1. Role of radiation in carcinoma
rectum and colon
Dr Bharti Devnani
Moderator:- Dr Manoj K.Sharma

2. RT for rectal cancer was first introduced in the 1980s, in
an attempt to decrease rates of local recurrence in
patients with locally advanced rectal cancer.
One of the first RCTs to show decrease in local
recurrence with the use of adjuvant therapy was
published in 1985 by the Gastrointestinal Tumor Study
Group (USA)
In the United States, the first official recommendation
for the use of adjuvant chemoradiation in patients with
rectal cancer came from the National Institutes of
Health (NIH) consensus statement, published in 1990.
Set the standard of care for patients with stage II and III.

3. Although postoperative regimens were being
optimized in 1990s within United States, around
the same period investigators in Europe were
exploring the potential benefits of treatment
given in the preoperative setting (Neoadjuvant
RT).
Two different regimens of neoadjuvant RT were
being assessed:
long course RT, used mainly in the United
States; and short course RT, used mainly in
Europe

4. Benefit with addition of preop
RT to Surgery

7. Pre-op RT v/s chemoradiation

10. Preop CTRT v/s postop CTRT

11. German Rectal Cancer Study
N Eng J Med 351;17 october 21, 2004

12. T3/T4/N+
N=421
Preop CT+RT
50.4 Gy/28# with CI 5-
FU1000mg/m2(D1-D5) in 1st
&5th wk foll by Sx at 6 wks and
4 cycles of adjuvant chemo
N=402
Post op setting
–additional
boost of 5.4
Gy

13. Local recurrence 6%
v/s 13% (p=0.006)
NO OS benefit

14. Rate of sphincter preservation -39% v/s 19%-more than
double

15. Acute and long term toxicities are less
Arm No of
pts
Any grade
3-4 acute
toxicity
Grade 3-4
acute
diarrhea
Any grade
3-4 long
term
toxicity
Stricture at
anastomotic
site
Preop CT
RT
405 27% 12% 14% 4%
Postop CT
RT
394 40% 18% 24% 12%
‘p’ value 0.001 0.04 0.001 0.003
Preop CTRT improved local control with reduced toxicity
and more sphincter preservation rate

16. No OS benefitBenefit in local control persisted at 11 yrs
Update of german trial

17. ADVANTAGES OF PRE-OP
CHEMORADIATION

18. 1.Tumor tissue is better oxygenated so irradiation
is more effective
2.Downstaging of the tumor leads to:-
More curative surgery
Conversion of APR to sphinctor preservation
(rate is doubled 39% v/s 19% in german study )
3.Local recurrence decreased
(6% v/s 13 % with a ‘p’ value of 0.006)
4. Compliance is better (Better tolerated)

19. With postop RT the soft tissues of the perineum
are at risk, for involvement after an APR because
of surgical manipulation and, need to be irradiated
with acute skin toxicity.

20. With postop RT, normal bowel is moved into the
pelvis for the anastomosis after a LAR & is
irradiated leading to late toxicity.
In the preoperative setting much of the
irradiated bowel is removed with the surgical
specimen and therefore is not at risk for
producing late bowel injury.
Avoidance of radiation to the neorectum.

21. Reduction in the risk of tumor seeding during
surgery.
Avoiding Tt. delays due to prolonged post-op
healing.
Higher pCR rates

22. Disadvantages
 Overtreatment of early stage tumors
(18 % in german study)
 Delay in surgery
 Wound healing problem

23. Indications of RT

24. Preoperative RT
For stage II-III resectable disease
Definitive treatment
Unresectable/unfit for surgery
Small rectal cancer
Palliative radiation
Advanced disease
For metastatic sites(liver SBRT etc)
IORT
Incomplete resection
Residual/recurrent disease

25. Preoperative setting
Preop CT RT for
Stage II –III disease
Stage II (T3 and
T4 disease)
&
Stage III that is
(any T with Nodal
positivity)

26. Postop Radiation

27. Synchronus metastasis

28. Techniques of Radiation

29. RT portals
1. Whole pelvic field:
PA/AP
 Lateral border - 1.5 cm
lateral to the widest bony
margin of the true pelvic
walls
 Distal border: 3 cm below
the primary tumor or at the
inferior aspect of obturator
foramina, whichever is the
most inferior
 Superior border: L5-S1
junction

30. RT portals
B: Lateral
 Posterior border: 1 to 1.5 cm
behind the anterior bony sacral
margin
 Anterior border:
1. T3 disease: post margin of
the symphysis pubis(to
treat only the internal iliac
nodes)
2. T4 disease: ant margin of
the symphysis pubis (to
include the external iliac
nodes)
T3
T4

31. RT portals
3. After an abdominoperineal
resection:
Wire the perineal scar
and create a 1.5 cm
margin beyond the wire
fields.
Bolus the perineal scar
every other day to bring
the dose to 100%

32. Methods to Decrease Radiation
Toxicity
RT technique
Physical maneuvers
Sequencing of RT and surgery
Surgical maneuvers in patients treated
postoperatively
Pharmacological approaches and radio
protectors

33. RT technique

34.  High-energy (>6 MV) linear accelerators.
 All fields should be treated each day.
 Shaped blocks and wedges on the lateral fields.
 A wire at the perineal scar after APR help to
guide field design.
 Small bowel contrast used to help Shielding of
small bowel.
 Rectal contrast :-Barium sulfate is injected with a
Foley catheter.
 Bladder protocol
 Computerised radiation dosimetery

35.  Multiple-field technique (3 or 4 field )
 3 field (PA + lat)rather than 4 field is preferred
in:-
 In males if the genitalia are in the treatment
field
 Colostomy is present
 For perineal scar coverage separate perineal
field should not be used(should be included in
the pelvic radiation field)

36. Physical Maneuvers

37. Prone position with abdominal wall
compression and bladder distension
Treatment in the prone position without
abdominal wall compression was not
consistently effective in displacing small bowel
and in some patients, most commonly
obese, the volume of small bowel increased.

