Radiation therapy techniques like external beam therapy, brachytherapy, and chemotherapy are used to treat cancer. External beam therapy uses radiation sources like cobalt-60 or a linear accelerator to emit beams that target cancer cells. Quality control ensures accurate radiation doses. When blood is exposed to radiation, white blood cells like lymphocytes and granulocytes are most affected, followed by red blood cells and platelets. Future work could study the effects of radiation on blood inside the body and for specific conditions like brain cancer.

1. Radiation Oncology Techniques and
Effect of Radiation on Blood
Amit Kr
A12423911001

2. Cancer and Oncology
• Cancer is uncontrolled growth of cells. They grow
and form new cancerous cells.
• Not all tumors are cancer; tumors that aren’t cancer
are benign.
• Why uncontrolled growth?
• Treatment of cancer is opted on the basis of medical
reports and type of cancer.

3. Cancer and Oncology
• Types of treatment techniques-
1. External Beam Therapy
2. Brachytherapy
3. Chemotherapy

4. Causes and Types of cancer
• DNA damage may be caused by inherited
genetics, cigarette smoking or sun exposure, or
other environmental factors (Diet, Obesity,
Infections, Stress, and Lack of physical activity,
Environmental pollution, and Radiation). It is
difficult to know exactly
what caused any one person’s cancer.

5. Causes and Types of cancer
• Carcinoma
• Sarcoma
• Lymphoma and leukaemia
• Germ cell tumor and
• Blastoma

6. Treatment Techniques
SMS medical college provides cancer treatment by following
techniques
• Teletherapy
• Linear Accelerator
• Brachytherapy

7. Teletherapy
• Working-
• Main Components-
A. Radioactive source,
B. Source drawer,
C. Source head,
D. Collimator and gantry,
E. Base housing,
F. Patient support system and
G. Control console.

8. Radioactive Source
• Cobalt-60 is used as a gamma source in Bhabhatron.
Cobalt-60 emits high-energy gamma rays of 1.17
MeV and 1.33 MeV. Bhabhatron has the capacity to
load a 15 kilocurie source.

9. Source Drawer
• The source is assembled in a source drawer. The pneumatically driven
drawer moves the source between shielded (beam-off) position and
treatment (beam-on) position. The cylinder will withdraw the source
automatically to beam-off position, in case of any emergency. In
beam-off position, the shape, size and location of the radiation beam
can be visualized using a light beam.

10. Source Head
• Source head is a heavily shielded container. Depleted uranium
and lead are used as shielding materials in the source head.
Low source-to-skin distance of 80 cm is achieved, by compact
design of the source head and the collimator.

11. Collimator and gantry
• The collimator assembly controls the size, shape and orientation of the
radiation beam. It’s fully closable collimator. During any emergency,
the collimator closes fully, protecting the patient from over-exposure.
Two sets of trimmers are provided to reduce the penumbra of the beam.
• Gantry holds the source head and counter weight. It can rotate around
the patient on a horizontal axis by ±180°, allowing source positioning at
any point on a circle of 80 cm radius.

12. Base Housing and mainframe:
• The gantry is mounted on the mainframe. Entire unit is mounted on a steel base below
floor level. The base supports the mainframe.
Patient Support System:
• The patient positioning table or couch consists of a turntable mounted eccentrically with
the isocentre.
Control Console:
• Bhabhatron controller is fully computerized. Data of treatment session registered on
hard disk can be retrieved for control and analysis. Many safety interlocks are provided,
to prevent the patient from over-exposure to radiation.

13. Gap Correction
• There is a chance that some patient may miss their treatment
and report later, I this case we use gap correction. The gap
correction can be calculated by the formula-
𝐷𝑒𝑐𝑎𝑦 𝑓𝑎𝑐𝑡𝑜𝑟 = (
𝑡𝑟𝑒𝑎𝑡𝑒𝑑 𝑑𝑎𝑦𝑠
𝑇𝑟𝑒𝑎𝑡𝑒𝑑 𝑑𝑎𝑦𝑠+𝑟𝑒𝑠𝑡 𝑑𝑎𝑦𝑠
)^0.11
Here is data of some patient who missed their treatment for a few
days-

