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Running Header: CASE STUDY OF RECURRENT
Case Study of Recurrent T2a N0 Prostate Cancer
Rob Cox-Vari
Argosy University- Twin Cities
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CASE STUDY OF RECURRENT
Case Study of Recurrent T2a N0 Prostate Cancer
The patient chosen for the case study was a 64 year old male, who for the purposes of
confidentiality will be called Joe. Joe came to the clinic with recurrent T2aN0 adenocarcinoma
of the prostate, meaning that the tumor had originally involved one-half of one lobe or less with
no local nodal involvement, and the tumor had returned. This case study documents the patient’s
journey from the initial consultation through the follow-up appointment one month after
completion of treatment, including prostate cancer natural history and other available treatment
options.
In July 2012 that patient was originally seen for elevated PSA, leading to a transrectal
ultrasound biopsy that showed adenocarcinoma, for which a radical retropubic prostatectomy
was performed in September 2012 with no concurrent radiation; however, included a regiment of
hormone therapy. A PET scan done 4 months later showed a possible right scapula lesion, but
the biopsy of the lesion was negative. Since the patient was experiencing pain in that region and
the radiation oncologist believed the region to be pre-cancerous, radiation treatment to the area
was given, involving 10 fractions with a total dose of 3000cGy.
A follow-up appointment was conducted in December 2013, where the Joe noted
increased nocturia, or waking up in the night repeatedly to urinate, and blood testing revealed
increased PSA of 4.0. A rectal exam, a procedure involving placing two lubricated fingers into
the rectum, was performed, noting a palpable mass with no blood in the sphincter. After the
Rectal exam was performed a CT was conducted along with a biopsy of the prostate bed and
seminal vesicle. The biopsies came back positive for adenocarcinoma and a Gleason score of 8
was assigned by the pathologist.
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The patient had no family history of cancer, does not smoke, only drinks occasional wine,
is on a vegan diet and regularly exercises. The patient does have hypothyroidism,
hyperlipidemia, GERD, sinus problems including a deviated septum, and had a basal cell cancer
removed on his left upper forehead by Moh’s surgery. The medications the patient was on at the
time of initial counsel included levothyroxine, simvastatin, Casodex and Trelstar.
After consulting with the patient, and considering the patient’s medical history, a plan for
treatment was developed. The patient was to continue the hormone therapy involving two drugs,
Casodex, an anti-androgen blocking the effects of testosterone in the body and Trelstar, a
medication that suppresses the body’s production of testosterone. Along with hormone therapy,
external beam radiation was utilized in the form of IMRT, requiring simulation and planning.
The first simulation was used to set the position of the patient. The patient was laying
supine with his head resting on a sponge pillow to support the head. His arms were placed on his
chest, where he held an O-ring for comfort and to keep the hands and elbows out of the treatment
fields. A vac-lock was then placed under the patient’s legs and air was removed from the device
to make a mold that would be important in reproducing the same position daily for treatment.
Once in position with the vac-lock in place, lasers were used to place temporary markers and
BB’s on the two greater trochanters for the lateral marks, and on the symphysis pubis for the AP
mark. Once the marks were placed, the CT scanner was ‘zeroed’ and the patient was moved
500cm in to the tube. An initial x-ray was utilized to check the field to be scanned and then the
CT was conducted that was then sent to dosimetry for planning. The patient was guided out the
CT machine and photographs were taken for the patient’s record.
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Planning the treatment began with contouring of the internal anatomy seen on the CT in
the simulation room, including small bowel, rectum, bladder, and femoral heads. The contouring
of the internal organs allows the planning program to keep track of dose to critical structures so
that the most sensitive organs can be avoided. Once the doctor drew on the GTV and PTV into
the CT, the maximum dosage parameters to the critical structures as well as dosage to the GTV
and PTV were inputted into the IMRT planning program. After about an hour of the program
optimizing, a plan was presented to the doctor for approval. The dose to the tumor was to be
7400 cGy, with 200 cGy to be delivered daily for 37 fractions at energy of 6MV, through the
utilization of 9 field IMRT with dynamic MLC. The 9 angles of treatment are PA, RPO-315,
RPO-280, RAO-250, RAO-220, LAO-140, LAO-110, LPO-80 and LPO-45. The plan was
approved by the doctor and the patient was called to setup the second simulation.
