Radiotherapy in gynaecology

Radiotherapy In Gynaecology

Prof. M.C.Bansal
MBBS., MS., FICOG., MICOG.
Founder Principal & Controller,
Jhalawar Medical College & Hospital Jjalawar.
MGMC & Hospital , sitapura ., Jaipur

RADIOTHERAPY IN GYNAECOLOGY

 Introduction
 Radiotherapy plays a major role in the treatment of
patients with Gynaecological malignancies.
Computer technology and information system have
transformed many aspects of radiotherapy practices
in last two decades.
 Three dimensional treatment planning based on
computed tomography (CT)and MRI, optimized
inverse planning , computer controlled treatment
delivery and remote after loading Brachytherapy.

 Introduction(contd)
these techniques enable radiation oncologists to
restrict radiation dose distribution to
specified target volumes .
 Maximal dose is delivered to tumor ,while normal tissue
is spared as much as possible.
 In1999 –2000 , results of randomized clinical trials
demonstrated a significant improvement in pelvic
disease control and survival when concurrent
chemotherapy was added to radiotherapy for patients
with locally advanced cervical cancer.
.


 Radiation Biology
 Cellular effects of ionizing
1. Cellular death defined as the loss of clonogenic capacity e.g.
inability to reproduce because of mitotic cell death.
2. Ionizing radiation may also cause programmed cell death
(apoptosis)
3. The critical target for most radiation induced cell death is the
DNA within the cells nucleus - Photons or charged particles inter
act with intra cellular water to produce free radicals . Free
radicals interact with DNA causing Breakage –Inability to
reproduce.
4. Such Reproductive cell death may not be expressed
morphologically until days and months . Some cells may still
continue to divide before they die.
5. Apoptosis ( programmed cell death) may also play an
important role in radiation induced cell death. The plasma
membrane and nuclear DNA may both be important targets for
this type of death.


 Fractination
 Conventional radiotherapy is usually given in a
fractionated course with daily doses of 180-200
cGy ( centi Gray)
 The difference between the Fractionation sensitivity
of tumors and normal cells is an important
determinant of the theraputic ratio of fractionated
irradiation.

RADIOTHERAPY IN GYNAECOLOGY Dose Rate
Effect

 As dose rate is decreased , tissue have more chance
to tolerate the insult and repair from sublethal injury
during therapy. This is called the Dose rate effect.

The four R’S

 The biological effect of a given dose of radiation is
influenced by the Dose, Fraction size, Inter fraction
interval and time over which the dose is given.

 Four R’s of radio-biology
1. Repair.
2.Repopulation
3.Redistribution.
4.Reoxygenation.

These Four govern the influence of dose
,time and
fractionation on the cellular response to radiation.

Repair

 Fraction irradiation permits greater recovery of
sublethal injury during treatment , a
higher dose of radiation is needed , to
achieve a required biological effect when
total dose is divided in to smaller fractions.
 Altered fractionation protocols usually require a
minimum interval of 4- 6 hours between treatment

Repopulation

 Repopulation refers to the cell proliferation during
the delivery of radiation.
 The magnitude of the effect of repopulation on the
dose required to produce cell death depends upon
the doubling time of the cells involved. For cells
with a relatively short doubling time ,a significant
increase may be required to compensate for a
protraction in the delivery time.

Repopulation

 The speed of repopulation of normal tissue that
manifest radiation injury soon after exposure
(skin, mucosal surfaces etc).
 Treatments including
chemotherapy, radiotherapy, surgery = its tissue
response is lethal as well as an increase in
proliferation of surviving cells(clonogens).
 This accelerated repopulation may increase the
detrimental effect of treatment delays.
 It may influence the effectiveness of sequential
multimodality treatments

RADIOTHERAPY IN GYNAECOL0GY
Redistribution
 Study of synchronized cell population have shown
differences in the radio sensitivity of cells in different
phases of cell cycle.
 Cells are most sensitive in the late G1 phase and during
mitosis . More resistant in mid to late S and early G1
phases.
 When synchronous dividing cells receive a fractionated
dose of radiation , the first fraction tends to synchronize
the cells by killing off those cells who are in most
sensitive phase.
 Cells those in phase S begin to progress to more
sensitive phase. during the interval between two
fraction delivery.
 This phenomenon gives overall increased cellular death
if cells have short cell cycle.

