radiotherapy techniques prostate

1. Role And Technique Of
External Radiation In
Carcinoma Prostate
G.Lakshmi Deepthi

2.  Second most common cancer in men worldwide
 Fifth leading cause of death from cancer in men
 Estimated 307,000 deaths in 2012 (6.6% of the total cancer
related deaths in men)
Globocan 2012.
TREATMENT OPTIONS :
 Active surveillance
 Radiotherapy
 Radical prostatectomy
 No data from randomized trials comparing all these
approaches

3. Risk stratification – NCCN-2016
VERY LOW RISK :
 T1c
 Gleason score ≤6
 PSA <10 ng/mL
 Fewer than 3 prostate biopsy cores positive, ≤50%
cancer in any core
 PSA density <0.15 ng/mL/g
LOW:
 T1-T2a
 Gleason score ≤6
 PSA <10 ng/mL
Active surveillance
EBRT
Brachytherapy
RP+/- PLND

4. INTERMEDIATE RISK
 T2b-T2c
 Gleason score 7 or
 PSA 10–20 ng/mL
HIGH:
 T3a
 Gleason score 8–10
 PSA >20 ng/mL
VERY HIGH:
 T3b-T4
 Primary Gleason pattern 5 or
 >4 cores with Gleason score 8–10
RP +PLND
EBRT +/- ADT +/- BT
EBRT + ADT
EBRT + BT +/- ADT
RP + PLND

5. REGIONAL:
 Any T, N1, M0
METASTATIC:
 Any T, Any N, M1
NCCN -- Patients in any risk group can be treated
with radiotherapy as a component of therapy or as
primary therapy.
EBRT + ADT
ADT
ADT

6. AUA: results are the same for all three
treatment modalities
PSA CURE RATES
Seeds External Surgery
Low risk
Intermediate
High

7. QUALITY OF LIFE :
Urinary Scores
Sanda et al, N Engl J Med. 2008 Mar
20;358(12):1250-61

8. Bowel scores :
Sexual Scores :

9. INTENT of Radiotherapy :
 Radical RT
RT -- conventional / 3DCRT /Hypofractionated
Teletherapy + Brachytherapy Boost
Brachytherapy alone
Protons alone
 Adjuvant post op RT
 Salvage RT / Re-irradiation
 Palliative RT

10. CONTRAINDICATONS TO EBRT :
Absolute :
 Prior pelvic irradiation
 Active inflammatory disease of rectum
 Permanent indwelling foley’s
Relative :
• very low bladder capacity,
• chronic moderate or severe diarrhea,
• bladder outlet obstruction requiring a suprapubic catheter
• inactive ulcerative colitis.

11. GENERAL GUIDELINES :
 Highly conformal RT techniques should be used to treat
prostate cancer.
 LOW RISK -- Doses of 75.6 to 79.2 Gy in conventional
fractions to the prostate
 INTERMEDIATE OR HIGH RISK -- doses up to 81.0
Gy provide improved PSA-assessed disease control.

12. • Moderately hypofractionated image-guided IMRT
regimens (2.4 to 4 Gy per fraction over 4-6 weeks) have
shown similar efficacy and toxicity to conventionally
fractionated IMRT.
• Emerging treatment modality : Extremely
hypofractionated image-guided IMRT/SBRT regimens
(6.5 Gy per fraction or greater)

13. RTOG- 9413
1323 patients with localized disease and
risk of LN involvement >15% & PSA <100
WP RT+ NCHT PO RT+ AHT
PFS 60% 50%
PO RT+ NCHT WP RT+ AHT
49%44%
Int J Radiat Oncol Biol Phys. 2006 Nov 1;66(3):647-53
Subset analysis of RTOG 9413 by Roach et al
694 patients studied
325 patients
WP RT N&CHT
324 patients
PO RT N&CHT.
No significant difference in PFS was
seen (p=0.99)
PORT vs WPRT

14. WPRT :
1. if +LN% >15%.
2. increases disease-free survival in itself.
3. WPRT combined with NCHT increases disease-free
survival.
4. doesn’t lead to more acute toxicity compared to PORT.
5. WPRT combined with NCHT increases Acute and late
toxicity.

