Imaging is vital in the diagnosis and management of thyroid cancer.   The doctors may make many treatment decisions based on what they see on the diagnostic scans, and many diagnostics scans are available. An overview of each is described below, and more detail discussions are available by following the appropriate link.  

These diagnostic scans may include:

Imaging is vital in the diagnosis and management of thyroid cancer.   The doctors may make many treatment decisions based on what they see on the diagnostic scans, and many diagnostics scans are available. An overview of each is described below, and more detail discussions are available by following the appropriate link.  

These diagnostic scans may include:

Radioiodine Imaging

Radioiodine whole body scanning for differentiated thyroid cancer (e.g. papillary and follicular) thyroid cancer is a valuable diagnostic imaging tool. The patient’s physician may use this type of scanning to help evaluate, manage, and monitor these types of thyroid cancers.  

A radioiodine scan involves the oral administration of a small amount of radioactive iodine. The iodine is like the iodine that has been added to most table salts sold in the grocery stores. However, the difference is that the iodine is “radioactive,” which means that it emits a small amount of energy that can be imaged with special cameras. We emphasize that the amount of energy released is small and in most cases is literally negligible. Then several hours or one to two days after the administration of the radioactive iodine, images are obtained of the patient’s whole body using a special camera in order to look for any thyroid tissue that takes up this small amount of radioactive iodine. Thyroid cells take up iodine because iodine is needed for the thyroid cells to try to make thyroid hormone. An image typically takes between 15 and 45 minutes depending on the location, and there are usually multiple images obtained. Longer imaging times and multiple images help maximize the information that we can obtain from the scan for the patient’s physician, and this in turn helps assure that any treatment is individually tailored to the patient’s specific situation.  

Although some facilities will not routinely perform radioiodine scanning prior to any radioiodine therapy, the Division of Nuclear Medicine at MedStar Washington Hospital Center routinely performs radioiodine scanning prior to any radioiodine therapy.  In addition, radioiodine scans can be performed in many different ways, and our staff will schedule the patient for the scanning technique that is most appropriate for that patient’s situation. 

In regard to the preparation for a radioiodine scan, there are many items such as withdrawal of thyroid hormone vs Thyrogen® injections, low iodine diet, and/or other special preparation. Although these can be confusing at times, our team will guide the patient through the process. In addition, the patient will receive our “Six-Step Instructional Binder,” which will help the patient understand and guide the patient through the preparation steps. The patient will also receive a complimentary copy of our book entitled “Thyroid Cancer: A Guide for Patients,” published by Keystone Press, which may also be purchased from the Thyroid Cancer Survivors Group, Inc. (ThyCa) online at www.ThyCa.org and Amazon.com.  Of course, Tasha Peterson, our Thyroid Cancer Scheduler, and Shari Moreau, our Thyroid Cancer Physician-Assistant, will be available by telephone or e-mail to help address any questions.

RETURN TO TOP


 

PET (Positron Emission Tomography) scans 

PET-CT scan is a Positron Emission Tomography-Computerized Tomography scan. It is an advanced, non-invasive test that allows an additional imaging tool to detect tumors, and this imaging study can sometimes detect tumors earlier and more reliably than other imaging tools . A PET-CT scan involves the injection of a small amount of radioactive sugar called FDG (fluoro-deoxy-glucose) into the patient’s vein followed by obtaining images of the patient’s whole body approximately 1 hour later. Because tumor cells are typically very active and need sugar, the tumor cells may take up the radioactive sugar. This allows the PET-CT camera to take pictures and image the degree of radioactivity.

A PET-CT also has a second imaging camera in it called Computed Tomography, which obtains a CT scan, and the CT scan shows the anatomy.   One analogy to understand these two imaging techniques is to compare it with a car engine. The CT obtains images of the anatomy of one’s car engine, while the PET gives images of the function of the anatomy of one’s car engine. The PET and CT pictures are taken essentially at the same time and the combination of both provides better diagnostic accuracy.

The Division of Nuclear Medicine at MedStar Washington Hospital Center was the second of two institutions in the United State to initiate the use of a PET-CT scanner with the technique of “Time-of-Flight.” “Time-of-Flight” technology represents an advance in the quality of a PET-CT scanner being allowing faster imaging, better images, and/or the use of lower doses of the radioactivity. The better images in turn allow better localization of the cancer sites, which helps the patient’s physicians to individualize better the treatment plan for that specific patient.

RETURN TO TOP


CT (Computer tomography scans)

As already noted a CT or CAT (Computer Axial Tomography) scanner allows excellent images of the patient’s anatomy called a CT or CAT scan. These images may be obtained at essentially the same time that a PET image is obtained or obtained at a completely different time or day than when the PET scan was obtained.   The terminology for these various scans can be confusing with terms such as PET-CT, PET, PET-CT with diagnostic CT, or diagnostic CT.

