prostate cancer Flashcards
Zones of the Prostate
central zone :5%-10%
transitional :10-15
peripheral :80-85
Signs and Symptoms of localised prostate
generally asymtomatic
usually diagnosed thru PSA or DRE screening based on risk factors
Signs and Symptoms locally advanced tumours
urinary hesistancy
weakened stream
increased frequency, urgency nocturia
ED
Signs and Symptoms of. Late stage tumours
bone pain eg lower back , hip , upper thigh
TURP
what does it stand for
transuretheral resection of prostate
how does TURP work
needle is inserted into urethra via penis
prostate tissue trimmed away to relieve urinary symptoms associated with Benign prostatic hyperplasia (BPH)
Tissue taken away to pathology , RT delayed for 4-6 wks
DRE (digital rectal exam)
prostate tumours are firm but surrounded by compressible tissue
difficult to palpate SVs: superior firm indiciates SV involvement
PSA
protein produced by prostate and found in blood , not cancer specific only organ specific
Increased PSA indicates
Infection
prostatitis
BPH
cancer
what PSA is considered elevated
greater than 4ng/ml
PSA elevation does not correspond w tumour stage, but will influence risk group
raised age related PSA
under 50 ≥2µg/L
50-59 ≥3µg/L
60-69 ≥4µg/L
70+ ≥5µg/L
Diagnostic Workup – Physical Examination
after PSA or DRE
What does TRUS stand for
transrectal ultrasound scan
Diagnostic Workup - TRUS
only 60% tumours are visible on TRUS
not great for screening, diagnosis or staging
Limitations of TRUS
-calfications can result in poor image quality
-peripheral zone cane be difficult to see
-operator dependent (am. of pressure can decrease image quality)
Core Needle Biopsy
Systematic biopsy:
10-12 samples taken
base , mid and apex bilaterally
Guided by US
Gleason score
1
2
-small uniform cell w minimal nuclear changes
-still separated by stroma but more closely arranged
Gleason score
3
4
-varaition in glandular size and organisation w infiltration in stromal and neighbouring tissues
-atypical cells w extensive infiltration into surrounding tissues
Gleason score 5
sheets of undifferentiated cancer cells
ISUP Grade group:
grade 1
2
3
4
5
GS ≤ 6
GS 3+4=7
GS 4+3=7
GS 4+4=8; 3+5=8; 5+3=8
GS 9-10
Gleason Score
added up to be :
-2-6
-7
-8-10
-well differentiated , low grade
-moderately differentiated, intermediated. risk
-poorly differentiated , high grade
system for staging
system for grading
-TNM
-ISUP
Further Imaging: based on PSA,DRE and GS
abdomen/pelvis CT w contrast
MRI
PSMA PET
Abdo/Pelvic CT w/ contrast
-for lymphatic spread , which can also be determined thru dissection
-mpMRI is preferred over CT for abdominal/pelvic mets
MRI
better soft tissue delineation than pelvic CT
asses extra capsular extension and SV involvement
if biopsy comes back negative but still suspicion of cancer
PSMA PET (or Isotropic Bone Scan)
reserved for patients with:
-high risk of skeletal mets
-T3a
-grade group 4or5
-PSA>20µg/L
when is PSMA PET used
all patients w symptoms of bony mets
biochemical recurrence following prostatectomy
in assessment of ADT every 6 -12 months
Most common sites of metastatic disease
bones
brain
lungs
liver
lymph nodes
Watchful Waiting:
1.tx intent:
2.follow up:
3.assessment/markers used:
4.life expectancy
5.aim:
6.for:
-1.palliative
-2.patient specific
-3.not predefined
-4.less than 10 years
-5.minimize toxicity
-6.patients w all stages
treatment options :watchful waiting
TURP for urinary support
hormone therapy
Watchful Waiting:
what is it
-Deferred treatment until local or distant disease progression
-if progression=observation continues until symptoms
-prostate cancer slow growing tf safe option for those w/ limited life expectancy
active surveillence:
1.tx intent:
2.follow up:
3.assessment/markers used:
4.life expectancy
5.aim:
6.for:
-1.curative
-2.predefined schedule
-3.DRE,PSA, mpMRI
-4.more than 10 yrs
-5.minimize toxicity w/o comprimising survival
-6.low-risk patients
Active Surveillance
patient selection:
-life exp >10 years
-ISUP group 1
-T1-T2
Treatment Options: Surgery
removal prostate , sv and surrounding tissue for clear margins
pelvic lymph node dissection (PLND)
may not improve oncology outcomes but gives important staging info
side effects of surgery
ED
Incontinence
management of incontinence
-pelvic muscle re-education, bladder training
-anticholinergic medications
-artifical sphincter surgery
Hormone Therapy
Androgens or male hormones stimulate prostate cancer cells to grow
Androgen deprivation therapy ADT supresses production of these hormones and shrink or slow the growth rate of prostate cancer
risk and ADT
low risk= ADT not recommends
intermediate risk= consider 6 month of neo-adjuvant ADT
especially at risk for SV involvement
high risk=long term ADT : 3 years
what is used to compliment ADT
EBRT
How is Brachytherapy delivered?