15. In high risk , node negative patients ,the
addition of WPRT demonstrated no survival
advantage compared to PORT.

16. External Radiotherapy Techniques :
• 2 D conventional
• 3 D Conformal
• IGRT
• Tomotherapy
• Proton
• IMRT
• Rapid Arc
• SBRT
• CYBERKNIFE
• SBRT - FFF

17. CONVENTIONAL PLANNING :
 Target volume :
prostate + seminal vesicles
obturator nodes
proximal internal and external iliac
 Position :
supine with arms on the chest

18. Field borders :
AP-PA portal
 Superior – L5-S1 interface
 Inferior – ischial tuberosity
 Lateral – 1.5-2cm lateral to pelvic brim
Lateral portal
 Anterior- anterior most aspect
of pubic symphysis
 Posterior – S2-S3 interval

19. Boost phase : prostate + SV
• Superior -- 3-5 cm above pubis
• Inferior - short of internal anal sphincter or caudal to ischial
tuberosity
• Laterally to include 2/3 of the obturator foramen
• Anterior -1.5 cm post to ant. margin of pubic symphysis
• Posterior - 2 cm behind the rectal marker

20. Beam Arrangement :
2 field AP-PA
4 Field AP-PA, rt lat-lt lateral
Limitations of 2D :
 Poor nodal coverage
 Higher normal tissue toxicity
 Dose escalation not possible beyond 60 – 66 Gy
 Tumor cannot be seen
 Dose to the target volume and organ at risk cannot be
predicted

21. 3DCRT :
 Conformal techniques –available since 1980’s
 CT based images referenced to a reproducible patient
position are used to localize the prostate and normal
structures and to generate high resolution 3D
reconstruction of the patient.
 Treatment fields are selected using
BEV and fields are shaped to conform to
the patients CT defined target volume thus
minimizing normal tissue irradiated.

22. 3DCRT :
 Placement of fiducial markers is done 1 week before the
day of planning CT for all patients.
 Bowel preparation has to be done the previous night .
 To visualize bowel in the vicinity of the prostate and
seminal vesicles, a barium sulfate suspension is
administered, and the rectal lumen is visualized by
inserting a rectal catheter
 Bladder filling protocol :
patient is asked to empty bladder half an hour before
scan and made to drink 500ml of water– to maintain a
comfortably full bladder
THERMOPLASTIC CAST ???

23. Supine position with knee support is
standard
 ADVANTAGES:
• Ease of daily setup for the patient and staff ,
• The ability to fuse treatment-planning images with
previously obtained diagnostic images (i.e., MRI),
• Comfortable
• Less prostate motion
in supine

24.  The patient is scanned through an approximately 20- to
30-cm region around the prostate with a slice thickness of
3 mm. i.e L1-L2 junction to 3cm below the ischial
tuberosity.
 Before start of the CT planning study, several transverse
images through the prostate and bladder are obtained to
ensure that
- the rectal lumen is clearly visible,
- the bladder and rectum are not excessively filled,
- and the patient is properly positioned within the
scan circle

25. CT for contouring !!!
Drawbacks –
 Poor visualization of intraluminal extension
 Merging of prostate apex with GUD
 Prostate– seminal vesicle interface difficult to define
T2 MRI – clearly demarcates prostate in relation to
adjacent structures.
apex identification – change in shape of levator ani
from concave to convex .

26. Roach et al.
CT prostate 32% larger than MRI

27. MRI- CT registration :
 The apex and the base in
particular represent regions
of the target volume – better
on MRI
 Recommendations :
- the inspection of lateral
view projections of the
contours to detect regions of
the irregularities of the target
geometry
- and improved recognition
of the GUD elements.

28. ROACH FORMULA :
ECE – 3/2PSA + 10 (GS-3)
SV – PSA + 10 (GS-6)
LN – 2/3PSA + 10 (GS-6)
TARGET DEFINITION
 GTV – not done as difficult to delineate on CT.
 CTV – whole prostate and any extracapsular extension .
SV – treated if involved
risk >15%
high risk cases

30.  WPRT – LN are treated if
node positive
high risk cases
 Lymph nodal stations –
external and internal iliac
Presacral
obturator

31. • 1cm presacral
• 1.7cm joining external and
internal iliac
• 1.7cm obturator strips

32. PTV
 Defined with margin around CTV for physiological
variation and setup
 1cm all around
0.6cm posterior for rectal sparing
But we should strive for defining our own population PTV
borders.

33. Organs at risk :
 Rectum -The rectal contour included the lumen and
rectal wall from the anal canal to the rectosigmoid
flexure .
 Bladder – entire circumference
 Femur heads
 Small Bowel or sigmoid within 1cm of PTV.

