Image-Guided Radiation Therapy

Image-Guided Radiation Therapy (IGRT) refers to an X-ray taken just prior to your radiation treatment, whichconfirms the correct position of the radiation field. This daily imaging allows for any small positional corrections and allows the radiation oncologist to use smaller treatment fields to treat your cancer, reducing the risk of side effects. IGRT may use two-dimensional on-board imaging or three-dimensional cone-beam computed tomography (CT). IGRT is especially helpful in treating prostate cancer because the prostate is located close to the bladder and rectum. By imaging the prostate fields daily, normal tissue is spared greatly, and the radiation dose to the prostate cancer can be safely increased, improving the chance of cancer cure.

On Board Imaging

On Board Imaging (OBI) refers to the use of daily X-rays (taken right on the linear accelerator) that help to confirm a match of treatment setup to the planned treatment. Radiation treatment is designed to be very precise and these images, taken just prior to treatment, allow the radiation therapist to correct for any daily treatment setup variation. OBI improves the accuracy of treatment and may allow the radiation oncologist to use smaller radiation treatment fields, reducing your risk of side effects.

Cone Beam Computed Tomography

Cone Beam Computed Tomography (CBCT or Cone Beam CT) involves the use of a CT scanner built into the linear accelerator. Images taken just prior to radiation treatment allow the radiation oncologist to correct any variation between intended and actual setup position. CT is anatomically more detailed than X-rays—and sometimes cone beam CT is used instead of X-ray imaging when extreme precision of treatment is needed.

Image-Guided Localization of the Prostate Gland-Acculoc®

The prostate gland is known to shift frequently in anatomical position. Radiation treatment of prostate cancer thus requires imaging to detect these variations to allow precise radiation dosing. Acculoc® image-guided radiation consists of three gold markers inserted into your prostate gland combined with imaging to confirm prostate position. Images taken just prior to treatment allow the treating radiation therapist to make small adjustments to the delivery, increasing the accuracy and safety of the radiation treatment. The gold markers are placed into the prostate by the urologist in the outpatient setting. The radiation oncologist may recommend Acculoc as a way of delivering a high dose of radiation to the prostate with optimal safety to the surrounding tissues around the prostate, including your bladder and rectum.