14. DATE PATIENT ID Treated Days Rest Days T+R Decay Factor
11-03-2015 1
10 20 30 0.886169221
11-03-2015 2
17 15 32 0.932787857
12-03-2015 3
4 35 39 0.778411946
18-03-2015 4
9 84 93 0.773452329
19-03-2015 5
9 53 62 0.808730068
28-03-2015 6
1 29 30 0.687886303
07-04-2015 7
8 173 181 0.709570016
15-04-2015 8
1 62 63 0.633975594
17-04-2015 9
12 134 146 0.759680752
18-04-2015 10
3 200 203 0.629011773

15. Linear Accelerator
Working-
Electrons are not accelerated by drift tube structure of
electrode, instead of that a waveguide is used for acceleration. A
traveling electromagnetic wave is made to propagate along the
axis of a metallic cylinder. This cylinder is known as waveguide.
Main Components-
Gantry;
a) Gantry stand or support;
b) Modulator cabinet;
c) Patient support assembly (i.e. treatment table) and
d) Control console.

16. LINAC Layout

17. Quality Control of Beam:
There are several systems built into the accelerator so that it will not deliver
a higher dose than the radiation oncologist has prescribed. Each morning
before any patients are treated, the radiation therapist performs checks on
the machine using a piece of equipment called a "tracker" to make sure that
the radiation intensity is uniform across the beam and that it is working
properly. In addition, the radiation physicist conducts more detailed weekly
and monthly checks of the linear accelerator

18. Quality Control of Beam:
Linac has two radiation detectors (ion chambers) to
calculate the dose given to patient. Dose is preset in the
system and as the desired dose is achieved beam is
closed

19. Effect of Radiation on Blood
When body is exposed to radiation it’s the blood that is always affected by the
radiation because every organ and tissue remains in life by blood supply and it’s
sensitivity to radiation also contributes to radiation effectiveness.
Irradiation of Blood outside the body is also practiced for research purpose as
well as in blood banks.

20. Blood Components
Blood Cell Components
Leukocytes (WBC) 1. Granulocytes (Neutrophils (or polymorphonuclear leukocytes), Eosinophils, Basophils)
2. Lymphocytes
3. Monocytes
Erythrocytes Red blood cells
Thrombocytes Platelets
Plasma Plasma proteins (Albumin Thrombin),
Globulins
(Alpha 1, Alpha 2, Beta, Gamma, Factor VIH (antihaemophilic globulin), Fibrinogen
Prothrombin, Plasma thromboplastin)

21. On an average five millions cells of Red Blood Cells per microliter are found in
human body (A 60 Kg person has 4.2 litres of blood in his body). WBC or White
Blood Cells count comes around 7000/µL and 64% of it is Granulocytes and 4% is
Lymphocytes.
RBC in Adults (males): 4.6 to 6.0 millions
(Females): 4.2 to 5.0 millions
Platelets that are responsible for preventing internal bleeding in human body
have their count from 150,000 to 450,000 per microliter of blood. Risk develops
when this count is decreased to 20,000. The blood was tested at CBC facility of
SMS Medical College Blood Bank.
Blood Components

22. Calculations and Results
• 𝑇𝑖𝑚𝑒 =
Required Dose
Calibrated Dose(per Second)∗Collimator Scattering 𝐹𝑎𝑐𝑡𝑜𝑟
S.No. Dose to be given (Gy) Time required (Minutes)
1. 2 1.52
2. 6 4.56
3. 10 15.2
4. 20 30.4
5. 50 76.01

23. 0
1
2
3
4
5
6
0 10 20 30 40 50 60
Counts(millions)
Counts(Gy)
RBC
Platelates

24. 0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
0 10 20 30 40 50 60
BloodCounts(Thousands)
Dose (Gy)
Granulocytes
Lymphocutes

25. 0
1
2
3
4
5
6
0 10 20 30 40 50 60
RBC
Platelates
Granulocytes
Lymphocutes
L>RBC>Granulocytes>Platelets

26. Future Work
• 1. Blood irradiation can be done inside the body and
recovery of cells can be seen by taking samples time to time.
• 2. Effect on Head & Neck and Lung can also be checked after
irradiation for hypoxic condition.
• 3. Brain cancer patient can be a volunteer to see the effect
of radiation on brain as oxygen level is very low here.
• Blood Banks may use irradiation facility. (in some countries
this facility is available)

27. Thank You