Re oxygenation

 The sensitivity of fully oxygenated cells to
sparsely ionizing radiation is
approximately 3 times more than anoxic
cells.
 O2 is most effective radiation sensitizer.
 It is believed that O2 stabilizes the reactive
free radicals produced by ionization.

Over coming Radio resistance

 Many treatment strategies have been explored to
overcome the relative radio resistance of hypoxic cells
in human solid tumor.
1. Hyperbaric oxygen or carbogen breathing
2. Red cell transfusion or growth factor.
3. Pharmacological agents e.g. Metronidazole , it
acts as hypoxic cell sensitizer.
4. High linear –energy transfer radiation.
tumor hypoxia continues to be one
probable cause of the failure of irradiation.

Linear Energy Transfer & Relative
Biological Effectiveness
 The rate of deposition of energy along the path of
radiation beam is called Linear energy Transfer .
 Photons, high energy electrons, protons produce
sparsely ionizing radiation beam of low energy
transfer.
 Larger atomic particles e.g. neutrons and alpha
produce much more densely ionizing beam with
high linear energy transfer.

High linear transfer beam

 The high linear energy transfer beam:
1.There is a little or no repairable injury to tumor
cells.
2.The magnitude of cell death from a given dose
is greater.
3.The oxygen enhancement ratio is diminished.
the high linear transfer beam’s use in the
treatment of gynaeclogical malignancies had
no major impact in producing results.

Hyperthermia

 Temperature is another factor which may modify
the effect of radiation.
 Temperature in the range of 42-43 degree
centigrade sensitize cells to radiation.

 This approach has given encouraging results but
technical problems still limit its wide use.

Interaction between Radiation & Drugs

 Drugs and radiation interact in many different ways
and modify cellular response.
Steel & Packham categorize these interaction in
Four groups
1.Spatial cooperation- Drugs and radiation act
independently at different target and with
different mechanism so that total effect is equal
to the sum of effects of individuals .
2.Addivity—when two agents act on same target
to cause damage – equal to sum of their
individual toxic effect.

Interaction Between Radiation & Drugs

3. Supra additivity—The drug potentiates the
effect of radiation , causing a greater
response than expected from simple
additivity.

4. Sub additivity—The amount of cell death is
less from use of two agents simultaneously.

Therapeutic Ratio

 The difference between tumor control and normal
tissue complications is referred to as Therapeutic
Gain? Therapeutic Ratio.
 Primary aim of research in radiotherapy is to
improve therapeutic ratio by increasing separation
between these dose response curves, maximizing the
probability of complication free tumor control.

Effects of Radiation on Normal Tissue
 Effect of radiation on normal tissue depends upon many
factors :-
1. Radiation dose, the target organ, volume of tissue
irradiated and division rate of irradiated cells.
2. Tissue that have rapid cell turnover (e.g. tissue which
require constant cell removal like skin , mucosal epithelium
, hair , bone marrow , reproductive tissue etc) tend to
manifest radiation injury soon after irradiation.
3. Tissues whose functional activity does not require
constant cell removal tend to manifest radiation injury late
after months/years. Examples of late reacting tissues are
connective , muscle and neural tissue. Some normal tissue
may die through mechanism of apoptosis e.g. lymphocytes
, salivary gland cells and intestinal crypt cells.

Effect of Radiation on Normal Tissue

 Acute Reaction Acute reaction to pelvic radiation
, such as diarrhea is associated with mucosal
denudation .The severity of acute reaction depends
upon nature and volume of normal tissue , dose of
radiation , interval between two fractions .
 Late Reaction It results from
1. Damage to vascular Struma that causes an
epithelial proliferation with decreased blood supply
and subsequent fibrosis.
2.Damage to slowly or in frequently proliferating
paranchymal stem cells it eventually results in loss of
functional capacity.