RETURN TO TOP


MRI (Magnetic Resonance Imaging)

Magnetic Resonance imaging is a very valuable imaging study. It is frequently abbreviated as either MRI or MR.   MR uses very strong magnets that align atoms in the various organs. When the magnet is turned off and the atoms go back to their original alignment radio signals are emitted. With a special machine, the radio signals are gather and excellent images are obtained.

RETURN TO TOP


 

Fusion of PET and MRI Scans

Just as a PET scanner and CT scanner have been combined into one single imaging scanning unit (e.g. PET-CT), a PET scanner and a MRI scanner have been combined into one single imaging scanner (e.g. PET-MR). Presently, very few of these combined PET scanners and MR scanners are available. However, with the use of computer software, the images obtained with the PET scanner may be electronically overlaid with the images obtain with the MRI scanner. The value of combining two different imaging technologies (e.g. fusion) allows the physician superior quality images with better localization of any cancer site.

RETURN TO TOP


 

Radioiodine Dosimetry

Dosimetry is a combination of specialized pretherapy radioactive iodine scans and measurements that allow our physicians to calculate the maximum dose of radioactive iodine that can be given to a patient for a therapy, and this may be requested for local thyroid cancer remaining in the neck or for thyroid cancer that has spread to a location outside of the neck. Our Center is one of a few centers in the United States to use this specialized measurement to help maximize the therapeutic effect to a patient’s thyroid cancer while helping to assure that the patient does not receive an excessive amount of radioiodine in order to reduce the likelihood and severity of any side effects of the patient’s bone marrow from the radioactive iodine.  This procedure has been used for over 60 years, and in 1980, Drs. Van Nostrand and Atkins was the third team in the United States to offer radioiodine dosimetry at Walter Reed Army Medical Center.

RETURN TO TOP


 

Simplified Radioiodine Dosimetry (e.g. Percent 48-hour Whole Body Retention)

Because some patients travel long distances to our facility and/or their schedule does not allow them to participate in the standard dosimetry scans and measurements described above, the Division of Nuclear Medicine at MedStar Washington Hospital Center offers a modified and significantly shortened method, which is called the “Simplified Dosimetry Measurement (or Percent 48 hour whole body retention.”   Like dosimetry, this simplified measurement helps to determine the maximum dose while also helping to assure that patients do not receive an excess amount of radiation exposure to their bone marrow. This was developed by Drs Atkins and Van Nostrand, and the initial protocol and data were previously published as well as subsequently validated as an alternative simplified method.

RETURN TO TOP

CT or CAT (Computer Axial Tomography) scans of chest, abdomen, and/or pelvis

Radioiodine Imaging

Radioiodine whole body scanning for differentiated thyroid cancer (e.g. papillary and follicular) thyroid cancer is a valuable diagnostic imaging tool. The patient’s physician may use this type of scanning to help evaluate, manage, and monitor these types of thyroid cancers.  

A radioiodine scan involves the oral administration of a small amount of radioactive iodine. The iodine is like the iodine that has been added to most table salts sold in the grocery stores. However, the difference is that the iodine is “radioactive,” which means that it emits a small amount of energy that can be imaged with special cameras. We emphasize that the amount of energy released is small and in most cases is literally negligible. Then several hours or one to two days after the administration of the radioactive iodine, images are obtained of the patient’s whole body using a special camera in order to look for any thyroid tissue that takes up this small amount of radioactive iodine. Thyroid cells take up iodine because iodine is needed for the thyroid cells to try to make thyroid hormone. An image typically takes between 15 and 45 minutes depending on the location, and there are usually multiple images obtained. Longer imaging times and multiple images help maximize the information that we can obtain from the scan for the patient’s physician, and this in turn helps assure that any treatment is individually tailored to the patient’s specific situation.  

Although some facilities will not routinely perform radioiodine scanning prior to any radioiodine therapy, the Division of Nuclear Medicine at MedStar Washington Hospital Center routinely performs radioiodine scanning prior to any radioiodine therapy.  In addition, radioiodine scans can be performed in many different ways, and our staff will schedule the patient for the scanning technique that is most appropriate for that patient’s situation.

In regard to the preparation for a radioiodine scan, there are many items such as withdrawal of thyroid hormone vs Thyrogen® injections, low iodine diet, and/or other special preparation. Although these can be confusing at times, our team will guide the patient through the process. In addition, the patient will receive our “Six-Step Instructional Binder,” which will help the patient understand and guide the patient through the preparation steps. The patient will also receive a complimentary copy of our book entitled “Thyroid Cancer: A Guide for Patients,” published by Keystone Press, which may also be purchased from the Thyroid Cancer Survivors Group, Inc. (ThyCa) online at www.ThyCa.org and Amazon.com.  Of course, Tasha Peterson, our Thyroid Cancer Scheduler, and Shari Moreau, our Thyroid Cancer Physician-Assistant, will be available by telephone or e-mail to help address any questions.