34. BEAM SELECTION AND PLANNING
• Standard 3D conformal beam arrangement- six coplanar
fields, including two lateral, two anterior and two oblique
beams
• Conformal apertures drawn around the PTV adding a
margin of ~5 to 6 mm in the axial directions to account
for beam penumbra.
• Beam shaping with MLC

35.  6-field plan : the two lateral beams typically deliver ~1/2 of
the dose and four oblique beams contributing the rest.
 The beam weights of the anterior oblique and posterior
oblique beams are adjusted to obtain a uniform dose within
the PTV and to place the hot spots away from the rectum
 Dose prescription is done and DVH evaluated.
PLAN NORMALIZATION :
• prescription isodose (100%) covered the PTV with a hotspot of
6%-9% within the PTV
•Rectal wall volume not ≥ 30%
receiving ≥ 75.6 Gy
•Femurs to ≤68 Gy (90%)
•Large bowel Dmax ≤ 60Gy (79%)
•Small bowel ≤ 50 Gy (66%)

36. Drawbacks :
 Dose escalation couldn’t be done
 Tumor localization was not possible
poor disease control rates

37. IMRT – Need ???
 Anatomical location: Prostate is bound by sensitive dose
limiting structures such as the bladder and the rectum .
 Vulnerable to displacements due to bladder and rectal volume
changes (filling/voiding) .
 Dose-escalation studies have shown an unequivocal benefit
for dose escalation beyond 72Gy, which is beyond the limits
achievable by 2DRT or 3DCRT .

38. Process :
 Process from image acquisition to segmentation remains
the same as 3DCRT .
 In this the planner defines the dose constraints or
objectives for target and normal tissues beforehand
 Special computer software is used to determine the
intensity pattern for each treatment field that results in a
dose distribution as close to the user-defined constraints
as possible.

39. Recommended dose
 Conedown boosts using IMRT to cover the prostate to
74–78 Gy.
 The minimum central axis dose is 78 Gy
 Involved LN receive 54–56 Gy or higher with IMRT.
 Prophylactic dose to the seminal vesicles is 54 Gy.
 Documented seminal vesicle disease should receive full-
dose.

40. IMRT dose plan :
 phase I : delivers 54Gy/27#/5wks to prostate + SV
45-54Gy/25#-30#/5wks to nodal volume
 Phase II is a cone-down boost to the prostate PTV –
18Gy/10#/2wks
. Therefore, the minimum total dose to the prostate
(prescribed to the PTV) is 72Gy.

41. Dose constraints :

42. IMRT – disadvantages :
 longer treatment time,
 more patient discomfort,
 higher dose delivery uncertainty because of
intrafractional organ motion.
 The large number of monitor units (MU) also raises
concern about secondary malignancies after curative
treatment due to the exposure to more leakage radiation.

43. VMAT :
 Volumetric Arc Therapy (VMAT) or Rapid Arc Radiotherapy
Technology is an advanced form of IMRT that delivers a
precisely-sculpted 3D dose distribution with a 360-degree
rotation of the gantry in a single or multi-arc treatment..
 Radiation dose is delivered in a single- or multiple-gantry
rotations with simultaneously varying shape of aperture
created by dynamically moving multi-leaf collimator,
variable dose rate, and gantry rotation speed.
 has potential in delivering IMRT- quality dose distribution
with significantly shortened treatment time and lower number
of MU

44. DOUBLE ARC IS THE STANDARD
IMRT SINGLE ARC DOUBLE ARC
Target coverage good Less than IMRT BEST
Normal tissue
sparing
GOOD POOR Same as IMRT
Integral dose High Same as imrt HIGHEST
Treatment time least
MU Least

45. SIB-IMRT
 Rationale : Post-radiotherapy local recurrence occurs at the
site of the primary tumor . (Cellini et al )
• Dose > 2 Gy/fraction to the tumor and 2 Gy/fraction to the
remaining PTV
• Small volume with dose/fraction > 2 Gy
• Benefit of a reduced over all treatment time
• PTV (P + SV) covering
prostate and seminal vesicle
receiving 74 Gy/27#/5.5 wks
• PTV (LN) covering lymph
nodes receiving dose of 54
Gy/27#/5.5 wks

46.  SIB-IMRT plans were significantly superior to sequential-
IMRT plans in terms of normal tissue sparing.
 Regarding PTV coverage, both the plans attained similar
PTV coverage.
 doses to organs at risk -- the SIB plans achieved
significantly lower doses to the rectum and bladder as
compared to sequential-IMRT plans.

