Download Case Study Using Stereotactic Radiosurgery to Treat Stage I Renal

Running head: STEROTACTIC RADIOSURGERY TO TREAT KIDNEY CANCER
Case Study Using Stereotactic Radiosurgery to Treat Stage I Renal Cell Carcinoma
Sara M. Engh
Argosy University-Twin Cities
January 2016
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Case Study Using Stereotactic Radiosurgery to Treat Stage I Renal Cell Carcinoma
A patient with a diagnosed renal cell carcinoma mass was followed through all stages of
treatment including the initial consultation, surgery, CT simulation, treatment planning,
CyberKnife stereotactic radiosurgery, and weekly doctor visit. His health history, diagnosis, and
treatment will be discussed in the background information portion, followed by research on the
disease, and then finished with an analysis of the treatment plan.
I. Background information
I am currently completing my clinical training at University Hospitals Case Medical
Center in Cleveland, Ohio. Luckily, it has so much to offer from high-technology equipment
such as GammaKnife, Cyberknife, and a soon to be Proton Therapy Center, to cutting-edge
research, and nationally recognized physicians. I was fortunate to be able to follow and learn
from the head physician of our Radiation Oncology department by sitting in on a consult with a
new patient. The patient was a 72-year-old Caucasian male with a fairly extensive medical
history who came to see this physician for a renal mass which originally appeared on a PET scan
a year earlier. A recent scan had shown that the mass had progressed over that time. There were
not any other presenting signs or symptoms in regards to the renal mass other than what appeared
on imaging. He has a history of non-small cell lung cancer with a T4N2M0 mass that was
previously treated with chemotherapy and radiation therapy. It responded well and there is
currently no evidence of that disease. Additionally, the patient has COPD, a family history of
colon cancer and prostate cancer, poor cardiac status because of hypertension, depression,
glaucoma, arthritis, a broken shoulder, and a bullet to his leg. Because of the COPD, he is
oxygen dependent at night and is prescribed ProAir inhaler. He was also a former smoker who
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smoked 1-pack per day for 55 years but stopped after his diagnosis with lung cancer in 2013.
Another aspect of this patients’ history that I am curious if it had any contribution to either
cancer diagnosis is his previous work history of being a tool and dye maker. I imagine both of
these professions could produce harmful exhausts in the air, and given the patients age, it is
possible that proper precautions were not taken that many years ago. During the consultation, a
physical examination was done which indicated poor lung function, possibly worsened by
previous radiation. He gets short of breath, however, he is in fair physical condition for his age
and stays moderately active.
The renal mass is located on the left inferior pole of the kidney which was consistent with
renal cell carcinoma. When it was originally found it was 3 centimeters in size, according to
imaging, but when it was re-imaged later it had grown to just over 4 centimeters. Because of the
growth, there was a more urgent need to treat the mass. The physician ordered an image guided
biopsy to be performed to confirm the histology of the mass to assure that it is a renal cell
carcinoma and not a metastatic mass from the patients previously diagnosed non-small cell lung
cancer. At the same time, gold fiducial markers placed to aid in treatment positioning.
This is a particularly interesting case because the physician discussed treating the patient
using a clinical trial that he is one of the principle investigators on. The case is CASE-12806,
Evaluation of a Radiosurgical Approach for the Treatment of Kidney Tumors in Poor Surgical
Candidates (University Hospitals of Cleveland, 2014). The physician was telling me that they are
one of the only centers, besides Harvard, doing research on treating renal masses using
CyberKnife. As the title indicates, the study focuses on patients who are not great surgical
candidates, which this patient is not because of his poor lung and heart function. CyberKnife is a
type of stereotactic radiosurgery which delivers a high dose of radiation through a pinpoint beam
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with a very high level of accuracy and sparing of normal, healthy tissue. As the physician
explained during the consultation, there are usually around 120 different angles that the beam
comes in at to paint over the tumor. He said to imagine an invisible bowl parallel to the floor
over the patient and the machine can move to to get an infinite amount of angles to reach the
tumor, it just cannot be treated from underneath because of the limitations of the machine design.
