Epidemiology
23% of all male cancers
5 years survival (at least)
2nd most common cause of death out of all male cancers
Aetiology
Family
age
HBOC syndrome
agent orange exposure
Diagnostic methods
PSA - prostate specific antigen. Not very conclusive
PSMA- Prostate specific membrane antigen. Protein produced in prostate, found freely in the blood • Higher than “Normal” level (age related) correlates with the presence of prostate cancer
DRE - Digital Rectal exam
Biopsy - TRUS (transrectal ultrasound scan) biopsy. Most reliable
Multiparametric MRI - for staging
Transperineal guided biopsy
Patterns of Spread
Multifocal - slow growing but metastatic
Extend out of gland - spread to seminal vesicles, neck of bladder, rectum, invasion of lymphatics and blood vessels
Highest incidence of met spread - bone
Also spreads to liver, brain, lung
Histology
Adenocarcinoma most common
also, transitional cell, sarcoma, SCC
Staging
Gleason score for staging - depends on how much it looks like healthy tissue (how differentiated it is)
Grade group can be converted to gleasons score, larger grade group -> higher gleason score-> worse prognosis
RT treatment technique advantage
prostate is retained, lower sexual dysfunction
RT treatment disadvantage
High dose required due to low alpha/beta ratio
Preparation for RT
full bladder (1hr before sim 500mL), empty rectum
Scan parameters for Prostate patient
scan L3/L4 to 1.5cm below inf border of ischial tuberosities. Superior border will be extended when nodes are involved L1/L2. 2-5mm slices
Room preparation
headrest, knee bolster, vacbag, foot-stocks
Clinical management options
- Watchful waiting: no treatment, active surveillance - repeat PSA every 6 months, complication - could miss curable disease period
- Surgery - radical prostatectomy, complication - operative mortality, urinary symptoms, impotence
- hormone therapy - oestrogen therapy, androgen deprivation (inhibit growth of prostate cancer), orchiectomy (removal of testicles), complications: impotence and general feminisation
- Ultrasound (HIFU)
- Cryotherapy: freezing cancer cells, not enough info on long term effectiveness and not recommended for men with large prostates
Radiation therapy: brachytherapy (LDR/HDR), external beam, proton therapy
OARs for prostate and tolerances
Rectum (V50<50%) Bladder (V65<50%) Femoral Heads (V45<60%) Penile bulb (mean dose <52.5Gy) Small bowel (minimise dose)
2 types of brachy
- Low dose rate - seeds, monotherapy for low intermediate risk patients, as a boost to EBRT
- High dose rate - needles, monotherapy for low-intermediate risk patients, as a boost combined with EBRT, done after failed EBRT with isolated local recurrence
Acute RT side effects
tiredness, bladder irritation, frequency and urgency.
Late RT side effects
urinary incontinence, radiation proctitis, erectile impotence
Management of Acute side effects
tiredness - routine screen for fatigue, manage underlying causes
bladder irritation - anti inflammatory medication, frequency and urgency- alpha blockers
Rectum irritation - managed with dietary modification
Management of late side effects
- urinary incontinence - prescribe alpha blockers
- radiation proctitis- referral to gastroenterologist
- erectile impotence- sexual counselling
Signs and symptoms of Prostate cancer
Urinary changes, dysuria, haematuria. Frequency and urgency difficulty maintaining bladder volume
Mets: Bone pain, weight loss, testicular pain
RT dose fractions
EBRT post radical prostatectomy - 64-66Gy in 32-33#
Definitive EBRT low risk - 73.8-74Gy/37.4#
Definitive EBRT intermediate/high risk- 78-81Gy/39-45#
Spare OAR
hydrogel that is injected in between prostate and rectum to create barrier between them and decrease dose to rectums, dissolvable
proton therapy
Protons are used in place of x rays - Protons do not exit tumour -> does not pass into healthy tissue (no exit dose) - Reduced radiation exposure and damage to healthy tissue - Effective in sensitive areas (e.g., brain, eye, spinal cord, heart, blood vessels)”
