[MRI and prostatic cancer: measurements of kinetic perfusion parameters of gadolinium with a computerized-aided diagnostic tool (CAD)]

OBJECTIVES

To assess with a CAD in the peripheral (ZP) and transitional (ZT) zones the areas with modifications of the kinetic parameter Kep (ratio of exchanges between vascular compartment and extravascular extracellular spaces) in prostatic cancers with DCE MRI before radical prostatectomy.

METHODS

Forty-two consecutive patients (mean age 67 years, mean PSA: 8.9 ng/ml) with a prostatic cancer proved after a set of 12 biopsies underwent, before radical prostatectomy, a dynamic MRI (1.5T) with a surface coil after injection of gadolinium. We look with a CAD for foci of voxels with an abnormal Kep in ZP and/or in ZT. Foci of abnormal voxels computerized were compared with histological results of radical prostatectomies: prostates were shared in 12 sectors (six peripheral and six central) and a total of 504 sectors were studied. The links between prostatic capsule and foci of voxels with elevated Kep were systematically evaluated. The location and the local extension of the various cancerous foci were estimated. A comparison with the results of the T2W and T1 DCE MRI sequences without use of the CAD was made.

RESULTS

Eighty-eight percent of investigated patients revealed at least a cancerous focus associated with a group of pathological voxels. Hundred and seventy-eight of the 504 investigated prostatic sectors revealed a cancerous lesion after radical prostatectomy (RP) and 116 a focus of voxels with a pathological Kep being linked to 71 isolated lesions, some of them filling several sectors (47 peripheral and 24 transitional). The automatic research with the software of foci of voxels with a parameter Kep more than 2,2 per minute to detect a cancerous lesion had a sensitivity by sector less than the reading without CAD (69% in ZP and 58% in ZT against respectively, 85 and 66% (p<0.01) but seemed more specific: 98% in PZ and 95% in ZT against respectively, 80 and 82% (p<0.01). After RP, 16 cancers were classified Pt2, 10 Pt2R+ and 16 Pt3. The CAD had a better accuracy (74%) than T2W MRI (60%) to look for an extracapsular extension (EPE) or a risk of positive margins: 86% of extraprostatic extension and 60% of positive margins were near a focus of pathological voxels.

CONCLUSIONS

CAD allowed a computerized qualitative and quantitative study of DCE MRI. It identified and localized with a good specificity the significant foci. A focus of voxels with elevated Kep against the capsule increased significantly the risk of an extraprostatic extension or a positive margin after radical prostatectomy.

Écho-Doppler et cancer de la prostate: option ou nécessité ?

PURPOSE

To evaluate the value of power Doppler sonography (PDS) in patients with a serum PSA level greater than 3.5 ng/ml and note the advantages of PDS in management of biopsy cores and staging in prostate cancer.

MATERIAL AND METHODS

A group of 579 patients with a serum PSA level greater than 3.5 ng/ml underwent sextant biopsies. PDS of the prostate was performed in all patients before biopsy indication. Patients underwent six initial sextant biopsies without Doppler. In 141 patients who retained an elevated serum PSA level, an additional series of six to eight ultrasound-guided biopsies with Doppler were indicated. A total of 299 cancers were diagnosed (126 palpable) after initial biopsies and 85 (13 palpable) after additional biopsies. One hundred seven patients with localized cancer (48 palpable) underwent a radical prostatectomy.

RESULTS

An echographic or vascular anomaly was detected in 335 patients; after biopsies this anomaly corresponded to 260 cancers, 39 of which were not visible (false-negative Doppler results). The negative predictive value was 84% and there was no significant relation between PSA level and negative predictive value. After initial biopsies, if an abnormal Doppler signal was present the risk of having positive additional biopsies was 83%. Abnormal disoriented irregular vessels were present in 69% of patients with a Gleason score of 7 or higher versus 31% in patients with a Gleason score less than 7 (p<0.01). Twenty out of 39 patients with T1c cancer invisible with PDS and not palpable (13% of all cancers) underwent a radical prostatectomy. Eleven of 16 cancers with a Gleason score of 6 or less were found insignificant, but in two cases the lesion was advanced (p<0.01). Of cancers with a tumor vessel crossing the capsule, 71% presented an extraprostatic extension (Se: 37.5%, Spe: 93%, PPV: 71%, NPV: 78%) (p<0.01).