Effect of Radiation on Normal Tissue

 For a given dose of radiation administered over a given
time interval , Risk of late effects is more with larger
fraction.
1. Uterus and cervix are typically described as radio
resistant except their mucosal linings.
2. Ovary is highly sensitive , it may lead to iatrogenic
ovarian failure which is dose dependent as well as
modulated by age of patient.
Pre-menarcheal girls exposed to 30 Gy dose may
continue to have mansturation and even may carry
pregnancy to term . Although they experience
premature ovarian failure later.
Most adult women develop premature failure after 20
Gy.

Effect Of Radiation On Normal Tissue

3. Vagina-- the Radiation tolerance varies with site
, duration as well as radiation dose. Apical vagina
require higher dose for atrophic changes
, shortening and loss of its elasticity as compared to
other areas.
4.Vulva can withstand some Radiation similar to
skin.

Effect Of Radiation

ORGAN Tolerance Dose Risk dose / serious side
effects
1.Small intestine 30Gy Diarrhea , Chronic Obstruction

2.Rectum 45-50 Gy Bleeding , fistula , obstruction .
Risk of stricture .
3.Ureter 85-90 Gy

4.Kidneys 18-22 Gy to both Renal hypertension & failure

4.Liver 30 Gy Hepatic dysfunction

5.Spinal cord & Nerves <50 Gy Uncommon
50 - 60 Gy Caudal equina

6.Bone <10 Gy Bone marrow resting tissue
fails to repopulate
30-40 Gy Aplastic anaemia , pathological

Treatment Strategies
1.Hyper fractionation Dose per fraction is reduced
, number of fractions and total dose is increased , but
total time of treatment remains unchanged.
Treatment is usually given 2-3 times per day at the
interval of 6-8 hrs
2.Accelerated Fractionation Dose per fraction is
unchanged , over all duration of radiation is reduced
, total dose is reduced or remain unchanged . It does
not reduce the incidence of late effects but increases
the acute effect of treatment.
3.Hypofractionation usually avoided . Necessary
reduction in dose reduces the likelihood of complete
eradication of tumor with in the treatment field. Rx of
malignant Melanoma is treated by this strategy , HDR
brachytherapy used to achieve it.

Combination Of Surgery and Radiotherapy
 Because both are effective treatment . Surgery removes
bulky tumor that may be difficult to control with tolerable
dose of radiation. Combined radiation will sterilize the
tumor bed and regional /distant Lymph Nodes.
1. Pre operative irradiation
2. Surgical staging followed by definite
irradiation.
3. Intra operative irradiation.
4. Surgical resection following Post operative
irradiation
5. Combination of these approaches.

1. Preoperative Irradiation

 It is used to make the inoperable tumor –
operable , example Ovarian Tumor , II
stage Endometrial Cancer , bulky Ca Cervix
.
 The greatest risk of this approach is that if
tumor remains un resectable , the effect of
further irradiation will be markedly
decreased by increased interval between
two treatment plans.

2. Intraoperative

 In some cases intra operative irradiation
can be delivered with a permanent implant
(using 125 I or 198 Au )with after loading
catheters in the operative bed or by ortho
voltage unit in OT.

3. Post Operative Irradiation

 It has been demonstrated to improve
local, regional control.
 In Vulva cancer ,post operative pelvic and
groin irradiation reduces the risk of
recurrence and improves patient’s survival.
 Same is true for Ca Cervix and
Endometrium With +ve lymph nodes.

Combination Approaches

 Combined therapy is optimized when treatment
plan exploits the complimentary advantages of
both treatment.
 It carries higher degree of morbidity.
 It should be limited to situation in which combined
approach is likely to improve survival ,permit
organ preservation, significantly less risk of local
recurrence compared to the expected result from
either modality alone.