The second simulation occurs in the treatment room, and is called the “dry run”, meaning
no treatment; rather images are taken to verify patient position. The patient was positioned on
the treatment table in the same position as the initial CT simulation and two kV images were
taken to confirm proper patient alignment based on bony anatomy. After remarking the patient
and confirming the SSD’s, the patient was given permanent tattoos, two laterals and one AP, for
ease of preserving marks for positioning.
Daily treatment was completed on a Varian Clinac brand machine with the patient placed
in the vac-lock and positioned by aligning the 3 tattoos the patient received on the first day.
Once in position and the SSD checked, the OBI or on-board imaging arms were lowered and
CBCT or cone beam CT taken to localize the tumor and prostate bed. Once localized, the
treatment began, monitor units were checked at each angle and the treatment was conducted,
with the gantry manually being moved from angle to angle and the MLC dynamically moving
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while the beam was on. The system used was Mosaiq, so all of the information from treatment
automatically got recorded daily, including MU’s, total dose received daily and cumulative dose.
Every five days the SSD’s of the lateral and AP were taken to ensure no significant weight loss
or change in body habitus.
Over the entire course of the treatment the patient is seen weekly by the doctor to monitor
any changes in patient due to radiation. During the first three weeks, Joe experienced no side
effects or symptoms. Through weeks 4 and 5 the patient experienced mild urinary symptoms
that were treated with cranberry juice, and mild diarrhea which was treated with Imodium.
Week 6 saw no new side effects or symptoms and by week 7 the patient was experiencing an
increase in diarrhea that was treated by increasing the Imodium. The main symptom concerning
the doctor, fatigue, never materialized, most likely as a result of the patient’s active lifestyle.
One month after completion of treatment, the patient returned to have his follow-up
appointment. The patient did not experience any lingering side effects such as organmegaly
from treatment. The patient was instructed to continue with his hormone therapy of Casodex and
Treslstar.
The prostate is a male reproductive gland responsible for producing the alkaline fluid part
of the seminal fluid ejected during sexual intercourse. The prostate is located anterior the rectum
and inferior the bladder, surrounding the prosthetic urethra which is a tube that extends from the
inferior bladder to the tip of the penis and is the tube that drains fluid from the bladder and
semen out the penis (Kelley, 2013).
The most common type of prostate cancer is adenocarcinoma, developing most
commonly in the peripheral glands and having the potential to invade surrounding tissue such as
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the seminal vesicles, rectum or bladder. If left untreated prostate cancer has the potential to
metastasize to the regional lymph nodes; periprostatic and obturator nodes first then the external
iliac, hypogastric, common iliac and periaortic nodes then to bone located throughout the body
(Washington, 2010).
Prostate cancer is the number one malignancy in males in the United States, with 1 in 6
men developing the cancer and accounting for 65% of cancers in males ages 65 and older
(Washington, 2010). It is estimated that in the year 2014 that there will 233,000 new cases of
prostate cancer, and account for 29,480 deaths (National Cancer Institute, 2014). According to
the American Cancer Society, 1 in 36 men will die from prostate cancer, second behind lung
cancer; however, the majority of males diagnosed with prostate cancer will not die, as there are
2.5 million men that have been diagnosed that are alive. The relative 5-year survival rate is about
100% with the 10-year rate at almost 99% and the 15-year survival rate is 94%, for all stages of
cancer (American Cancer Society, 2014).
The cause of prostate cancer is unknown, but there are factors that have been
correlated with higher rates of incidence. The first risk factor is age, with only about 1 in 10,000
under the age of 40 being diagnosed, but the rate jumps dramatically when compared to the age
group of men ages 60 to 69, where the ratio goes to 1 in 14 (Prostate Cancer Foundation, 2014).
