Transrectal Ultrasonography of the Prostate

Transcription

1 Ae3 (13) Transrectal Ultrasonography of the Prostate Author: Sugandh Shetty, MD; Chief Editor: Bradley Fields Schwartz, DO, FACS Background Urologists have incorporated transrectal ultrasonography (TRUS) of the prostate into their practices; moreover, TRUS is also widely used to deliver treatments such as brachytherapy and to monitor cryotherapy treatment for prostate cancer. TRUS has become an extension of the urologist s finger in the early detection of prostate cancer. The evolution of end-firing probes has further enhanced urologists ability to monitor the entire process of prostate biopsy. The use of sound waves to detect distant objects on the basis of their reflective properties became popular after World War II. In medicine, the initial use of ultrasound was in the detection of brain tumors. In urology, ultrasound was first used to detect renal stones during surgery. The early applications of ultrasonography in medicine involved sound-wave generators, cathode-ray tubes, Polaroid photography, or 35-mm film recording. However, the invention of the silicone microchip gave birth to the modern ultrasonography revolution. Early investigators in prostatic ultrasonography conducted experiments with ultrasound probes and recording devices. One of the earliest devices was a chair-type apparatus with a probe mounted in the center of the chair. The patient sat on the probe, which was guided into the rectum. Improvements in gray-scale ultrasound display and multiplanar scanning have resulted in user-friendly hand-held probes. Earlier studies concentrated on the ultrasonographic appearances of prostate abnormalities such as benign prostatic hyperplasia (BPH), carcinoma of the prostate (CAP), prostatitis, prostatic abscess, and prostatic calculi. Since the introduction of the prostate-specific antigen (PSA) screening test and early detection of prostate cancer, the role of TRUS has changed; it is mainly used to visualize the prostate (see the image below) and to aid in guided needle biopsy. 1

2 Axial image of a prostate. White arrows show the asymmetrical anterior prostate. This could only be appreciated on TRUS images. Future applications Possible future applications involving TRUS include the following: Color Doppler scanning Contrast-enhanced prostate biopsy Intermittent and harmonic ultrasonography High-intensity focused ultrasound (HIFU) Color Doppler scanning has been used to enhance the diagnosis of CAP as an adjunct to TRUS. Several investigators have demonstrated that the addition of color Doppler improved the specificity of prostate biopsy findings. However, differentiating a focus of prostatitis from cancer was difficult. The addition of power Doppler was not advantageous. The use of microbubble contrast agents can enhance gray-scale imaging and Doppler imaging. Newer agents that remain in the vascular compartment have been used for prostate imaging. Currently available agents include the following: Perflenapent emulsion (EchoGen) Galactose palmitic acid (Levovist) Perflexane lipid microspheres (Imavist) Galactose suspension (Echovist) Perflutren lipid microsphere (DMP 115, Definity) Perfluorobutane microspheres (NC , Sonazoid) Several investigators have evaluated contrast-enhanced prostate ultrasonography. Ragde et al used EchoGen to study 15 patients with rising PSA levels and previous negative biopsy findings and found that only 2 of the 8 patients with abnormal vascular patterns were diagnosed with cancer. [1] Similarly, Watanabe et al studied 9 cases in which Levovist was used and demonstrated enhanced images of all cancers. [2] Halpern et al evaluated 26 patients with elevated PSA levels and found 2