Physical Principles

Ionizing radiation lies in the high energy portion of the
electromagnetic spectrum .
Characterized by their ability to excite or ionize the atoms in
absorbing material.
The Nuclear decay of radioactive nuclei can produce several
types of radiations , including uncharged Gamma(Y) rays
, negatively charged beta rays (B) electrons , Positively
charged alpha (a) particles (Helium ions) and neutrons .
The resulting ionizing radiations are exploited therapeutically
in Brachytherapy( using 226 Ra ,137 Cs 186 Ir and other
isotopes ) .
To produce Teletherapy Beams (e.g. 60 Co )
The average energy of the photons produced by the decaying
radioactive Cobalt is 1.2 million electron Volts (Me V) .

Interaction of Radiation & Matter
 X Rays and Y rays Photons interact with matter by means of
three distinct mechanisms : Photoelectric effect , compton
scatter,and pair production.
 Photo electric effect is used for diagnostic purpose--X rays having
different absorbability by different tissue. Effect is proportional to
Z3 . Z is the atomic number of the absorbing material.
 Modern therapeutic beams of 1-20 mega volts produce photons
that interact with tissue primarily by compton scatter.indepedant
of Z . These photons produce an increasing number of electrons
and ionization as they penetrate beneath the surface of absorbing
material. Skin sparing effects and penetration of energy beams of
15 MeV or greater make them useful in pelvic treatment.
 Pair production is related to Z2. this type of absorption begins to
dominate only at photon energies of more than 30 MeV . It is of
limited value in current radiation therapy planning.

Electron and other Particles

 Several types of particle beams are used in radiation
therapy: electron beam, proton beam and neutron
beams.
 Electrons are very light particles . When they interact
with matter ,they loose their energy in a single
interaction. Hence used to treat superficial targets
without delivering significant dose to underlying tissue.
 Protons are +vely charged particles ,much heavier than
electrons.
 Neutrons are neutral particles that tend to deposit
most of their energy in a single intranuclear event.
They are not used in gynaecology.

Measure of Absorbed Dose

 Absorbed dose is a measure of energy deposited by
the radiation source in the target material.
 Unit currently used to measure radiation dose is
the Gray(Gy) ,equal to 1 Joule per Kg of absorbing
material.
 1Rad= 1cGy= 100 rads.
 Safe radiation depends upon precise calibration of
radiation source activities and machine output.
 Periodic calibration of equipment and sources are
vital part of quality assurance in any radiotherapy
department.

Relationship between radiation dose and surviving fraction of
cells treated in vitro with radiation delivered in a single dose or
in fractions. Top = Most tumors and acutely responding
normal tissues. Bottom = Late-responding normal tissues.
For most tumors and acutely responding normal tissues, the
cellular response to single doses of radiation is described by a
curve with a relatively shallow initial shoulder (Top, yellow
line). Cellular survival curves for late-responding normal
tissues (Bottom, yellow line) have a more pronounced
shoulder, suggesting that these cells have a greater capacity to
accumulate and repair sublethal radiation injury.
When the total dose of radiation is delivered in several smaller
fractions (Dose A [dose/fraction] = blue line, or a larger
fraction Dose B [dose/fraction] = red line), the response to
each fraction is similar and the overall radiation survival curve
reflects multiple repetitions of the initial portion of the single-
dose survival curve.
Note that the total dose required to kill a specific proportion of
the cells decreases as the dose per fraction increases (red line).
Arrows indicate the differential effects of relatively large
versus small fractions of radiation.
The greater differential effects of fractionated irradiation on
normal tissues (Bottom) than on tumor (Top) reflect the
greater capacity of late-responding normal tissues to
accumulate and repair sublethal radiation injury.

Inverse Square Law

 The dose of radiation from a source to any point in
space varies according to the inverse of square of
the distance from the source to the point.
 This relationship is particularly important for
brachy therapy applications because it result in
rapid fall off of dose as distance from intracavitary
or interstitial source is increased.


