AP and Lateral X-ray’s are taken to verify the position of the applicator
Radiotherapy of cervical cancer
Modalities of Radiotherapy• BRACHYTHERAPY• TELETHERAPY
BRACHYTHERAPY• Internal radiation treatment achieved by implanting radioactive material directly into the tumor or very close to it.• Sometimes called internal radiation therapy.• Prefix “brachy” – from Greek for “short range”
TYPES OF BRACHYTHERAPY1)Intracavitary irradiation using radioactive sources that are placed in body cavities in close proximity to the tumor and2) Interstitial brachytherapy using radioactive seeds implanted directly into the tumor volume.
WHY BRACHYTHERAPY• Delivering the high dose of radiation to the tumor• Sparing of the surrounding normal tissues• Delivered in a short period of time – Tumor repopulation• Limited to localized tumors
TELETHERAPY• Teletherapy or External Beam Radiation Therapy" involves delivery of therapeutic radiation from a source• that is placed away• from the body.
INITIAL TREATMENT2 Components of CA Cervix• Central: Growth in the cervix which is best treated by Brachytherapy• Peripheral: Growth in parametrium & lymph node metastasis which is best controlled by Teletherapy
PRINCIPLES OF MANAGEMENT• Patients with Stage I - IIA can be managed by surgery alone.• Patients in Stage IIB - IV CHEMORADIATION – Brachytherapy followed by Teletherapy 4 –6 weeks later. – Chemotherapy
PRINCIPLES OF MANAGEMENT• The relative proportion of Teletherapy increases with bulk & stage of tumor.• Usually Brachytherapy followed by teletherapy 4 to 6 weeks later.
INDICATIONS FOR EBRT PRIOR TOBRACHYTHERAPY• Bulky tumours• Distorted cervical canal• Exophytic or bleeding tumors• Tumors with necrosis or infection
ROLE OF CHEMOTHERAPYCertain chemotherapeutic drugs such asCisplatin, carboplastin , 5 FU etc act asradiosesitizers & may be given prior to anyform of radiotherapy to enhance the lethaleffect of radiation.
Patient Preparation • GA • Lithotomy position • Perineal area is disinfected • Draping • Catheterization
•Applicator set is check forL/e integrity and completeness •Uterine sounding •Correct size of ovoid is selected and mounted onto the ovoidtubes •Dilatation of the cervix •Length of uterus is measured
IU- Tube Insertion• Correct length of IU- •Select proper size ovoids tube is selected and •Fixate these to the ovoid tubes inserted •Insert one by one and attach to the fixing mechanism
Applicator packing • Insert gauze packing to push rectum and bladder away reducing the dose to these organs • Radio opaque rectal marker inserted
TECHNIQUES OF BRACHYTHERAPY• PARIS METHOD• STOCKHOLM METHOD• MANCHESTER TECHNIQUE
PARIS METHOD•Radium is applied continously for 5 days.•Removed daily for cleaning and reinserted back.
STOCKHOLM•Radium is inserted on 3 occasions•1 week interval between 1st & 2ndinsertion•2 week interval between 2nd & 3rdinsertion
MANCHESTER•Two Insertions•Each insertion lasts for 72hrs•1 week interval between twoinsertions
PRINCIPLES IN BRACHYTHERAPY• Uniform distribution to avoid Hot & Cold spots• Two points Point A - -The point A was described fixed point 2cm lateral to uterine axis and 2 cm above the lateral fornix. It represents Anatomical location of Ureter. Dose not to exceed 8000 rads
PRINCIPLES IN BRACHYTHERAPYPoint B: 5cm from the patient’s midline, at the same level as point A.It represents Lateral pelvic wallDose not to exceed 500o rads
TELETHERAPY• SSD(Source to Skin Distance) is 5 to 10 times the depth of tumour.• Cobalt-60 and Caesium-137 are commonly used• Fractionated radiotherapy is preferred
TELETHERAPY• Pelvic Radiation: 180 – 200 cGy• Abdominal Radiation: 100 – 120 cGy• About 4-5 fractions per week is given• Total of 25 – 30 fractions is given over 5-6 weeks