corrections and suggestions are welcome.

1. TOTAL
BODY
IRRADIATIO
N
PRESENTED BY : KATYA
MODERATED BY: MR MAYANK
TYAGI

2. INTRODUCTION
 TBI is used as a part of myeloblative
conditioning regimen for bone
marrow transplantation in treatment
of variety of diseases such as
leukemia, multiple myelomas,
autoimmune disorders etc.
 patients are prepared for
transplantation with chemotherapy
combined with TBI.
 TBI was started in 1956 by Dr. ED
Thomas to treat patients with end
stage leukemia.
 He was awarded Nobel prize for
medicine in 1990.

3. PURPOSE OF TBI
To
eradicate
diseased
bone
marrow.
To
reduce
tumor
burden.
Immunosupr-
ession to
create space
for new
marrow.

4. TARGET VOLUME
WHOLE BODY,
including SKIN
All malignant
cell including
those
circulating.
Whole cellular
immune system.

5. INDICATIONS
 Leukemias: ALL,AML,CML.
 Lymphomas
 Multiple myeloma
 Pediatric solid tumors
 Neuroblastoma
(experimental)
 Ewing’s sarcoma
 Aplastic anemia
 Autoimmune disease
 Inborn errors of metabolism

6. EQUIPMENTS REQUIRED
 LINAC or cobalt with large treatment room
dimensions .
 simulator.
 Positioning devices and aids .
 Beam modification devices like (compensators,
bolus, shieldings, beam spoilers).
 Computers for dose calculation and planning.
 Dosimetry and calibration devices.

7. CONVENTIONAL
TECHNIQUES
FOR TBI
DELIVERY
 Bilateral TBI.
 AP/PA TBI.
 Translational
couch based.

8. Bilateral TBI
 Irradiation with bilateral
fields with patient
treated in semi-fetal
position.
 Patient seated
comfortably with back
supported & legs semi
collapsed.
 Arms positioned laterally
to shadow the lungs
instead of spinal
column.
Advantage:
 Comfortable for patient
Disadvantages:
• Less homogeneous dose
distribution due to variable
body thickness.
• Does not allow effective
shielding of lungs and kidney.

9. TRANSLATIONAL COUCH
 Patients are transported
through a vertical 6MV
photons beam in supine and
prone positions while lying on
the couch.
 Source to couch distance is
fixed at 160cm.
 Disadvantage-complicated
Dosimetry due to moving
beam dose delivery.

10. AP/PA TECHNIQUE
 The most common and
standard irradiation technique.
 Patient can stand or lie down
on their side on a gurney.
 ADVANTAGE:
 less thickness variation of the
body, hence more dose
homogeniety.
 More Effective shielding.
 DISADVANTAGE :
 Patient fatigue leading to poor
reproducibility.
A TBI setup in which the
patient lies on their side on a
gurney.
Standing TBI

11. TECHNICAL PARAMETERS
 Patient height - is recorded to determine
source-to-surface distance to
appropriately fit the patient within the
beam with sufficient margin. (5cm)
 Position Standing or lie down,Hands by
 extended SSD between 200 to 600 cm
(Shorter SSDs : multiple fields required).
 Field size - 40*40cm sq or 35* 35cm sq.

12. Contd...
BEAM ENERGY -Photon beams in 6-10 MV
are used .
Dose rates - 6to15cGy/min
Gantry -rotated at 90 or 270
degrees.
Collimator- rotated at 0 or 45 degree.
AP separation- are measured at:
forehead, Neck, chest, abdomen, pelvis,
thigh, knee, ankle for dosimetric purpose.
purpose.
In vivo dosimetry is done by medical

13. Position of patient and comfort should be a
priority as treatment times may last up to 30 or
40 minutes.
Patient positioning parameters depends on:
 Patient comfort.
 Campatible with treatment plan and technical parameters.
PATIENT POSITIONING

14. TBI stand
COMPENSATORS
 Dose homogeneities due to body contour
can be overcome by using tissue
compensators.
 Tissue compensators are used in:
 Head and neck region
 Lower extremities.
 Raise the patient height to prevent
under dose near extremities.
 Hand bars and a bicycle seat is present
for additional support.
 The stand allows a slotted plastic tray
to be attached for
blocks,compensators.

