The Radiotherapy Department at the Hermitage Medical Clinic has two state-of-the-art Linear Accelerators (LINACs) that are used to deliver all modern modalities of radiation treatment- stereotactic radiotherapy, intensity modulated radiotherapy (IMRT), image guided radiotherapy (IGRT), and superficial radiotherapy are all available.
These LINACs, incorporate on-board CT and megavoltage imaging, allowing more accurate target localization during radiation. A sophisticated treatment couch called a HexaPOD bed is in use on both LINACs which allows for 6 dimensions of freedom facilitating better positioning of patients during treatment.
Linear Accelerators (LINAC’s)
A linear accelerator is the machine used to deliver radiotherapy treatment. In the machine electrons are accelerated at a target to produce a high energy beam of x-rays. Filters, lead blocks and shielding leaves are used to shape this beam to replicate the treatment fields. The LINAC’s used at the Hermitage Medical Clinic are from Elekta (manufacturing company). These machines are serviced daily, weekly, monthly and annually by radiation therapists and physicists. The LINAC’s at the Hermitage Medical Clinic have the following capabilities:
A HexaPOD bed is a treatment couch which allows for 6 degrees of freedom. Patient positioning and organ motion are two of the main obstacles which limit the accuracy of radiotherapy delivery. By combining a HexaPOD bed with 3D volume imaging at the time of treatment, any positional discrepancies are highlighted before treatment begins. Radiation Therapists are able to correct for any of these discrepancies and this in turn allows for the reduction of margins and escalation of dose. It facilitates stereotactic radiotherapy treatment as precision is paramount for this technique.
Intensity Modulated Radiotherapy (IMRT)
IMRT is an advanced form of conformal radiotherapy which shapes a series of radiation beams to replicate the shape of the target volumes. It allows for more precise radiation delivery while relatively limiting dose to the surrounding normal tissues. IMRT is therefore essential to minimizing acute treatment-related morbidity, making dose escalation feasible which may ultimately improve local tumour control.
Image Guided Radiotherapy (IGRT)
IGRT is a type of radiation therapy treatment that utilizes imaging technology during treatment to ensure tumour location and beam delivery accuracy. The goal of IGRT is to decrease radiation dose to normal tissue, decrease side effects and improve radiotherapy outcomes. Traditionally, diagnostic imaging technologies such as CTs, X-rays, Ultrasounds, PET/CT, Gamma cameras, PET scanners and MRIs have been employed to determine tumour location and size for treatment planning procedures. However, difficulty arises when trying to ensure accuracy of the beam delivery since many body parts may have moved from the time the original images had been taken. IGRT systems provide frequent two and/or three-dimensional imaging to correlate the actual tumour position with the radiation treatment plan.
Cone-beam computed tomography (CBCT) based image guided systems have been integrated with medical linear accelerators to great success. With improvements in flat- panel technology, CBCT has been able to provide volumetric imaging, and allows for radiographic or fluoroscopic monitoring throughout the treatment process.
This is an IGRT technology using the short linear accelerator treatment beams to detect tumour location right before treatment to ensure accuracy and patient positioning. The detectors used are called Electronic Portal Imaging Devices (EPID) and they transform the megavoltage x-rays into digital imaging information that can be compared to reference scans from the simulation room such as CT simulator and/or conventional simulator images.
A specialized type of external beam radiation therapy called stereotactic radiation uses focused radiation beams targeting a well-defined tumour, relying on detailed imaging, computerized three-dimensional treatment planning and precise treatment set-up to the radiation dose with extreme accuracy (i.e. stereotactically).
Electron treatment is the type of superficial radiotherapy used at the Hermitage Medical Clinic. This treatment is very similar to photon treatment; however an applicator is attached to the LINAC which should come close to your skin for each treatment. This treatment can be radical or palliative treating a variety of sites such as skin lesions and is sometimes used to boost photon treatments such as surgery scars. There is a wide range of applicators to suit each individual patient and/or treatment site.
Brachytherapy is a type of radiation therapy that involves placing an ionizing radiation source or live source in the direct vicinity of the target volume which can often be within a body cavity or tumour.
The prostate brachytherapy treatment involves inserting tiny radioactive seeds directly into the prostate gland. It is performed under general anaesthetic in a specialist theatre within the Radiotherapy Department.