| The IMRT process:
| Step 1: The physician
obtains a treatment planning CT scan and then contours both
the tumor and the normal organ structures.
Dr. Weppelmann preparing
a patient for IMRT treatment planning.
| Step 2: The physician,
with the close collaboration of the medical dosimetrist and
physicist, use the inverse treatment planning software to create
an optimal treatment plan.
Medical physicist Ken Cashon, M.S.
working on an IMRT computer treatment plan.
| Step 3: For each daily
session, the treatment plan is computer linked to the linear
accelerator (treatment machine) and multileaf collimator, a
series of small metallic leaves attached to the head of the
treatment machine capable of delivering thousands of small beam
arrangements tailored to fit the individual patient's anatomy.
The multileaf collimator is able to shape
thousands of small radiation beamlets
to produce a highly conformal treatment volume.