 Radiation therapy is delivered in three ways :-
1.TeletherapyXrays are delivered from a source
at distance from the body(external beam
therapy)
2.BrachytherapyRadiation source are put
within OR adjacent to the target to be
irradiated.(intra cavitary/interstitial)
3.Radioactive Solution solution that contain
isotopes ( radioactive colloidal gold or 32 P) are
instilled in in peritoneal cavity to treat the intra
peritoneal metastatic nodules

Teletherapy

 Several terms are used –
 Percentage depth dose – change in dose with depth along
the central axis of radiation beam.
 D max—The maximum dose delivered to the treated
tissue.
 Source to skin distance – distance between source of X
rays to skin surface.
 Iso center— a point in patient which remain constant at a
fixed distance from source even when source is rotated.
 Source to axis distance—distance between source to iso
center.
 Iso dose curve—is a line or surface that connects the
point of equal radiation dose.

Teletherapy

 Following factors influence the dose distribution
in tissue from a single beam of photons--
1.Energy of beam –Higher energy photon
beams are more penetrating than the low
energy beam. Higher energy beam have a
larger buildup region resulting in relative
sparing of skin surface.
2.Distance from source to tissue—as the
distance of source to skin surface increases
,the percentage depth dose increases.
3.The size of radiation field–the percentage
depth increases with the increasing radiation
field size.

Teletherapy

4.The patient’s contour and the angle of the beams
incidence.
5.The density of tissue in the largest volume.
6.A variety of beam-shaping devices placed between
source and patient alter shape or distribution of
radiation dose.
Most radiation therapy treatment combine two or
more beams to create dose distribution designed to
accomplish three aims
(i)Maximize dose delivered to tissue
(ii)To produce homogenous dose within the volume
of tissue
(iii)to minimize dose to healthy tissue.

Teletherapy

 Multiple fields may be used to focus the high dose
region more closer to deep target volume.
 Multi leaf collimators are computer controlled that
can form irregularly shaped fields , replacing hand
loading devices.
 Recently attention has been focused on IMRT to
optimize delivery of radiation from multiple beam
angles.
 The leaves of multi leaf collimators enter the field or
retract dynamically to deliver desired dose of
radiation to the tissue within target.

RADIOTHERAPY IN GYNAECOLOGY Brachy
Therapy

 It involves placement of radioactive source within the existing
body cavity.Termed as intra cavitary treatment .
 Most gynaecologic applications of intra cavitary therapy
involves intrauterine/intra vaginal applicators that are
subsequently loaded with encapsulated radioactive sources.
 These applicators are consisting of hollow tube /tandem and
intra vaginal ovoids /receptacles.
 This technique has proven very useful in treatment of cervical
cancer as it allows a very high dose of radiation to cervical ,
parametrial tissue & pelvic lymph nodes with out excessive
radiation to surrounding normal tissue.
 To minimize the exposure to medical personnel ,modern
applicators are first placed ,their position is checked with x
rays and then applicator system is loaded. Remote after
loading devices are used to automatically retract sources from
the applicator to a lead lined safe when some one enters the
room.

Isotopes Used in Gynaecological Treatment
Element Isotope Half life Ey (MeV) Eb (MeV)

Phosphorus 32P 14.3 days None 1.7( max)
Iodine 125I 60.2 days 0.028 avg None

131I 8.06 days 0.08-0.63 0.61(max)

Cesium 137 Cs 30 yrs 0.662 0.514,1.17

Iridium 192 Ir 74 days 0.32-0.61 0.24,0.67

Gold 198Au 2.7 Days 0.41-1.1 0.96(max)

Radium 229Ra 1,620 yrs 0.19-0.6 3.6(max)

Cobalt 60 Co 5.26 yrs 1.17-1.33 0.313(max)
E y,
gamma ray energy Eb MeV
beta ray energy Million Electron
Volts

Dose Rate
 Historically, most brachy therapy was delivered at low
dose. Most commonly 40-60 cGy / hr
 The advent of computer controlled remote after loading
has made it possible to deliver higher doses.
 HDR treatment is given as OPD procedure.
 In this technique a single very high activity source of 192
Ir is loaded in the intra cavitary applicators.
 An alternative to HDR therapy commonly used in
Europe, has recently been replaced by Pulse Dose Rate
(PDR) brachy therapy in USA.
 The total brachy therapy dose to point A must be reduced
when converting from LDR to HDR.