3 significant image enhancement after using Imavist. [3] However, the extra cost of this technique may be the limiting factor in its widespread use. The rationale for intermittent and harmonic ultrasonography is that conventional ultrasonography destroys the microbubbles of the contrast agents used in ultrasonographic imaging. Intermittent ultrasonography increases the enhancement provided by the contrast agents. In harmonic imaging, the reverberations produced by the contrast agent are visualized at a different frequency than the insonating frequency, which can provide a better image. With extracorporeal HIFU, temperatures higher than 60 C can be achieved in the target tissue. The prostate can be easily treated with this modality via a transrectal probe. The size of the thermal lesion can be controlled by the power and the duration of the ultrasound pulse. Higher in situ intensities (>3055 W/cm 2 ) create the cavitation phenomenon and bubble effect, which are difficult to monitor. The currently available HIFU devices use 3-4 MHz transducers. Experimental studies have shown core temperatures of 75 C, with a peak of 99 C during insonification. Gelet et al pioneered the use of transrectal HIFU in the treatment of prostate cancer. [4] Currently, the procedure is used in Europe to treat localized prostate cancer and is performed with the patient under anesthesia and in a decubitus position. Rectal cooling is employed to prevent rectal burns. Prostates smaller than 40 ml or those with an anteroposterior diameter of less than 5 cm are best suited for this treatment. During the procedure, the whole gland is treated (in contrast to focal therapy). After the procedure, a suprapubic tube is left in place for 5-7 days. In a multicenter trial of 402 patients treated with HIFU, the median duration for catheter use was 5 days. [5] Prolonged retention occurred in 9% of patients, and 3.6% developed urethral strictures. Incontinence following HIFU was rare (0.6%). Rectourethral fistula developed in 1.2% of the patients. Complication rates are higher with salvage HIFU after radiation therapy, radical prostatectomy, or HIFU. Erectile function can be preserved in 20-46% of patients who undergo only 1 session of HIFU. After a minimum follow-up period of 6 months, Thuroff et al reported negative biopsy results in 87% of patients and a median nadir PSA level of 0.4 ng/ml after HIFU. [5] Gelet at al reported that 78% of lowrisk patients were disease-free and had negative biopsy results at an actuarial 5-year follow-up. [4] Gelet et al also reported salvage HIFU after failed radiation in 71 patients. [6] Among these patients, biopsy results were negative in 80%, and 61% had a PSA level nadir below 0.5 ng/ml. Complication rates after salvage HIFU were higher: total incontinence developed in 6%, rectourethral fistula in 6%, and vesical neck contracture in 17%. 3

4 Indications TRUS has both diagnostic and therapeutic indications. Diagnostic indications for TRUS include early diagnosis of CAP. However, ultrasonographic findings alone cannot be used to establish or exclude the diagnosis of CAP: definitive diagnosis must be based on biopsy results, along with abnormal digital rectal examination (DRE) findings, elevated PSA levels, or both. TRUS is also used diagnostically to determine the volume of the prostate gland and thereby facilitate the planning of brachytherapy, cryotherapy, or minimally invasive BPH therapy (eg, radiofrequency or microwave therapy). In addition, TRUS is used to evaluate prostate volume during hormonal downsizing for brachytherapy. Finally, TRUS is used in the evaluation of men with azoospermia to rule out ejaculatory-duct cysts, seminal vesicular cysts, müllerian cysts, or utricular cysts. Therapeutic indications for TRUS include the following: Brachytherapy for CAP Cryotherapy for CAP Deroofing or aspiration of ejaculatory ducts, prostatic cysts, or prostatic abscesses Contraindications Contraindications for TRUS-guided biopsy of the prostate include an acute painful perianal disorder and a hemorrhagic diathesis. As a rule, patients should be discouraged from taking aspirin or nonsteroidal anti-inflammatory drugs for at least 10 days before the procedure, but recent use of these agents should not be considered an absolute contraindication for prostate biopsy. Technical Considerations Prostate anatomy The adult prostate is a chestnut-shaped organ enveloped in a fibrous capsule. The base of the prostate is attached to the bladder neck, and the apex is fixed to the urogenital diaphragm. The prostatic urethra traverses the gland. The verumontanum is a longitudinal ridge in the prostatic apex onto which the ejaculatory ducts open. The prostate is located superior and posterior to the seminal vesicles. The ampullae of the vas deferens run medial to the seminal vesicles along the posterior surface of the prostate. Anteriorly, the fibrous capsule thickens at the level of the apex to form puboprostatic ligaments, which attach the prostate to the back of the symphysis pubis. The dorsal venous complex (ie, the Santorini plexus) runs along the puboprostatic ligaments. The prostate gland lies beneath the endopelvic fascia. Posteriorly, the 2 layers of Denonvilliers fascia 4

