Radiation Oncology Victoria

Excellence in cancer radiotherapy

ROV Prostate IMRT / IGRT Program

ROV has a well established prostate radiotherapy program using the most advanced technologies available to-date.

What is IMRT for prostate cancer

Intensity Modulated Radiation Therapy (IMRT) is an advanced form of radiotherapy. It is delivered using a linear Accelerator that emits a high energy X-ray beam. IMRT uses many thinner beams to precisely treat the prostate gland and spare other nearby organs such as the bowel and bladder from radiation. Therefore, IMRT allows for an increased radiation dose to be delivered to the prostate gland, potentially resulting in better elimination of cancer cells and in fewer side effects than for standard conformal radiotherapy treatment.

How is it delivered

IMRT is a highly complex process and requires special expertise and equipment. IMRT is administered in short sessions five times a week for approximately seven weeks. Hospitalisation is not required and treatment does not make you radioactive.

Standard conformal radiotherapy versus IMRT

Above are 4 images to explain the difference between standard conformal radiotherapy and IMRT. The standard plan are on the left columns, A1 and A2; and the IMRT plans are on the right B1 and B2. A1 and B1 represent a view of the body "cut-through" whereas A2 and B2 represent a view of the body from the side.

The prostate is shown "shaded" in light blue, the rectum (bowel) is outline in brown and the bladder is outlined in dark blue.

The dose of radiation is shown by the multi-colored lines. Red presents the "hot spots", yellow and green: the "ideal dose".

Comparing the two types of plan, the IMRT plan is more conformal than the standard plan: the dose lines wrap more smoothly and tightly around the prostate cancer. There are smaller areas of "hot spots" (in red) seen with the IMRT plan. More of the yellow "ideal dose" in the IMRT plan is delivered into the prostate rather than outside the prostate. Because the IMRT plan is more conformal, less of the rectum and bladder get radiation; potentially resulting in less side effects.

Improving treatment accuracy with prostate IGRT

Image guided radiotherapy (IGRT) refers to the use of special imaging techniques within the treatment room. It is now well known that the prostate can move internally, despite the body remaining completely still. ROV have an established gold seed program, whereby 3 gold seeds are implanted into the prostate before any treatment begins. When commencing treatments, images are taken each day prior to treatment. The implanted gold seed markers show up clearly on these images representing the exact location of the prostate.

Who performs the gold seed implant procedure?

A urologist or radiologist inserts 3 gold seeds using ultrasound guidance. The procedure is similar to the prostate biopsy procedure you should have already experienced.

Planning for radiotherapy: Simulation

Simulation involves a radiation therapist positioning you on a specialised CT scanner. The scan will take approximately 20-30 minutes. Planning involves the doctor, radiation therapist and physicists using the information obtained during the CT scan to create your individualised treatment plan. Planning ensures that the radiation is delivered precisely to the prostate while nearby organs are protected. The planning process and associated validation procedures may take several days to complete.

Treatment

Treatment is painless and usually takes between 10 and 20 minutes to complete. Most of this time is spent positioning you correctly in relation to the machine. Radiation therapists will position the patient on the treatment unit; similar to how you were positioned for the CT scan.

Daily Image Guidance: IGRT process

Each day, after you have been positioned, and before treatment is delivered, images are taken on the treatment machine to confirm the exact location of the gold seeds which should represent the prostate location. Using specialized software, these images are compared and matched with images from the CT scan information obtained during your simulation. If required, small adjustments can be made to the position of the treatment couch to ensure a high degree of treatment accuracy.

Where is IMRT available

Prostate IMRT is available at East Melbourne, Ringwood, Frankston, Footscray and Epping.

Are you a candidate?

For further information, please email