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Radiotherapy for Prostate Cancer
This document discusses radiation therapy options for prostate cancer. It notes that treatment depends on risk level: low risk may receive external beam radiation or seeds alone, intermediate risk should receive some external beam, and high risk should receive hormone therapy plus radiation. Newer techniques like IMRT and IGRT reduce side effects by more precisely targeting the prostate. Side effects of radiation include short term issues like urinary frequency and diarrhea as well as long term risks like radiation cystitis and impotence in some cases.
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Radiotherapy for Prostate Cancer
- 1. Radiation Therapy forProstate Cancer Robert Miller MD www.aboutcancer.com
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- 4. Prostate Guidelines 1. Lowrisk of extracapsular spread, then external beam or seeds alone 2. Intermediate risk then some (or all) of the radiation should be by external 3. High risk then hormone therapy should be added to the radiation 4. External beam should be daily image guided intensity modulated (IGRT) 5. Need high dose radiation (75 to 81 Gy)
- 5. The prostate gland hasa capsule around it, and cancers arise close to the capsule, the cancer may invade through the capsule
- 6. Age: 67 /Stage T1c / Gleason 6 / PSA 5 = 27.6% risk of extracapsular spread Age: 67, Stage T2b, Gleason 7/ PSA 12 = 86.2% risk of extracapsular spread
- 7. Laparoscopic Prostate Surgery The surgeon tries to dissect the prostate away from the rectum, bladder, the neurovascular bundle (nerves) and penile urethra
- 8. Radiation Fields withProstate Cancer A Low Dose Large Area (Phase 1) With radiation it is possible to include a wider area around the prostate to cover any cells that may have escaped After the highest safe dose is reached, the radiation target will be made smaller
- 9. Radiation Fields withProstate Cancer A High Dose Large Area (Phase 2) The final, high dose radiation target will be focused very precisely only on the prostate gland
- 10. Prostate Cures Ratesby Treatment and Dose External beam > 72Gy Surgery or Seeds External beam < 72Gy IJROBP 2004; 58:25 Months
- 11. Prostate Cancer RelapseRate by Radiation Dose < 72Gy 72 - 82Gy 82Gy Years Kupelian. IJROBP 2008:71:16
- 12. Salvage (postOp) radiationworks best if the radiation dose is high
- 13. Survival Hormone Therapy plus Radiation by Gleason Score 95 5 year cure rate radiation radiation plus hormones 90 85 80 75 70 65 60 3+3 3+4 4+4 4+5 5+5 Gleason Score
- 14. Cure Rates forHigh Risk Prostate Cancer Hormones + External + Seeds Surgery Seeds alone IJROBP 2006;66:1092 Months
- 15. 10 Year CureRates for Patients with High Risk Prostate Cancer (PSA >20 or Gleason 8-10 or T3) Treatment Number Cure Rate Radical 1,238 92% Prostatectomy Radiation plus 344 92% Hormones Radiation 265 88% Mayo Clinic Study (Cancer Jan 10, 2011)
- 16. Typical PSA Declineafter External Beam Months Since Completing Radiation
- 17. Declining PSA Levelsafter Seed Implant PSA bounce Years
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- 19. CT scan isobtained at the time of the Simulation Fiducials may be inserted before this step. CT images are then imported into the treatment planning computer
- 20. Goal = radiationzone precisely around the prostate cancer with small margin bladder prostate Radiation zone rectum
- 21. IMRT (intensity modulated radiation therapy) 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
- 22. After IMRT wasestablished then IGRT (image guided) was introduced
- 23. Lower Risk ofSide Effects with Image Guided IMRT compared to IMRT
- 24. Better Cure Rateswith Image Guided IMRT compared to IMRT for Prostate Intermediate Risk High Risk
- 25. The most sophisticatedtechnique for image guided IMRT is Tomotherapy. 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)
- 26. There is significantmovement of the prostate gland based on daily gas in rectum Planned target No Rectal gas Planned target, missed badly if rectal gas pushes the prostate Rectal gas forward