Another factor that can increase the risk of prostate cancer is family history. If a family member
has prostate cancer or there is a history of breast cancer, including BRCA1 and BRCA2 positive,
the individual is at higher risk of being diagnosed with prostate cancer. (Mayo Clinic, 2014).
Race can also be a major risk factor, as African Americans have a higher incidence rate and are
2.5 times more likely to die from the disease (Prostate Cancer Foundation, 2014). According to
the US National Library of Medicine, other risk factors include being exposed to Agent Orange,
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having a high fat diet, drinking excessive amounts of alcohol, working at a tire plant, painting for
a living, being a farmer, and cadmium exposure can increase the chances of getting prostate
cancer, but being a vegetarian can decrease the risk.
There are multiple methods utilized to detect, diagnose and stage prostate cancer.
The two most common means in detecting the presence of prostate cancer are a DRE or digital
rectal exam and a PSA or prostate-specific antigen blood test. The digital rectal exam is
performed by a physician wearing gloves, lubricating two fingers and inserting them into the
rectum to feel for any bumps or swelling of the prostate gland. A PSA blood test performed
looking for prostate-specific antigen that is found in low levels in blood, about 4 nanograms per
milliliter of blood, as having prostate cancer should increase these levels in the blood (American
Cancer Society, 2014). When a test comes back with an elevated PSA or a mass is palpated
during a DRE, a transrectal ultrasound guided biopsy is performed. The core of the biopsy is
then sent to a pathologist who evaluates the morphology and differentiation of the sample, giving
them both a score of 1 to 5 with both those scores added together to give the Gleason score
which is closely tied to prognosis (Washington, 2010). Other modalities for diagnosing and
staging of prostate cancer include the use of MRI, CT, and PET scans if it is believed to have
metastasized to other parts of the body.
In the event that a positive diagnosis is confirmed, a number of treatment options that are
available to patients with this disease outside the most common approaches of watchful waiting,
radical prostatectomy, hormonal therapy and external beam radiation. Another option available
to patients is internal radiation or brachytherapy, coming in two forms LDR, low-dose rate, and
HDR, high-dose rate.
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For the LDR setup, a patient is placed in the dorsal lithotomy position, where they are on
their back with their legs above their heads typically in stirrups for support. A template or grid is
pressed against the perineum, the region between the male anus and scrotum, and transrectal
sonography is used to guide about 25 needles into the prostate, where about 100 seeds are
permanently deposited about 1 cm apart. The most commonly used isotopes for treatment are I125, iodine, with a half-life of 60 days, and Pd-103, palladium, with a half-life of 17 days. The
typical dose delivered for treatment by iodine is 145Gy and the dose for palladium is 115Gy. The
planning is accomplished with the patient in the treatment room prior to insertion of the needles
with the use of ultra sound images and then verified after seeds are inserted by taking CT images
of seed placement which are recalculated to verify dose to the prostate. The seeds are
permanently implanted into the region and the dose is delivered slowly over time over the course
of many days or months (Washington, 2010).
HDR brachytherapy places the patient in the same position, dorsal lithotomy, and places
the template or grid against the perineum just like LDR. Rather than implanting permanent seeds
into the prostate, HDR utilizes the hollow tubes or catheters placed into the prostate via the use
of transrectal ultrasound for guidance. Once the tubes are placed within the region to be treated,
a CT scan is done to verify tube placement and measure length of catheter into the prostate. The
images are sent to dosimetry for planning, where the critical organs are contoured, rectum, small
bowel and bladder, and the dose is planned. An after loading device is used to guide the
radioactive source, usually Ir-192 or iridium 192, through the catheter into the prostate stopping
at certain locations based on planning and dose distribution required. This is an ‘in-patient’
procedure requiring the patient to be hospitalized for 2 days because they are not allowed to
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move or it would change dose to the organs and desired area. Typical dose to tumor bed is 3600
to 4000 cGy given over two days with treatments twice a day (Mondalek, 2008).
