Radiation Therapy in Prostate Cancer Current Status and New Advances

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1 Radiation Therapy in Prostate Cancer Current Status and New Advances Arno J. Mundt MD Professor and Chairman Dept Radiation Oncology Moores Cancer Center UCSD

2 Presentation Welcome Overview of UCSD, Moores Cancer Center and Radiation Oncology Radiation Therapy and Prostate Cancer Questions and Answers

3 University of California San Diego Youngest UC School (Founded in 1960) Medical School (1968)

4 UCSD True Gem of the UC system 16 Nobel Prize Winners 3 Nobel Prize Winners in Medicine Annual Government Research grants exceed 700 Million Ranked in the top 15 Medical Schools in the USA (alongside Harvard, Stanford, etc.)

5 Rebecca and John Moores Cancer Center Opened in May ,000 square foot state-of-the-art facility One of only 39 National Cancer Institute Designated Comprehensive Cancer Centers in the USA

6 UCSD Cancer Center

7 UCSD Radiation Oncology New Department New Faculty Recruiting experts from around the country New Equipment Focus on bringing the San Diego region the latest in treatment technologies

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9 Radiation Oncology University of California San Diego Current Department Expansion Research Center Proton Treatment and Research

10 Radiation Therapy Wilhelm Roentgen ( ) Discovers X-rays in 1895 Use of high energy x-rays to treat cancer Long history in the treatment of cancer 1 st patient in 1896 within 2 months of the discovery of X-rays

11 Radiation Therapy RT is used today in the treatment of nearly all cancers in the body Two-thirds of all cancer patients in the USA receive RT Both adults and children Many non-cancers as well

12 Radiation Modalities External Beam Involves the use of photons and electrons Brachytherapy Close therapy Radioactive sources (Cs 137, Ir 192, I 125 ) placed either in a cavity (intracavitary) or within (interstitial) a tumor

13 Radiation Therapy and Prostate Cancer First used to treat prostate cancer in 1909 Radioactive Radium inserted into the urethra (brachytherapy) Machines of the day could not produce sufficiently penetrating beams London (1920)

14 Radiation Therapy and Prostate Cancer Recognized that a superior approach would be to insert radium needles directly into the prostate (interstitial brachytherapy) More of the prostate could be treated with less damage to the urethra Prostate Brachytherapy Urology Textbook (1926)

15 Early Prostate Brachytherapy Prostate Implant (1917)

16 Radiation Therapy in Prostate Cancer Enthusiasm for brachytherapy and RT in general in prostate cancer decreased after WWII Many patients treated were not cured Mainstay of treatment became radical surgery Excitement also surrounding discovery of the ability to treat with hormones

17 Radiation Therapy in Prostate Cancer Interest in RT returned in the 1960s Development of megavoltage (high energy) machines Highly penetrating beams which treat the prostate without excessive skin toxicity Malcolm Bagshaw Stanford University Demonstrated that prostate cancer is curable with external beam (megavoltage) RT Stanford University (1962)

18 Radiation Therapy in Prostate Cancer Brachytherapy revived in the late 1960 s Radioactive seeds were implanted directly at the time of the surgery Long-term results were not good Difficult to obtain good distribution of the radioactive seeds in the prostate Parts of the tumor were not treated adequately

19 Prostate Brachytherapy Brachytherapy later improved by performing procedure under ultrasound guidance Better distribution of seeds in prostate Free Hand Technique Ultrasound Guided Interest decreased today due to urinary side effects and advances in external beam RT

20 External Beam Advances Better, more powerful machines Intensity Modulated RT (IMRT) Image-Guided RT (IGRT) Proton Therapy

21 External Beam Treatment Machines 1920 s Low energy Poor penetration Unable to treat the prostate without skin toxicity 1950s Moderate Energy Improved penetration Less skin toxicity Today Computer controlled Linear accelerators Multiple high energy beams IMRT and IGRT

22 Conventional Prostate RT Multiple beams focused on the prostate Attempts made to shield surrounding normal rectum and bladder Considerable volumes of normal tissues treated exposing patients to toxicity