5 separate the prostate from the rectum. The rectourethralis muscle attaches the rectum to the prostatic apex. A rich plexus of veins encompasses the prostate gland between the true fibrous capsule of the gland and the lateral prostatic fascia; these are visible landmarks on sonograms (see the image below). The neurovascular bundles run craniocaudally along the posterolateral aspects of the prostate. The prostate gland is supplied by the prostatic artery, which is usually a branch of the inferior vesical artery. The prostatic artery divides into a urethral branch, which supplies the transition zone, and a capsular branch. Sagittal image of a prostate. White arrows show darkly hypoechoic areas suggestive of periprostatic veins. Venous drainage from the prostate moves into the Santorini plexus and eventually into the internal iliac vein. The prostatic venous plexus communicates freely with the extradural venous plexus (ie, the Batson plexus), and this communication is thought to be a factor in the spread of prostate cancer. Initially, lymphatic drainage of the prostate is into the obturator lymph nodes and into the hypogastric chain. The nerve supply to the prostate is both sympathetic, from the hypogastric plexus (L1-2), and parasympathetic, from the pelvic nerve (nervi erigentes, S2-S4). Although the cavernous nerves run along the posterior aspect of the prostate, the 2 distinct areas from which prostatic nerves leave the gland are thought to be the superior and inferior pedicles. These areas are the first sites of extraprostatic spread of cancer. Internal anatomy According to the classic work by McNeal, the prostatic urethra, which is the main reference point of the prostate, divides the gland into an anterior fibromuscular stroma and a posterior glandular organ. The urethra is angled 35 anteriorly in the proximal portion of the prostate. The ejaculatory ducts run in the same plane as the distal prostatic urethra to join the verumontanum. Lowsley s concept of a 5-lobed prostate has been replaced by McNeal s concept of zonal architecture. In this scheme, the prostate has 4 glandular zones, each with its own ductal system. The peripheral zone, the transition zone, and the periurethral glands have a similar histologic appearance and are 5

6 derived from the urogenital sinus. However, the central zone is histologically distinct from the other 3 zones and is derived from mesonephric tissues (ie, wolffian tissue). Peripheral zone The peripheral zone constitutes almost 75% of the normal prostate gland. It occupies the distal prostate gland, the area around the urethra distal to the verumontanum. The acini are small, round, and smooth-walled, and their ducts drain into the urethra distal to the verumontanum. The stroma is loosely woven with randomly oriented muscle fibers. Approximately 70% of CAP cases arise in this zone. Central zone The central zone constitutes 25% of the normal prostate and occupies the part of the prostate behind the proximal prostatic urethra. The ejaculatory ducts pass through the central zone. The acini are large and irregular, with significant intraluminal folds and ridges. They are also surrounded by muscular tissue that closely follows the shape of the acini. Approximately 5-10% of CAP cases arise in this zone. Transition zone The transition zone makes up approximately 5-10% of the normal prostate gland (see the image below). The transition zone lies on either side of the proximal prostatic urethra, lateral to the internal sphincter. The glandular architecture is similar to that of the peripheral zone; however, the stroma is more compact. The transition zone is where BPH originates and where approximately 20% of CAP cases arise. Transverse image of the prostate showing a hypertrophied transition zone (yellow arrows) and a compressed peripheral zone (blue arrows). Periurethral glands The periurethral glands make up less than 1% of the glandular tissue. These glands are embedded in the smooth muscle of the prostatic sphincter. This is the site of origin of the large median lobe of BPH. Anterior fibromuscular stroma 6