However, even though so many angles are available the treatment length must also be
considered. This treatment modality is perfect for the location and size of the tumor because it
does not require much dose to go through the healthy portions of the kidney and it is not near any
other critical structures. It is also important to note that before this patient could continue with
treatment that he had to be deemed eligible for the clinical trial through the Case Cancer
Institutional Review Board and that the pathology confirmed renal cell carcinoma. Eligibility
requirements for this trial include that the patient is a poor surgical candidate, is at least 18 years
of age, is able to make his or her own medical decisions, does not have any prior radiation in the
treatment field, is not pregnant, has a confirmed diagnosis of a renal tumor, and a Karnofsky
status of greater than 60%. A patient can be deemed ineligible if they do not meet any of the
listed requirements, as well as, if they have an active connective tissue disease, Crohn’s disease
or active ulcerative colitis, or a major psychiatric illness that could interfere with treatment or
follow-up. Even after a patient is approved for the trial they still have to get required imaging
done which includes both a CT and MRI of both the chest and abdomen and then have multiple
image guided needle biopsies of the tumor done. At the time of the biopsies the surgeon also
placed gold fiducial markers inside the tumor. The fiducials are used for treatment planning, to
help monitor movement during treatment, and to confirm the location of the treatment area.
Treatment planning begins about 7-10 days after the fiducials are placed and it starts with a CT
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simulation. They have this waiting period in case the fiducials move a little after placement.
Likewise, they do not want to have too long of a waiting period that they move too much so this
is a very crucial and delicate stage of the treatment planning process.
The patient was approved by the board for the clinical trial and was brought in to have his
biopsy and fiducial placement. Everything went according to plan and tissue samples were
obtained. A few day slater the pathology report came back and confirmed that the mass was in
fact renal cell carcinoma.
Since the lesion is 4 centimeters in diameter, contained to the kidney, is not invasive, of
spread to lymph nodes it is considered stage I (T1a, N0, M0). He was brought in for a treatment
planning CT simulation, which is the same one used for our external beam radiation therapy
(EBRT) located in the Radiation Oncology department. I mention this because it is across the
hospital from where the old Radiation Oncology department is and where the CyberKnife is
located. During the CT simulation, the patient was positioned supine, with a pillow under his
head, arms on chest, a knee sponge under knees, and a very long Vac-Lok bag called a BodyFIX
bag which was placed under his entire body and the other immobilization devices. Additionally,
he was wearing a Synchrony vest, which is a tight black vest that zips down the back and has
long Velcro strips down the front. This vest is used for most CyberKnife cases to track the
patient’s respiration and synchronize the beam accordingly. The CT simulation was performed
with contrast, with a scan range that began midway through the lungs and extended all the way
through the pelvis. One scan was free breathing, the second had the patient hold their breath on
inspiration, and another had him hold his breath on expiration. The physician also requested a 4D
scan which shows how much the patients breathing moves the tumor and the surrounding
anatomy. It is a much slower scan and gives the patient more dose so the scan range is shortened
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to minimize extra dose to the patient. The scan with the contrast showed the kidney’s nicely lit
up, which means we timed the scan very well. After the CT simulation, the patient had to go
upstairs for an MRI, and unfortunately, he had to wait a long time and was getting a little
restless.
For treatment planning, one the physicist fused the CT and MRI scans together.
Disappointingly, I was unable to be present for the treatment planning portion because of the
school schedule, however, I made sure to have a conversation with the physicist and physician
who made the plan. The patient was prescribed three fractions of 1,800cGy for a total dose of
5,400cGy to be administered every other day using 6MV energy and fiducial tracking. The plan
was prescribed to the 74% isodose line, uses 151 beams, a variety of Iris sizes, and delivers about
50-300 monitor units per beam. The plan had to conform to RTOG standards for normal tissue
limits which included constraints for the bowel, spinal cord, stomach, liver, and contralateral
kidney.
On the day of treatment, the patient had to first see the nurse to get vitals. He was then
brought into the treatment room and set up exactly how he was during his CT simulation, except
that we wrapped an strap around his thorax, arms, and table. Also, sensors were attached to the
Velcro on his Synchrony vest and he was hooked up to a pulse oximeter to monitor his vitals.
Once we were out in the control room, a series of scans were done and his spine and fiducials
were aligned by moving the table top. Unlike a linear accelerator table top, the CyberKnife table
can tilt in either direction. Once everything was aligned, the physicist and physician signed off
and the treatment began. In total, the treatment took about an hour and a half. He did very well,
in fact, he fell asleep for the last portion of treatment and held very still the entire time. After
treatment, the nurse saw him again and had no complaints except for experiencing minor fatigue.
