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understanding and treating prostate cancer
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Prostate Cancer
Understanding the disease Treatment options Side effects of treatment
Understanding prostate cancer
Anatomy Importance of Stage Importance of the Gleason Score Significance of the PSA
The prostate gland has a capsule around it, and cancers arise close to the capsule
Prostate Anatomy…the nerves that can results in impotence are on the side of the gland
There are lymph nodes that may be involved
CT scans and MRI demonstrate the anatomy of the prostate well
Prostate CT Anatomy
Prostate
rectum
bladder
Cross section anatomy of the male pelvis
Cross section anatomy of the male pelvis
Bladder
Prostate
Rectum
Prostate CT Anatomy
CT Scan = large prostate cancer
MRI showing Cancer Nodule
Prostate Stages
T1c = too small to feel and biopsied because of an
elevated PSA
T2 lesion = big enough to feel
T3 if spread to the seminal vesicles
Stage IV if spread to the lymph nodes or bone
Prostate Cancer Cure Rate After Radical Prostatectomy Based on Pathologic Stage
Prostate Cancer Cure Rate After Radical Prostatectomy Based on PSA Prior to Surgery
PSA (prostate specific antigen) and radiation results
PSA LevelRelapsed after
Radiation
0.1 to 4 4%
4 to 10 7%
10 to 20 22%
20 - 50 48%
over 50 67%
Note that the PSA levels slowly decline after completing radiation
Note that the PSA levels slowly decline after completing radiation
Prostate Cancer Cure Rate After Radical Prostatectomy Based on Pathologic Grade (i.e. how mutated the cancer cells appear)
Gleason Scoring System
From the biopsy, the pathologist grades the appearance of the cells. From least serious (slow growing or Grade 1) to the fastest growing and most dangerous or grade 5).
The Gleason score doubles the scoreSo the slowest is a 2 and thefastest is a 10.
50
55
60
65
70
75
80
85
90
95
6 7 8
5 Year Cure Rate
10 Year Cure Rate
The higher the Gleason Score, the lower the cure rates after surgery
Gleason Score
60
65
70
75
80
85
90
95
3+3 3+4 4+4 4+5 5+5
5 year cure rate radiation
radiation plus hormones
The higher the Gleason Score, the lower the cure rates after radiation
Gleason Score
Prostate Cancer Risk Groups
•Low risk: (T1c, T2a Gleason 6, PSA <10)
•Intermediate risk: (T2b, T2c, Gleason 7, PSA 10-20)
•High risk: (T3, Gleason 8-10 or PSA > 20)
What is considered the proper treatment for prostate cancer?
•Advice from the AUA (American Urologic Association)
•Advice from the NCCN (National Comprehensive Cancer Network)
Treating prostate cancer
Surgery?
Radiation?
American Urologic Association (AUA) came out with new treatment guidelines for prostate cancer in 2007
AUA: results the same for all three treatment modalities
PSA Cure Rates
Seeds External Surgery
Low risk
Intermediate
High
RT = radiation therapy. IMRT = intensity modulated radiation therapy, IGRT = image guided RT e.g. Tomotherapy Brachytherapy = seeds
RT = radiation therapy. IMRT = intensity modulated radiation therapy Brachytherapy = seeds
Androgen deprivation therapy = Lupron or Zoladex shots
Cure Rates with Radiation versus Surgery for Early Stage Prostate Cancer are the same
from the Cleveland Clinic. Kupelian. JCO Aug 15 2002: 3376-3385
CT scan is obtained at this time
CT images are then imported into the treatment planning computer
In the simulation process the CT and PET scan images are used to create a computer plan
The CT scan images are then converted into a 3 dimensional view inside the patient
You can actually see inside the man’s body and locate the key organs
IMRT
Identify organs and tumor target
prostate
rectum
bladder
bladder
Radiation zone
prostate
rectum
Goal = radiation zone precisely around the prostate cancer
IMRT using 7 different beams to target the prostate
The computer can determine the optimal number of beams to deliver the radiation dose to hit the target and avoid other structures
IMRT
Intensity modulated radiation therapy
The computer then can generate different techniques of delivering the radiation
IMRT
Computer will determine the optimal number of beams and beam angles
IMRT