LDR
-permanent radioactive seeds are deposited at pre-defined position and left there for 1-7 days.
Brachytherapy: LDR
Treatment delivery/Seed placement
mick applicator: single seed placement
strand technique: preloaded needles and less chance of seed migration
Brachytherapy: HDR
how does it work
temporary implant of catheters of IR-192 w different dwell times at each stopping point
How is Brachytherapy delivered?
HDR
-sources are left to dwell in prostate
-positions and dwell times are pre defined
-just 10 to 20 minutes at a time
Brachytherapy: HDR
benefits
improve target coverage
improved sparing of normal structures
improve potential to dose escalate sub volumes
Brachytherapy: HDR
methods
single step procedure (ultrasound guided)
two step procedure (ultrasound for implantation and CT/MRI for planning)
Brachytherapy: HDR
steps involved
1.placement of catheters
2.imaging with catheters in place
3.target volume defintion
4.dosimetry/planning (dwell time optimisation)
5.QA
6.Treatment delivery
Brachytherapy: HDR
planning
verification
forward or inverse depending of software available
catheter tip verification is done pre irradiation
Side Effects: Brachytherapy
what side effects
when they start
how long they last
Urinary side effects:
-frequency, urgency, pain and obstruction due to prostate swelling
-6-12 weeks following seed insertion
-2-12 months
adjuvant radiation therapy
performed 4 months after surgery and triggered by tumour size or surgical margin …..60-64Gy
salvage radiation therapy
perfomed when PSA levels increase during follow up
Treatment decisions should take into account:
-TNM classification
-gleason score
-baseline PSA
-patient age , co-morbidity, life expectancy and QoL
-wishes and circumstance of patient
RT: CT Simulation
what is needed
how is it achieved
empty rectum
diet
enema- microlax
endo-rectal balloon- filling the rectum for consistency
RT: CT Simulation
-slice thickness
2.5-3mm
RT: CT Simulation
scan length
SUPERIOR: sacroiliac joint for prostate +/-SVs OR
post prostatectomy
L4/L5 for distal common iliac or proximal pre-sacral lymph nodes for high risk patients
INFERIOR:fixed border taken from ischial tuberiosties eg 5cm inf
Advantages of MRI at Pre Treatment
- decreases of CTV which leads to:
Prostate CTV
entire prostate gland as defined on planning CT with aid of MRI
strengths of HDR
-implant large glands
-implant extra capsular extension/SV
-Accurate dose delivery
-Focal subvolume boosts
limitations of HDR
-Fractionation
-Requires HDR facility
strengths of LDR
-single step procedure
-convenient
-Well established technique with large amounts
of historical data
limitations of LDR
-Volume limited
-Limited cover of extra capsular extension/SV
-Possible seed migration
-Less flexible for boosts
-Low radioprotection
