Radiation therapy for Early Stage Prostate Cancer

John A. Kalapurakal MDProfessor, Radiation Oncology

Northwestern University Medical School

Chicago, IL

ARS

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RACE/ETHNICITY INCIDENCE MORTALITY

All Races156.9 per 100,000 men

24.7 per 100,000 men

White150.4 per 100,000 men

22.8 per 100,000 men

Black234.6 per 100,000 men

54.2 per 100,000 men

Asian/Pacific Islander

90.0 per 100,000 men

10.6 per 100,000 men

American Indian/Alaska Native

77.7 per 100,000 men

20.0 per 100,000 men

Hispanic 125.8 per 100,000 men

18.8 per 100,000 men

It is estimated that 217,730 men will be diagnosed with and 32,050 men will die of cancer of the prostate in 2010 (SEER DATA)

Anatomy

Risk stratification of Prostate Cancer

• Low risk

T1c-T2a and PSA<10 and Gleason score <6

• Intermediate risk

T2b-T2c or PSA 10-20 or Gleason score 7

• High risk

T3-T4 or PSA >20 or Gleason score 8-10

Low-risk Prostate Cancer

• External beam RT: (x-rays, protons)– 70.2Gy-79.2Gy in 39-45 sessions (5 treatments/week, 8-9 weeks)

– 3D Conformal, Intensity Modulated RT, Protons

• Brachytherapy: I-125 (Iodine), Pd-103 (Palladium)– 144Gy in single session

Intermediate-risk Prostate Cancer

• External beam RT: (x-rays, protons)– 75.6-79.2Gy in 42 sessions (5 treatments/week, 8-9 weeks)

– 3D Conformal, Intensity Modulated RT (IMRT), Protons

• External beam RT + Short term Hormone therapy (6-8 months)

• External beam RT + Brachytherapy: I-125 (Iodine), Pd-103 (Palladium)– 45 Gy in 25 sessions (5 weeks) + brachytherapy (seeds, HDR)

Image Guided RT (IGRT)

• ALL MODERN RT DELIVERY SHOULD BE IGRT

• Improve accuracy of treatment

• Track daily position of the prostate before delivering RT

• Fiducial markers (x-rays), ultrasound scans, electromagnetic tracking, CT scans (cone beam CT, fiducials), endorectal balloon (x-rays, CT scan)

3D conformal versus IMRT versus Protons

Prostate Seed Implantation: Indications, Techniques and

Outcomes

Post Implant CT scan dosimetry

Long-term results: Brachytherapy alone (Low-risk) and RT+Brachytherapy in intermediate-risk Prostate Cancer

IJROBP 2010

IJROBP 2007

Higher RT dose (79.2Gy) resulted in higher PSA control in low and intermediate-risk prostate cancer without any increase

in toxicity

JCO 2010

Low risk Intermediate-risk

Harvard Study: Adding 6 months of hormones to RT improved survival in intermediate-risk and high-risk disease

Intermediate-risk High-risk

IJROBP 2010

MD Anderson Study: Higher RT dose (78 Gy) for intermediate-risk patients resulted in better PSA control and

cancer–specific survival

IJROBP 2010

Low-intermediate risk Prostate Cancer: RTOG 94-08 Study

• T1b-T2b, PSA <20

• RT: 66.6Gy + 4 months of hormone therapy

• 1979 patients randomized

• Overall survival significantly better RT+ hormones (51% vs. 4%)

• PSA control significantly higher with RT+ hormones in low and intermediate risk patients

• Subset analysis: survival benefit mainly for higher GS and PSA

• Final results awaited

• IJROBP 2009

Radiation-related Side Effects

• Likely– Increased urinary frequency, burning and urgency

– Increased bowel frequency, burning and urgency

– Fatigue

• Less likely– Rectal bleeding, urinary bleeding

– Chronic bowel/bladder symptoms

– Temporary blockage of urination requiring a catheter

• Rare but serious– Permanent Rectal and Bladder injury requiring surgery

Hormone-related Side Effects

Conclusions – RT for Early Prostate Cancer

• Best Results: Higher tumor RT doses with improved technology treatments (Brachytherapy, IMRT, Proton therapy)

• Role of hormone therapy with RT in low and intermediate-risk patients remains to be defined

• Stereotactic Body Radiotherapy (SBRT): Cyberknife, Linear Accelerator, Tomotherapy

• Role of hypofractionated RT (70 Gy in 28 fractions, 50Gy in 5 fractions) ?

• Role of protons

• PATIENT’S CHOICE: Surveillance vs. Surgery vs. Radiation* vs. Seeds

Radiation therapy for Early Stage Prostate Cancer

John A. Kalapurakal MDProfessor, Radiation Oncology

Northwestern University Medical School

Chicago, IL