Post-Operative Radiation for Prostate Cancer

• Understanding the disease
• Treatment options
• Side effects of treatment

Stephen Shamp, MD MSEE

David Bloom, MD PhD

Matthew Culbert, MD

​

Understanding Prostate Cancer

Anatomy, Stage, PSA level, Gleason Score (pathology), Treatment Options and Side Effects

Prostate Stages

Laparoscopic Prostate Surgery

The surgeon tries to dissect the prostate away from the rectum, bladder, the neurovascular bundle (nerves) and penile urethra

the nerves that can results in impotence if cut are on the side of the gland

Post-Prostatectomy

• After prostatectomy your PSA should fall to be undetectable.
• If it becomes or stays detectable there may be residual prostate cancer cells.
• External beam radiation therapy is often used in this situation.
• If the location of these cells cannot be found on imaging they are most likely to be in the area of the prostate and/or lymph nodes

Composite MRI showing relapse sites at the anastomosis (red) or behind the bladder (green)

PostOp Radiation (after a previous radical prostatectomy)

bladder

rectum

pubic

Area of� recurrence

www.nccn.org

PSA Cure Rate after Salvage Radiation Based on Gleason Score

Gleason 2-6

Gleason 7

Gleason 8-10

Time in Months

Cure Rate Based on the PSA Level at the Time of the Radiation

Tendulkar JCO 2016;34:3648

Risk of Developing Metastases

Tendulkar JCO 2016;34:3648

CT simulation (planning session)

• We will build a cradle to hold you in the same position with each treatment.
• Temporary or permanent marks will be made
• CT images are obtained and then imported into the treatment planning computer
• You bladder should to be full and your rectum empty

At the time of the simulation a small rectal tube may be inserted into the rectum in order to remove a gas bubble if present. This may be done during treatment if needed

To get a good image, the bladder should be full and the bowels empty!

Using Vitalbeam with RapidArc IMRT and daily CBCT IGRT to tightly target the prostate with very little radiation hitting the bladder or rectum

Logistics of External Beam Radiation:

• Usually 33-39 daily treatments
• If hormone therapy (ADT) is recommended, you will often start this prior to radiation
• Treatment days are Monday-Friday 5 days per week, 6.5 to 8 weeks in total
• Daily treatment takes 15 minutes or less. You will be given a schedule
• You do not feel anything during treatment, you will not be radioactive, you are allowed to drive yourself to and from treatment if you are currently allowed to drive

• Lasers and daily CBCT imaging is used to precisely deliver the daily radiation treatment.
• Full bladder and empty rectum
• Expect to be on the treatment table less than 15 minutes.
• You will not feel any immediate effects.

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

Side Effects of Prostate Radiation

The structures that will get hit by radiation and have inflammation or irritation: bladder, urethra and rectum

Radiation

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Short Term Side Effects: Irritation of bladder, urethra and rectum

1. Urinary frequency or urgency (getting up at night very few hours, take NSAID’s, or may benefit from medication)
2. Slight burning or stinging with urination (drink cranberry juice)
3. Diarrhea or more frequent, softer bowel movements, rectal soreness (take Imodium)
4. Mild skin irritation is now rarely seen
5. Fatigue is common

Radiation

zone

Chronic radiation cystitis or proctitis: about 6% of the men will have occasional episodes of blood in the urine or with bowel movements, this usually responds to medication (e.g. cortisone suppositories) The risk of serious damage to the bladder and rectum is now less than 1%�Impotence: about 30% of men have problems after radiation with intact prostate, in men with previous prostatectomy this is much higher. Change in consistency of ejaculate and infertility is also common.

Very low risk of rare but serious complications including but not limited to secondary malignancy, ulcer, fistula

Long Term Side Effects: Irritation of bladder, urethra and rectum

Radiation

zone

• Follow-up: Your PSA will be monitored post treatment.
• Note that the PSA levels slowly decline after completing radiation.
• Maximum radiation effect on PSA can take 1-2 years