A Pilot Study of Setup Variation in the Supraclavicular Lymph Nodes Treatment in Breast Cancer Patients Using On-Board Imaging System With Linear Accelerator
The Study Imaging Techniques for Radiation Treatment Planning:
The standard way to set up a patient to receive radiation therapy on the lymph nodes in the
neck is by using an EPID, which uses high-energy X-rays to make images to see if the
patient's body positioning for radiation therapy is correct or not. It is important for the
doctors to see the position of the patient's lower neck so that radiation can be delivered
to the right place.
The position of the patient's body during radiation therapy is typically checked once a week
using an EPID or a similar device. While the patient is lying on the treatment table, the
EPID system takes the necessary images. In this study, along with using an EPID,
researchers will use the OBI KV system and CBCT scanning, in order to look at how well the
standard EPID is describing the patient's neck position.
OBI KV imaging is designed to make images using low-energy X-rays, and the images are
considered reasonably clear and easy for the doctors to read. CBCT scanning uses low-energy
X-rays that let the doctors see the lymph nodes in the lower neck. Unlike regular CT
scanning, CBCT scanning does not require "contrast" material to be used.
Since all 3 of the pieces of equipment (the EPID, OBI KV, and CBCT systems) are built into
the same treatment machine, you will not need to move for the extra pieces of equipment that
are being used in this study. You will lay very still, as usual, and the images will all be
taken in a row.
The study doctor will review your medical chart to decide if you are eligible to take part
in this study. If you are found to be eligible and you agree to take part, you will then
begin the normal radiation treatment planning process. You will sign a separate consent
form that will describe the radiation therapy and EPID procedures in more detail, as well as
During the treatment period when you are receiving radiation treatments once a day for 5
weeks, you will have CBCT scanning and OBI KV imaging performed once a week.
Before you receive radiation treatment, while you are lying on the treatment table, the EPID
will be used. After that, the OBI KV and CBCT devices will rotate around you to take the
images for this study. During the radiation therapy treatment, the EPID, OBI KV, and CBCT
scans will be performed once a week, on the same day if possible. Sometimes the EPID and
OBI KV scans will be performed during the same treatment, while the CBCT scan may be
performed during another treatment that same week. It should take about 30 minutes to
finish taking both the OBI KV and CBCT images.
The results of the CBCT scanning and OBI KV imaging will not, in any way, be used to plan
your radiation therapy.
Length of Study Participation:
After your 5-week radiation treatment period, your participation in this study will be over.
This is an investigational study. The EPID is commercially available and FDA approved for
use in setting up a patient to receive radiation therapy. OBI KV imaging and CBCT scanning
are also commercially available and FDA approved for use in this purpose, but they are not
typically used. What is experimental in this study is using additional procedures (OBI KV
imaging and CBCT scanning) to check how reliably the EPID can set up a patient to receive
radiation therapy on the lymph nodes in the neck.
Up to 30 evaluable patients will take part in this study. All will be enrolled at M. D.
Observational Model: Case-Only, Time Perspective: Prospective
System Failure (defined as 2 or more disagreements between the EPID and either OBI systems or CT-on-rail from among the 5 evaluations for a particular patient)
CBCT scanning and OBI R or CT-on-rial system, 5 evaluations per patient, during 5-week radiation treatment period
Xiaochun Wang, PhD
M.D. Anderson Cancer Center
United States: Institutional Review Board
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