47. Problems with IMRT :
 Prostate motion :
interfraction – daily base
intrafraction – during treatment
 Relation between prostate and bony anatomy
Schallenkamp et al.
the average prostate displacement are 9mm(SI),
16mm(AP), and 15 mm(RL)

48. Solution :
 Bowel and bladder protocol – to decrease inter and
intrafraction motion .
 Prostate immobilization can be done using rectal balloon
 Image guidance – using implanted fiducials or
microtransponders
IGRT

49. IGRT :
 Frequent imaging during a course of treatment used to
direct radiotherapy
 Improves both accuracy and precision of radiation
delivery by decreasing uncertainty related to systematic
and random setup errors .
 Ideal localization device -
cost very little
visualise both prostate and normal structures
perform before and during treatment
compatible with LINAC

50. Modalities :
1. Rectal balloon
 Inflated with air or water
 Placed in rectum to push prostate against the pubic
symphysis
 Aims : to decrease anteroposterior movement of prostate
to decrease amount of posterior rectal wall in
treatment field
 Not much useful in IMRT

51. 2.Fiducials :
 Portal images – provide good bony anatomy but do not
show prostate and prostate position is not constant in
relation to bony anatomy.
 Hence gold seeds or coils are implanted into prostate
which act as surrogates of prostate position .
 Procedure :
done with help of an urologist

52. Advantages :
Good alignment
Allows target tracking
Less subjectivity
Basis for multimodality image fusion
Disadvantages :
Invasive procedure
Can only track prostate, not normal structures
Do not account for prostate deformation
Shifts may not be representative of volume
However most commonly used method
EPID with fiducial marker matching

53. 3.Radiographic fiducials :
 Used in cyber knife treatment system
 Orthogonal kv source is used
 In this continuous tracking of tumor motion is done and
it automatically corrects the aim of the treatment beam
when movement is detected .
 Images are acquired every 90-120 sec
 Disadvantage – expensive
custom installation
not visualize normal structure

54. 4.USG :
 Brightness mode acquisition is done to visualize changes
in acoustic impedance found in tissue planes
 BAT USG – prostate localised via orthogonal images in
sagittal and transverse planes
 Planning contours from CT simulator are overlapped
onto USG images and shift applied

55. Advantages
 Inexpensive
 Interfraction localization can be done
 Not invasive
 No radiation exposure
Disadvantages :
 Inter and intra observer variation
 inaccurate

56. 5.Onboard volumetric imaging :
 Varian and elekta systems :
CBCT with an orthogonally mounted kv imaging
source with opposed flat panel imager
 Siemens : MV-CBCT

57. Advantage –
 allows visualization of both soft tissue & bony anatomy.
 Detect prostate deformation
 Allows real time replanning
Disadvantage – each image -1.5-8 cGy
1-5 min
inter/intra observer segmentation error.

59. 6.CT on rails :
 Custom linac setup where treatment table can be moved
into a CT scanner
 Disadvantages:
time taking
costly
daily re-planning

60. 7.Electromagnetic tracking system :
Calypso 4D localization system :
 Continuous real time tracking system
 High precision ,real time inter/intra fraction monitoring
system
 Implantable passive transponders are used whose
positions are continuously measured at 10Hz during
radiation by electromagnetic array placed over the
patient.
 Advantages : continuous tracking
no radiation
compatible with LINAC

61.  DISADVANTAGE :
expensive
only prostate ,no normal tissue visualization

62. SBRT
an external beam radiation therapy method used to very
precisely deliver a high dose of radiation to an extracranial
target within the body, using either a single dose or a small
number of fractions.
Goals :
 deliver the high dose safely
 Rapid dose falloff to control the excessive risk of radiation
damage.
Planning CT :
Strict bladder and bowel protocol to be followed.
1.5mm slice thickness

63.  Isocenter
Isocentric (Linac gantry based)
non-isocentric (Cyber knife)
 Beam arrangement
– Coplanar vs. non-coplanar beams
– Static gantry angle IMRT vs. Volumetric arc modulated
treatment (VMAT)
 PTV dose distribution
– Homogenous vs. Heterogeneous vs. Simultaneous
boost

