It is the summed up representation of total body irradiation and hemibody irradiation.

1. HEMIBODY & TOTAL BODY
IRRADIATION
Dr. Dhiman Das
2nd year resident.
Dept. of Radiotherapy
Medical College & Hospital
kolkata

2. Total Body Irradiation
• TBI is a special radiotherapy technique
that delivers to a patients whole body a
dose uniform to within +/- 10% of the
prescribed dose.
• It is performed as conditioning regime

3. Journey started only a decade after
discovery of X-ray by German
biophysical engineer Friedrich J.
Dessauer

4. • In 1907, Aladár Elfer,a medical professor in Hungary,
reported his experience using a TBI technique .
• Arthur C. Heublein, in collaboration with Gioacchino
Failla, is credited with the development of the first TBI unit
in North America, located at Memorial Hospital in New
York City.

5. • In 1959, a kidney was successfully
transplanted between dizygotic twins after TBI
at exposures of up to 450 R.
• In 1957, Nobel laureate E. Donnall Thomas first
reported the use of bone marrow infusion in
humans following whole body irradiation or
chemotherapy, and less than 1 year later he
published his experience in using TBI with
exposures up to 600 R followed by bone
marrow transplantation.

6. Diseases treated with TBI
• Malignant
– Leukaemia.
– Aplastic anaemia.
– Lymphoma.
– Multiple Myeloma.
• Non Malignant
– Autoimmune
Diseases.
– Inborn errors of
metabolism.
– Aplastic anaemia

7. Mode of Action
1. Cytotoxicity-Destroy the bone marrow &
tumour cells of the recipient.
2. Immunosuppression-Immunosuppress
the patient sufficiently.

8. • auto-SCT
– cytotoxicity
• allo-SCT
– cytotoxicity
– immunosuppression

9. Types of allo-SCT
Myeloablative
a) immunosuppression
b) To create space in bone
marrow for donor cells.
c) To provide further
cytoreduction.
• Example- total dose of 12-
15Gy
Nonmyeloablative
• Mainly a) & b)
• c) to a much lesser degree.
• Example- 2Gy single #

10. Types of TBI
TOTAL DOSE NO. OF #
1.HIGH DOSE TBI 12Gy 1-6
2.LOW DOSE TBI 10-15cGy/# 10-15
3.TOTAL NODAL
IRRADIATION
40Gy 20

11. TBI based regime vs Chemotherapy alone

12. To conclude..
• TBI
• Pros.
 Access to sanctuary sites
 Controllable dose delivery.
• Cons.
 Interstitial pneumonitis.
 Catarct.
 Endocrine deficiency
• Chemotherapy.
• Pros.
 No special arrangements
needed like TBI
• Cons.
 Hepatic VOD/SOS.(BuCy)
 Haemorrhagic
cystitis.(BuCy)
 Seizures.(oral busalphan)

13. Mode of Delivery
A. Dedicated irradiator.
B. Modified conventional irradiator.

14. A. Dedicated Irradiators.
1. Treatment at extended SSD.

16. 2.Treatment at standard SSD after the
Co⁶°collimator is removed.

17. B.Modified Conventional Irradiator.
1.Treatment with a translational
beam

18. 2.Treatment with a sweeping
beam.

20. Choice of Technique
• Depends on-
Available equipment
Photon beam energy
Maximum possible field size
Treatment distance
Dose rate
Patient dimension

21. Choice of Beam Energy

22. Choice of Portals
1. AP/PA.
o Pros –
a) Better dose uniformity along the longitudinal
body axis.
b) Convenient for treating small children.
o Cons-patient positioning (other than standing
upright) may pose problem.
 Developed in Memorial Sloan Kattering hospital,New
York.
 Shielding (Dusenbery & Gerbi)- Lung,kidney, Brain.

24. 2.Bilateral TBI
• Pros-
– More comfortable to the patient.
• Cons-
– Greater variation in body thickness along the path
of the beam.

26. Patient
positioning
• Semifetal
position(khan et
al.)
• Arms are
positioned
laterally to follow
the body contour.
• Arms should
shadow the lungs,
not the Spinal
Column.
• Pt set-up.
• SAD

27. • Compensators
are designed for
H&N ,lungs,legs.
• Reference
thickness for
compensator is
the lateral
diameter of the
body at the level

28. Compensator Design
• Challenges –
– Large variation in body thickness.
– Lack of complete body immobilisation.
– Internal tissue heterogeneities.

29. Compensator Thickness along a ray
line
a) Tissue deficit, compared to the reference
depth at the prescription point.
b) Material(density).
c) Distance from the point of compensation.
d) Depth of the point of compensation.
e) Field size.
f) Beam energy.

30. Thickness Ratio(τ)
• The required thickness of a tissue equivalent
compensator that gives the same dose at the
point of interest as would a bolus of thickness
equal to the tissue deficit.
• For TBI an average value of 0.7 provides good
approximation of all beam energies &
compensation conditions.

31. Formulae to obtain compensator
thickness
1.
• Tc=comp thickness
• TD=tissue deficit
• Ρc=density of comp
2.
• I/I̥=doses before & after
comp added.
• T(Aᴿdᴿ) &T(A d)=TPR for
ref body section & sectn
to be compensated.

33. Dosimetry
A.Directly
• By using a 0.6cmᵌ Farmer-
type ionisation chamber
placed in a 40cmᵌ water
phantom.
• By placing TLD
capsule/chips in strategic
locations in body.(in-vivo
dosimetry)
B.Indirectly
• By using this formula.

34. Adverse effects
In nonmyeloablative regimen
Acute
Nausea
Vomiting
Long term
cataract

35. Adverse effects
In myeloablative regimens
Acute
 Nausea, Vomiting
 mucositis
 Diarrhoea
 Xerostomia
 Headache
 Fever
 HTN
 Reversible alopecia
 Parotiditis
Long-term
 Lung-interstitial
pneumonitis.
 Lens-cataract.
 Growth & gonadal &
Endocrine effects.
 Liver-VOD & SOS
 Kidney.
 2° cancers.

36. HEMI BODY IRRADIATION
• INDICATIONS-
– To alleviate symptoms in metastatic diseases.
– Delaying progression of existing
asymptomatic mets.
– Defers development of new mets.

37. Difference with TBI
• Different therapeutic goal.
• Smaller field size.
• Lesser side effects

38. Technique
• Bottom of L4 separates uper & lower half.
• A/P parallal opposed fields.
• Patients positioned with vertical beam
allowing coverage of hemibody.
• Necessary shielding.
• Dose prescribed to mid-plane of the
patient at the central axis of the beam.

39. Dose
• Upper HBI-6Gy
• Lower HBI-8Gy
Rx for other half
• Wait for 6-8 weeks.

40. Side effects
Nausea ,vomiting(M/C)
Fatigue.
Cough, breathlessness.
Interstitial pneumonitis.
Reversible alopecia
Dry mouth, stomatitis.
Parotid swelling.