38. Prone position with
Abd wall compression
and bladder distension
Immobilization molds
(belly boards)
Shanahan and colleagues reported that the
combination of the prone position and
immobilization molds decreased the mean
small-bowel volume in the radiation field by
66% compared with patients treated in the
supine position without the immobilization mold.

39. Sequencing of RT and surgery

40. Preop CTRT preferred :-
 Less acute and chronic toxicities
 Mobile small bowel
 Coverage of perinium not required
 Strictures at the anastomotic site reduced

41. Surgical maneuvers in patients
treated postoperatively

42.  Placing surgical clips
 Placement of an absorbable Dexon or Vicryl
mesh temporarily remove the small bowel from
the pelvis.
 Other methods:-
 Construction of omental pedical flap
 Small bowel displacement prosthesis
reconstruction of pelvic floor
 Retroversion of uterus

43. Pharmacological approaches
and radio protectors

44.  Sucralfate enemas
 Olsalazine
 Mesalazine
All of these trials
have been negative
Final Results of a Randomized Phase III Trial of
Chemoradiation treatment Amifostine in Patients with
Colorectal Cancer: Clinical Radiation Oncology Hellenic
Group
By Antonadou et al
Amifostine significantly reduced the incidence of grade 2
gastrointenstinal toxicity. There was no evidence of
compromised treatment efficacy.

45. Advantages with conformal
techniques

46.  Ability to plan and localise the target and
normal tissues.
 Less toxicites
 Obtaining DVH
 More conformal plans

47. Target delineation as per RTOG
contouring guidelines

48. Sites of recurrence

54. Short course v/s long course RT

56. Results of Polish trial
ARM SC LC
pCR(%) 1 16
Radial margin
positivity(%)
13 4
Sphinctor preservation(%) 58 NS 61
Early radiation toxicity 3 18
LC DFS & late toxicity NS

57. 326 patients
radomaly
assigned
Long course
RT
50.4 Gy @ 1.8 in 5.5 wks with
CI 5-FU foll by Sx at 4-6 wks &
4 cycles adj CT
Short course
RT
RT 5x5 in 1 wk foll by early Sx & 6 cycle
adj CT

58. No difference in OS
Locoregional recurrence
No stastically significant
difference but
• Favouring long course
•pCR better with long course
•Long course better for distal
tumor (12.5% v/s 0%)

59. Endocavitory Radiation
(Papillon technique)
Papillon is the name of the
French professor
from Lyon who popularised this
technique.

60. Selection criteria
Early noninvasive tumors
For more advanced tumors (T2,T3) used in conjunction
with BT or XRT
G1-G2 tumors
Without deep ulceration
With in 10 cm from dentate line
Tumors with diameter <3 cm (size of the proctoscope is
3 cm)

61. Method
 Anus is dilated
 4-cm proctoscope
is introduced.
 low-energy x-ray
(50-kV x-rays) unit is placed
through the scope against
the tumor.
 Delivered at 30 Gy per fraction in three or four fractions
over 1 month.

62. Local control rates of 76% can be achieved at 10 years after
treatment with this technique

63. Lyon technique
Créteil technique
Template technique

64. Intra-operative Radiotherapy (IORT)
IOERT HDR-BT

65. Intra-operative Radiotherapy (IORT)
Tumor site accessible to IORT applicator
Locally advanced tumor
Recurrent tumor
Tumor not resected/Gross residual tumor
Positive surgical margin
Critical structures (dose limiting) are excluded

66. Advantages with IORT
Radiation can be delivered at the time of
surgery to the site with highest risk of
local failure
Normal tissue sparing
Very useful in recurrent setting

67. Dose
Ro resection:-7.5-10 Gy
R1 resection:-10-12.5 Gy
R2 resection:-15-20 Gy

68. Chances of local failure decreased
In margin negative cases from 15% 11%
After R1 resection 83% 32%
After R2 resection 83% 43%

70. Side effects and managment

71. Early complications
 Diarrhea
 Increased bowel frequency
 Dysuria
 Acute proctitis
 Malabsorption of fat,carbohydrate,protein and
bile salts
Mechanism:- depletion of actively dividing cells

72. Late complications
Small bowel obstruction
Bleeding
Persistent diarrhea
Scrotal/perineal tenderness
Urinary incontinence
Stricture
Second cancer

73. Role of RT in colon cancer
Treatment recommendations should be made on a
case-by-case basis with existing data in setting of an
informed consent.
Adj tumor bed RT with concurrent 5-FU based
chemo should be considered for pts with tumors
(a) invading adjoining structures
(b) those complicated by perforation or fistula
(c) Incomplete resection is performed

74. THANK YOU