Download Chapter 10 The Prostate REDUX

Prostate
Holdorf
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Normal Anatomy
Terms and Landmarks
Zonal Anatomy
Classifications of Prostate Cancers
Image Orientation
Prostate Cancer
Indications for Transrectal Ultrasound
Laboratory Values
Sonographic Appearance
Transrectal Ultrasound
Prostate Staging
Benign Prostatic Hyperplasia (BPH)
Prostate Volume
Treatments
Transrectal ultrasound of the prostate gland is
performed to:
 Detect disorders within the prostate.
 Determine whether the prostate is enlarged, with
measurements acquired as needed for any
treatment planning.
 Detect an abnormal growth within the prostate.
 Help diagnose the cause of a man's infertility.
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A transrectal ultrasound of the prostate gland
is typically used to help diagnose symptoms
such as:
 A nodule felt by a physician during a routine
physical exam or prostate cancer screening exam
(AKA Digital rectal exam)
 An elevated blood test result
 Difficulty urination
 Frequent urination
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Patient should wear comfortable, loose-fitting clothing for the
ultrasound exam.
Patient may be asked to wear a gown during the procedure.
Patient may be instructed to avoid taking blood thinners, such as
aspirin, for seven to 10 days prior to the procedure if a biopsy is
planned. An enema may be taken two to four hours before the
ultrasound to clean out the bowel.
The ultrasound image is immediately visible on a video display
screen that looks like a computer or television monitor. The image
is created based on the amplitude (strength), frequency and time
it takes for the sound signal to return from the area of the patient
being examined to the transducer and the type of body structure
the sound travels through.
For ultrasound procedures requiring insertion of the transducer,
such as transvaginal or transrectal exams, the device is covered
and lubricated.
The prostate gland is located directly in front of the rectum, so the
ultrasound exam is performed transrectally.
 For a transrectal ultrasound, the patient is asked to lie on his side
with his knees bent. A protective cover is placed over the
transducer; it is lubricated, inserted through the anus and placed
into the rectum.
 The images are obtained from different angles to get the best
view of the prostate gland.
 If a suspicious lesion is identified with ultrasound or with a rectal
examination, an ultrasound-guided biopsy can be performed. This
procedure involves advancing a needle into the prostate gland
while the radiologist or urologist watches the needle placement
with ultrasound. A small amount of tissue is taken for microscopic
examination.
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Transrectal Biopsy
 Through the wall of the rectum 6-12 samples
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Transurethral biopsy
 Cystoscope is inserted into the urethra.
 Direct access to the prostate
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Transperineal biopsy
 Access is through the perineum
 Not as common
Transrectal ultrasound (TRUS) of the prostate initially was
thought to be the gold standard test for the prostate,
providing clinically important information of benign and
malignant conditions, including prostatic hyperplasia,
prostatitis, obstructive infertility and prostate cancer
evaluation including screening, diagnosis, biopsy, staging
and monitoring of response to therapy.
 Over time, the strengths and limitations of transrectal
ultrasound have become better defined. Patients today
are mainly referred for TRUS related to cancer evaluation
and biopsy. Transrectal ultrasound was initially considered
a primary screening test for prostate cancer. This has now
been replaced by prostate specific antigen (PSA) and
digital rectal examination. Occasionally, patients are
referred for TRUS for infertility and prostatitis.
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The prostate is located in the
retroperitoneum and is bordered:
 Anteriorly by the pubic bone
 Posteriorly by the rectum
 Superiorly by the urinary bladder
 Inferiorly by the urogenital diaphragm
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The inferior vesical artery is typically the
arterial supply to the prostate with
branches from the internal iliac artery.
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Transrectal ultrasound (TRUS) produces
transverse and sagittal images. With
Transrectal Sonography, the image is
inverted to maintain standard medical
imaging orientation. The rectum is displayed
at the bottom of the screen.
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APEX- inferior portion of the gland
situated superior to the urogenital
diaphragm.