Dose rate
 If the tumor is very large or vaginal anatomy is
unfavorable, radiation doses to tumor and normal
tissue may be same.
 Dose fraction schemes used for HDR therapy
produce tumor control and complication rates
equivalent to LDR.
 Increasing the number of fractions and
concomitantly decreasing the dose per fraction
reduces rate of moderate and severe complications.
 Commonly used regimen in USA is % fraction of 5.5
-6 Gy each to point A , after 45 Gy to the pelvis with
wide variation in fractions(2-13)and dose per
fraction (3-9Gy).

Dose rate

 the appropriate dose and dose per fraction is based
on calculation on estimated biologically effective
dose (BED) on tumor and normal tissue.
 Bed= (nd)x (1+d/(a/b) where ,d is the dose per
fraction
For example :
Tumor BED = (30) x(1+6/10) = 48 Gy
Normal Tissue BED = (30)x( 1+6/3) = 90 Gy

Interstitial Therapy

 It refers to the placement of radioactive source with in the
tissue.
 VARIOUS SOURCES OF RADIATION : Such as - 192Ir ,
198Au , 125I , 103Pd , can be obtained as radioactive wires
and seeds.
 Sources can be positioned in the tumor/tumor bed in
variety of ways
1.Permanent seed implants (usually125I,103Pd,198Au)
can be inserted using a specialized seed inserter.
2. Temporary Teflon catheter implants can be placed
intra operatively and subsequently loaded with
radioactive source.

Complications of radiotherapy
 Early Transient nausea and vomiting----
antiemetic drugs will help.
 Bladder and rectal irritation
 GIT irritation--. Anorexia , diarrhoea and weight
loss. octreotide is used.
 Malaise, irrtability,depression and headache
 Flare up of sepsis
pyometra,t.o.masses,peritonitis ansepticaemia.
 Cystiis, pyeliis, pyelonephritis.
 Pyerexia
 Pulmonary Embolism.
 Skin reaction

Late complications
 Persistant anaemia.
 Chronic pelvic pain followingfibrosis involving nerve
trunks.
 Pyometra.
 Proctiis--.rectal ulcer,bleeding,strcture and rectovaginal
fistula.
 Post radiation cystitis,ulcer,haemturea, UTI and
vesicovaginal fistula.
 Smallbowel strictures ,ulcers, obstruction, gut perforation.
 Colonin-
stricture,ulcer, telangiectasia,perforaton, obstructiontropic
vagints, ca, stenosis, dyspreunia.
 Ureterc obstruction and obstructive uropathy.
 Osteporosis and fracture neck of femur.
 Overian dysfunction/failureUterine sarcoma 8% cases

Contra Indication To radiotherapy
 Sever anaemia.
 Poor general health.
 Sepsis.
 Pregnancy.
 Presence of fibroid in uerus.
 Tubo- ovarian masses.
 Utero vaginal prolapse.
 Fistulas.
 Radio resistant tumors

Interstitial Therapy

3.Temporary transperineal template guided interstitial
needle implants can be placed using a Lucite template with
regularly placed holes and a central obturator that can hold
tanden or additional needles. Needles are after loaded
with192 Ir. These implants are used to treat vaginal and
some cervical tumors
4.Temporary transperineal implants can also be placed
freehand an approach that may allow better control of
needle placement in selected cases. Useful in treating
vaginal and urethral cancers.
Most gynaecological implants are temporary LDR
implants like  intracavitary therapy. Interstitial therapy
delivers a relatively high dose of radiation to a small volume
sparing the surrounding normal tissues. The risk to normal
tissue adjacent to tumor or in the tumor bed still will be
significant, particularly when needle placement is
inaccurate.