Another option available for treatment of prostate cancer is called cryosurgery or
cryotherapy, which involves freezing the tumor. The patient is given epidural anesthesia or
general anesthesia, and much like HDR brachytherapy hollow tubes are placed into the prostate,
using transrectal ultrasound for guidance. Once the tubes are placed, warm saltwater is circulated
through the urethra to prevent it from freezing, and cold gas is passed through the tubes creating
‘ice balls’ that destroy the prostate. Once the procedure is completed, the catheter placed is left
in the urethra for about 3 weeks to allow emptying of the bladder during recovery. (American
cancer Society, 2014)
One last form of treatment to discuss available to prostate cancer patients is called highintensity focused ultrasound, which is still in the experimental stages in the US but common
practice in the UK. It works in the opposite manner as cryosurgery, in that as cryosurgery cause
death to the tissue by freezing, high-intensity focused ultrasound heats the tissue to death. The
patient is placed under general anesthesia and then the probe is inserted into the rectum where
very high intensity ultrasound waves are aimed and delivered at the target. The ultrasound waves
vibrate and heat up the prostate cells killing them. The treatment can take up to 3 hours to
complete (Prostate Cancer UK, 2014).
Due to the patient’s medical history, and options available for treatment, the dual
modalities utilized were the best options for the patient. Brachytherapy of the prostate is best
when the prostate is present in the patient, and since Joe had his prostate removed, any seeds or
catheters have to chance to migrate around the prostate bed altering the dosage to tumor volume.
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Cryotherapy would not be an option since the patient already had his prostate and works best
when the tumor is present in the prostate. High-intensity focused ultrasound is still in the
experimental stage here in the United States, though is a common method in the United
Kingdom, so in order to get easy access to the treatment a trip to England would be necessary.
Plus cryosurgery and HIFU is often used as an alternative when radiation is not effective at
destroying the cancer. So as a result of previous prostatectomy, external radiation utilizing
IMRT combined with hormonal therapy was the best option for the patient to get the best results.
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References
American Cancer Society. (2014). Can prostate cancer be found early? at
http://www.cancer.org/cancer/prostatecancer/detailedguide/prostate-cancer-detection retrieved
5/24/2014
American Cancer Society. (2014). Cryosurgery for prostate cancer at
http://www.cancer.org/cancer/prostatecancer/detailedguide/prostate-cancer-treating-cryosurgery
retrieved on 5/24/2014
American Cancer Society. (2014). Survival rates for prostate cancer at
http://www.cancer.org/cancer/prostatecancer/detailedguide/prostate-cancer-survival-rates
retrieved 5/24/2014
Kelley, L.L. & Petersen, C.M. (2013). Sectional Anatomy for Imaging Professionals. St.
Louis, Missouri: Mosby-Elsevier
Mayoclinic. (2014). Diseases and Conditions- Prostate Cancer at
http://mayoclinic.org/diseases-conditions/prostate-cancer/basics/causes/con-20021597 retrieved
on 5/23/2014
Mondalek, P.M. (2010). Review of Prostate Brachytherapy: LDR and HDR at
http://www.medicaldosimetry.org/pub/397b5a7d-2354-d714-516a-27fb07acdedd retrieved on
5/25/2014
National Cancer Institue. (2014). Prostate Cancer at
http://cancer.gov/cancertopics/types/prostate retrieved on 5/23/2014
CASE STUDY OF RECURRENT
Prostate Cancer Foundation. (2014). Prostate Cancer Risk Factors at
http://www.pcf.org/site/c.leJRIROrEpH/b.5802027/k.D271/Prostate_Cancer_Risk_Factors.htm
retrieved on 5/23/2014
Prostate Cancer UK. (2014). High-Intensity Focused Ultrasound at
http://prostatecanceruk.org/information/prostate-cancer/treatment/treatment-choices/hifu
retrieved on 5/24/2014
U.S. National Library of Medicine. (2014). Prostate Cancer at
http://ncbi.nlm.nih.gov/pubhealth/PMH00148/ retrieved on 5/23/2014
Washington, C.M. & Leaver, D. (2010). Principles and Practice of Radiation Therapy.
St. Loius, Missouri: Mosby-Elsevier.
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