Brachytherapy is a radiation therapy treatment technique which is used for controlling cancers of several sites. Its name is derived from two terms, ‘Brachy’ means short and ‘Therapy’ means treatment. In this modality, radiation source is placed at very short distance to the diseased region to damage cancer cells and destroys their ability to proliferate. It gives superior accuracy, conformity and localization as physician is able to place the source in close proximity to the tumour.
Brachytherapy can be temporary or permanent depending on the duration for which radioactive source remains inside the patient body. It is also classified as Low dose rate, Medium dose rate, High dose rate and pulse dose rate defined by the used dose rate for treatment. Various types of brachytherapy include Interstitial, Intraluminal, Intracavitary and Surface application. It is extensively used for curative treatment of cervical cancer with Intracavitary method in which an applicator is placed inside a “cavity”. The applicator is placed in the vagina in cases where the cervix and uterus have been removed such as in endometrial cancer known as IVBT (Intra Vaginal Brachytherapy) or into the uterus for cervical cancer known as ICRT (Intracavitary Brachytherapy).
The delivery of brachytherapy requires a treatment team which comprises of Radiation Oncologist, Medical Physicist, Radiation Therapist, Radiation therapy nurse. The radiation oncologist will evaluates the patient and decide if the candidate is suitable for this method of treatment approach and prescribes amount of radiation to be given. The applicator placement (brachytherapy devices, such as catheters or needles) is performed by Radiation oncologist inside the patient assisted by nursing. Application procedure is followed by CT scans to confirm position of the applicator. These images taken will be used for contouring normal tissue and tumour, Source placement and treatment time calculation using a dedicated Software. The Medical Physicist makes detailed treatment calculations for source position and the amount of time needed to deliver the desired dose of radiation. Radiation oncologist determines the prescribed dose and checks dose to surrounding normal structures and after overall final assessment approves the plan for treatment.
The Dedicated Computer-Controlled HDR Remote Afterloading machine is used for treatment delivery that has a motorized cable with a small radiation source (Iridium-192) welded to the end of it. Machine is operated by Radiation therapists under the supervision of the physicist. The patient is well informed by radiation therapy nurse regarding the treatment and possible adverse reactions as directed by physician.
Workflow for IVBT: For the first treatment, Patient is taken to CT and vaginal cylinder is gently placed in the vagina by a physician and stabilized with a base plate followed by scan to confirm cylinder position and using images for treatment planning part. After planning tailored as per individual patient and approval, end of the vaginal applicator is connected via a transfer tube to the HDR afterloading machine. This radiation source is pushed to the cylinder and delivers a radiation treatment. The source is then retracted back into the afterloader, the vaginal cylinder is removed, and then the patient goes home same day. Treatment is given as 3 fractions in 3 weeks and duration for each fraction ranges from 10 to 20 minutes.
Workflow for ICRT: Patients are given moderate sedation for the tandem and ovoid applicator (Brachytherapy devices) placement followed by CT scan is to visualize the applicator relative to the patient’s anatomy and then customized plan generated and delivered by remote afterloading machine. The source is then retracted back into the afterloader after the treatment. The applicator is then removed, and the patient goes home. The whole process typically takes 2-3 hours. Treatment is given as 3 fractions in 3 weeks and duration for each fraction ranges from 10 to 30 minutes.
During the treatment patients may hear a clicking noise from the machine as the radioactive material is being transferred to the tumour site. The patient will remain alone during the procedure but is able to communicate with treatment team. After discharge from the hospital after temporary brachytherapy, no radiation remains in your body, so there is no risk to others.
The brachytherapy treatment has always remained standard of care for cervical cancer from ages. At our institution brachytherapy is most commonly given after completing external beam radiation therapy as an outpatient treatment with Microselectron HDR brachytherapy afterloader machine. With this technologically advanced and clinically reliable machine and under careful supervision of experts at Narayana we provide complete solutions to clinical needs and are dedicated to remain at the forepart of brachytherapy by providing precision treatment of cancer.