7 The anterior part of the prostate is composed mainly of fibromuscular stroma, which is continuous with detrusor fibers. Toward the apex of the gland, this fibromuscular tissue blends with striated muscle from the levator. Puboprostatic ligaments also blend with this area. Invaginated extraprostatic space As the ejaculatory ducts enter the prostate posteriorly, an invaginated extraprostatic space (IES) surrounds them and invaginates into the prostate. The IES surrounds the ejaculatory ducts, ends at the verumontanum, and communicates with the periurethral space. In 1989, Lee introduced the concept that invasion of the IES may be the first sign of extraprostatic extension of prostate cancer and an early sign of invasion of seminal vesicles. In 2005, Amin et al evaluated the pathological significance of the invasion of IES in 80 patients with prostate cancer and concluded that IES involvement was consistently seen in cases with seminal vesicle invasion. [7] Bladder neck and internal sphincter The internal sphincter runs from the bladder neck to the level of the verumontanum. The smooth muscle fibers of the sphincter are continuous with the superficial layer of the trigone. In healthy males, the bladder neck and the internal sphincter are closed. In males with a neurogenic bladder, the bladder neck and the prostatic urethra are wide open, and some investigators have used TRUS to monitor the lower urinary tract in patients with spinal injuries. Complication prevention Gill and Ukimura, in a study reporting on the use of TRUS monitoring with Doppler during laparoscopic radical prostatectomy to identify the blood flow in the neurovascular bundles, found that identification and preservation of pulsatile blood vessels within these bundles resulted in superior recovery of erectile activity postoperatively. [8] Preprocedural enema More than 80% of urologists administer an enema before TRUS and prostate biopsy. However, some authors consider this practice unnecessary. Antibiotic prophylaxis More than 90% of urologists administer prophylactic oral antibiotics. Reported regimens include a total of 11 different antibiotics, with 20 different dosages and treatment durations ranging from 1 to 17 days. There is increasing support for a simpler prophylactic regimen in patients with uncomplicated medical conditions. The protocol most commonly recommended consists of 2 doses of a fluoroquinolone, with 7

8 the first given before the procedure and the second 12 hours later. Targeted antimicrobial prophylaxis has been employed in cases of infections caused by fluoroquinolone-resistant organisms. [9] In patients with prosthetic implants or valvular heart disease, additional prophylaxis with ampicillin 1 g intramuscularly (IM) or, in penicillin-allergic patients, vancomycin 1 g intravenously (IV) plus gentamicin 80 mg IM is recommended. Equipment Transrectal ultrasonography (TRUS) of the prostate has made use of both side-fire and end-fire ultrasound probes. Understanding the differences between them is critical for mastery of TRUS, in that the 2 probe types yield entirely different viewpoints that create confusion if one type is used in the manner that is appropriate for the other. The directions of imaging should be obvious from the names of the probe types, but the full implications for TRUS of the prostate may not be. Side-fire probes project laterally. Thus, twisting the probe while keeping its axis neutral with respect to the sagittal plane laterally enables lateral visualization. In contrast, end-fire probes project an imaging plane either directly or at a slight angle from the end of the probe. Thus, to visualize the lateral areas, the probe handle must be angled away from the side of interest, with the anus used as a fulcrum to gain accurate placement. For example, to visualize the right side of the prostate, the handle would be moved downward and toward the patient s dependent left side. Currently, the most widely used probe for TRUS is a 7-MHz transducer within an endorectal probe. This can produce images in both sagittal and axial planes. Patient Preparation Anesthesia In the past, TRUS was performed without any infiltrative anesthesia. Currently, however, it is a common practice to infiltrate lidocaine into the periprostatic area. Pareek et al, in a randomized, double-blind, placebo-controlled study using a technique of periprostatic nerve blockade, reported significant pain control during and after biopsy. [10] This technique involved injection of 2.5 ml of lidocaine on each side at the prostate base at the junction of the prostate and the seminal vesicle (using a 5-in, 22-gauge spinal needle through the ultrasound probe). Alavi et al, in a study comparing the efficacy of intrarectal lidocaine gel with that of periprostatic nerve block, concluded that the nerve block was superior for pain control. [11] With this technique, saturation biopsies including as many as 20 cores could be performed. 8

