Radiation Therapy

IMRT and IGRT in the treatment of prostate cancer: state of the art radiation treatment at Urology Centers of Alabama

One of the more exciting developments over the past year at the Urology Centers of Alabama has been the addition of Radiotherapy to the treatment options offered to patients with Prostate Cancer and other malignancies.  The construction of the Radiation Oncology department - The Van Scott Cancer Center – at the Homewood office has been the culmination of much effort on the part of the Urologists and Dr. Brian Larson, a Radiation Oncologist.  Dr Larson has worked the past 16 years in Birmingham at BMC Montclair (Trinity Medical Center) and BMC Princeton, as well as Medical Center East. 

By bringing state of the art equipment including a new top-of-the line Varian Linear Accelerator, as well as the latest in computer planning and treatment techniques to the new facility, we are able to provide treatment for prostate cancer that is second to none. 

IMRT and IGRT represent a great treatment choice for many patients with prostate cancer. It is a relatively non-invasive treatment, not involving surgery or radioactive seed placement. The cure rates are very good with the current dosages of around 80 Gy used, and the side effects appear to be quite tolerable with IMRT.

How does IMRT work?

IMRT (Intensity Modulated Radiation Therapy) represents an evolution of radiation technology, offering the possibility of better cure rates with fewer side effects. Until recently, 3D-conformal radiation was the standard of care. The prostate, bladder, and rectum were outlined the CT images, and multiple radiation beams were used. The physician and dosimetrist shaped the beams to match the contour of the prostate. Beams could be angled so that they passed through the prostate, but missed most of the bladder and rectum. IMRT is even more intensive than 3D. Every beam is broken down into many tiny "beamlets", and each beamlet can be given a different dose, resulting in beams with different intensities across their surfaces. Multiple beams are used for each treatment. The beams converge on the prostate, allowing a high radiation dose covering the prostate gland, and a lower dose hitting the normal tissues, such as rectum and bladder and other pelvic organs.

Studies consistently show that the higher the radiation dose a patient receives, the better the chance of curing prostate cancer. A radiation dose 66 Gray (Gy) resulted in a 65% chance of being cancer-free at five years, but a dose of 80 Gy may result in a 90% chance for early stage cancer. The possibility of normal tissue damage has prevented radiation oncologists from using higher dosages of radiation in the past. Now, with IMRT, giving doses approaching 80 Gy has become safer and more common.

IGRT - Image Guided Radiation Therapy

IGRT is an advanced technology that allows radiation to be delivered to tumors with more precision than was traditionally possible. One of the challenges encountered when radiation is delivered to a tumor is that the tumor can move based on the patient's day to day position on the treatment table, as well as internal organ motion. IGRT uses advanced imaging technology with on-board imaging (OBI). This OBI uses radiation beams with diagnostic x-ray energies in order to optimize the quality of the x-ray image and allow the radiation oncologist to visualize a patient's anatomy such as pelvic bones or implanted markers, with each radiation treatment. The Urology Centers of Alabama physicians use a special technique to insert fiducial markers into the prostate for Image Guided Radiation Therapy. This technique can be performed on an outpatient basis in the Homewood office. This added accuracy allows radiation to be delivered to a tumor based on its location in the body at the precise moment of treatment. Thus IGRT allows the delivery of radiation to tumors in real time while allowing normal tissues to receive minimal radiation.

State of the Art Radiation Treatment

IMRT and IGRT, used together, allow the Radiation Oncologist to optimize the delivery of radiation to the prostate in order to give higher doses than were possible even a few years ago, while reducing the normal tissue doses, and minimizing the toxicity of radiotherapy. The techniques used at the Urology Centers of Alabama have been developed to take advantage of the advances in technology to give our patients the best possible treatment available anywhere today.