Intraperitoneal Radioisotopes

 Radioactive phosphate(32P) and colloidal gold(198Au)
used for treatment of epithelial cancers of ovary in an
effort to address the transperitoneal spread of cancer .
 If a radioisotope is evenly distributed within peritoneum
, it is theoretically possible to irradiate the entire surface.
However the energy deposition within the abdomen and
the dose delivered beneath the peritoneal surface
depends on many factors i.e. distribution of isotope and
energy of decay product.
 In practice isotope is seldom distributed evenly in
peritoneal cavity and omental surface. This approach is
rarely used now a days.

 Half Life of commonly used Radio isotopes

Xray of pelvis showing position of radium
in Manchestr insertion

Clinical uses of radiation Cancer Cervix

The curative treatment of cancer cervix usually includes
external pelvic irradiation and brachy therapy often with
concurrent chemotherapy.
The goal of therapy is to eliminate cancer in cervix para
cervical tissues and regional lymph nodes.
Because bulkiest tumor is usually in cervix, this region
typically requires higher dose than the rest of pelvis to
achieve loco regional control. Fortunately it is possible to
deliver higher dose with intra cavitary therapy.


 Treatment Volume :
Typical external- beam fields are designed to include
the primary tumor , para cervical iliac and pre sacral
nodes ,all with 1.5- 2.5 cm margins. If common iliac and
aortic nodes are involved, then the treatment fields are
extended at least to lower para aortic region.
The borders of field are as follows 
1.Inferior - at the mid pelvis / 2-3 cm below cervical
lesion.
2.Superior - at the L4-5 interface / bifurcation of
aorta.
3.Lateral to pelvic lymph nodes 1-2cm / at east 1cm
lateral to margin of bony pelvis.

Isodose curves of a standard radium insertion using the
Manchester Technique in Ca Cx

Different methods of brachy therapy A.
Manchester , B Paris , C. Stockholm.


 Using four beams (anterior, posterior, right and left
lateral)rather than opposed pair of anterior and
posterior beams may some times reduce volume of
tissues irradiated to a high dose.
 4 to 5 weeks (40 - 45 Gy ) of radiation and combined
chemotherapy usually reduces endo cervical disease
and shrinks exophytic tumor , fascilitating optimal
intra cavitary therapy.
 Intra cavitary therapy is critically important for
successful treatment , even for patients with very
bulky stage III tumors.


 Patient with FIGO stage IA can often be treated with
intracavitary irradiation alone.
 Most patients with stage IB1 have high risk of
metastasis to pelvic lymph nodes , hence need
atleast moderate dose of pelvic radiation (39.6Gy) to
sterilize possible microscopic regional disease.
 For patient of Ca Cx having vaginal bleeding
haemostasis can be achieved with vaginal packing
,application of Monsel’s solution and rapid initiation
of External Beam Irradiation.


 Radiation Dose--
 1.Point A – a point 2cm lateral and 2cm superior to
external cervical os.
 2.Point B - a point 3cm lateral to point A.

The total dose to point A - from external beam and LDR
intacavitary therapy adequate to achieve central disease
control is between 75 Gy (for IB1 stage) & 90 Gy (for bulky
or locally advanced disease).
Prescribed dose to point B is 45-65Gy , depending on extent
of parametrial and side wall disease.

Prescription and treatment planning can not be limited to
specification of the dose to these reference points . Other factors to be
considered are as follows :—
1.The position and length of intrauterine tandem
2.The type and size of vaginal applicators.
3.Quality of vaginal packing.
4.The size of central tumor(before and after external beam therapy
5.The vaginal surface dose ( usually limited to 120 to 140 Gy).
6.Oroximity of system to bladder and rectum
7. The dose rate or fraction size.
There is growing move toward use of image guided brachytherapy.
Treatment planning based on CT / MRI images obtained with
implant in place.


 Results of treatment :
 Radiation therapy is extremely effective in the treatment
of stage IB1 . Disease control achieved in central and
pelvic lesion is greater than 98%and 95% respectively.
 Pelvic control rate decreases as tumor size and FIGO stage
increases. 5 year pelvic control rate of 50-60% even for bulky
stage IIIB have been reported.
 During the past decade significant improvement in pelvic
disease and survival when Cis-platin containing chemotherapy
is delivered concurrently with radiation to patients with
advanced pelvic lesions.
 5 fluouracil a potent radiosensitizer is not that effective in
Rx of Ca Cx . Mitomycin C and Epirubicin given along with
radiotherapy also help control advanced disease.