15. Beam spoilers
 Special beam modification
device where shadow tray
made up of acrylic or Lucite
is placed approx 10-15cm
from the patient.
 It produces scattered
electrons, which deposit
most of their energy at
shallow depths near the skin
surface.

16. SHIELDING
organs at risk (OAR):
 Lungs (major dose limiting structure)
 lens of the eyes.
 heart
 gonads .
 previously irradiated sites.
 liver and kidneys may require partial shielding.
 Shielding can be done by using:
 Cerrobend alloy based blocks.
The position of shields are verified under treatment conditions
conditions prior to each session.

17. DOSE PRESCRIPTION
POINT
The TBI dose is prescribed at Midpoint,at the
level of the umbilicus.
Dose and
fractionation
12Gy total in 6# in 3
days.
2Gy each # with min 6
hr gap

18. BASIC APPA TBI SET UP

19. ACUTE COMPLICATIONS
Nausea and
vomiting Headache Fatigue Ocular dryness
Esophagitis Loss of apetite Erythma
hyperpigmentat
ion
Mucosities Diarrhea Fever

20. CHRONIC COMPLICATIONS
Ocular –
cataract,
dryness,
keratitis.
Salivary gland –
xerostomia
dental caries,
tooth
abnormalities.
Pneumonitis. Hepatotoxicity.
Radiation
nephropathy.
Growth
abnormalities in
children.
Sterility or
endocrine
abnormalities.
risk of
Secondary mets.

21. ADVANTAGES OVER
CHEMOTHERAPY
No sparing of sanctuary sites
(testis,brain).
Dose homogeneity regardless of
bloodsupply.
Independent of hepatic& renal functions.
Ability to tailor the dose distribution by
shielding specific organs or by boosting
specific sites.

22. CHALLENGES OF TBI
Dose homogenity hard to
maintain due to variable
body thickness.
Large room requirements.
Complex and stringent
dosimetry and QA program
me.
Labour intensive and time
consuming..
Long list of acute
and chronic
complications.

23. Total marrow Irradiation
(conformal)

24. Total marrow Irradiation (conformal)
 TMI is targeted and conformal form of TBI delivery.
 Increasing numbers of centers have begun to use 3-D
planning, IMRT and inverse planing for targeted tbi
delivery.
 With IMRT based TBI there is:
 Increased conformality & OAR sparing.
 3D,CT-based simulation and planning.
 No need for specialized equipment such as partial
shieldings ,beam spoilers etc.
 Dose escalation possibility.
 Reduced treatment time and more patient comfort.
 VMAT and tomotherapy are preferred techniques for TMI.

25. PROCEDURE
 Patient is treated in supine position.
 Full Body immobilization using vacloc and thermoplastic casts.
 Planing ct from vertex to mid femur with 3mm slice thickness
 4D CT to evaluate organ motion.
 All the bone marrow in body from head to femur are included in
target volume.
 For lower extremities simple AP/PA field is sufficient.

26. • Slice by slice treatment delivery with
fan beam thickness from few mms to
5cm.
• Target volume that can be treated upto
is 135cm.
• Atleast 3 plans are required for:
head&neck,thorax,pelvis.
• Alternative to tomotherapy.
TOMOTHERAP
Y
VMAT

27. ROLE OF
RADIATION
THERAPY
TECHNOLOGIST
 Patient counselling and assessment of the
patient's tolerance during the treatment
course.
 Setting up the patient in the treatment
position using appropriate treatment
devices.
 Position of patient should be comfortable
and reproducible, as treatment times may
last up to 30 or 40 minutes.
 Operating the machine & Maintaining visual
and audio contact with patient.
 To construct shielding blocks/compensators
and place them according to treatment
plan.
 Keep detailed records of treatment.
 Assisstance in image matching.
 Co-ordination of patient care with other
services like oncology, wards, nursing etc.

28. CONCLUSION
 TBI/TMI are one of the most
challenging technique.
 It requires clinical knowledge and
specialized treatment setup as well
as the presence of trained staff .
 ±10% of inhomogenity in the
prescribed dose is accepted.
 Overall accuracy of dose delivery of
± 5% is recommended.
 Conformal techniques are the
present and future of TBI due
to their better OAR sparing,
reduced field size and
homogeniety in dose
distribution...

29. THANK YOU!!