CONCLUSION

In prostatic cancer, PDS allows evaluation of aggressiveness features and can optimize the number of useful biopsy cores.

Value of power doppler and 3D vascular sonography as a method for diagnosis and staging of prostate cancer

OBJECTIVES

To compare the value of Power Doppler Sonography (PDS) and B mode sonography in the diagnosis of prostate cancer and to assess the value of PDS to specify capsular effraction of the cancer.

PATIENTS AND METHODS

323 patients were investigated: 41 control subjects allowed the establishment of normal vascular semiology and 282 patients with suspected cancer (PSA >4ng/ml). Power Doppler Sonography with 3D reconstruction was used to describe Power Doppler Sonography features of normal or abnormal vessels. Three types of blood supply(a: regular avascular posterior peripheral margin, b: irregular avascular posterior peripheral margin, c: vessels crossing the posterior peripheral margin) were described as a function of the presumed stage of cancer (a: intraprostatic, b: undetermined, c: extraprostatic). Comparison with histology was performed on random biopsies without Doppler (282 cases) (median PSA level = 15.8ng/ml), on second biopsies indicated with PDS (72 cases), and radical prostatectomy specimens (63 cases).

RESULTS

A cancer was diagnosed in 157 of the 282 patients (55.7%) with suspected cancer. The overall sensitivity of PDS in the initial diagnosis of prostatic cancer was 92.4% and its specificity was 72% (versus 87.9% and 57.6% for sonography alone respectively). The negative predictive value of PDS was elevated to 80.6% (p<0.0001). Targeting area presenting abnormal blood flow in any part of the prostate was useful to detect isoechoic or lesions in patients with first negative biopsy results (in 41 of 72 targeted patients with first negative biopsies with PDS a cancer was diagnosed: 58% of these cancers had less than 3 positive biopsies and 34% only one positive biopsy). The 3 vascular types a, b, c were evaluated prospectively in the detection of capsular effraction. The presence or absence of vessels crossing the capsule to determine an extracapsular extension was a significant sign (p<0.0001). Capsular effraction was detected in 3 of the 27 cases (11%) of type a cancer and in 16 of the 18 cases (87%) of type c cancer.

CONCLUSION

PDS improves the accuracy of echographic imaging in the diagnosis of cancer. Combining first sextant biopsies and targeted areas presenting abnormal blood flow using PDS can increase cancer detection with an optimized number of biopsy cores. The risk of extracapsular involvement can be evaluated by the presence of vessels perforating the capsule.

Treatment of benign ureterointestinal anastomotic strictures with permanent ureteral Wallstent after Camey and Wallace urinary diversion: long-term follow-up

BACKGROUND AND PURPOSE

Ureterointestinal anastomotic stricture follows urinary diversion in 4% to 8% of patients and may lead to a progressive deterioration of renal function. There are problems with all current management techniques: surgical revision, endourologic incision, nephrostomy drainage, external ureteral stents, and dilation with a high-pressure angioplasty balloon. The authors present their long-term results with permanent ureteral Wallstents for the treatment of benign ureterointestinal stricture.

PATIENTS AND METHODS

Eight patients with 10 strictures were treated by placement of self-expanding permanent indwelling stents via percutaneous nephrostomy between September 1993 and January 1998. The mean age of the group was 59.2 years. Development of strictures occurred a mean of 20.9 months after urinary diversion. There were seven complete and three partial strictures. Of 49 patients treated by the Camey procedure, 7 patients (14%) developed 9 (18%) strictures. Of 28 patients having the Wallace procedure, 1 patient (3.5%) developed one stricture. After recanalization of the distal ureter by a Terumo guidewire and dilation with a high-pressure angioplasty balloon, a Wallstent was placed across the stricture via a percutaneous approach.