The cross sectional CT will show the dose clouds that surround the prostate and how close they are to other vital structures like the bladder or rectum
bladder
prostate
rectum
IMRT
The cross sectional image reconstruction of beams and targets
IMRT
The radiation dose clouds that surround the target
bladder
prostate
rectum
The computer identifies targets and using IMRT techniques applies low doses to some structures (like lymph nodes) and high doses to the main target (prostate)
Even if the prostate has been removed radiation can be used to target the prostate bed (Tomo)
In the treatment the lasers are used to line up the beam and the patient receives the radiation treatment
Combine a CT scan and linear accelerator to ultimate in targeting (IGRT) and ultimate in delivery (dynamic, helical IMRT) ability to daily adjust the beam (ART or adaptive radiotherapy)
With Tomotherapy the beam can hit the target (nodes) in the upper abdomen and avoid the bladder and small intestine and lower in the pelvis hit the prostate, nodes and seminal vesicles and still avoid the bladder and rectum
With daily image guided with a CT using Tomotherapy, radiation field can be very tight (‘close’) around prostate
Significant movement of the prostate gland based on daily gas in rectum
Planned target
Rectal gas
No Rectal gas
Planned target, missed badly if rectal gas pushes the prostate forward
Significant movement of the prostate gland based on daily gas in rectum
Initial computer target for prostate (red circle) would have badly missed the target if no adjustments were made based on the amount of rectal gas
Importance of daily CT targeting on Tomotherapyand adjusting the treatment daily
Very little bowel gas on initial study and the dose (red) targets the prostate gland closely
large bowel gas on later treatment day and the dose (red) will cover half the rectum if an adjustment is Not made
If no adjustment was made
Actual treatment on Tomotherapy
Tomotherapy is particularly useful in men with hip replacements
Tampa Bay Cyberknife Center
Cyberknife Radiosurgery
With cyberknife you can use multiple beams from any direction
CyberKnife
Multiple beamlets of radiation striking the prostate
bladder
prostate
rectum
Radiation doses are conformed very closely or tightly to prostate avoiding the rectum and bladder
Seed Implants
Prostate Seed Implants
Prostate Seed Implants
Rectal ultrasound used to image the prostate
A grid or template with holes every 5mm are used to line up the needles
The needles are distributed
The Mick ‘Gun’ is used to push the radioactive seeds into the gland
The seeds are left behind, distributed through the gland and slowly radiate the cancer
CT scans of the prostate will show the seeds and the studies will be used to calculate the radiation dose
Side Effects of Prostate Radiation
Is related to the size and area of normal structures that are over lapped by the radiation zone…the goal is to keep the radiation zone as small as possible
Side Effects of Prostate Radiation
With IMRT and image guided techniques the goal is to shape the radiation zone very precisely , based on the type of cancer (high Gleason might require a larger margin around the gland)
Side Effects of Prostate Radiation
The structures that will get radiation irritation: bladder, urethra and rectum
Radiationzone
Irritation of bladder, urethra and rectum
Radiationzone
1. Urinary frequency (getting up at night very few hours)
2. Slight burning or stinging with urination
3. Diarrhea or more frequent, softer bowel movements, rectal soreness
4. Mild skin irritation
5. Fatigue
Long Term Side Effects of Radiation
Typical Radiation Protocols for Low Risk
•Daily external beam radiation, Monday through Friday for ~ 8weeks
•Seeds (one time)
•Combination: 5 weeks or external radiation then 3-5 weeks later a seed implant
Typical Radiation Protocols for More Advanced Risk Group
•May start with hormonal therapy (e.g. Zoladex or Lupron) for several months prior to starting radiation
•May need to continue on hormone therapy for up to 2 to 3 years
Radiation prescription for #
Diagnosis: #
Hormones: #
Seeds: #
External radiation: #