Quick and Easy Notes of Radiation Biology for UG and PG students.

1. Radiation Biology
Effect of Radiation on
Male Reproductive
System
PRANJAL SHARMA
20-PZO-016

2. Male Reproductive System
The testicles are the male reproductive organs. Coiled within each testicle are the
seminiferous tubules. The seminiferous tubules are lined with spermatogonia cells.
These are cells that produce sperm. Semen is the fluid that a man ejaculates. Sperm
are found within semen and are the cells that fertilize a female's egg resulting in
pregnancy. The ability to produce sperm is dependent on adequate levels of hormones,
called FSH (follicle stimulating hormone) and LH (luteinizing hormone). LH and FSH are
released by the pituitary gland, located in the brain.
Testosterone is the male hormone responsible for secondary sexual characteristics
(facial hair, deep voice, mature genitalia) and maintaining normal male sexual function.
Testosterone is produced by Leydig cells, which are found throughout the testicle.

3. ★ Spermatogenesis is a process of dynamic cell differentiation. Ionizing radiation
impairs spermatogenesis, and spermatogonia are more radiosensitive than
spermatocytes or spermatids. Consistent with this assumption and due to
improvement in tumor curability, nowadays, fertility preservation represents a
public health need.
Sources of Radiation in daily life
People are exposed to radiation in mainly two modes:
● From radiation sources outside the body (external exposure).
● From radioactive substances that are inhaled or ingested into the body (internal
exposure).
EXTERNAL EXPOSURE:
● Occupational sources.
● Medical treatments.
● Nuclear weapons,
● reactors or accidents.

4. ● Devices or instruments which work on EMR.
INTERNAL EXPOSURE:
● Intake of radioactive material inside the body.
● Irradiation of the deposited and surrounding organs and tissues by the rays
emitted by radioactive materials.
Negative Effect of Radiation on Males
INFERTILITY : The testicles are very sensitive to the effects of radiation. Radiation can
reduce the number of sperm produced or damage sperm and affect their ability to
function. Temporary or permanent infertility (inability to father a child) can occur
because of radiation to the testicles.
ASPERMIA: Direct irradiation to the testis will, in lower doses, affect the germinal
epithelium: doses of irradiation greater than 0.35 Gy cause aspermia, which may be
reversible. The time taken for recovery increases with larger doses; however, with
doses in excess of 2 Gy aspermia may be permanent.
ERECTILE DYSFUNCTION: Radiation therapy to the pelvic area may cause erectile
dysfunction (ED). ED means that a man can’t get or keep an erection. It happens
because radiation lowers testosterone levels and can affect the arteries that carry blood
to the penis, which is necessary for a firm erection.
LEYDIG CELL DYSFUNCTION: At higher radiation doses (>15 Gy), Leydig cell function
will also be affected. In addition to radiation dose, the vulnerability of the testis is
dependent on the age at irradiation and the pubertal status of the male.
HYPOGONADISM: Another possible effect of cancer therapy on the male reproductive
system is testosterone deficiency, also known as “hypogonadism”. This is the inability to
produce enough of the male hormone, testosterone, and can result from damage to the
Leydig cells or pituitary gland caused by radiation to the testicles or brain.
LOW HORMONAL LEVELS: Brain radiation can result in damage to the pituitary gland
leading to low levels of the hormones (FSH and LH) needed to signal the testicles to
make sperm and testosterone. Males with low levels of these hormones will need to
take testosterone for the rest of their lives. However, it is sometimes possible for these
men to attain fertility with the use of specialized hormone treatments.

5. Effects of radiation on a boy’s (teenager) reproductive
system
Boys who receive radiation to the pelvis may experience:
1. Lack of testosterone production.
2. If the testicles are affected by radiation, they may not produce male sex hormones.
3. A lack of male sex hormones prevents the development of secondary sex changes,
such as growth of facial hair, development of heavy bones and muscles and lowering of
the voice.
4. Low sperm count or temporary zero sperm count (azoospermia) with low doses of
radiation to the testicles.
5. Infertility with higher doses of radiation.
(Infertility may sometimes occur with low doses of radiation because testicular tissue is
very sensitive to radiation).
Every effort is made to shield the testicles from radiation unless they contain cancer, but
sometimes radiation scatter (radiation energy given off outside the treatment area)
occurs and the testicles receive small amounts of radiation that will affect their
functioning.
Effects of cell phone radiation on male reproductive
system
In an experiment, a few male rats were exposed with a mobile phone continuously for 2
hours a day for 35 days. The findings showed a significant decrease in GPx and SOD of
exposed rat sperm (p< 0.001), whereas Catalase activity shows significant increase in
sperm (p <0.001). Also observed the decrease in apoptosis and sperm count in the
exposed group. All datapsilas are expressed as mean plus standard deviation (SD) and
were analyzed by analysis of variance (One way- ANOVA). Our results convey that the
regular use of mobile phones at domestic level can have a negative impact on human
health.
Additionally, sperm are electrically active cells and their exposure to cell phone
electromagnetic waves and currents may affect their motility, morphology and even their
count.

