Radiation therapy has also become a most important part of cancer treatment

1. RADIATION THERAPY
Ms. NISHA MATHEW

2. INTRODUCTION
It is the use of ionizing radiation as a
part of cancer treatment to control or
kill malignant cells.
It is used as curative, adjuvant,
neoadjuvant, therapeutic or palliative.

3. Principle of radiation therapy
It works by
damaging
DNA either
by direct
or indirect
ionization
of atom.

4. Dose
 The amount of radiation used in photon
RT is measured in gray(Gy), and varies
depending on the type and stage of
cancer being treated.
 For solid epithelial tumor: 60-80 Gy
 Lymphomas :20-40 Gy
FRACTIONATION
The total dose is fractioned (spread out
over time).
for e.g:1.8-2 GY per day,five days a week.

5. Techniques of radiation
therapy
 Teletherapy
 Brachytherapy
 Systemic radiation therapy

6. Radiotherapy machines
 Linear accelerator machines

8. Brachytherapy

9. Teletherapy
 EBRT: External beam radiation
therapy
 Stereotactic radiation:
 Virtual simulation
 3D CRT: 3 Dimensional conformal
radiation therapy
 IMRT: Intensity modulated radiation
therapy
 IGRT: Image guided radiation therapy

10. EBRT
 External beam radiation therapy
 Treatment is planned on simulators to
achieve a desired plan.
 Aim of simultaion- accurately target or
localize the volume to be treated

11. Stereotactic Radiation therapy
 Focused radiation Beam targetting a
well-defined tumor using extremely
detailed imaging scans
 Two types:
1. Stereotactic Radiosurgery(SRS): use of
single or several stereotactic radiation
of Brain & Spine
2. Stereotactic Body Radiation
Therapy(SBRT): Use of one or several
stereotactic radiation with the body such
as Lungs.

12. Virtual Simulation
 Allows more accurate placement of
radiation beam
 Normal tissues are protected.

13. 3 Dimensional conformal
radiation therapy
 Profile of each radiation beam is
shaped to fit the profile of the target
from a beam’s eye view using a multi-
leaf collimator

14. Intensity modulated Radiation
Therapy
 Next Gen 3 DCRT
 Highly tailored computing applications
 Radiation dose consistent with the 3D
shape of tumor by Controlling,
modulating, radiation beams intensity

15. Difference in 3DCRT & IMRT

16. Image guided radiation
therapy
 Real time Images with real time
adjustments of therapeutic beams

17. Brachytherapy
 Intracavitary
 Intraluminal
 Interstitial

18.  Intracavitary

19.  Interstitial

20.  Intraluminal

21. Systemic radioisotope therapy
 Through IV or Oral route
For eg:In NEUROBLASTOMA- MIBG(
meta-iodo-benzyl guanidine) given IV.
In thyroid cancer Iodine 131 IS GIVEN
ORALLY

22. Radiation safety
 ALARA philosophy: as low as
reasonably achievable
 Lead aprons
 TLD badges
FACTORS AFFECTING
 Time
 Distance
 Intensity

24. Side effects
 Nausea and vomiting
 Damage to epithelial surfaces
 Fatigue
 Skin irritation
 Swelling
 Infertility
 Fibrosis
 Dryness
 Epilation or alopecia