BASE-Superior portion of the gland
situated below the inferior margin of the
urinary bladder.
SEMINAL VESICLES: Two Sac-like outpouchings of the vas defferens situated
adjacent to the superior/posterior aspect
of the prostate, between the urinary
bladder and rectum.
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EJACULATORY DUCTS: Duct that passes
through the central zone and empties into
urethra. This duct originates from the
combination of the vas defferens and the
seminal vesicles.
VERU MONTANUM: A longitudinal ridge
within the urethra in which the orifices of
the ejaculatory ducts are located on either
side.
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CORPORA AMYLACEA-calcifications
commonly seen in the inner gland of the
prostate.
SURGICAL CAPSULE-demarcation
between the inner gland (central and
transitional zones) and the outer gland
(peripheral Zone).
EIFFEL TOWER SIGN-is shadowing created
by calcification in the area of the urethra
and Veru monianum.
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The original concept of a 5-lobed prostate has
been replaced by McNeal’s concept of zonal
architecture.
The prostate glandular zones include the
following:
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Peripheral zone
 Posteriorly located portion of the prostate containing
70% of the prostatic glandular tissue, thus it is the
location of mot prostate cancers.
 Central zone
▪ Superiorly located portion of the prostate containing 25% of
the prostatic glandular tissue. Ejaculatory ducts pass through
this zone from the seminal vesicles to the urethra.
 Transition zone
▪ Contains 5% of the prostatic glandular tissue. It is the site of
origin of benign prostatic hyper plasia (BPH).
 Fibromuscular zone
▪ Anteriorly located non-glandular portion of the prostate. Nonglandular tissue; thus, it is not affected by cancer, prostatitis or
hyperplasia.
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Frequent urination, especially at night
Difficulty starting or stopping urination
Weak or dribbling stream
Not able to urinate
Pain or burning sensation when urinating
Blood in the urine or semen
Constant pain in the lower back, pelvis, or
upper thigh
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Stages A and B: Cancer is confined to the
prostate
Stages C and D: Cancer has spread outside
the prostate.
 Symptoms
▪ Fatigue
▪ Pain in bones
▪ Weight loss
▪ Low RBC count
▪ Urinary obstruction
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Gleason Score is the most commonly used
system of classifying the histological
characteristics of prostate cancer.
It predicts the aggressiveness of the disease.
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The incidence of prostate cancer in the US is
approximately 200,000 cases per year with a
mortality of 30,000 cases per year.
Risk factors include:
 Age
 Race
 Genetics
>80% of prostate cancers are diagnosed in
men older than 65 years.
African American men are 2 times more
likely to develop prostate cancer than
white men.
First-degree relative up to 2-3 x greater
risk of developing prostate cancer.
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Abnormal digital rectal exam
Elevation of PSA (>4.0 ng/ml) Nanogram/milliliter
 Prostate-specific antigen. PSA (an enzyme) is
present in small quantities in the serum of men
with healthy prostates, but is often elevated in the
presence of prostate growth, hence may be an
indicator of prostate cancer.
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Prostate Specific Antigen (PSA)
 PSA (an enzyme) increases with age and prostate
volume. Elevation occurs with benign conditions
such as prostatitis and BPH, and with prostate
cancer.
 Prostate cancer will elevate PSA 10x greater than
BPH.
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< 4 ng/ml*
4 - 10 ng/ml
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>10 ng/ml
Most likely cancer
There are also age and volume adjusted PSA levels.
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Normal
Benign/Potential Malignancy
* Ng/ml is an indication of concentration. Ng stands
for nanograms. ml stands for milliliters. It shows
how much solid substance there is in any particular
milliliter of liquid.
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Elevated in association with prostate
carcinoma.
Not used as routine screening test as it
may be elevated with other conditions.
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A series of six biopsies from the right and left
upper, middle and lower lobes of the
prostate, which increases diagnostic yield
and the likelihood of detecting prostate
cancer.
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Prostate cancer may have a varied
appearance depending on the size of the
lesion (focal vs. diffuse) and background of
the prostate (normal vs. hyperplastic).
