Doctors:
Radiation Oncology refers to the treatment of cancer patients using radiation, which could be X-ray, Gamma ray or high dose of radium. Radiation Oncology services are clinical specialties devoted to the treatment of patients with cancer and other tissue growths. The Radiation Oncology department is located on the ground floor A of the hospital. The department of Radiation Oncology is equipped with state of the art Linear Accelerators, Simulator, High Dose Rate Remote after - loading Brachytherpay system, dedicated treatment planning computers, and Mould Room to fabricate lead shields and templates in house. Department has been networked to CT scan and MRI with DICOM compatible image transfer capability.
The Rajiv Gandhi Cancer Institute and Research Centre is the first cancer centre in the country to put IMRT into clinical practice.
Image Guided Radiation Therapy (IGRT)
With the intention to deliver the best, RGCI has recently installed and commissioned the state of art “Image Guided Radiation Therapy IGRT”- equipment - ARTISTE from Siemens.
The ARTISTE is engineered specifically for Adaptive Radiation Therapy (ART). The linear Accelerator is an integrated imaging and workflow solution that offers a comprehensive portfolio of image-guided and advanced treatment delivery protocols, including in-room CT imaging capabilities and a new multileaf collimator, 160 MLC Respiratory gating systems used to synchronize imaging and close delivery with a patient’s breathing cycle.
In standard radiation therapy, the area at risk is targeted and a margin is added around it to allow for changes in the patient’s position and potential movement of the target area.
Using IGRT, margins can be minimized, thus sparing normal tissue that does not otherwise need to be treated. A tumor can be imaged just before the delivery of radiotherapy or even during a treatment, enabling radiation oncologists to verify its exact location, thereby reducing the margin of healthy tissue exposed to radiation to five millimeters and , in certain cases, to as little as one or two millimeters. If a tumor has shifted even slightly since a patient’s last visit, the radiation beams can be adjusted so that they hit it precisely.
IGRT system is one that can produce different kinds of images just prior to treatment and then help clinicians make use of those images in a clinically practical way. Clinicians will require online visualization of bony anatomy, soft tissue- with or without implanted markers- and real –time tumor motion. Sophisticated software then compares the images with reference images from earlier treatment planning, calculates how the patient must be moved in 3D so that the tumor lines up with the radiation beams, and instructs the treatment couch accordingly.
Cone – beam CT uses a mounted CT scanning device on the linear accelerator to aid in patient positioning. After the patient is placed in treatment position, he/she is scanned using cone – beam CT, and this is fused to planning CT. The patient is then repositioned accordingly to match the position at the time of the planning CT. Because the patient is precisely positioned. The radiation oncologist is able to minimize the margins used in treatment.
IGRT has recently opened the door to true four dimensional (4D) radiation treatment. In addition to dealing with the three dimensions of space, radiation therapy techniques also deal more effectively with the problem of tumor motion in time - the fourth dimension using 4D imaging, 4D simulation. 4D treatment planning, 4D treatment delivery, and 4D verification, clinicians will be able to precisely determine the margin around the tumor and program the technology to deliver treatment that adapts to the motion, keeping that margin constant. Ultimately, that is the path that IGRT has forged. For some tumor sites, such as the brain or the head and neck, IGRT will help shrink margins by elimination patient set-up uncertainties. For tumors in the chest or abdomen where respiratory motion has a very big effect, IGRT presents a solution towards overcoming this problem.
• Imtensity Mdodulated Radiation Therapy (IMRT)
This technique is the highest form of the conformal radiotherapy currently available where regardless of planning and delivery technique, the intensity of the beam is varied across the treatment field crossfiring the target with beams of varying intensities allowing a relatively uniform dose to the tumour and a sharp cut off of the dose to surrounding normal organs. It delivers an especially non-uniform radiation exposure to patient to create a uniform dose distribution at the target site. The treatment is delivered by using a multileaf collimators (MLC) or physical modulator (compensating filter) mounted on a linear accelerator.