64. Dose constraints:
 PTV margin : 5mm all around
3mm posterior
 Dose to PTV –V100% --95%
 Rectum – V50%<50%
V80%<20%
V90%<10%
V100% <5%
 Bladder – V50%<40%
V100% <1.1%
 Femur --V40% <5%
 Small Bowel --V40% <1%

65. VMAT for SBRT :
 Simultaneously changes :
Gantry rotation speed
Treatment aperture shape (MLC)
Delivery dose rate
 Improved conformity
 Fast plan delivery
Agazaryan N. et. Al.
 Plans with two arcs provided improved conformity and
homogeneity compared with single arc .
 Plans with ±45o collimator angles provided more homogeneous
dose distribution
 Increasing the number of arcs to 3 did not provide significant
improvement
 Selection of beam energy between 6MV and 10MV did not show
notable dosimetric difference

67. VMAT IMRT

68. CYBERKNIFE
 CyberKnife is a frameless robotic radiosurgery system
 It has the ability to deliver non-coplanar non-isocentric
arcs and can yield maximal conformal isodose.
 It is the only integrated system capable of target position
verification and real-time tracking during delivery of
conformal stereotactic radiotherapy.

69.  is a 6MV linear accelerator (linac) mounted on a
computer-controlled robotic arm with 6o of freedom
which allows for large amount of non co planar beams to
be delivered with excellent spatial precision.
• It is equipped with an
orthogonal pair of
diagnostic quality digital x-
ray imaging devices, and is
the only integrated system
that is designed to use real-
time image-guidance
during radiotherapy
delivery.

70.  superior DVHs for sparing of rectum and bladder
 excellent DVHs for target coverage compared with
IMRT,
 dose heterogeneities to the same degree as IMRT plans.
 longer delivery times ---best suited for hypo-fractionated
regimens.
Such dose regimens might allow for
biologically equivalent dose escalation without increased
normal tissue toxicity.

71. Accurate tumor localization and
tracking

72. FFF SBRT :

73. TOMOTHERAPY :
 Form of IMRT based on rotating fan beam
 Tumor volume is helically irradiated to achieve a highly
conformal 3D dose distribution by modulating intensity
pattern by incidental x ray beam profile during rotation
by fan beam MLC
 Adaptive radiotherapy.
 Total time – 15-20mins –image guidance- 10min
treatment time- 4-7min

74. Process :
 Planning CT –
supine with beam bag below knees
Straps on feet
Kvct taken with cystourethrogram
3mm thick slices
 Tranferred to tomotherapy planning station
 Image segmentation :
 ROI – OAR, couch top and setup marks should be drawn
 CTV – p+sv
high risk –prox 1-1.5cm of SV included with 3mm
post
PTV – 3mm setup margin

75. Localization :
 Daily MVCT comparison with planning kvCT

77. Advantages over IMRT & 3DCRT
 Dose sparing of normal tissues
 No increased risk of secondary malignancy

78. PROTON THERAPY :
Characteristics :
 characteristic Bragg peak at the end of ionization track
 Sharp distal fall off of dose

79.  The Bragg peak is spread out by introducing extra
absorbing material before the beam enters the patient.
 The Bragg peak can be spread out to a useful plateau by
the use of a rotating stepped absorber


80. Advantages :
 Complete dose to the tumor
 Sparing of normal tissues
Disadvantages :
 Underestimation -- miss of tumor
 Overestimation -- normal tissue toxicity
HENCE inter /intrafraction motion
setup variation
bladder/rectal filling
weight loss
Significant
consequenc
es
PROTON THERAPY – TWO EDGED
SWORD

81. IMPT
 Decreased integral dose
 Better dose homogeneity.
 Quicker planning time.

82. TUMOR LOCALISATION :
 CBCT
 CT on rails
 fiducial markers,
 beacon transponders
ADVANTAGE OVER IMRT :
 Low integral dose to anterior and posterior structures
 Decrease GI toxicity
 Equivalent cancer control rates
NCCN – No Clear Evidence Supporting A
Benefit Or Decrement To Proton Therapy
Over IMRT.