Although prostate cancers can appear as
hyperechoic, isoechoic, or hypoechoic, the
CLASSIC appearance of prostate cancer in
ultrasound is a hypoechoic, peripherallyoriented lesion.
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Keep in mind that not all cancers are
hypoechoic, and not all hypoechoic lesions
are cancerous.
The larger the lesion and the higher the PSA
level, the more likely hypoechoic lesion will
be a cancer.
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Since the introduction of PSA screening, the
role of TRUS has been limited to aid in guided
needle biopsy.
Pre exam preparation may include:
 Cleansing enema
 Pre and post prophylactic antibiotics.
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The patient is placed in the left lateral
lithotomy or knee-elbow position.
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Lesion directed biopsy
 Biopsy based on a sonographic lesion is
infrequently used due its poor detection rate.
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Systematic Sextant Biopsy
 Hodge et al demonstrated that taking systematic
biopsies ( 3 on right and 3 on left) that the cancer
detection rate was superior to the lesion-directed
method.
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Parasagittal Sextant Biopsy
 To improve on the traditional sextant biopsy
method, urologist are including additional biopsy
cores in the lateral aspects of the peripheral zone.
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Staging is used to determine the type of
treatment for prostate cancer and is an
indicator of prognosis.
1. Clinically non-palpable
2. Palpable nodule confined to prostate
3. Palpable nodule extending through capsule
4. Metastases
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Treatment options include
 Watchful waiting
 Hormonal therapy
 Radiation treatment
 Cryotherapy: the use of extreme cold in surgery.
 surgery
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Permanent prostate brachytherapy (seed
implants) is a prostate cancer treatment that
uses ionizing radiation to destroy cancer cells.
The radioactive material is placed either directly
into a malignant tumor or very close to it, thus
the term brachytherapy, which means short
therapy in Greek. Radiation kills the tumor by
destroying the DNA within the cancer cell. When
the cancer cell attempts to divide and reproduce
itself, it is unable to do so because the DNA is no
longer intact and as a result, the prostate cancer
dies.
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BPH is an enlargement of the prostate that
occurs in the peri-urethral and transitional
zones of the gland.
Symptoms include:
 Difficult initiation of voiding
 Urinary frequency
 Small stream
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BPH is an enlargement of the inner gland
which is hypoechoic relative to the
peripheral zone.
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Prostate volume is utilize to determine PSA
density (volume adjusted PSA) and to better
determine the best method of treatment.
Prostate volume formula
 Volume =height x width x length x 0.52
Reason for determining prostate volume:
 Ultrasound Volume Estimation is the typical
procedure that doctors use to ascertain the size,
interpret the type and elevation of PSA levels.
This procedure will also be used after the doctor
has employed a course of anti-cancer treatment,
to determine if the course of action is effective
against the prostate cancer. The UVE can use
different techniques to determine volume,
ranging from planimetry measurements (crosssectional imagining across a plane of the
prostate) or based on its diameter.
Prostate homework
1.
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4.
Name the four zones of the prostate
What zone of the prostate is the source of
most prostate cancers?
What zone of the prostate is not affected by
cancer?
Describe Benign Prostatic Hyperplasia
(BPH).
Anatomical Spatial Relationships
5.The ejaculatory ducts pass through the
______________ and empties into the urethra.
6.Seminal vesicles are two sac-like out-pouchings of the
vas deferens situated adjacent to the __________
aspect of the prostate between the urinary bladder
and the rectum.
7.The base of the prostate id the ______________
portion of the gland.
8.The apex of the prostate is the _______________
portion of the gland.
9.The demarcation between the inner gland and the
outer gland is called the ___________.’
The prostate is situated in the
retroperitoneum and is bordered:
10.Anteriorly by the ____________
11.Posteriorly by the ____________
12.Superiorly by the ____________
13.Inferiorly by the ____________
14.Describe Prostate-Specific Antigen. (PSA)
15.When do PSA levels rise?