RESULTS

The endourologic placement of the Wallstent was well tolerated by all patients. The hospital stay averaged 2 days. Seven patients with nine strictures after the Camey procedure are doing well with a follow-up of 7 to 68 months (mean 22.4 months). One major complication was observed in one patient necessitating an additional procedure (lithotripsy) because of stone formation at the lower part of the stent extending into the neobladder in order to maintain patency after 68 months. The other patient, who had a Wallace procedure, is doing well 1 year 8 months afterward.

CONCLUSION

An endourologic ureteral Wallstent approach to ureterointestinal stricture is a successful alternative, providing satisfactory management of the problem in most patients. No complication such as stent migration, hematuria, pain, or recurrent stricture was observed.

[Lower urinary tract function and its disorders]

The lower urinary tract provides two modes of operation--storage and elimination of urine. The normal function results in the coordination of contraction and relaxation of muscles of the urinary bladder and urethral sphincters. Disorders of these activities or their interaction lead to the development of lower urinary tract dysfunctions. The nervous system plays an essential role in the regulation of the functions. The control of micturition is coordinated by several regious of the central nervous system. Afferents and efferents of the peripheral nervous system carry signals from and to the lower urinary tract. The reflex circuitry controlling micturition consists of five components: spinal efferent neurons, peripheral efferent neurons, primary afferent neurons, spinal interneurons and neurons in the brain. Preganglionic neurons located in the sacral parasympathetic nucleus and lumbar sympathetic nucleus excite the peripheral efferent neurons innervating smooth muscles of the urinary bladder and urethra. Motoneurons of sacral Onuf's nucleus excite the striated muscle of the external urethral sphincter. Myelinated and unmyelinated afferent axons transmit information from the lower urinary tract to the lumbosacral spinal cord. Three receptor types of the lower urinary tract are present: tension receptors, volume receptors and "silent receptors", which become nociceptors following the sensitization. Afferent pathways terminate on spinal interneurons. Spinal interneurons relay information to the brain or to other regions of the spinal cord. Because micturition reflexes are mediated by disynaptic or polysynaptic pathways, interneuronal mechanisms are of crucial importance in the regulation of lower urinary tract. Central pathways involved in micturition reflexes are located in spinal and supraspinal areas. Micturition reflexes can be modulated at the level of the spinal cord by viscero--bladder and somato--bladder reflexes. Supraspinal areas have a more complicated organization: critical component of the micturition reflex is the pontine micturition center and the periaqueductal gray. Inhibitory and excitatory areas in the pontomedullary and hypothalamic systems and the brain play an important role in the regulation of micturition reflexes.

[Power Doppler and 3D vascular sonography of intraprostatic blood supply: assessment criteria and value for the diagnostic and clinical staging of prostatic cancer]

OBJECTIVES

To compare the value of Power Doppler Sonography (PDS) and B mode sonography in the diagnosis of prostate cancer and to assess the value of PDS to assess cell differentiation as a function of the degree of blood supply and to specify capsular effraction of the cancer.

PATIENTS

133 patients, divided into 2 groups, were investigated: one group consisted of 41 patients with no suspicion of cancer (15 control subjects and 26 patients with acute prostatitis) and a second group consisted of 92 patient with suspected cancer (PSA > 4 ng/ml).

METHODS

Power Doppler sonography with 3D reconstruction was used to calculate a graduated blood supply index from 1 to 3 for nodules of the peripheral zone. Three types of blood supply (A: regular avascular capsule, B: irregular avascular capsule, C: vessels crossing the capsule) were described as a function of the presumed stage of cancer (A: intraprostatic, B: undetermined, C: extraprostatic). Comparison with histology was performed on randomized biopsies (92 cases) and radical prostatectomy specimens (21 cases).