9 Mutaguchi et al reported that local anesthesia with an intraprostatic block provided better pain control for prostate biopsy than the use of a periprostatic block. [12] In the intraprostatic block technique, 10 ml of 1% lidocaine was injected into 2-3 sites of each prostate lobe. In the periprostatic block technique described by the investigators, 5 ml of 1% lidocaine was injected via a 7-in. 22-gauge spinal needle into the region of the prostatic vascular pedicle just lateral to the junction of seminal vesicles and the prostate. [12] The needle was slowly withdrawn to the prostatic apex, and an additional 5 ml of lidocaine was injected at the apex. A randomized controlled trial comparing pelvic plexus block to periprostatic nerve block demonstrated better pain control with the former technique. While the procedure is more foreign to urologists, the patients experience less pain and this technique should be considered in men undergoing office prostate biopsy. [13] Positioning The left lateral, lithotomy, and knee-elbow positions have all been used for TRUS. If a patient is undergoing TRUS of the prostate with a side-fire probe, the probe should remain essentially in the midline and should be twisted to reach the lateral aspects. Thus, patient positioning is relatively unimportant, as long as the anus is accessible. Conversely, if a patient is undergoing TRUS of the prostate with an end-fire probe, he must be positioned so that the ultrasound probe handle can be dropped far enough to reach beneath the plane of the examination table when the right lateral border of the prostate is being visualized. This is most readily accomplished if the patient s buttocks are directly over the corner of the table, with his legs flexed toward his chest and held by the table extension. Transrectal Prostate Ultrasonography General procedure In transrectal ultrasonography (TRUS) of the prostate, scanning begins in the axial plane, and the base of the prostate and seminal vesicles are visualized first. A small amount of urine in the bladder facilitates the examination. Seminal vesicles are identified bilaterally, with the ampullae of the vas deferens on either side of the midline (see the image below). The seminal vesicles are convoluted cystic structures that are darkly anechoic. Men who have abstained from ejaculation for a long period may have dilated seminal vesicles. 9

10 Axial images of the seminal vesicles. White arrows indicate the ampulla of the vas deferens. Next, the base of the prostate is visualized. The central zone comprises the posterior part of the gland and is often hyperechoic. The midgland is the widest portion of the gland. The peripheral zone forms most of the gland volume. Echoes are described as isoechoic and closely packed. The transition zone is the central part of the gland and is hypoechoic. The junction of the peripheral zone and the transition zone is distinct posteriorly and is characterized by a hyperechoic region, which results from prostatic calculi or corpora amylacea. The transition zone is often filled with cystic spaces in patients with benign prostatic hyperplasia (BPH). Scanning at the level of the verumontanum and observing the Eiffel tower sign (anterior shadowing) help to identify the urethra and the verumontanum. The prostate distal to the verumontanum is composed mainly of the peripheral zone. The capsule is a hyperechoic structure that can be identified all around the prostate gland. Several hypoechoic rounded structures can be identified around the prostate gland. These are the prostatic venous plexi. The position of the neurovascular bundles can often be identified by the vascular structures. Imaging in the sagittal plane allows visualization of the urethra. The median lobes of the prostate are often visualized. Volume measurement Volume assessment of the prostate is an important and integral part of TRUS. Of the several formulas that have been developed for this purpose, the most commonly used is the ellipsoid formula, which requires measurement of 3 different prostate dimensions. First, the transverse dimension and the anteroposterior dimension at the estimated point of the widest transverse dimension are measured in the axial plane. Next, the longitudinal dimension is measured in the sagittal plane just off the midline (because the bladder neck often obscures the cephalad extent of the gland). The ellipsoid volume formula is then applied, as follows: Volume = height width length

11 Biopsy Directed biopsies are obtained from any area that is considered suggestive on the basis of ultrasonographic findings or palpable abnormalities found on digital rectal examination (DRE). Because the incidence of nonpalpable isoechoic prostate tumors is high, limiting biopsy sites to either ultrasonographically hypoechoic lesions or to areas of palpable abnormality tends to miss many malignancies. Obtaining separate biopsy samples from each sextant of the prostate improves the odds of sampling clinically inapparent tumors. Originally, these biopsy sites included the midlobe parasagittal plane at the apex, the midgland, and the base bilaterally. Subsequently, however, changes to this protocol were recommended. Various authors suggested that the 6 biopsy samples should be obtained from the lateral third of each lobe rather than from the mid lobe or that 2 lateral biopsy samples should be obtained from each lobe in addition to the original sextant samples. Some authors recommend obtaining even larger numbers of biopsy cores to increase the diagnostic sensitivity. (See Prostate Biopsy.) Complications of prostate biopsy include hematuria, rectal bleeding, hematospermia, urosepsis, and perineal pain. [14] Although most of these complications subside within hours, patients should be warned that hematospermia can last for 3-4 weeks. In rare cases (< 1%), bacteremia develops that necessitates hospitalization and administration of intravenous antibiotics. Early diagnosis of prostate cancer Advances in TRUS coincided with the development of prostate-specific antigen (PSA) testing. The PSA has proved the most valuable tumor marker test for early diagnosis of carcinoma of the prostate (CAP). TRUS was also evaluated to determine whether it could be used for CAP screening. However, it was not found to be highly effective for this purpose, because of its lack of specificity: CAP lesions may appear hypoechoic, hyperechoic, or isoechoic on TRUS. Therefore, TRUS is used primarily to direct the physician to suggestive areas in the prostate (see the images below) or to guide the performance of prostate biopsies. 11