23 Intensity Modulated RT (IMRT) Novel RT approach First developed in the early 1990s Increasingly popular today Use of computers to conform the radiation dose in 3 dimensions to the shape of the prostate ( shrink wrap ) Reduces dose to bladder and rectum Reduces toxicity risk

24 IMRT field divided into different beamlets Conventional RT field with shaped edges The beam has equal intensity across its surface

25 IMRT in Prostate Cancer IMRT Plan Conventional RT

26 IMRT in Prostate Cancer Better focusing allows us to reduce risk of toxicity to rectum and bladder Also allows us to safely use higher doses to improve cure rates Also being used to potentially reduce risk of impotence by reducing irradiation of the penile bulb

27 RT in Prostate Cancer Results of RT in prostate cancer now rival best results of surgery Long-term comparisons show equal cure rates for early stage patients

28 Early Stage Prostate Cancer n Endpoint 10-year Result External Beam RT Mass General 1396 PSA Control* 42% MD Anderson 643 PSA Control* 61%*** Fox Chase 408 PSA Control** 59%*** Radical Prostatectomy Mayo Clinic 3170 PSA <2 µg/l 52% Washington University 925 PSA <6 µg/l 61% Johns Hopkins 2404 PSA <2 µg/l 74% *Defined as PSA <10 µg/l and absence of 2 rises after a nadir **Absence of 3 consecutive rises after a nadir ***8-year results

29 Prostate IMRT Higher doses possible with IMRT may even result in better PSA control rates Memorial Sloan Kettering Data Favorable n=275 Intermediate n=322 Unfavorable n=175

30 RT and Prostate Cancer Excellent results also achieved treating patients with a rising PSA after prostatectomy If initiated prior to significant rise in PSA, high cure rates are possible Also commonly used to improve the outcome of patients who undergo surgery but have a positive margin

31 Image Guided RT (IGRT) Current interest focused on image guided RT (IGRT) Method to use imaging in the treatment room to improve the delivery of IMRT Not a replacement for IMRT IMRT focuses the radiation on the prostate while IGRT ensures that it is aimed correctly everyday

32 IGRT New Radiation Machines image patients and deliver radiation Allows one to see where the tumor is everyday immediately before treatment Very important since many tumors including prostate cancer may move from day to day If you do not account for movement, you will miss the prostate

33 Bladder Bladder Prostate Prostate Rectum Rectum

34 Varian On-Board Imaging System Radiation Imaging Varian Trilogy Machine (UCSD)

35 IGRT and Prostate Cancer Two Approaches Track implanted (non-radioactive) seeds in the prostate Perform daily CT scans of the prostate Both methods allow the treatment beams to be re-adjusted based on prostate location

36 On-Board Imaging IGRT DRR Planning Film OBI Small gold seeds implanted in prostate IGRT system used to match position everyday <1-2 minutes

37 On-Board Imaging IGRT DRR Planning Film OBI Alternatively, a daily CT can be performed Used to ensure proper alignment of prostate

38 IGRT in Prostate Cancer Currently studying the benefit of IGRT in these patients Studying which method (seeds or CT) is the optimal approach

39 IGRT Increasing interest focusing on using sophisticated imaging to improve targeting of IMRT treatment Traditional approaches simply treat the entire prostate New approaches help focus treatment on the tumor itself Allow higher more effective doses to be concentrated on the cancer

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41 Color Doppler

42 Proton Therapy Revolution in the treatment of cancer Protons unlike conventional x-rays enter the body and stop! Allows treatment to be highly focused Proton Treatment Prostate Cancer

43 Proton Therapy Prostate Cancer The future of prostate cancer treatment Current approaches not ideal Unable to do IMRT or IGRT Prostate immobilized by placing a balloon in the rectum everyday New proton machines will be substantially better with ability to do IMRT and localize the prostate with imaging

44 Conclusions Radiation therapy has a long history in the treatment of prostate cancer Currently RT occupies a major role in the treatment of prostate cancer New approaches (IMRT and IGRT) improve the delivery and efficacy of treatment Proton therapy with IMRT and IGRT is clearly the future

45 Questions and Answers A.J. Mundt MD Professor and Chair Ajay Sandhu MD Chief, Prostate Cancer Service Kevin Murphy MD Medical Director