Adjuvant pelvic radiation after
radical Hysterectomy.
 For patient with stage IB and IIA Ca Cx who had radical
hysterectomy along with pelvic lymphadenectomy , involvement
of nodes is strongest predictor of local recurrence and death.
Survival rate of patients with +ve nodes is 50-60% much lower
than that achieved by chemo- radiotherapy. Post operative
radiotherapy is must for them.
 Patients with – ve nodes but bulky cervix > 4cm and deep
stromal invasion also require post operative radiotherapy.
Adjuvant radiotherapy carries high risk of complications and
Patients who have high risk factors at initial evaluation should
be treated by radical radio –chemotherapy.


 Recurrent Cervical cancer
 Patient who have an isolated pelvic recurrence after
radical hysterectomy can be treated by aggressive
radiotherapy.
 Patients with local recurrence with no fixation to
bone/+ve pelvic nodes have 5 year survival rate as
60-70-%
 Patient having +ve nodes/fixation to bone have very
poor survival rate of 20% after radiotherapy.

Endo cervical Cancer

 1.Chemotherapy.
2. Radiotherapy.
3. surgery
all three are combined
In endo cervcal cancer the best survival is seen when
concomitant Cisplatin weekly and 6 weekly
radiotherapy is followed by surgery.

Endometrial cancer
 As adjuvant to surgery comprising : TAH-1-BSO
 By administrating vaginal radiation via colpostsat
,vaginal vault recurrence drops by 20%.
 To prevent local vaginal recurrence which is reported
in 13 %
 The survival improves in stage 1C and II when post
operative radiation is given to pelvic nodes.
 It is indicated in Sarcoma.
 To treat pt unfit for surgery.
 To treat pt with pelvic/ vaginal recurrence.
 For palliation in cases of non resectable intra pelvic /
metastatic disease.s

Ovarian Cancer
 Post surgery and chemotherapy ; ― Moving Strip
Technique ― of external radiation is applied to par
aortic nodes and residual abdominal metastasis.
 In this a strip of 2.5b cm area is radiated front and
back(starting from pelvis) over 2days and then
moved upwards until whole abdomen and back is
irradiated.Liver and Kidneys are shielded.
 The total tumor dose of 2600- 2800 cG y is
administered.
 CT and MRI are use ful in detecting involved para
aortic and pelvic metastasis.

Ovarian Cancer----------
 Intra abdominal instillation of AU 198, P
34 and thiotepa is not used now a days
owing to intestinal injury and adhesion
formation.
 Approximately 49-50% 5 year survival rate
can be achieved in stage II.
 5 year survival rate drops to 5-15% if larger
residual lesions are left after intial surgery
combined with chemotherapy.

Vulvar Cancer
 The aim of integrated multimodality therapy including
surgery, chemo radio therapy is to reduce the risk of
local, regional failure in patients with advanced
primary or distant nodal involvement.
 To obviate the need of exenteration in women having
urethra , Anal extension of cancer.
 The dose of radiation given is 4500-5000cGy
to woman with microscopic disease and 6000-
6400cGy to woman with macroscopic disease.
 Pre operative Radium needles (60 Gy in 6 days)
shrinks the tumor and facilitates extirepation of tumor
at later date . Post operative radiotherapy is prefered
to women with +ve inguinal nodes.

Vaginal Cancer

 Radiotherapy is preferred then
surgery.
 If cancer is located in upper 1/3rd ., it is
radiated as ca Cx.
 If located in middle/ lower 1/3rd of
vagina , interstitial needles (Iridium -
192) are inserted in vaginal tumor.

Chorio Carcinoma

 It respond well to chemotherapy which replaced
surgery in young women.

 Radio therapy is applicable in the distal metastasis in
few cases.

Radiotherapy in gynaecology

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