12 Large hypoechoic area along the left peripheral zone, suggestive of carcinoma. Sagittal image of the prostate showing a hypoechoic area (white arrow). This area was a focus of cancer on biopsy findings. A large hypoechoic area in the left peripheral zone suggestive of prostate cancer. Axial and sagittal images of the prostate showing extensive hypoechoic areas. This patient had a prostatespecific antigen level of 17 ng/ml and digital rectal examination findings highly suggestive of cancer. Biopsy revealed granulomatous prostatitis. Prostate volume is assessed during the TRUS examination. The decision to perform biopsy in patients with abnormal PSA levels can be bolstered by PSA density (PSAD), which is defined as the PSA level divided by the prostate volume. The sensitivity of PSAD is enhanced by a cutoff value of 1.5. BPH tissue produces one tenth as much PSA per gram as cancer tissue does; accordingly, a gland with a large amount of BPH tissue indicates an elevated PSA level. CAP is diagnosed in 30% patients with a PSA value of 4-10 ng/ml and in 60% of patients with a PSA value of ng/ml. PSAD has been used to decrease the number of prostate biopsies performed. Other methods that have been used to aid in the decision whether to perform biopsy include the following: 12

13 Expected PSA value for a given prostate volume Volume and PSAD of the transition zone A PSA value that increases at a velocity greater than 0.75 ng/ml per year The volume of the prostate gland can also be used to determine treatment options. Both perineal prostatectomy and brachytherapy are easier to perform when the gland is smaller than 50 g. In large glands, the anterolateral portion of the gland is behind the pubic arch, and these areas cannot be reached with the perineal brachytherapy needles. Hormonal downsizing is useful in such cases, and TRUS is used to monitor gland size. Measuring prostate volume is also useful in large BPH glands to help determine whether transurethral resection or an open procedure is appropriate for prostatectomy. Whether TRUS has a role in staging prostate cancer is debatable. Most early cancers are confined to the organ. Lee et al popularized staging biopsies of the neurovascular bundles and the seminal vesicles. Positive results from biopsy of the neurovascular bundles and seminal vesicles signified extracapsular disease and a poor outcome. Currently, however, the greatest amount of information is available on staging approaches using the PSA value and the Gleason score of prostate cancer based on several published nomograms (eg, Partin nomograms). Moreover, biopsy of the periprostatic venous plexus may result in pelvic hematoma. Perineural invasion found on prostate biopsy samples should not be considered an indicator of extraprostatic spread. TRUS can help identify extraprostatic CAP in advanced-stage T3 cases. Brachytherapy Localized prostate cancer can be treated by means of brachytherapy using permanent radioactive iodine seeds, with or without preimplant external beam irradiation (depending on the tumor grade). After initial volume assessment, the seeds are placed according to a computer-generated grid under ultrasonographic guidance. [15] To exclude violation of the urethra or bladder, cystoscopic evaluation is necessary at the end of the procedure. Although iodine seeds are most commonly used, palladium seeds are often employed to treat more aggressive cancers (usually defined as those with a Gleason score higher than 7 and a PSA value higher than 10 ng/ml). Alternatively, patients with more aggressive tumors may receive high-dose radiation therapy consisting of external beam irradiation during the second and fourth weeks along with a brachytherapy boost with temporary implants. With temporary seeds, trocars are placed under ultrasonographic guidance according to a computer-generated grid, and the radioactive source is threaded in and out of each of the trocars. 13