83. DOSE ESCALATION STUDIES
Rectal toxicity
urinary
erectile
IS NEVER FREE
CONVENTIONAL
escalation of total doses
HYPOFRACTINATED
escalation of fraction sizes
very low α/β ratio of
1.5 Gy for prostate
cancer
moderate
extreme

84. Rationale for Hypofractionation
 Low α/β is consistent with a greater capacity for repair
between fractions
 Prostate tumors have exceptionally low values of of 1.5-3 Gy
same or less than late-reacting normal tissues
 Rationale-
Dose escalation to increase tumor control while maintaining the
same normal tissue complication probability
Ritter et al 2009
Cancer
Brenner et al 2002
IJROBP

85. PSA control after conventional
70Gy
IJORB 2001.

86. Increasing therapeutic advantage with
increasing hypofractionation

87. MD
ANDERSON
70 Gy vs 78Gy Increase in
biochemical
control
63% vs 88%
(8yrs)
ZIETMANN et
al.
70.2 vs 79.2Gy 51% risk reduction
in biochemical
relapse
61% vs 80%
(5yrs)
ZELEFSKY et al. 64.8Gy to
86.4Gy
If > 75.6Gy –PSA
Relapse free
survival increases
70% vs 84%
(10yrs)
POLLACK et al. 70Gy vs 78Gy No advantage in
low risk
21.4 vs 25.3%
bPFS
SYMON et al. 71.7 +/- 4.3Gy No advantage in
low risk
-
LOW RISK

88. INTERMEDIATE RISK
Diez et al. IJROBP 2010

89. HIGH RISK
SATHYA et
al.
66Gy vs 40Gy
+35 Gy BT
Increased PSA
control
+
PEETERS et
al.
68 s 78Gy Increased PSA
control
45%vs 56%
(70months)
DEARNEY
et al.
64 vs 74 Gy Increased PSA
control
79% vs 85
%
ZIETMANN
et al.
70.2 vs 79.2Gy Increased PSA
control
41%
reduction in
BPFS
KUBAN et
al.
70 vs 78 Gy Increased
DMFS & PSA
88vs 63%
(8yrs)

90. Moderate Hypo fractionation
CHIPP trial
 Conventional versus Hypofractionated high-dose intensity
modulated radiotherapy for prostate cancer:
Preliminary safety results from the CHHiP randomized
controlled trial
TREATMENT ARMS: BFF at 5yrs toxicity>GR2 RTOG
1) 74 Gy in 37 #’s(n=153) 88.3% 13.7%,9.1%
1) 60 Gy in 20 #’s (n=153) 90.6% 11.9%,11.7%
3) 57 Gy in 19 #’s (n=151) 85.9% 11.3%,6.6%
Radiotherapy with Hypofractionated high-dose radio-therapy
seems equally well tolerated as conventionally fractionated
treatment at 2 years
Dearnaley D et al. Lancet Oncol.2012

91. Dutch HYPRO trial: 820 patients of IM or high risk
 78 Gy/39# versus 64.6/19#
 Preliminary results have been presented in 2015
ASTRO meeting- No difference in 5 year relapse free
survival
RTOG 0415 trial: 1115 low risk prostate cancer pts,73.8
Gy/41 # vs 70.8 Gy/28#
 Preliminary results have been presented in 2015
ASTRO meeting
 At a median FU of 5.9 years, estimated 5 year DFS was
85% vs 86% (Non-inferiority)

92. Extreme hypo fractionation :
FFBF :
LOW RISK 97-100%
INTERMEDIATE 93-97%
HIGH 75-90%

93. SBRT as boost :
 Katz et al.
45Gy/25# f/b 18Gy/3# vs SBRT alone
SBRT alone is better than WPRT
 Oermann et al
IMRT 50.4Gy/28# f/b SBRT 19.5Gy /3 #
good PSA response
 Lin et al.
WPRT 45Gy /25 # f/b SBRT boost 21Gy/3#
biochemical failure free rate – 91.9%

94. SUMMARY – hypo fractionation
 With intermediate follow-up, moderate hypo
fractionation appears safe..
 Long-term results of non inferiority studies of both
methods are required before use in routine treatment
outside of clinical protocols.
 Excellent local control and acceptable toxicity
 There is no survival advantage
 Not a standard of care because of the small number of
patients, less follow up and lack of randomized trials
 However, preliminary results are promising and SBRT
adoption in rapidly increasing

95. ADJUVANT RADIOTHERAPY :
 3-6 months after surgery
INDICATIONS :
• Positive margins and close margins
• pT3 disease
• Extra capsular extension
• Invasion to seminal vesicles ,extra prostatic tissue
• Multiple nodes
• R1 resection