RETURN TO TOP


 

PET (Positron Emission Tomography) scans 

PET-CT scan is a Positron Emission Tomography-Computerized Tomography scan. It is an advanced, non-invasive test that allows an additional imaging tool to detect tumors, and this imaging study can sometimes detect tumors earlier and more reliably than other imaging tools . A PET-CT scan involves the injection of a small amount of radioactive sugar called FDG (fluoro-deoxy-glucose) into the patient’s vein followed by obtaining images of the patient’s whole body approximately 1 hour later. Because tumor cells are typically very active and need sugar, the tumor cells may take up the radioactive sugar. This allows the PET-CT camera to take pictures and image the degree of radioactivity.

A PET-CT also has a second imaging camera in it called Computed Tomography, which obtains a CT scan, and the CT scan shows the anatomy.   One analogy to understand these two imaging techniques is to compare it with a car engine. The CT obtains images of the anatomy of one’s car engine, while the PET gives images of the function of the anatomy of one’s car engine. The PET and CT pictures are taken essentially at the same time and the combination of both provides better diagnostic accuracy.

The Division of Nuclear Medicine at MedStar Washington Hospital Center was the second of two institutions in the United State to initiate the use of a PET-CT scanner with the technique of “Time-of-Flight.” “Time-of-Flight” technology represents an advance in the quality of a PET-CT scanner being allowing faster imaging, better images, and/or the use of lower doses of the radioactivity. The better images in turn allow better localization of the cancer sites, which helps the patient’s physicians to individualize better the treatment plan for that specific patient.

RETURN TO TOP


CT (Computer tomography scans)

As already noted a CT or CAT (Computer Axial Tomography) scanner allows excellent images of the patient’s anatomy called a CT or CAT scan. These images may be obtained at essentially the same time that a PET image is obtained or obtained at a completely different time or day than when the PET scan was obtained.   The terminology for these various scans can be confusing with terms such as PET-CT, PET, PET-CT with diagnostic CT, or diagnostic CT.

RETURN TO TOP


MRI (Magnetic Resonance Imaging)

Magnetic Resonance imaging is a very valuable imaging study. It is frequently abbreviated as either MRI or MR.   MR uses very strong magnets that align atoms in the various organs. When the magnet is turned off and the atoms go back to their original alignment radio signals are emitted. With a special machine, the radio signals are gather and excellent images are obtained.

RETURN TO TOP


 

Fusion of PET and MRI Scans

Just as a PET scanner and CT scanner have been combined into one single imaging scanning unit (e.g. PET-CT), a PET scanner and a MRI scanner have been combined into one single imaging scanner (e.g. PET-MR). Presently, very few of these combined PET scanners and MR scanners are available. However, with the use of computer software, the images obtained with the PET scanner may be electronically overlaid with the images obtain with the MRI scanner. The value of combining two different imaging technologies (e.g. fusion) allows the physician superior quality images with better localization of any cancer site.

RETURN TO TOP


 

Radioiodine Dosimetry

Dosimetry is a combination of specialized pretherapy radioactive iodine scans and measurements that allow our physicians to calculate the maximum dose of radioactive iodine that can be given to a patient for a therapy, and this may be requested for local thyroid cancer remaining in the neck or for thyroid cancer that has spread to a location outside of the neck. Our Center is one of a few centers in the United States to use this specialized measurement to help maximize the therapeutic effect to a patient’s thyroid cancer while helping to assure that the patient does not receive an excessive amount of radioiodine in order to reduce the likelihood and severity of any side effects of the patient’s bone marrow from the radioactive iodine.  This procedure has been used for over 60 years, and in 1980, Drs. Van Nostrand and Atkins was the third team in the United States to offer radioiodine dosimetry at Walter Reed Army Medical Center.

RETURN TO TOP


 

Simplified Radioiodine Dosimetry (e.g. Percent 48-hour Whole Body Retention)

Because some patients travel long distances to our facility and/or their schedule does not allow them to participate in the standard dosimetry scans and measurements described above, the Division of Nuclear Medicine at MedStar Washington Hospital Center offers a modified and significantly shortened method, which is called the “Simplified Dosimetry Measurement (or Percent 48 hour whole body retention.”   Like dosimetry, this simplified measurement helps to determine the maximum dose while also helping to assure that patients do not receive an excess amount of radiation exposure to their bone marrow. This was developed by Drs Atkins and Van Nostrand, and the initial protocol and data were previously published as well as subsequently validated as an alternative simplified method.

RETURN TO TOP

Other Services