is only possible in vitro. The in vivo application of these technologies in the treatment of stones of unknown composition could provide important information, but major restrictive factors pose difficulties. Further clinical studies are necessary, especially to define the role of bone densitometry.

Absorptiometry, Photon↗
PubMed1993

Tuberculosis of the adrenal glands: diagnosis by CT-guided fine needle biopsy.

Bilateral adrenal masses were found in a 64-year-old man with pulmonary tuberculosis and a pulmonary mass lesion suspicious for carcinoma. CT-guided fine needle biopsy of the left adrenal gland revealed tuberculosis. Adrenal metastases were thus excluded and probably Addison's disease, considered to be a potential complication of adrenal tuberculosis, could be prevented.

Adrenal Gland Diseases↗
PubMed1993

Xanthogranulomatous pyelonephritis in a child.

Xanthogranulomatous pyelonephritis is an uncommon form of chronic aggressive infection of the kidney and surrounding tissues usually affecting middle aged women. It is rarely seen in childhood. We report the case of a female child with a history of fatigue, progressive anorexia, and fever in whom a diagnosis of pyelonephritis on a predisposing factor of lithiasis was suggested. After initial antibiotic treatment, nephrectomy was needed for an acute general deterioration. Pathology demonstrated xanthogranulomatous pyelonephritis.

Child, Preschool↗
PubMed1993

Value of MRI in the diagnosis and staging of testicular tumors.

Ultrasound is currently the primary imaging modality for the assessment of scrotal disease. In acute pathology, colour Doppler adds further confirmation about blood flow to the testicles and surrounding structures. MR is emerging as a powerful tool to image the scrotum. Compared with sonography, MR has a wider field of view and a greater tissue contrast. The current status of MR imaging and its role in the evaluation and local staging of testicular tumors is evaluated in this retrospective study. MR is able to differentiate seminomatous from non-seminomatous tumors in nearly all cases. However, stromal tumors (e.g. Leydig cell tumors) cannot be differentiated from seminomatous tumors, and some benign lesions, as an intratesticular hematoma, cannot be differentiated from non-seminomatous tumors. Microscopic extension in or beyond the tunica albuginea cannot be evaluated.

Dysgerminoma↗
PubMed1992

Temperature steering in prostate by simultaneous transurethral and transrectal hyperthermia.

Localized hyperthermia (HT) is presently under investigation as a treatment for benign prostatic hyperplasia and carcinoma of the prostate (CaP). One popular approach employs a transrectal (TR) device, a directional microwave (MW) applicator inserted into the rectum and aimed at the prostate. Alternatively, in the transurethral (TU) technique, a symmetrically radiating MW antenna is placed directly within the prostatic urethra. Used individually, TR applicators are capable of effectively heating (> 42 degrees C) the prostate up to 2 cm from the rectum, whereas TU applicators selectively heat the periurethral tissue with effective radial penetration of about 0.6 cm. Neither technique is of much value in heating the anterior prostate. In general, the highest temperatures are produced in the tissue immediately adjacent to the surface of intracavitary microwave devices. However, when MW antennas are used in arrays, the resulting heating pattern can differ significantly from that of the individual antennas. Heating at depth can be selectively enhanced and "steered" by adjusting the phase relationship between the devices. Prostatic temperature profiles were measured in 6 patients treated with TR alone, TU alone, and simultaneous TR and TU heating. In the combined treatments different phase relationships between the antennas were applied. We found that a higher temperature could be produced in the center of the prostate than on the surface of either applicator for certain phase relationships, and that the temperature profiles could be changed by shifting phase. The results of these measurements are in agreement with those of a computer simulation. Based on the above data we feel the combined use of TU and TR hyperthermia may be justified in Phase I-II trials for patients with locally advanced CaP.

Aged↗
PubMed1992

Endovaginal sonography: new diagnostic approach for urethral diverticula.

Too often a urethral diverticulum is a long-standing and unrecognized problem. Suprapubic sonography has been proposed for assessment of this pathological condition. We report on endovaginal sonography as a new improved imaging modality for the diagnosis of urethral diverticula. In positive cases additional morphological information can be obtained from positive pressure urethrography or from diverticulography via fine needle puncture under digital guidance or under sonographic control. Direct puncture of the lesion allows the injection of contrast material to facilitate the diverticulectomy.

Adult↗
PubMed1992

Spontaneous rupture of the bladder: an uncommon finding on excretory urography.

A case of recurrent intraperitoneal bladder rupture is reported. Tearing occurred after minor trauma in a woman who had suffered a fracture of the pelvic rim 6 years earlier. Spontaneous rupture of the bladder is rare. The symptoms of an intraperitoneal bladder rupture may suggest intestinal disease and intravenous urography may be misleading. A retrograde cystogram is required to obtain the diagnosis.

Adult↗
PubMed1992

Radical prostatectomy for localized prostate cancer.

A retrospective analysis of 70 patients, undergoing a radical prostatectomy in 1989 and 1990 is reported. The value of computed tomography (CT) scanning in preoperative lymph node staging should be reconsidered. Evaluation of the resection margins is of utmost importance as is the distinction between capsular invasion, penetration and transgression. The etiology of local failure and its treatment are discussed.

Adenocarcinoma↗
PubMed1992

Neo-adjuvant hormonotherapy does not facilitate radical prostatectomy.

Sixty-eight patients who underwent radical prostatectomy without or after neo-adjuvant hormonotherapy for B2 or C stage prostate cancer were evaluated as concerned to the ease of the surgical procedure. Although it is difficult to assess this parameter, we experienced more difficulties and blood loss was higher in patients who had preoperative hormonal deprivation. Ongoing randomized trials could demonstrate an oncological benefit of neo-adjuvant hormonotherapy before radical prostatectomy. This eventual benefit will have to be balanced against an increased surgical difficulty.

Aged↗