Prostate Update ~

What’s New in Radiation Therapy

DR. RAPHAEL CHEE FRANZCR

Asst. Prof. School of Surgery, UWA Radiation Oncologist &

Director of Cancer Services Genesis CancerCare Shenton House

“Holy Grail” of Radiation Therapy

The tumour receives 100% of the prescribed radiation therapy dose

The adjacent normal tissue receives 0% of dose

The dose is adequate to completely eradicate all cancer cells

Organ function is maintained

Case Study

Clinical • 57yo with PSA 6ug/L • DRE early T3a • TRUS = Gleason 4+4 • Staging CT = cN0M0 • WBBS = NED

RP & Pelvic node sampling • Gleason 4+5 • Bilateral periprostatic

invasion • Positive margins bladder

and lateral • Bilateral seminal vesicle

invasion • 0/6 pelvic nodes

Post-op Course

• PSA 2 months post-op = 0.1 ug/L

• Choline PET = NED

• Regained good urinary control & continence 2 months post-op

High Risk Prostate Cancer - Not necessarily poor prognosis • cT3-T4 or, • Gleason ≥ 8 (new ISUP Grade 4 & 5), or • PSA > 20 ug/L

• Predicts for >15% risk nodal metsPartin

• Prognosis for 1 vs 2 vs 3 features • PCSS (Belgium retrospective series post-open RP at 10

years): – 95% vs 88% vs 80% – Multi-modality Rx, multiple lines

Standard of Care

Treatment Plan

• Prostate/SV bed RT 66-70Gy (6-7 weeks)

• 2-3 years concurrent & adjuvant Androgen Deprivation Therapy (ADT)TROG 1996, RTOG 1986 & 1992

Toxicity Profile • Hot flushes • Fatigue • Impaired performance • Emotional lability/depression • Weight gain • Late Bladder/Bowel 3D-CRT

toxicity – 70% Grade 0 – 25% Grade 1 – 3% Grade 2 – 1% Grade 3

Volumetric Modulated Arc Therapy

Dose-Target Conformity VMAT vs 3DCRT

Daily treatment 7-10 mins VS 15-20mins

IGRT - Daily Cone-Beam CT

Pelvic RT with VMAT has low toxicity

• Genesis Cancer Care WA – 60 cases since 2013

• Bowel & bladder late effects – Grade 1 = 30% Bowel, 12% Bladder – Grade 2/3/4 = 0%

• PSA failure rate 15% at 3 years

– Most failures occur within 12 months of completing RT

– Rx ADT

PSMA PET is useful

• Prostate Specific Membrane Antigen • Still experimental • But sensitivity seems to drop if PSA < 0.5ug/L

Summary

• Curative-intent Pelvic VMAT is highly tolerable • Patient selection is important

– Nodal disease confined to pelvis – Predicted longevity of life

• If not curative, at least prolongs interval before ADT required

• Maintains Quality of Life