RESULTS

A cancer was diagnosed in 57 of the 92 patients (62%) with suspected cancer. The overall sensitivity of PDS in the initial diagnosis of prostatic cancer was 94.7%, and its specificity was 77.1% (versus 93% and 42.8% for sonography alone, respectively). For a prevalence between 0.4 and 0.9, the PPV ranged from 73.4% to 97.4% and the NPV ranged from 95.6% to 62% (p = 0.02). The correlation between tumour blood supply and Gleason score showed that 20/40 tumours (50%) with a Gleason score > or = 7 had a blood supply index of 3 versus 6/17 (35%) of tumours with a Gleason score < 7 (r = 0.283, p = 0.033). The 3 vascular types, A, B, C, were evaluated prospectively in the detection of capsular effraction. Capsular effraction was detected in one of the 8 cases of type A cancer and in 6 of the 8 cases (75%) of type C cancer.

CONCLUSION

PDS improves the reliability of sonography in the diagnosis and staging of prostate cancer. There is a correlation between tumour blood supply and Gleason score.

[Power Doppler ultrasonography and hypoechoic nodules of the peripheral prostate: prospectives and limitations]

OBJECTIVE

Power Doppler Ultrasonography contributes to better characterization of hypoechoic area of peripheral gland improving detection of cancer or inflammatory diseases of the prostate.

PATIENTS AND METHODS

Power Doppler US was performed in eighty patients: 15 normal glands and 65 patients with acute prostatitis (25), chronic prostatitis (17) and cancer (23) were studied and a pattern was defined in each pathology. A second group of 45 patients with hypoechoic area was prospectively selected.

RESULTS

In normal glands, capsular and parenchymal arteries were seen in a radial and symmetrical fashion on coronal scans. These arteries increased in size and in divisions in diffuse and acute prostatis. In chronic prostatitis, an isolated capsular vessel was sometime present (9/17). Focal hypervascularity (18/23) with vasculogenesis (14/23) increased the specificity of transrectal ultrasound in detection of a cancer and the sensitivity in evaluation of the tumor size.

[Campylobacter fetus ssp fetus septicemia associated with a colonic abscess]

Campylobacter is considered to be an opportunistic agent. The authors relate an unusual case with Campylobacter fetus ssp fetus (CF) septicemia and colic abscess. Human Campylobacteriosis is presumed to be a food-born disease related to contaminated animal products such as milk or meat. In some cases CF may be transmitted by drinking water or by fecal soiling via the hands. Conventional treatment uses macrolides with decrease the duration of diarrhea and reduce the fecal excretion of CF. Macrolides are ineffective in CF septicemias. In such cases aminoglycosides seem to be the drug of choice.

[Echography and pulsed Doppler of the arteries of the renal parenchyma in obstructive syndromes and dilatation of the excretory cavities of the kidney]

Ultrasonography is highly effective in diagnosing pyelocalyceal dilatation. Confirming the distension of these collecting structures, indicating probable obstruction, is more difficult since the degree of dilatation does not always correspond to the degree of distension. Renal studies were performed in 244 patients including 51 patients with dilation or renal obstruction. Doppler ultrasonography was used to measure the Pourcelot's resistive index of arcuate and interlobar arteries for each kidney. Results demonstrate: 1) for healthy patients the average vascular resistive index is 0.54 +/- 0.02 (minimum 0.48 +/- 0.02, maximum 0.60 +/- 0.02). 2) in cases of acute obstruction, this resistive index for pathologic kidney is elevated greater than 0.7. The difference in resistive indices between the pathologic and contralateral kidney was greater than 0.10. 3) in the patients with intermittent junctional syndromes when an intravenous furosemide test is used, there is an increase in the resistive index. 4) in case of chronic obstruction well tolerated, the increase in resistive index is moderate. If there is an acute deterioration, the resistive index become greater than 0.8. Concurrent abnormalities which affect only one kidney (pathology of the renal hilum, tumoral syndromes) may make it difficult to interpret certain results. Ultrasonography together with Doppler scanning may be in certain cases a reasonable alternative with IVP.