14 Cryotherapy Gonder and associates were the first to use cryoablation in urologic disorders in the 1960s. In 1988, Onik et al used real-time ultrasonography to monitor the freezing process during radical cryoablation of the prostate. Currently, cryotherapy is acceptable as salvage therapy for radiation failures. Radical cryoablation is defined as the freezing of the entire prostate, the periprostatic tissue, the neurovascular pedicles, and the proximal seminal vesicles. Probes are placed in the prostate gland via the perineum under ultrasonographic guidance, and cryotherapy is begun. The ice ball, which is an anechoic lesion with a hyperechoic edge that can be seen advancing or receding, is directly monitored as it occupies the entire prostate gland. Most centers use a urethral warming device to prevent urethral necrosis. The following 3 techniques have been used: Single freeze-thaw cycle Double freeze-thaw cycles Pullback freeze technique A suprapubic catheter is kept in place until the patient is able to void satisfactorily with minimal residual urine. Follow-up biopsies are performed at 6 months, 1 year, and 2 years. Using the current double freeze-thaw technique, Cohen et al reported an 11% positive biopsy rate after 4 years of follow-up. All positive results occurred in patients with a PSA value higher than 10 ng/ml or tumors at stage T3. [16] Ghafar et al reported the results of salvage cryotherapy for recurrence after external beam radiation therapy. [17] In this study, 38 men were treated with the double freeze-thaw technique on an argonbased system. The biochemical recurrence-free survival rate was 86% at 1 year and 74% at 2 years. Complications included rectal pain (39.5%), urinary tract infection (2.6%), incontinence (7.9%), hematuria (7.9%), and scrotal edema (10%). None of the patients developed rectourethral fistula, urethral sloughing, or retention. Medication Summary The goals of pharmacotherapy are to reduce pain and morbidity and prevent complications. References Available on request 14

15 INSTRUCTIONS Read through the article and answer the multiple choice questions provided at the back of the article. Please note that some questions may have more than one answer; in the case of the latter please tick every correct answer. When done only fax through your answer sheet to the fax number given on the answer sheet. QUESTIONNAIRE Ae3 (13) TRANSRECTAL ULTRASONOGRAPHY OF THE PROSTATE Question 1: Is it TRUE or FALSE that TRUS is used to screen the prostate for early detection of prostate cancer, monitor cryotherapy treatment and to deliver treatments such as brachytherapy? A TRUE B FALSE Question 2: Which of the following has become the main role of TRUS since the introduction of the PSA screening test? A To visualize the prostate B To aid in guided needle biopsy C Both of the above Question 3: Was the addition of power Doppler to enhance the diagnosis of CAP as an adjunct to TRUS beneficial? A YES B NO Question 4: Which of the following statements are TRUE with regard to future applications involving TRUS? A Micro-bubble contrast agents can enhance gray-scale imaging and Doppler imaging B In a study, image enhancement after using Imavist was insignificant C Intermittent ultrasonography decreases the enhancement provided by the contrast agents D Conventional ultrasonography destroys the microbubbles of the contrast agents E In harmonic imaging, a better image is provided because the reverberations produced by the contrast agent are visualized at a different frequency than the insonating frequency Question 5: Which of the following prostates are best suited for transrectal HIFU treatment? A Prostates between 50mL and 55mL B Prostates larger than 45mL C Prostates smaller than 40mL D Prostates with an anteroposterior diameter of more than 5cm E Prostates with an anteroposterior diameter of less than 5cm Question 6: Is it TRUE or FALSE that complication rates are higher with salvage HIFU after radical prostatectomy, as well as HIFU and radiation therapy, but erectile function can be preserved in 20-46% of patients who undergo only one session of HIFU? A TRUE B FALSE Question 7: A definitive diagnosis of CAP must be based on which of the following? A Ultrasonographic findings alone B Biopsy results C Ultrasonographic findings, biopsy results, along with abnormal DRE findings and/or elevated PSA levels D Elevated PSA levels alone Question 8: For which of the following are TRUS therapeutically indicated? A Brachytherapy for CAP B Cryotherapy for CAP C Deroofing or aspiration of ejaculatory ducts, prostatic cysts, or prostatic abscesses D All of the above Question 9: Which of the following are absolute contraindications for TRUS guided biopsy of the prostate? A An acute painful perianal disorder B A hemorrhagic diathesis C Aspirin intake prior to biopsy D Nonsteroidal anti-inflammatory drug intake prior to biopsy E All of the above Question 10: Is it TRUE or FALSE that the free communication of the prostatic venous plexus with the Santorini plexus is thought to be a factor in the spread of prostate cancer? A TRUE B FALSE 15

