Transcript Radiotherapy In prostate cancer

Radiotherapy in prostate cancer
Dr.Mina Tajvidi
Radiation oncologist
indication
Radical
Adjuvant
Salvage
 palliative
Radiotherapy
Radiotherapy
Radiotherapy
Radiotherapy
Radical radiotherapy
clinical T1, T2
The optimal management of localized (clinical T1 or T2)
prostate cancer is controversial . Standard options include
radiation therapy (external beam and/or brachytherapy,
with androgen deprivation therapy [ADT] in selected cases),
radical prostatectomy, or active surveillance (also termed
watchful waiting) in carefully selected patients at low risk of
recurrence.
There are no randomized trials that have resolved the
question of what constitutes the best treatment for these
men
The goal of RT for men with localized prostate cancer is
the delivery of the planned dose of radiation to the tumor
while minimizing radiation to surrounding normal tissues
CONFORMAL RT TECHNIQUES
Three-dimensional conformal RT
Intensity-modulated RT
Image-guided RT
Experimental
techniques(Stereotactic body RT,
Particle irradiation)
Three-dimensional conformal RT
Three-dimensional conformal RT (3D-CRT)
delivers radiation to a three-dimensional volume
using imaging studies and computer software to
more precisely target RT delivery by better
delineating the prostate gland and its surrounding
structures
The review concluded that 3D-CRT had a better
therapeutic index than conventional EBRT for
clinically localized prostate cancer
Intensity-modulated RT
IMRT delivers nonuniform beam intensities to
the target volume by changing the intensity of the
beam, in contrast to 3D-CRT, in which a uniform
intensity is administered to a defined field
There are no randomized trials comparing IMRT
with 3D-CRT. In observational studies, IMRT
appears to be less toxic at an equivalent dose
Image-guided RT
Image-guided radiation therapy (IGRT) is a
technique that acquires two- or threedimensional images prior to each
treatment, thus tracking the location of
the tumor and surrounding organs.
Commonly used imaging approaches for
prostate IGRT include gold marker
(fiducial) tracking with megavoltage portal
imaging, fluoroscopy, abdominal
ultrasound, or CT. IGRT provides accurate
localization of the prostate gland, which
can vary on a daily basis.

Stereotactic body RT
Stereotactic body radiation therapy
(SBRT) is an extreme form of
hypofractionation, in which the entire
dose of radiation is administered in one or
a very limited number of fractions.
 Longer follow-up in larger numbers of
patients is required to assess the safety
and efficacy of this approach; at present
SBRT should only be performed within the
context of a clinical trial
Particle irradiation
The most data are available for
particle beams using protons, and
there is more limited, ongoing
research with carbon ions
Particle beam RT requires
adaptation of particle accelerators
designed for other purposes or
specialized equipment. These
techniques are not widely available
.
Radiation dose and schedule
The incidence of biochemical failure
after treatment with 74 to 80 Gy was
significantly lower than with doses of 64 to
70 Gy (25 versus 35 percent, odds ratio
0.60, 95% CI 0.47-0.76)
there was no evidence that mortality
was improved with higher doses of RT
 radiation doses of 72 Gy or higher given
with contemporary conformal techniques
(Grade 1A)
Hypofractionation
52.5 to 55 Gy in 20 fraction
Although hypofractionation has not been shown
to be equivalent to a longer course of therapy, it
may be appropriate for elderly or handicapped
patients who are unwilling or unable to undertake
an eight week course of therapy
Multiple randomized trials are ongoing, and
long-term results are required before
hypofractionation can be considered a standard
alternative
Brachytherapy for localized
prostate cancer
 For men with low-risk, clinically localized prostate cancer
A large prostate gland size (>50 to 60 g) is relative
contraindications to prostate brachytherapy
For men with intermediate-risk or high-risk localized
disease we suggest external beam radiation therapy (EBRT)
with or without brachytherapy or radical prostatectomy
rather than brachytherapy alone
There is no consistent evidence to suggest that androgen
deprivation improves the oncologic outcome for men
undergoing prostate brachytherapy, and we do not suggest
its use
ANDROGEN DEPRIVATION WITH
RT
Men with intermediate-risk disease (clinical T2 stage and 
either PSA 10 to 20 ng/mL or Gleason score 7) appear to
benefit from four to six months of neoadjuvant and
concurrent ADT during RT.(RT (Grade 2B)
Those with high-risk disease (Gleason score 8 to 10 or
serum PSA >20 ng/mL) should receive neoadjuvant and
concurrent ADT with RT and also continue adjuvant ADT for
two more years after completing RT
Clinical stage T3 prostate cancer
EBRT is more commonly employed than
surgery
whole pelvis RT rather than prostate only
RT
 use a gonadotropin-releasing hormone
agonist for at least two months prior to
the initiation of RT, followed by concurrent
treatment during RT, and adjuvant
treatment for at least two years.
Whether the addition of brachytherapy
to EBRT provides benefit beyond that
achievable with adequate doses of EBRT
(≥72 Gy) plus ADT is unclear.

Adjuvant radiotherapy
The optimal management of patients with
undetectable serum PSA levels who have pT3
disease or positive surgical margins after radical
prostatectomy, but randomized clinical trials
support the use of adjuvant RT compared to
observation.
Large randomized clinical trials have
demonstrated that adjuvant RT significantly
improves biochemical relapse-free survival (RFS)
and metastasis RFS
 Radiation dose:60 to 64 Gy
Additional trials will be required before higher
doses can be recommended
ADT to adjuvant RT after surgery
for pT3 prostate cancer
Whether there is benefit from adding
ADT to adjuvant RT after surgery for pT3
prostate cancer is unknown
 ADT should be considered only in the
context of a clinical trial.
For men with pT3 disease who refuse or
are ineligible for a clinical trial, and who
understand and accept the risks,
concurrent ADT could be considered
Salvage radiotherapy
For men who have a PSA-only recurrence following radical
prostatectomy and an otherwise favorable life expectancy,
we recommend salvage RT
 Although there are no randomized trials that address this
topic, this approach is well tolerated and appears to extend
cancer-specific survival compared to management with
observation alone.
 For men receiving salvage RT, we recommend a minimum
RT dose of at least 64 Gy
 Based upon recent historical series that suggest that
higher doses may be beneficial,
 We suggest that outside of a clinical trial setting, RT be
limited to the prostate bed and not include the pelvic lymph
nodes (Grade 2C).

The benefit of ADT in
conjunction with RT
The benefit of ADT in conjunction with RT
is uncertain
 we suggest limiting the use of ADT to
men with very unfavorable risk factors at
the time of radical prostatectomy (eg,
Gleason score ≥8 or preoperative PSA >20)
(Grade 2C).
When we do use hormonal therapy, we
use ADT before and during salvage RT (four
to six months total).

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