96. Procedure :
 During surgery – 2 fiducial gold seed markers implanted into-
- bladder neck
anastomotic site
TARGET VOLUME:
 Prostate bed, including the bladder neck (which is pulled
down into the prostatic fossa)
 Periprostatic bed clips
 seminal vesicles
◦ + Ve – to include original site also
 Sometimes Remnants of the seen and should also be
treated
◦ - Ve – include base only

97. High risk areas-
 Central: The urethra- vesical anastomosis;
 Cranial: The bladder neck
 Caudal: the apex (15 mm cranially from the penile
bulb)
 Lateral: Up to the neurovascular bundles
 Anterior: Including the anastomosis and the urethral
axis.
Radiotherapy and Oncology 84 (2007)
121–127.. EORTC guidelines

98. POST OP- CTV
 Anterior: posterior edge of pubic symphysis
 Posterior : to anterior aspect of rectum and mesorectal
Fascia .
 Lateral : to medial edge of obturator internus muscles.
 Superior : just above pubic symphysis anteriorly and
including surgical clips or 5 mm above inferior border of
vas deferens.
 Inferior : top of penile bulb or 1.5 cm below urethral
beak or 8 mm below vesicourethral anastamosis
 PTV expansion: 0.6–1.5 cm.

99. Dose :
 we prescribe
50Gy/25#/5wks – tumor bed
45Gy/25#/5wks –nodes
16Gy/9#/1.3 wk---boost to tumor bed
Total dose to tumor bed –66Gy
 the postoperative setting, the prostate bed is typically
treated to 64.8–66.6 Gy at 1.8-Gy per fraction.
 But may be boosted higher if local residual disease is
documented.

101. TRIALS : observation v/s adjuvant
RT
There is increased 5yr QOL with adjuvant RT
compared to observation
EORTC 22911 SWOG8794 ARO 9602
Increase in PSA relapse free survival

102. SALVAGE RT :
 Radiotherapy that is given when a previously undetected
PSA becomes detectable.
 Source :
prostate bed – salvage EBRT
nodal disease – surgery , RT, or systemic
systemic failure – systemic therapy
 Evidence :
controlling local recurrences
decreasing distant metastasis
lowering prostate cancer mortality

103.  AUA/ASTRO guidelines :
grade C recommendation
 Maximum effect when RT is given when
PSA < 0.5ng/ml
 Adverse pathology at radical prostatectomy –
60% risk of biochemical recurrence
hence ideal time to be recognised
ADJUVANT vs SALVAGE RT

104. PALLIATIVE RT
 Locally advanced / unresectable
 Hormone failed patients
 Painful bony metastasis
◦ 20Gy/5# or 30 Gy/10# or 8Gy SF
◦ ↓ pain/ stabilizes bone/ ↓ chances of pathological #
 Multiple painful sites/bony metastasis – hemi body
irradiation
 Cord compression
◦ Palliative XRT
◦ Systemic therapy

105. TOXICITY :
Acute – 60% in 3rd week of RT
• Rectal:
Diarrhea: 25-75%.
Rectal irritation, pain &discomfort: 10-20%.
Tenesmus.
• Urinary:
frequency, urgency, nocturia.
Urinary incontinence (any 0–60%, severe 2–15%).
Fatigue.

106. LATE :
• Chronic diarrhea , proctitis, rectal-anal stricture.
• Bleeding PR- 3.3%, bowel obstruction/
perforation- 0.6%
• Rectal toxicity is proportional to volume of rectal
wall exposed to high dose (any 2–100%, severe 0–
20%) .
• Urinary stricture <4% (higher if prior TURP)
• Erectile dysfunction (10–85%).
• Fatal complication- 0.2%.

107. MSKCC- 3DCRT vs IMRT

108. Late Urinary toxicity :
Meier et al., ASTRO 2012

109. Late Bowel toxicity :
Meier et al., ASTRO 2012

110. Conclusion :
 Radiotherapy dose to Prostate should be 70-75 Gy in low-
risk cases and 75-80 Gy in intermediate and high-risk cases
for tumor control
 Higher dose reduces biochemical relapse in intermediate
and high risk
 No survival advantage with dose escalation.
 IMRT and VMAT are techniques of choice for treatment of
Carcinoma Prostate where dose escalation is required Image
guidance is very crucial for radiotherapy of prostate.
 Proper case selection and target localization is very
important for treatment with newer modalities such as
SBRT, proton therapy , etc.

111. Thank you…