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He said he felt good otherwise and took naps as needed. Some side effects that could be
experienced with this treatment include nausea, diarrhea, fatigue, and weight loss. However, the
physician was not surprised he was not experiencing much in terms of side effects because the
tumor was in an ideal location on the kidney where it was away from other organs. He was able
to spare normal, healthy tissue because of this.
II. Research
According to the American Cancer Society (2016), kidney cancer is one of the top ten
cancers in both men and women, however, men are more at risk. To understand kidney cancer,
knowing the basic anatomy and function of the urinary system is important. This system includes
the kidneys, bladder, ureters, and urethra. Essentially, the job of the kidneys is to filter the blood
in order to eliminate waste and excess fluid from the body by producing urine. The other organs
in the system work to store and eliminate that urine from the body. The kidneys are bean-shaped
organs located posteriorly and laterally within the abdomen. Each kidney is located on opposite
sides of the spine near the bottom of the thoracic vertebrae and the beginning of the lumbar
vertebrae. Attached to the renal pelvis are the ureters that carry the urine produced in the kidneys
to the bladder to be stored until it can be eliminated. The urine passes through the urethra before
it exits the body. Understanding the functioning of the kidneys is also important because it is
comprised of many components. Each one of the kidneys is made up of a renal medulla, renal
cortex, renal pelvis. The renal cortex is the outer portion of the kidney and contains almost a
million functioning units called nephrons whose job is to each filter a small amount of blood
blood (The National Institute of Diabetes and Digestive and Kidney Diseases, 2014). Then each
one of those nephrons is broken up into two parts, the glomerulus and tubule. The glomerulus is
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the filter and it allows the waste and excess fluid to pass but keeps the larger molecules like
blood cells and proteins in the circulatory system. Then the tubules then send the filtered fluid
on. The renal medulla is the inner portion of the kidney and contains renal pyramids which are
part of the collecting system. Lastly, is the renal pelvis which is the renal hilum. It is where the
blood vessels, nerves, and ureters are attached to the kidney and allow the urine to be transported
to the bladder and blood to enter and exit the filtration process.
The American Cancer Society (2016) estimated that there would be 61,560 new cases of
kidney cancer in the United States in 2015 and around 60% of those cases would be men.
Additionally, they estimated that 14,080 people will die as a result of their diagnosis during that
year. Renal cell carcinoma is rarely diagnosed in people younger than 45 years old, the mean age
is 64 years old. Despite having an older mean age, it is actually in the top ten most common
cancers for both men and woman. Again, the American Cancer Society (2016) says that both
men and woman have a lifetime risk of 1 in 63 of developing kidney cancer, although men have
a slightly higher incidence rate. Some epidemiologic factors that increase one’s risk of
developing kidney cancer are smoking, obesity, high blood pressure, a family history of the
disease, certain medications, possible workplace exposures to certain herbicides and metals, and
other disorders or syndromes such as von Hippel-Lindau disease or Birt-Hogg-Dube (BHD)
syndrome.
Tumors on the kidneys can easily go unnoticed due to their location deep inside the body
and the fact that they do not cause many signs or symptoms to appear until they are of a
significant size. However, some signs and symptoms that may appear include hematuria, low
black pain limited to one side, a palpable mass on the lower back or side of abdomen, fatigue,
loss of appetite, unintentional weight loss, anemia, and a persistent fever. Many times a renal
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mass is found accidently like the patient in my case study, where it was found on imaging that
was done for his previous lung cancer. There are many diagnostic tools used to determine if
someone has kidney cancer and it starts with a physical exam and complete health history, a
series of lab tests, and a urinalysis. Different types of imaging can also be done, such as an
ultrasound, intravenous pyelogram, and a CT, PET and/or MRI scan. Lastly, a biopsy is
performed to confirm the pathological characteristics of the mass and determine if it is benign or
malignant.
Renal cell carcinoma (RCC) is the most common type of kidney cancer, with the subtype
called clear cell renal carcinoma being the most prevalent (National Cancer Institute, 2015). This
type of cancer arises in the renal cortex where the cancerous tumors most commonly form. Other
examples of different types of kidney cancer include transitional cell carcinoma which develops
from the lining of the renal pelvis and look similar to cancer that arises in the bladder,
nephroblastoma, also known as Wilms tumor, is a kidney cancer most common in children, and
renal sarcoma which arises from either the blood vessels or connective tissue of the kidney.