6. Leaky plasma membranes, calcium depletion and oxidative stress are the postulated
cellular mechanisms mediating the harmful effects of cell phones radiation on sperm
and male fertility potentials.
Diagrammatic representation of various source of RF EMF exposure effect
on brain and testicular organ and deleterious outcome

7. Effect of Radiation Therapy
Radiation therapy can cause infertility in two distinct ways:
Primary testicular damage occurs from radiation aimed directly at or near the testicles.
Spermatogonia (sperm forming) cells are extremely sensitive to the effects of radiation
therapy. Doses as low as 600 cGy cause irreversible damage to the sperm forming
cells. Doses less than this may cause a temporary drop in the number and quality of
sperm produced.
The type and dimensions of cancer determine the area of the body to be radiated and
how much radiation will be given. For example, radiation may be delivered directly to
the testicles, as is used for treatment of testicular leukemia and as part of the total body
irradiation used in bone marrow transplant.
Scatter radiation is the term used to describe radiation that occurs in areas not directly
within the treatment field, but near to it. Examples of radiation sites that may result in
scatter radiation to the testis include: radiation to the lymph nodes in the lower abdomen
used for treatment of higher stage Hodgkin's Disease or testicular cancer, or radiation
delivered to the upper thigh for a tumor located in this area. Lead shields are used to
protect the testis when the treatment field is nearby, but small amounts of radiation
exposure may still occur.
Leydig cells are relatively resistant to the damaging effects of radiation therapy. Normal
function remains following exposure or treatment with doses less than 2400cGy. This is
important because Leydig cells produce testosterone, which is required for normal
sexual development and normal sexual activity.
Secondary or indirect testicular failure may occur following radiation therapy to the
brain. Radiation may damage the pituitary gland, located in the brain, which is
responsible for secreting hormones needed for normal sexual function. Pituitary
damage may result in low doses of the hormones (FSH and LH) needed to stimulate the
sperm forming cells and Leydig cells. Both LH and FSH are produced in the brain by the
pituitary gland. High levels of radiation to the brain can damage the pituitary gland,
resulting in an inability to produce the hormones FSH or LH. This in turn causes
infertility and low testosterone levels.
★ Radiation therapy to the reproductive organs as well as radiation near the
abdomen, pelvis, or spine may lower sperm counts and testosterone levels,
causing infertility. Radiation may also destroy sperm cells and the stem cells that
make sperm. Radiation therapy to the brain can damage the pituitary gland and

8. decrease the production of testosterone and sperm. For some types of cancers,
the testicles can be protected from radiation through a procedure called testicular
shielding.
Fertility Preservation Options for Boys and Men
Men and boys with cancer have options to preserve their fertility. These procedures may
be available at the hospital where you are receiving cancer treatment or at a fertility
preservation clinic.
Sperm banking (also called semen cryopreservation) is the most common and easy
option for young men of reproductive age who would like to have children one day.
Samples of semen are collected and checked under a microscope in the laboratory. The
sperm are then frozen and stored (banked) for the future. Sperm can be frozen for an
indefinite amount of time.
Testicular shielding (also called gonadal shielding) is a procedure in which a
protective cover is placed on the outside of the body to shield the testicles from scatter
radiation to the pelvis when other parts of the body are being treated with radiation.
Testicular sperm extraction (TESE) is a procedure for males who are not able to
produce a semen sample. Sperm is collected through a medical procedure and frozen
for future use.
Testicular tissue freezing (also called testicular tissue cryopreservation) is still
considered an experimental procedure at most hospitals. For boys who have not gone
through puberty and are at high risk of infertility, this procedure may be an option.