- 27. Significant movement ofthe 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
- 28. Importance of dailyCT targeting on Tomotherapy and 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
- 29. If no adjustment was made Actual treatmenton Tomotherapy
- 30. Using Tomotherapy totightly target the prostate with very little radiation hitting the bladder or rectum
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- 34. Non Isocentric Deliverywith CK Beams
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- 36. SBRT Prostate Cancer/ Naples-Tampa Experience Feb 2005 – Apr 2008 (Naples, FL) • 164 monotherapy, 35 Gy • 168 monotherapy, 36.25 Gy • 59 EBRT + CK boost Jul 2008 – Dec 2011 (Tampa, FL) • 121 monotherapy, 36.25 Gy • 10 monotherapy, 38 GY • 12 EBRT + CK boost
- 37. PSA Response toCyberKnife Mean PSAi 6.8ng/ml Mean PSAp 0.78ng/ml 97% biochemical control at 30 months median follow-up
- 38. Cure Rate afterCyberknife N = 515, Alan Katz in New York
- 39. PSA Response afterCyberknife Follow-up median 54 months (range, 7 - 78) 7 Median PSA 6 35 Gy 36.25 Gy – 36 m 0.20 ng/ml 5 – 60 m 0.10 ng/ml PSA ng/ml 4 3 By 48 months 2 – 290 of 329 pts 1 PSA < 0.5 0 0 12 24 36 48 60 72 Months
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- 41. A grid ortemplate with holes every 5mm are used to line up the needles
- 42. The needles aredistributed
- 43. The Mick ‘Gun’is used to push the radioactive seeds into the gland
- 44. The seeds areleft behind, distributed through the gland and slowly radiate the cancer
- 45. CT scans ofthe prostate will show the seeds and the studies will be used to calculate the radiation dose
- 46. Side Effects ofProstate Radiation
- 47. Side Effects of ProstateRadiation 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
- 48. Side Effects ofProstate 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)
- 49. Side Effects ofProstate Radiation Radiation zone The structures that will get hit by radiation and have inflammation or irritation: bladder, urethra and rectum
- 50. Radiation zone Short Term Side Effects: Irritation of bladder, urethra and rectum 1. Urinary frequency (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
- 51. Radiation zone Long Term Side Effects: Irritation of bladder, urethra and rectum 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 (see the next slides)
- 52. GETUG Dose Trialfor Prostate Cancer, Long Term Side Effects Score 70Gy 80Gy GI grade 3 1.9% 5.9% GU grade 3,4 2.6% 1.9% IJROBP 2011:80;1056
- 53. Long Term SideEffects from MD Anderson Dose Trial Grade 70Gy 80Gy GI grade 2 13% 26% GI grade 3 1% 7% GU grade 2 8% 13% GU grade 3 5% 4% IJROBP 2008:70:67
- 54. Long Term SideEffects in 9 Trials of SBRT for Prostate Cancer Grade Percent GI Grade 3 0 – 7% GI Grade 4 0 – 1.5% GU Grade 3 1.6 – 13% GU Grade 4 0% IJROBP 2012:82:877
- 55. Quality of Life/ Medicare Survey Prostate Cancer Patients Symptom Surgery Radiation Wear Pads 30% 7% Potent (< 70y) 11% 33% Potent (>70y) 12% 27% More frequent bowel 3% 10% movements J Clin Oncol 14 (8): 2258-65, 1996
- 56. Potency Rates afterProstate Cancer Treatment Treatment Probability Range Seeds 80% 64 – 96% Seeds + External 69% 51 – 86% External 68% 51 – 95% Radical Prostatectomy Nerve Sparing 22% 0 – 53% Standard 16% 0 – 37% Cryotherapy 11% 0 - 53% IJROBP
- 57. Potency Results afterExternal Radiation can range from 16% to 92% Did they get hormone therapy along with the radiation? How high was the PSA prior to radiation? How good was their sexual function before?
- 58. Potency Results afterExternal Radiation can range from 16% to 92%
- 59. Potency Results afterSeeds can range from 6% to 98% Patient Age? Race? Obese or thin? How good was their sexual function before?
- 60. Potency Results afterSeeds range from 6% to 98%
- 61. Responded to Viagra Surgery: 60% External Radiation: 63% Seeds: 85% JAMA 2011:306:1205
- 62. Responded to Viagra Surgery: 43% Radiation: 70 – 91% General Population: 80% from other studies in the literature
- 63. Understanding Prostate Cancer Robert Miller MD www.aboutcancer.com