IMRT/ IGRT

IMRT, IGRT & PET
The goal of curative radiation therapy treatment is two fold: Deliver a lethal dose of radiation to the tumor; and spare nearby healthy structures such as normal tissues, nerves, spinal cord and organs. The IMRT System is one of the most sophisticated technologies in the world which can meet this goal.
What is IMRT?
Intensity Modulated Radiation Therapy [IMRT] is a revolutionary new radiation therapy treatment technology that is able to shape or conform radiation beams to the size, shape and location of a tumor, matching the radiation dose to the contour of the tumor while minimizing the impact on surrounding healthy tissue or organs. Considered to be one of the most significant technological breakthroughs in cancer treatment in the last 30 years, IMRT can be used to treat tumors in most areas of the body, including odd-shaped tumors that may have wrapped themselves around healthy tissue. IMRT allows very precise external beam radiotherapy treatments.
Rather than having a single large radiation beam pass through the body, with IMRT the radiation is effectively broken up into thousands of tiny pencil-thin radiation beams. With millimeter accuracy, these beams enter the body from many angles and intersect on the cancer. This results in a high dosage to the tumor and a lower dose to the surrounding healthy tissues. There is no limit to the size of tumor which can be treated, thus IMRT may be used to treat large, malignant tumors. It can also be used to treat multiple tumors, such as metastasis lesions, with a single treatment plan.
IMRT is especially valuable with benign tumors, such as meningioma and acoustic neuroma, when the tumor is adjacent to a functional cranial nerve. As IMRT conforms a high dose to the tumor and a lower dose to sensitive structures, IMRT may also benefit patients who have already received the maximum allowable dose with conventional radiation therapy.
IMRT can also allow us to treat tumors to a higher dose, retreat cancers which have previously been irradiated, and safely treat tumors which are located very close to delicate organs like the eye, spinal cord, or rectum. Simply put, this can translate into a higher cancer control rate and a lower rate of side effects.
To more accurately locate tumor locations for the daily application of IMRT, often IGRT is applied.
What is IGRT?Image Guided Radiation Therapy (IGRT): Is the process of imaging the location of the patient's organ/tumor on a daily basis and comparing the tumor's current location to the location the organ/tumor was on the day the CT for the radiation treatment plan was completed. Example: The prostate often will move in excess of 2 cm in any direction based on the content of the patient's bladder and bowels. With IGRT we track the exact location of the prostate and compensate for the change in position on a daily basis.
IGRT is very important when using IMRT because this technology allows us to decrease the margin we treat around the tumor to 3mm or less. This precision of the exact position of the organ/tumor allows the application of IMRT to be even more effective.