All types of cancer are treated with the Intensity-Modulated Therapy. CNS cancer, Head and Neck Cancer, Breast Cancer, Lung Cancer, Pancreatic Cancer, Esophagus Cancer are some of the cancer successfully treated with the technique 3D conformal Radiation therapy (3D-CRT) 3D conformal radiotherapy is a technique in which the prescribed dose volume is made to conform closely to the target volume in three dimensions. It delivers the radiation dose to the cancerous area with adequate margins and at the same time minimizes the dose to the normal surrounding tissues.
Localization of the disease and normal organs in three dimensions is the prerequisite to carry out such a treatment plan with three-dimensional treatment planning, treatment delivery verification, and plan documentation.
Patient is immobilized to deliver the treatment. After the immobilization the patient is simulated on the radiotherapy simulator. CT scan is taken in the treatment position with immobilization mask and the entire area is scanned at 3-5-mm intervals. CT Scan slices are used for the target (tumour area) and other surrounding normal organ planes and dose volume histograms are generated. Digitally reconstructed radiographs are used for verifying the treatment position. This is followed by transfer of the treatment parameters to treatment machine. Online portal imaging is used to verify that treatment is delivered exactly as planned.
• Linear Accelerator (LINAC)
Linear accelerator is a recent technology to treat a wide range of Cancer cases.
Linear accelerator is the equipment in which high-energy X-rays are used for the treatment of Cancer. The department has two LINAC Machines, one with dual energy and second machine with only one energy. Mevatron M2-6700 is a digital accelerator with 6 Mev Photon energy and Mevatron KDS-2 is a digital unit with 18MeV Photon energy and 6-18 Mev electrim energies. Both the machines have on line portal imaging providing the real time verification of the anatomical position of treatment while patient is on treatment. In additional the department has monitors, and intercom facilities, patient calling system and quality control machine named Trinotron beam view.
Brachytherapy
It involves using high dose of radiation by inserting radioactive source in or around the tumar. Generally it is used for the Tongue implant, Breast Implant, Esophagus and Lung cancer. Besides this soft tissue sarcomas (Intra Operative Implant), Carcinoma Prostate, Paediatric solid tumours (Rhabdo Myosarcoma), Carcinoma Nasopharynx, Buccal mucosa and carcinoma penis, Surface Moulds for are some of other applications of Brachytherpy. It is specially helpful for conservation of ansering the organ
The treatment is given with machine Microslectron HDR. The applicator is inserted into the body for the treatment. The applicator is linked to the main source through connecting tubes.The number of connecting tubes, time duration, area to be treated is all decided with the help of treatment Planning computers and transferred to a card. The card is then received by the technologist for treatment
Simulator
Simulator is specialized X-Ray flouroscopy unit having the same parameters as those of the therapy unit without its treatment capabilities. It sets the teletherapy fields to the location of the Tumour. It is used to for treatment the patient may need to spend from 15 minutes to 45 minutes under this unit for treatment positioning, localization and verification of computer planned portals. A change of planning through the course of treatment may again be done after a few days of radiation for selected cases using this equipment. It saves the therapy unit’s time to deliver a quality assured treatment.
Medical Radiation Physics
Medical Radiation Physics Division provides service for physico- clinical radiation dosimetry with image based and quality assured cum radiologically safe radiation treatment planning for cancer patients to be treated by conventional as well as High-tech techniques like 3DCRT, MLC and Compensator based IMRT. National and International (IAEA) dosimetry standards are maintained. It provides Radiological service for Radio Diagnosis and Nuclear Medicine. Following equipments are used for these purposes : - Dose Leader and Capintec Dosimetry systems with multiple Ion chambers including MARKUS chamber - Wellhofer water phantom Dosimetry
System with OMNI-PRO software - VIDAR-16 scanner with dosimetry-Pro software - Two Inverse treatment planning systems for IMRT & 3DCRT and one Indian 3DCRT-TPS. All systems are connected through networking with CT,MRI, Simulator and Three Linear Accelerators. - Solid Water and Acrylic Phantoms for 3DCRT and IMRT verification by Ion chamber and EDR-2 films - Gaf-chrom film dose reader - Radiation Survey meters and Contamination monitors for radiological and health safety service.