16 Question 11: Which zone of the prostate makes up the largest part of the normal prostate gland? A The central zone B The transition zone C The peripheral zone D The periurethral glands Question 12: Which approximate percentage of CAP cases arises from the transition zone? A 75% B 70% C 50% D 25% E 20% Question 17: Which one of the following projects an imaging plane at a slight angle from the end of the probe? A Side-fire probes B End-fire probes Question 18: Is it TRUE that intrarectal lidocaine gel was superior to periprostatic nerve block for pain control? A YES B NO Question 19: Which of the following positions have been used for TRUS? In which Question 13: Is it TRUE that according to Amin et al, IES involvement was consistently seen in cases with seminal vesicle invasion? A YES B NO Question 14: Which of the following statements are TRUE with regard to the bladder neck and internal sphincter? A In healthy males the bladder neck and the internal sphincter are wide open B In healthy males the bladder neck and the internal sphincter are closed C In males with a neurogenic bladder the bladder neck and the prostatic urethra are closed D In healthy males the bladder neck and the prostatic urethra are wide open Question 15: Can the identification and preservation of pulsatile blood vessels within the neurovascular bundles result in superior recovery of erectile activity postoperatively? A YES B NO Question 16: TRUS of the prostate has made use of which of the following probes? A The left lateral position B The lithotomy position C The knee-elbow position D All of the above Question 20 Should there be urine in the bladder to facilitate examination of the prostate in TRUS? A YES, a small amount of urine facilitates the examination B NO, the bladder should be empty C YES, the bladder should be full Question 21: Which of the following helps to identify the urethra and the verumontanum? A Scanning at the level of the verumontanum B Observing the Eiffel tower sign C Both of the above Question 22: Is it TRUE or FALSE that limiting biopsy sites to either ultrasonographically hypoechoic lesions or to areas of palpable abnormality is acceptable because not many malignancies are missed this way and the incidence of nonpalpable isoechoic prostate tumors is not high? A TRUE B FALSE A End-fire probes B Side-fire probes C Both end-fire and side-fire probes 16

17 Question 23: Which of the following complications of prostate biopsy can last for three to four weeks? A Hematuria B Rectal bleeding C Perineal pain D Urosepsis E Hematospermia Question 24: Which one of the following has proved to be the most valuable tumor marker for early diagnosis of CAP? A TRUS B PSA Question 25: CAP is diagnosed in what percentage of patients with a PSA value of ng/ml? A 30% B 40% C 50% D 60% Question 26: Perineal prostatectomy and brachytherapy are easier to perform when the gland is what size? A Smaller than 50g B Between 60 and 70g C Bigger than 50g Question 27: Should perineural invasion found on prostate biopsy samples be considered an indicator of extraprostatic spread? A YES B NO Question 28: During brachytherapy, which one of the following seeds are often employed to treat cancers with a Gleason score higher than 7 and a PSA value higher than 10ng/mL? A Iodine seeds B Palladium seeds Question 29: Which of the following are frozen during radical cryoablation? A Only the periprostatic tissue B Almost the entire prostate and the neurovascular pedicles C The neurovascular pedicles, parts of the prostate and the proximal seminal vesicles D The entire prostate, the neurovascular pedicles, the periprostatic tissue and the proximal seminal vesicles E The periprostatic tissue and the entire prostate Question 30: After cryotherapy, when should follow-up biopsies be performed? A At 1 year B At 6 months and 4 years C At 6 months, 1 year, and 2 years D After 2 years 17

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