Tumors are also prone to spreading either locally or distantly to other areas in the body
and renal cell carcinoma is no exception. This type of tumor can spread locally through the renal
capsule, directly extend through the renal vein or the inferior vena cava, or through the blood and
lymph nodes. The routes of lymphatic spread include the renal hilar, paraortic, and paracaval
nodes. In some cases, these nodes will be removed during surgery along with the mass to avoid
further spread. About 50% of patients will eventually develop metastases to the lungs, soft tissue,
bone, liver, central nervous system, and cutaneous areas (Washington & Leaver, 2010).
There are many treatment options for RCC but the most common is to have a
nephrectomy which removes part or all of the affected kidney. This is the preferred method of
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treatment, however if the patient is not a great surgical candidate there are other options being
explored through clinical trials. These include the use of stereotactic body radiation therapy
(SBRT) and CyberKnife which both use very high energy and precise photons, cryotherapy
which essentially freezes and kills the mass, and an immunotherapy drug called Nivolumab.
Both external beam radiation therapy and chemotherapy are not very effective in treating kidney
cancer and traditional radiation may only be used for palliation. Each treatment has their benefits
and limitations so the medical oncologist has to take many different factors into consideration
such as the size and location of the mass, the condition of the patient, and the extent and
aggressiveness of the disease.
III. Analysis
The case study patient is a perfect example of treating RCC without surgery. He was not a
good surgical candidate because of his poor heart and lung function and his tumor was too large
to use cryotherapy because it is not effective with tumors over 3 centimeters in diameter.
Because of these restraints, it was decided that CyberKnife was the best option and luckily, he
qualified for the clinical trial that his radiation oncologist spearheaded which is sponsored by
University Hospitals of Cleveland. According to this radiation oncologist, there is only one other
clinical trial in the entire country that is looking at how to alternatively treat patients with renal
masses with CyberKnife who are poor surgical candidates. There is no question in my mind that
this course of treatment is what is best for the patient and thankfully he has these amazing
resources available to him. Any other course of treatment would not have been a good fit for him
because of the qualities of his tumor, with an exception of SBRT. However, CyberKnife is much
more precise because it is able to move with the patients breathing and the beam has the ability
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to come in at many more angles which allows for greater sparing of healthy tissue. As for the
immunotherapy clinical trial that uses Nivolumab, the patient must receive a nephrectomy
afterwards so he would not have qualitied for that protocol either. I discussed this with other
therapists but they did not know much about these treatment options and how they relate to RCC
however I was witness to a conversation the radiation oncologist had with one of the residents
who also acknowledged that this is the best course of treatment for the patient.
To conclude, I believe this patient received the best care he possibly could have. Based
on his health status, features of his tumor, and diagnosis there were very limited treatment
options. His outstanding physician was able to provide him with an option that was highly
technical and precise, that minimally effected healthy tissue, was non-invasive, and that was
effective in killing cancerous cells. The technology and research that is available at this
institution gave him the opportunity for a superior treatment that will hopefully allow him to live
a long and healthy life.
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References
Boundless (2016). Boundless Anatomy and Physiology. Retrieved from
https://www.boundless.com/physiology/textbooks/boundless-anatomy-and-physiologytextbook/the-urinary-system-25/the-kidneys-239/internal-anatomy-of-the-kidneys-11684690/
Kidney Cancer (Adult) - Renal Cell Carcinoma. (2016). In American Cancer Society. Retrieved
January, 2016, from http://www.cancer.org/cancer/kidneycancer/detailedguide/index
Nivolumab Cancer Treatment Drug. (2013). In Nivolumab. Retrieved January 5, 2016, from
http://www.nivolumab.co
Renal Cell Cancer Treatment. (2015, July 7). In National Cancer Institute. Retrieved January 10,
2016, from http://www.cancer.gov/types/kidney/patient/kidney-treatment-pdq
The Kidneys and How They Work. (2014, May). In The National Institute of Diabetes and
Digestive and Kidney Diseases. Retrieved January 10, 2016, from
http://www.niddk.nih.gov/health-information/health-topics/Anatomy/kidneys-how-theywork/Pages/anatomy.aspx
Washington, C. M., & Leaver, D. (2010). Principles and Practice of Radiation Therapy (3rd ed.,
pp. 854-861). St. Louis, MO: Mosby, Inc.